Maximum power point tracker for portable photovoltaic systems with resistive-like load

Energy Technology Data Exchange (ETDEWEB)

De Cesare, G.; Caputo, D.; Nascetti, A. [Department of Electronic Engineering, University of Rome La Sapienza via Eudossiana, 18 00184 Rome (Italy)

2006-08-15

In this work we report on the design and realization of a maximum power point tracking (MPPT) circuit suitable for low power, portable applications with resistive load. The design rules included cost, size and power efficiency considerations. A novel scheme for the implementation of the control loop of the MPPT circuit is proposed, combining good performance with compact design. The operation and performances were simulated at circuit schematic level with simulation program with integrated circuit emphasis (SPICE). The improved operation of a PV system using our MPPT circuit was demonstrated using a purely resistive load. (author)

Implementasi Algoritma Perturb and Observe untuk Mengoptimasi Daya Keluaran Solar Cell Menggunakan MPPT di Laboratorium Energi Baru Terbarukan

Directory of Open Access Journals (Sweden)

Sri Utami

2017-02-01

Full Text Available Energi yang dihasilkan oleh sel surya sangat bervariasi dan sangat tergantung pada kondisi cuaca. Untuk mengoptimasinya digunakan maximum power point. Penelitian ini mengimplementasikan algoritma Perturb and Observe pada Maximum Power Point Tracker (MPPT sebagai kontroller untuk pembangkitan energi surya. Sistem dibangun menggunakan Arduino Uno R3 untuk mengekstraksi daya maksimum panel surya. Microcontroller ini mengontrol DC buck converter dan digunakan untuk charging baterai 6V. Metode ini beroperasi dengan memberi perturbing tegangan atau arus terminal array dan membandingkan daya yang dihasilkan dengan output panel surya. Diperlukan perturbing yang sesuai untuk mendapatkan nilai optimasi yang tepat. Validasi dari panel surya menggunakan metode yang diusulkan pada MPPT-nya memberikan performansi yang lebih baik dibuktikan pada nilai daya dan tegangannya. Menggunakan parameter perturbation 0.1, MPPT mampu mengoptimasi daya ouput panel surya sebesar 24.49 W dengan beban 5 ? dan nilai irradiasi 523 W/m2  dibandingkan dengan metode konvensional dengan beban sama dan nilai irradiasi sebesar 527 W/m2 yang menghasilkan daya keluaran 15.37 W

Solar Panel System for Street Light Using Maximum Power Point Tracking (MPPT Technique

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Wiedjaja A.

2014-03-01

Full Text Available Solar energy is one form of the renewable energy which is very abundant in regions close to the equator. One application of solar energy is for street light. This research focuses on using the maximum power point tracking technique (MPPT, particularly the perturb and observe (P&O algorithm, to charge battery for street light system. The proposed charger circuit can achieve 20.73% higher power efficiency compared to that of non-MPPT charger. We also develop the LED driver circuit for the system which can achieve power efficiency up to 91.9% at a current of 1.06 A. The proposed street lightning system can be implemented with a relatively low cost for public areas.

A Single Phase Doubly Grounded Semi-Z-Source Inverter for Photovoltaic (PV Systems with Maximum Power Point Tracking (MPPT

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Tofael Ahmed

2014-06-01

Full Text Available In this paper, a single phase doubly grounded semi-Z-source inverter with maximum power point tracking (MPPT is proposed for photovoltaic (PV systems. This proposed system utilizes a single-ended primary inductor (SEPIC converter as DC-DC converter to implement the MPPT algorithm for tracking the maximum power from a PV array and a single phase semi-Z-source inverter for integrating the PV with AC power utilities. The MPPT controller utilizes a fast-converging algorithm to track the maximum power point (MPP and the semi-Z-source inverter utilizes a nonlinear SPWM to produce sinusoidal voltage at the output. The proposed system is able to track the MPP of PV arrays and produce an AC voltage at its output by utilizing only three switches. Experimental results show that the fast-converging MPPT algorithm has fast tracking response with appreciable MPP efficiency. In addition, the inverter shows the minimization of common mode leakage current with its ground sharing feature and reduction of the THD as well as DC current components at the output during DC-AC conversion.

Comparative evaluation of photovoltaic MPP trackers: A simulated approach

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Barnam Jyoti Saharia

2016-12-01

Full Text Available This paper makes a comparative assessment of three popular maximum power point tracking (MPPT algorithms used in photovoltaic power generation. A 120 Wp PV module is taken as reference for the study that is connected to a suitable resistive load by a boost converter. Two profiles of variation of solar insolation at fixed temperature and varying temperature at fixed solar insolation are taken to test the tracking efficiency of three MPPT algorithms based on the perturb and observe (P&O, Fuzzy logic, and Neural Network techniques. MATLAB/SIMULINK simulation software is used for assessment, and the results indicate that the fuzzy logic-based tracker presents better tracking effectiveness to variations in both solar insolation and temperature profiles when compared to P&O technique and Neural Network-based technique.

Global Maximum Power Point Tracking (MPPT of a Photovoltaic Module Array Constructed through Improved Teaching-Learning-Based Optimization

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Kuei-Hsiang Chao

2016-11-01

Full Text Available The present study proposes a maximum power point tracking (MPPT method in which improved teaching-learning-based optimization (I-TLBO is applied to perform global MPPT of photovoltaic (PV module arrays under dissimilar shading situations to ensure the maximum power output of the module arrays. The proposed I-TLBO enables the automatic adjustment of teaching factors according to the self-learning ability of students. Incorporating smart-tracking and self-study strategies can effectively improve the tracking response speed and steady-state tracking performance. To evaluate the feasibility of the proposed I-TLBO, a HIP-2717 PV module array from Sanyo Electric was employed to compose various arrays with different serial and parallel configurations. The arrays were operated under different shading conditions to test the MPPT with double, triple, or quadruple peaks of power-voltage characteristic curves. Boost converters were employed with TMS320F2808 digital signal processors to test the proposed MPPT method. Empirical results confirm that the proposed method exhibits more favorable dynamic and static-state response tracking performance compared with that of conventional TLBO.

Maximum power point tracking controller for PV systems using neural networks

Energy Technology Data Exchange (ETDEWEB)

Bahgat, A.B.G. [Cairo Univ. (Egypt). Faculty of Engineering; Helwa, N.H.; Ahmad, G.E.; El Shenawy, E.T. [National Research Center, Dokki, Cairo (Egypt). Solar Energy Dept.

2005-07-01

This paper presents a development and implementation of a PC-based maximum power point tracker (MPPT) for PV system using neural networks (NN). The system consists of a PV module via a MPPT supplying a dc motor that drives an air fan. The control algorithm is developed to use the artificial NN for detecting the optimal operating point under different operating conditions, then the control action gives the driving signals to the MPPT. A PC is used for data acquisition, running the control algorithm, data storage, as well as data display and analysis. The system has been implemented and tested under various operating conditions. The experimental results showed that the PV system with MPPT always tracks the peak power point of the PV module under various operating conditions. The MPPT transmits about 97% of the actual maximum power generated by the PV module. The MPPT not only increases the power from the PV module to the load, but also maintains longer operating periods for the PV system. The air velocity and the air mass flow rate of the mechanical load are increased considerably, due to the increase of the PV system power. It is also found that the increase in the output energy due to using the MPPT is about 45.2% for a clear sunny day. (Author)

Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

Science.gov (United States)

Othman, Ahmed M.; El-arini, Mahdi M. M.; Ghitas, Ahmed; Fathy, Ahmed

2012-12-01

In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV) systems. Maximum power point tracking (MPPT) plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT) using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O) algorithm and is compared to a designed fuzzy logic controller (FLC). The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

On the Perturb-and-Observe and Incremental Conductance MPPT methods for PV systems

DEFF Research Database (Denmark)

Sera, Dezso; Mathe, Laszlo; Kerekes, Tamas

2013-01-01

This paper presents a detailed analysis of the two most well-known hill-climbing MPPT algorithms, the Perturb-and-Observe (P&O) and Incremental Conductance (INC). The purpose of the analysis is to clarify some common misconceptions in the literature regarding these two trackers, therefore helping...

Development of intelligent MPPT (maximum power point tracking) control for a grid-connected hybrid power generation system

International Nuclear Information System (INIS)

Hong, Chih-Ming; Ou, Ting-Chia; Lu, Kai-Hung

2013-01-01

A hybrid power control system is proposed in the paper, consisting of solar power, wind power, and a diesel-engine. To achieve a fast and stable response for the real power control, an intelligent controller was proposed, which consists of the Wilcoxon (radial basis function network) RBFN and the improved (Elman neural network) ENN for (maximum power point tracking) MPPT. The pitch angle control of wind power uses improved ENN controller, and the output is fed to the wind turbine to achieve the MPPT. The solar array is integrated with an RBFN control algorithm to track the maximum power. MATLAB (MATrix LABoratory)/Simulink was used to build the dynamic model and simulate the solar and diesel-wind hybrid power system. - Highlights: ► To achieve a fast and stable response for the real power control. ► The pitch control of wind power uses improved ENN (Elman neural network) controller to achieve the MPPT (maximum power point tracking). ► The RBFN (radial basis function network) can quickly and accurately track the maximum power output for PV (photovoltaic) array. ► MATLAB was used to build the dynamic model and simulate the hybrid power system. ► This method can reach the desired performance even under different load conditions

Design and simulation of maximum power point tracking (MPPT) system on solar module system using constant voltage (CV) method

Science.gov (United States)

Bhatara, Sevty Satria; Iskandar, Reza Fauzi; Kirom, M. Ramdlan

2016-02-01

Solar energy is one of renewable energy resource where needs a photovoltaic module to convert it into electrical energy. One of the problems on solar energy conversion is the process of battery charging. To improve efficiency of energy conversion, PV system needs another control method on battery charging called maximum power point tracking (MPPT). This paper report the study on charging optimation using constant voltage (CV) method. This method has a function of determining output voltage of the PV system on maximal condition, so PV system will always produce a maximal energy. A model represented a PV system with and without MPPT was developed using Simulink. PV system simulation showed a different outcome energy when different solar radiation and numbers of solar module were applied in the model. On the simulation of solar radiation 1000 W/m2, PV system with MPPT produces 252.66 Watt energy and PV system without MPPT produces 252.66 Watt energy. The larger the solar radiation, the greater the energy of PV modules was produced.

Analysis of MPPT Failure and Development of an Augmented Nonlinear Controller for MPPT of Photovoltaic Systems under Partial Shading Conditions

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Mingxuan Chen

2017-01-01

Full Text Available The output–voltage–power curves of photovoltaic (PV arrays exhibit complex multi-peak shapes when local shading occurs. The existing maximum power point tracking (MPPT algorithms to solve this multi-peak problem do not consider the possibility of tracking failures due to the time of the irradiance change. In this study, first, the reason for the failure of the global MPPT (GMPPT algorithm is analyzed based on the PV array mathematical model and its output characteristics under partial shading conditions; then, in order to estimate the MPP voltage, an artificial neural network (ANN is trained using environmental information such as irradiance. A hybrid MPPT method using an augmented state feedback precise linearization (AFL controller combined with an ANN is proposed to solve problems such as the shift of the static operating point of the DC/DC boost converter. Finally, numerical simulations are conducted to validate the proposed method and eliminate the possibility of MPPT failure. The proposed hybrid MPPT method is compared with the conventional perturb and observe (P & O method and the improved P & O method through simulations. Using the proposed neural network and nonlinear control strategy, the MPP can be tracked rapidly, accurately, and statically, proving that the method is feasible and effective.

Maximum power point tracker for photovoltaic power plants

Science.gov (United States)

Arcidiacono, V.; Corsi, S.; Lambri, L.

The paper describes two different closed-loop control criteria for the maximum power point tracking of the voltage-current characteristic of a photovoltaic generator. The two criteria are discussed and compared, inter alia, with regard to the setting-up problems that they pose. Although a detailed analysis is not embarked upon, the paper also provides some quantitative information on the energy advantages obtained by using electronic maximum power point tracking systems, as compared with the situation in which the point of operation of the photovoltaic generator is not controlled at all. Lastly, the paper presents two high-efficiency MPPT converters for experimental photovoltaic plants of the stand-alone and the grid-interconnected type.

Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

Directory of Open Access Journals (Sweden)

Ahmed M. Othman

2012-12-01

Full Text Available In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV systems. Maximum power point tracking (MPPT plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O algorithm and is compared to a designed fuzzy logic controller (FLC. The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

Power converter with maximum power point tracking MPPT for small wind-electric pumping systems

International Nuclear Information System (INIS)

Lara, David; Merino, Gabriel; Salazar, Lautaro

2015-01-01

Highlights: • We implement a wind electric pumping system of small power. • The power converter allowed to change the operating point of the electro pump. • Two control techniques were implemented in the power converter. • The control V/f variable allowed to increase the power generated by the permanent magnet generator. - Abstract: In this work, an AC–DC–AC direct-drive power converter was implemented for a wind electric pumping system consisting of a permanent magnet generator (PMG) of 1.3 kW and a peripheral single phase pump of 0.74 kW. In addition, the inverter linear V/f control scheme and the maximum power point tracking (MPPT) algorithm with variable V/f were developed. MPPT algorithm seeks to extract water in a wide range of power input using the maximum amount of wind power available. Experimental trials at different pump pressures were conducted. With a MPPT tracking system with variable V/f, a power value of 1.3 kW was obtained at a speed of 350 rpm and a maximum operating hydraulic head of 50 m. At lower operating heads pressures (between 10 and 40 m), variable V/f control increases the power generated by the PMG compared to the linear V/f control. This increase ranged between 4% and 23% depending on the operating pressure, with an average of 13%, getting close to the maximum electrical power curve of the PMG. The pump was driven at variable frequency reaching a minimum speed of 0.5 times the rated speed. Efficiency of the power converter ranges between 70% and 95% with a power factor between 0.4 and 0.85, depending on the operating pressure

Comparison of four MPPT techniques for PV systems

International Nuclear Information System (INIS)

Atik, L.; Ternifi, Z. T.; Petit, P.; Sawicki, J. P.; Aillerie, M.; Bachir, G.

2016-01-01

The working behavior of a module / PV array is non-linear and highly dependent on working conditions. As a given condition, there is only one point at which the level of available power at its output is maximum. This point varies with time, enlightenment and temperature. To ensure optimum operation, the use of MPPT control allows us to extract the maximum power. This paper presents a comparative study of four widely-adopted MPPT algorithms, such as Perturb and Observe, Incremental Conductance, Measurements of the variation of the open circuit voltage or of the short-circuit current. Their performance is evaluated using, for all these techniques. In particular, this study compares the behaviors of each technique in presence of solar irradiation variations and temperature fluctuations. These MPPT techniques will be compared using the Matlab / Simulink tool.

Comparison of four MPPT techniques for PV systems

Energy Technology Data Exchange (ETDEWEB)

Atik, L., E-mail: lotfi.atik@univ-usto.dz; Ternifi, Z. T. [University of science and technology of Oran, USTO, LDDE, Oran (Algeria); Université de Lorraine, LMOPS, EA 4423, 57070 Metz (France); Petit, P.; Sawicki, J. P.; Aillerie, M., E-mail: aillerie@metz.supelec.fr [Université de Lorraine, LMOPS, EA 4423, 57070 Metz (France); CentraleSupélec, LMOPS, 57070 Metz (France); Bachir, G. [University of science and technology of Oran, USTO, LDDE, Oran (Algeria)

2016-07-25

The working behavior of a module / PV array is non-linear and highly dependent on working conditions. As a given condition, there is only one point at which the level of available power at its output is maximum. This point varies with time, enlightenment and temperature. To ensure optimum operation, the use of MPPT control allows us to extract the maximum power. This paper presents a comparative study of four widely-adopted MPPT algorithms, such as Perturb and Observe, Incremental Conductance, Measurements of the variation of the open circuit voltage or of the short-circuit current. Their performance is evaluated using, for all these techniques. In particular, this study compares the behaviors of each technique in presence of solar irradiation variations and temperature fluctuations. These MPPT techniques will be compared using the Matlab / Simulink tool.

Comparative study of adaptive controller using MIT rules and Lyapunov method for MPPT standalone PV systems

Science.gov (United States)

Tariba, N.; Bouknadel, A.; Haddou, A.; Ikken, N.; Omari, Hafsa El; Omari, Hamid El

2017-01-01

The Photovoltaic Generator have a nonlinear characteristic function relating the intensity at the voltage I = f (U) and depend on the variation of solar irradiation and temperature, In addition, its point of operation depends directly on the load that it supplies. To fix this drawback, and to extract the maximum power available to the terminal of the generator, an adaptation stage is introduced between the generator and the load to couple the two elements as perfectly as possible. The adaptation stage is associated with a command called MPPT MPPT (Maximum Power Point Tracker) whose is used to force the PVG to operate at the MPP (Maximum Power Point) under variation of climatic conditions and load variation. This paper presents a comparative study between the adaptive controller for PV Systems using MIT rules and Lyapunov method to regulate the PV voltage. The Incremental Conductance (IC) algorithm is used to extract the maximum power from the PVG by calculating the voltage Vref, and the adaptive controller is used to regulate and track quickly the PV voltage. The two methods of the adaptive controller will be compared to prove their performance by using the PSIM tools and experimental test, and the mathematical model of step-up with PVG model will be presented.

Application of Copper Indium Gallium Diselenide Photovoltaic Cells to Extend the Endurance and Capabilities of the Raven RQ-11B Unmanned Aerial Vehicle

Science.gov (United States)

2010-09-01

POWER POINT TRACKER A more suitable component used in photovoltaic appli- cations is the Maximum Power Point Tracker ( MPPT ). An MPPT ... MPPT / power converter (Solar Charge Controller ) weighed 6.5-Oz, but without the casing it weighed only 3.6-Oz. We preferred to use it without the...for this test was the GV-4 Low Power Charge Controller from GENASUN used in previous the- sis work [5]. This MPPT was programmed to charge up

On application of a new hybrid maximum power point tracking (MPPT) based photovoltaic system to the closed plant factory

International Nuclear Information System (INIS)

Jiang, Joe-Air; Su, Yu-Li; Shieh, Jyh-Cherng; Kuo, Kun-Chang; Lin, Tzu-Shiang; Lin, Ta-Te; Fang, Wei; Chou, Jui-Jen; Wang, Jen-Cheng

2014-01-01

Highlights: • Hybrid MPPT method was developed and utilized in a PV system of closed plant factory. • The tracking of the maximum power output of PV system can be achieved in real time. • Hybrid MPPT method not only decreases energy loss but increases power utilization. • The feasibility of applying PV system to the closed plant factory has been examined. • The PV system significantly reduced CO 2 emissions and curtailed the fossil fuels. - Abstract: Photovoltaic (PV) generation systems have been shown to have a promising role for use in high electric-load buildings, such as the closed plant factory which is dependent upon artificial lighting. The power generated by the PV systems can be either directly supplied to the buildings or fed back into the electrical grid to reduce the high economic costs and environmental impact associated with the traditional energy sources such as nuclear power and fossil fuels. However, PV systems usually suffer from low energy-conversion efficiency, and it is therefore necessary to improve their performance by tackling the energy loss issues. The maximum power point tracking (MPPT) control technique is essential to the PV-assisted generation systems in order to achieve the maximum power output in real time. In this study, we integrate the previously proposed direct-prediction MPP method with a perturbation and observation (P and O) method to develop a new hybrid MPPT method. The proposed MPPT method is further utilized in the PV inverters in a PV system installed on the roof of a closed plant factory at National Taiwan University. The tested PV system is constructed as a two-stage grid-connected photovoltaic power conditioning (PVPC) system with a boost-buck full bridge design configuration. A control scheme based on the hybrid MPPT method is also developed and implemented in the PV inverters of the PVPC system to achieve tracking of the maximum power output of the PV system in real time. Based on experimental results

Dynamic Performance of Maximum Power Point Trackers in TEG Systems Under Rapidly Changing Temperature Conditions

Science.gov (United States)

Man, E. A.; Sera, D.; Mathe, L.; Schaltz, E.; Rosendahl, L.

2016-03-01

Characterization of thermoelectric generators (TEG) is widely discussed and equipment has been built that can perform such analysis. One method is often used to perform such characterization: constant temperature with variable thermal power input. Maximum power point tracking (MPPT) methods for TEG systems are mostly tested under steady-state conditions for different constant input temperatures. However, for most TEG applications, the input temperature gradient changes, exposing the MPPT to variable tracking conditions. An example is the exhaust pipe on hybrid vehicles, for which, because of the intermittent operation of the internal combustion engine, the TEG and its MPPT controller are exposed to a cyclic temperature profile. Furthermore, there are no guidelines on how fast the MPPT must be under such dynamic conditions. In the work discussed in this paper, temperature gradients for TEG integrated in several applications were evaluated; the results showed temperature variation up to 5°C/s for TEG systems. Electrical characterization of a calcium-manganese oxide TEG was performed at steady-state for different input temperatures and a maximum temperature of 401°C. By using electrical data from characterization of the oxide module, a solar array simulator was emulated to perform as a TEG. A trapezoidal temperature profile with different gradients was used on the TEG simulator to evaluate the dynamic MPPT efficiency. It is known that the perturb and observe (P&O) algorithm may have difficulty accurately tracking under rapidly changing conditions. To solve this problem, a compromise must be found between the magnitude of the increment and the sampling frequency of the control algorithm. The standard P&O performance was evaluated experimentally by using different temperature gradients for different MPPT sampling frequencies, and efficiency values are provided for all cases. The results showed that a tracking speed of 2.5 Hz can be successfully implemented on a TEG

Discrete Model Predictive Control-Based Maximum Power Point Tracking for PV Systems: Overview and Evaluation

DEFF Research Database (Denmark)

Lashab, Abderezak; Sera, Dezso; Guerrero, Josep M.

2018-01-01

The main objective of this work is to provide an overview and evaluation of discrete model predictive controlbased maximum power point tracking (MPPT) for PV systems. A large number of MPC based MPPT methods have been recently introduced in the literature with very promising performance, however......, an in-depth investigation and comparison of these methods have not been carried out yet. Therefore, this paper has set out to provide an in-depth analysis and evaluation of MPC based MPPT methods applied to various common power converter topologies. The performance of MPC based MPPT is directly linked...... with the converter topology, and it is also affected by the accurate determination of the converter parameters, sensitivity to converter parameter variations is also investigated. The static and dynamic performance of the trackers are assessed according to the EN 50530 standard, using detailed simulation models...

A Newton-Based Extremum Seeking MPPT Method for Photovoltaic Systems with Stochastic Perturbations

Directory of Open Access Journals (Sweden)

Heng Li

2014-01-01

Full Text Available Microcontroller based maximum power point tracking (MPPT has been the most popular MPPT approach in photovoltaic systems due to its high flexibility and efficiency in different photovoltaic systems. It is well known that PV systems typically operate under a range of uncertain environmental parameters and disturbances, which implies that MPPT controllers generally suffer from some unknown stochastic perturbations. To address this issue, a novel Newton-based stochastic extremum seeking MPPT method is proposed. Treating stochastic perturbations as excitation signals, the proposed MPPT controller has a good tolerance of stochastic perturbations in nature. Different from conventional gradient-based extremum seeking MPPT algorithm, the convergence rate of the proposed controller can be totally user-assignable rather than determined by unknown power map. The stability and convergence of the proposed controller are rigorously proved. We further discuss the effects of partial shading and PV module ageing on the proposed controller. Numerical simulations and experiments are conducted to show the effectiveness of the proposed MPPT algorithm.

MPPT Based on Fuzzy Logic Controller (FLC) for Photovoltaic (PV) System in Solar Car

OpenAIRE

Aji, Seno; Ajiatmo, Dwi; Robandi, Imam; Suryoatmojo, Heri

2013-01-01

This paper presents a control called Maximum Power Point Tracking (MPPT) for photovoltaic (PV) system in a solar car. The main purpose of this system is to extracts PV power maximally while keeping small losses using a simple design of converter. Working principle of MPPT based fuzzy logic controller (MPPT-FLC) is to get desirable values of reference current and voltage. MPPT-FLC compares them with the values of the PV's actual current and voltage to control duty cycle value. Then the duty cy...

Advanced algorithm for MPPT control of photovoltaic systems

Energy Technology Data Exchange (ETDEWEB)

Liu, C.; Wu, B.; Cheung, R. [Ryerson Polytechnic Univ., Toronto, ON (Canada). Dept. of Electrical and Computer Engineering

2006-07-01

Although photovoltaic (PV) energy is a renewable, environmentally sound source of electricity, it is relatively costly. The maximum power point tracking (MPPT) of the PV output for all sunshine conditions is key to keeping the output power per unit cost low for successful PV applications. The MPPT control is challenging, because the sunshine condition that determines the amount of sun energy into the PV array may change at any time, and the voltage/current characteristic of PV arrays is highly nonlinear. The 5 components of a PV system for the grid-connected applications are a PV array that converts solar energy to electric energy; a dc-dc converter that converts low dc voltages produced by the PV arrays to a high dc voltage; an inverter that converts the high dc voltage to a single- or three-phase ac voltage; a digital controller that controls the converter operation with MPPT capability; and, an ac filter that absorbs voltage/current harmonics generated by the inverter. The technical requirements in developing a practical PV system include an optimal control that can extract the maximum output power from the PV arrays under all operating and weather conditions, and a high performance-to-cost ratio to help commercialize developed PV technologies. This paper proposed a new method for the MPPT control of PV systems. The new method uses one estimate process for every two perturb processes in search of the maximum PV output for all sunshine conditions. In this estimate-perturb-perturb (EPP) method, the perturb process conducts the search over a highly nonlinear PV characteristic, and the estimate process compensates the perturb process for irradiance-changing conditions. The EPP method improves the tracking accuracy and speed of the MPPT control compared to other methods. This paper demonstrated that the EPP method can provide accurate and reliable MPPT even under rapidly changing irradiance conditions. A grid-connected PV system using three MPPT controls was

Recent Developments in Maximum Power Point Tracking Technologies for Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Nevzat Onat

2010-01-01

Full Text Available In photovoltaic (PV system applications, it is very important to design a system for operating of the solar cells (SCs under best conditions and highest efficiency. Maximum power point (MPP varies depending on the angle of sunlight on the surface of the panel and cell temperature. Hence, the operating point of the load is not always MPP of PV system. Therefore, in order to supply reliable energy to the load, PV systems are designed to include more than the required number of modules. The solution to this problem is that switching power converters are used, that is called maximum power point tracker (MPPT. In this study, the various aspects of these algorithms have been analyzed in detail. Classifications, definitions, and basic equations of the most widely used MPPT technologies are given. Moreover, a comparison was made in the conclusion.

MPPT-Based Control Algorithm for PV System Using iteration-PSO under Irregular shadow Conditions

Directory of Open Access Journals (Sweden)

M. Abdulkadir

2017-02-01

Full Text Available The conventional maximum power point tracking (MPPT techniques can hardly track the global maximum power point (GMPP because the power-voltage characteristics of photovoltaic (PV exhibit multiple local peaks in irregular shadow, and therefore easily fall into the local maximum power point. These conditions make it very challenging, and to tackle this deficiency, an efficient Iteration Particle Swarm Optimization (IPSO has been developed to improve the quality of solution and convergence speed of the traditional PSO, so that it can effectively track the GMPP under irregular shadow conditions. This proposed technique has such advantages as simple structure, fast response and strong robustness, and convenient implementation. It is applied to MPPT control of PV system in irregular shadow to solve the problem of multi-peak optimization in partial shadow. In order to verify the rationality of the proposed algorithm, however, recently the dynamic MPPT performance under varying irradiance conditions has been given utmost attention to the PV society. As the European standard EN 50530 which defines the recommended varying irradiance profiles, was released lately, the corresponding researchers have been required to improve the dynamic MPPT performance. This paper tried to evaluate the dynamic MPPT performance using EN 50530 standard. The simulation results show that iterative-PSO method can fast track the global MPP, increase tracking speed and higher dynamic MPPT efficiency under EN 50530 than the conventional PSO.

COMPARATIVE ANALYSIS ON PERFORMANCE OF POWER CONVERTERSFOR MPPT USING PAO TECHNIQUE

OpenAIRE

Dr. S. Rajeswari*

2017-01-01

This research work is mainly spotlight to identify a suitable power converter for tracking the Maximum Power Point, an analysis of MPPT based power converters has been carried out in this work. A PV system is a non-linear power source due to the variations in the climatic conditions, hence tracking the maximum power point is difficult. It mainly explains about the PAO algorithm based MPPT method to track the maximum power. It also discuss about different types of conventional power converters...

Issues regarding the usage of MPPT techniques in micro grid systems

Science.gov (United States)

Szeidert, I.; Filip, I.; Dragan, F.; Gal, A.

2018-01-01

The main objective of the control strategies applied at hybrid micro grid systems (wind/hydro/solar), that function based on maximum power point tracking (MPPT) techniques is to improve the conversion system’s efficiency and to preserve the quality of the generated electrical energy (voltage and power factor). One of the main goals of maximum power point tracking strategy is to achieve the harvesting of the maximal possible energy within a certain time period. In order to implement the control strategies for micro grid, there are typically required specific transducers (sensor for wind speed, optical rotational transducers, etc.). In the technical literature, several variants of the MPPT techniques are presented and particularized at some applications (wind energy conversion systems, solar systems, hydro plants, micro grid hybrid systems). The maximum power point tracking implementations are mainly based on two-level architecture. The lower level controls the main variable and the superior level represents the MPPT control structure. The paper presents micro grid structures developed at Politehnica University Timisoara (PUT) within the frame of a research grant. The paper is focused on the application of MPPT strategies on hybrid micro grid systems. There are presented several structures and control strategies and are highlighted their advantages and disadvantages, together with practical implementation guidelines.

Thermoelectric Generator Emulator for MPPT Testing

DEFF Research Database (Denmark)

Man, Elena Anamaria; Sera, Dezso; Máthé, Lászlo

2015-01-01

This paper presents a novel approach to use a DC power supply as a thermoelectric generator (TEG) emulator to perform static and dynamic maximum power point tracking (MPPT). First, the electrical characterization of a calcium-manganese-oxide module is performed on a TEG test rig. Afterwards...

Random Forest-Based Approach for Maximum Power Point Tracking of Photovoltaic Systems Operating under Actual Environmental Conditions.

Science.gov (United States)

Shareef, Hussain; Mutlag, Ammar Hussein; Mohamed, Azah

2017-01-01

Many maximum power point tracking (MPPT) algorithms have been developed in recent years to maximize the produced PV energy. These algorithms are not sufficiently robust because of fast-changing environmental conditions, efficiency, accuracy at steady-state value, and dynamics of the tracking algorithm. Thus, this paper proposes a new random forest (RF) model to improve MPPT performance. The RF model has the ability to capture the nonlinear association of patterns between predictors, such as irradiance and temperature, to determine accurate maximum power point. A RF-based tracker is designed for 25 SolarTIFSTF-120P6 PV modules, with the capacity of 3 kW peak using two high-speed sensors. For this purpose, a complete PV system is modeled using 300,000 data samples and simulated using the MATLAB/SIMULINK package. The proposed RF-based MPPT is then tested under actual environmental conditions for 24 days to validate the accuracy and dynamic response. The response of the RF-based MPPT model is also compared with that of the artificial neural network and adaptive neurofuzzy inference system algorithms for further validation. The results show that the proposed MPPT technique gives significant improvement compared with that of other techniques. In addition, the RF model passes the Bland-Altman test, with more than 95 percent acceptability.

AN EVALUATION OF PHOTOVOLTAIC SYSTEMS MPPT TECHNIQUES UNDER THE CHARACTERISTICS OF OPERATIONAL CONDITIONS

Directory of Open Access Journals (Sweden)

I. A. Elzein

2017-01-01

Full Text Available In this article an extended literature surveying review is launched on a set of comparative studies of maximum power point tracking (MPPT techniques. Different MPPT methods are addressed with an ultimate aim of how to be maximizing the PV system output power by tracking Pmax in a set of different operational circumstances. In this paper maximum power point tracking, MPPT techniques are reviewed on basis of different parameters related to the design simplicity and/or complexity, implementation, hardware required, and other related aspects.he technology of solar systems has been booming for a while due to its ability to replace current fossil fuels like coal and gas for generation of electricity that produce air, water, and land pollution. In addition it decreased the issue of global warming and climate changes substantially due to being produced in a clean environmental manner and was proved to be an Eco-friendly resource of energy. The photovoltaic systems’ manufacturing process has been improving continuously over the last decade and photovoltaic systems have become an interesting solution. Precisely, PV systems are constituted from arrays of photovoltaic cells, choppers (mainly buck-boost or boost DC/DC converter, MPPT control systems and storage devices and/or grid connections. To improve the efficiency of such systems, various studies have been performed. The demand of PV generation systems seems to be increased for both standalone and grid-connected modes of PV systems. Therefore, an efficient maximum power point tracking (MPPT technique is necessary to initialize the process of tracking the maximum power point MPP at all environmental conditions and then force the PV system to operate at that MPP point.

A Standalone PV System with a Hybrid P&O MPPT Optimization Technique

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S. Hota

2017-12-01

Full Text Available In this paper a maximum power point tracking (MPPT design for a photovoltaic (PV system using a hybrid optimization technique is proposed. For maximum power transfer, maximum harvestable power from a PV cell in a dynamically changing surrounding should be known. The proposed technique is compared with the conventional Perturb and Observe (P&O technique. A comparative analysis of power-voltage and current-voltage characteristics of a PV cell with and without the MPPT module when connected to the grid was performed in SIMULINK, to demonstrate the increment in the efficiency of the PV module after using the MPPT module.

MPPT for PM wind generator using gradient approximation

Energy Technology Data Exchange (ETDEWEB)

Hong, Ying-Yi; Lu, Shiue-Der; Chiou, Ching-Sheng [Department of Electrical Engineering, Chung Yuan Christian University, 200, Chung-Pei Road, Chung Li 320 (China)

2009-01-15

This paper applies new maximum-power-point tracking (MPPT) algorithms to a wind-turbine generator system (WTGS). In this paper, the WTGS is a direct-drive system and includes the wind-turbine, permanent-magnet (PM) synchronous generator, three-phase full bridge rectifier, buck-boost converter and load. The new MPPT method uses gradient approximation (GA) algorithm. Three methods based on GA for achieving MPPT are discussed in this paper: (1) full-sensor control with anemometer and tachometer, (2) rule-based method and (3) adaptive duty cycle method. The third method has merits of no PID parameters, proportional constant, anemometer, tachometer and characteristics of WTGS required. This method enables the permanent-magnet synchronous generator (PMSG) to operate at variable speeds to achieve good performance. Simulation results show that the tip-speed ratio (TSR) and power coefficient obtained by the adaptive duty cycle method with GA can be almost identical to the optimal values. (author)

MPPT for PM wind generator using gradient approximation

International Nuclear Information System (INIS)

Hong, Y.-Y.; Lu, S.-D.; Chiou, C.-S.

2009-01-01

This paper applies new maximum-power-point tracking (MPPT) algorithms to a wind-turbine generator system (WTGS). In this paper, the WTGS is a direct-drive system and includes the wind-turbine, permanent-magnet (PM) synchronous generator, three-phase full bridge rectifier, buck-boost converter and load. The new MPPT method uses gradient approximation (GA) algorithm. Three methods based on GA for achieving MPPT are discussed in this paper: (1) full-sensor control with anemometer and tachometer, (2) rule-based method and (3) adaptive duty cycle method. The third method has merits of no PID parameters, proportional constant, anemometer, tachometer and characteristics of WTGS required. This method enables the permanent-magnet synchronous generator (PMSG) to operate at variable speeds to achieve good performance. Simulation results show that the tip-speed ratio (TSR) and power coefficient obtained by the adaptive duty cycle method with GA can be almost identical to the optimal values

Application of Copper Indium Gallium Diselenide Photovoltaic Cells to Extend the Endurance and Capabilities of Unmanned Aerial Vehicles

Science.gov (United States)

2009-09-01

power point trackers ( MPPT ) or Photovoltaic Power Converters (PVPC). We will use the more common MPPT ...with MPPT (From [102]). ......................79 Figure 80. Genasun GV-4 Low- Power MPPT /Charge Controller . ...................................80...at up to 96% efficiency [5], but for the sake of this discussion, we will use the power consumption of the specific MPPT used in the

Improved Fractional Order VSS Inc-Cond MPPT Algorithm for Photovoltaic Scheme

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R. Arulmurugan

2014-01-01

Full Text Available Nowadays a hot topic among the research community is the harnessing energy from the free sunlight which is abundant and pollution-free. The availability of cheap solar photovoltaic (PV modules has to harvest solar energy with better efficiency. The nature of solar modules is nonlinear and therefore the proper impedance matching is essential. The proper impedance matching ensures the extraction of the maximum power from solar PV module. Maximum power point tracking (MPPT algorithm is acting as a significant part in solar power generating system because it varies in the output power from a PV generating set for various climatic conditions. This paper suggested a new improved work for MPPT of PV energy system by using the optimized novel improved fractional order variable step size (FOVSS incremental conductance (Inc-Cond algorithm. The new proposed controller combines the merits of both improved fractional order (FO and variable step size (VSS Inc-Cond which is well suitable for design control and execution. The suggested controller results in attaining the desired transient reaction under changing operating points. MATLAB simulation effort shows MPPT controller and a DC to DC Luo converter feeding a battery load is achieved. The laboratory experimental results demonstrate that the new proposed MPPT controller in the photovoltaic generating system is valid.

New MPPT algorithm for PV applications based on hybrid dynamical approach

KAUST Repository

Elmetennani, Shahrazed

2016-10-24

This paper proposes a new Maximum Power Point Tracking (MPPT) algorithm for photovoltaic applications using the multicellular converter as a stage of power adaptation. The proposed MPPT technique has been designed using a hybrid dynamical approach to model the photovoltaic generator. The hybrid dynamical theory has been applied taking advantage of the particular topology of the multicellular converter. Then, a hybrid automata has been established to optimize the power production. The maximization of the produced solar energy is achieved by switching between the different operative modes of the hybrid automata, which is conditioned by some invariance and transition conditions. These conditions have been validated by simulation tests under different conditions of temperature and irradiance. Moreover, the performance of the proposed algorithm has been then evaluated by comparison with standard MPPT techniques numerically and by experimental tests under varying external working conditions. The results have shown the interesting features that the hybrid MPPT technique presents in terms of performance and simplicity for real time implementation.

New MPPT algorithm for PV applications based on hybrid dynamical approach

KAUST Repository

Elmetennani, Shahrazed; Laleg-Kirati, Taous-Meriem; Djemai, M.; Tadjine, M.

2016-01-01

This paper proposes a new Maximum Power Point Tracking (MPPT) algorithm for photovoltaic applications using the multicellular converter as a stage of power adaptation. The proposed MPPT technique has been designed using a hybrid dynamical approach to model the photovoltaic generator. The hybrid dynamical theory has been applied taking advantage of the particular topology of the multicellular converter. Then, a hybrid automata has been established to optimize the power production. The maximization of the produced solar energy is achieved by switching between the different operative modes of the hybrid automata, which is conditioned by some invariance and transition conditions. These conditions have been validated by simulation tests under different conditions of temperature and irradiance. Moreover, the performance of the proposed algorithm has been then evaluated by comparison with standard MPPT techniques numerically and by experimental tests under varying external working conditions. The results have shown the interesting features that the hybrid MPPT technique presents in terms of performance and simplicity for real time implementation.

Random Forest-Based Approach for Maximum Power Point Tracking of Photovoltaic Systems Operating under Actual Environmental Conditions

Directory of Open Access Journals (Sweden)

Hussain Shareef

2017-01-01

Full Text Available Many maximum power point tracking (MPPT algorithms have been developed in recent years to maximize the produced PV energy. These algorithms are not sufficiently robust because of fast-changing environmental conditions, efficiency, accuracy at steady-state value, and dynamics of the tracking algorithm. Thus, this paper proposes a new random forest (RF model to improve MPPT performance. The RF model has the ability to capture the nonlinear association of patterns between predictors, such as irradiance and temperature, to determine accurate maximum power point. A RF-based tracker is designed for 25 SolarTIFSTF-120P6 PV modules, with the capacity of 3 kW peak using two high-speed sensors. For this purpose, a complete PV system is modeled using 300,000 data samples and simulated using the MATLAB/SIMULINK package. The proposed RF-based MPPT is then tested under actual environmental conditions for 24 days to validate the accuracy and dynamic response. The response of the RF-based MPPT model is also compared with that of the artificial neural network and adaptive neurofuzzy inference system algorithms for further validation. The results show that the proposed MPPT technique gives significant improvement compared with that of other techniques. In addition, the RF model passes the Bland–Altman test, with more than 95 percent acceptability.

Open- and Short-Circuit Fault Identification for a Boost dc/dc Converter in PV MPPT Systems

Directory of Open Access Journals (Sweden)

Diego R. Espinoza Trejo

2018-03-01

Full Text Available This paper proposes a fault identification system for short and open-circuit switch faults (SOCSF for a dc/dc converter acting as a Maximum Power Point Tracker (MPPT in Photovoltaic (PV systems. A closed-loop operation is assumed for the boost dc/dc converter. A linearizing control plus a Proportional-Derivative (PD controller is suggested for PV voltage regulation at the maximum power point (MPP. In this study, the SOCSF are modeled by using an additive fault representation and the fault identification (FI system is synthesized departing from a Luenberger observer. Hence, an FI signal is obtained, which is insensitive to irradiance and load current changes, but affected by the SOCSF. For FI purposes, only the sensors used in the control system are needed. Finally, an experimental evaluation is presented by using a solar array simulator dc power supply and a boost dc/dc converter of 175 W in order to validate the ideas this study exposes.

Highly efficient maximum power point tracking using DC-DC coupled inductor single-ended primary inductance converter for photovoltaic power systems

Science.gov (United States)

Quamruzzaman, M.; Mohammad, Nur; Matin, M. A.; Alam, M. R.

2016-10-01

Solar photovoltaics (PVs) have nonlinear voltage-current characteristics, with a distinct maximum power point (MPP) depending on factors such as solar irradiance and operating temperature. To extract maximum power from the PV array at any environmental condition, DC-DC converters are usually used as MPP trackers. This paper presents the performance analysis of a coupled inductor single-ended primary inductance converter for maximum power point tracking (MPPT) in a PV system. A detailed model of the system has been designed and developed in MATLAB/Simulink. The performance evaluation has been conducted on the basis of stability, current ripple reduction and efficiency at different operating conditions. Simulation results show considerable ripple reduction in the input and output currents of the converter. Both the MPPT and converter efficiencies are significantly improved. The obtained simulation results validate the effectiveness and suitability of the converter model in MPPT and show reasonable agreement with the theoretical analysis.

Optimization of a Fuzzy-Logic-Control-Based MPPT Algorithm Using the Particle Swarm Optimization Technique

Directory of Open Access Journals (Sweden)

Po-Chen Cheng

2015-06-01

Full Text Available In this paper, an asymmetrical fuzzy-logic-control (FLC-based maximum power point tracking (MPPT algorithm for photovoltaic (PV systems is presented. Two membership function (MF design methodologies that can improve the effectiveness of the proposed asymmetrical FLC-based MPPT methods are then proposed. The first method can quickly determine the input MF setting values via the power–voltage (P–V curve of solar cells under standard test conditions (STC. The second method uses the particle swarm optimization (PSO technique to optimize the input MF setting values. Because the PSO approach must target and optimize a cost function, a cost function design methodology that meets the performance requirements of practical photovoltaic generation systems (PGSs is also proposed. According to the simulated and experimental results, the proposed asymmetrical FLC-based MPPT method has the highest fitness value, therefore, it can successfully address the tracking speed/tracking accuracy dilemma compared with the traditional perturb and observe (P&O and symmetrical FLC-based MPPT algorithms. Compared to the conventional FLC-based MPPT method, the obtained optimal asymmetrical FLC-based MPPT can improve the transient time and the MPPT tracking accuracy by 25.8% and 0.98% under STC, respectively.

A comparative study of the maximum power point tracking methods for PV systems

International Nuclear Information System (INIS)

Liu, Yali; Li, Ming; Ji, Xu; Luo, Xi; Wang, Meidi; Zhang, Ying

2014-01-01

Highlights: • An improved maximum power point tracking method for PV system was proposed. • Theoretical derivation procedure of the proposed method was provided. • Simulation models of MPPT trackers were established based on MATLAB/Simulink. • Experiments were conducted to verify the effectiveness of the proposed MPPT method. - Abstract: Maximum power point tracking (MPPT) algorithms play an important role in the optimization of the power and efficiency of a photovoltaic (PV) generation system. According to the contradiction of the classical Perturb and Observe (P and Oa) method between the corresponding speed and the tracking accuracy on steady-state, an improved P and O (P and Ob) method has been put forward in this paper by using the Atken interpolation algorithm. To validate the correctness and performance of the proposed method, simulation and experimental study have been implemented. Simulation models of classical P and Oa method and improved P and Ob method have been established by MATLAB/Simulink to analyze each technique under varying solar irradiation and temperature. The experimental results show that the tracking efficiency of P and Ob method is an average of 93% compared to 72% for P and Oa method, this conclusion basically agree with the simulation study. Finally, we proposed the applicable conditions and scope of these MPPT methods in the practical application

MPPT Based on Fuzzy Logic Controller (FLC for Photovoltaic (PV System in Solar Car

Directory of Open Access Journals (Sweden)

Seno Aji

2013-12-01

Full Text Available This paper presents a control called Maximum Power Point Tracking (MPPT for photovoltaic (PV system in a solar car. The main purpose of this system is to extracts PV power maximally while keeping small losses using a simple design of converter. Working principle of MPPT based fuzzy logic controller (MPPT-FLC is to get desirable values of reference current and voltage. MPPT-FLC compares them with the values of the PV's actual current and voltage to control duty cycle value. Then the duty cycle value is used to adjust the angle of ignition switch (MOSFET gate on the Boost converter. The proposed method was shown through simulation performed using PSIM and MATLAB software. Simulation results show that the system is able to improve the PV power extraction efficiency significantly by approximately 98% of PV’s power.

MODEL PREDICTIVE CONTROL FOR PHOTOVOLTAIC STATION MAXIMUM POWER POINT TRACKING SYSTEM

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I. Elzein

2015-01-01

Full Text Available The purpose of this paper is to present an alternative maximum power point tracking, MPPT, algorithm for a photovoltaic module, PVM, to produce the maximum power, Pmax, using the optimal duty ratio, D, for different types of converters and load matching.We present a state-based approach to the design of the maximum power point tracker for a stand-alone photovoltaic power generation system. The system under consideration consists of a solar array with nonlinear time-varying characteristics, a step-up converter with appropriate filter.The proposed algorithm has the advantages of maximizing the efficiency of the power utilization, can be integrated to other MPPT algorithms without affecting the PVM performance, is excellent for Real-Time applications and is a robust analytical method, different from the traditional MPPT algorithms which are more based on trial and error, or comparisons between present and past states. The procedure to calculate the optimal duty ratio for a buck, boost and buck-boost converters, to transfer the maximum power from a PVM to a load, is presented in the paper. Additionally, the existence and uniqueness of optimal internal impedance, to transfer the maximum power from a photovoltaic module using load matching, is proved.

Neuro-Fuzzy Wavelet Based Adaptive MPPT Algorithm for Photovoltaic Systems

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Syed Zulqadar Hassan

2017-03-01

Full Text Available An intelligent control of photovoltaics is necessary to ensure fast response and high efficiency under different weather conditions. This is often arduous to accomplish using traditional linear controllers, as photovoltaic systems are nonlinear and contain several uncertainties. Based on the analysis of the existing literature of Maximum Power Point Tracking (MPPT techniques, a high performance neuro-fuzzy indirect wavelet-based adaptive MPPT control is developed in this work. The proposed controller combines the reasoning capability of fuzzy logic, the learning capability of neural networks and the localization properties of wavelets. In the proposed system, the Hermite Wavelet-embedded Neural Fuzzy (HWNF-based gradient estimator is adopted to estimate the gradient term and makes the controller indirect. The performance of the proposed controller is compared with different conventional and intelligent MPPT control techniques. MATLAB results show the superiority over other existing techniques in terms of fast response, power quality and efficiency.

New algorithm using only one variable measurement applied to a maximum power point tracker

Energy Technology Data Exchange (ETDEWEB)

Salas, V.; Olias, E.; Lazaro, A.; Barrado, A. [University Carlos III de Madrid (Spain). Dept. of Electronic Technology

2005-05-01

A novel algorithm for seeking the maximum power point of a photovoltaic (PV) array for any temperature and solar irradiation level, needing only the PV current value, is proposed. Satisfactory theoretical and experimental results are presented and were obtained when the algorithm was included on a 100 W 24 V PV buck converter prototype, using an inexpensive microcontroller. The load of the system used was a battery and a resistance. The main advantage of this new maximum power point tracking (MPPT), when is compared with others, is that it only uses the measurement of the photovoltaic current, I{sub PV}. (author)

An Improved PSO-Based MPPT Control Strategy for Photovoltaic Systems

Directory of Open Access Journals (Sweden)

M. Abdulkadir

2014-01-01

Full Text Available This paper presents a control strategy proposed for power maximizing which is a critical mechanism to ensure power track is maximized. Many tracking algorithms have been proposed for this purpose. One of the more commonly used techniques is the incremental conductance method. In this paper, an improved particle swarm optimization- (IPSO- based MPPT technique for photovoltaic system operating under varying environmental conditions is proposed. The approach of linearly decreasing scheme for weighting factor and cognitive and social parameter is modified. The proposed control scheme can overcome deficiency and accelerate convergence of the IPSO-based MPPT algorithm. The approach is not only capable of tracking the maximum power point under uniform insolation state, but also able to find the maximum power point under fast changing nonuniform insolation conditions. The photovoltaic systematic process with control schemes is created using MATLAB Simulink to verify the effectiveness with several simulations being carried out and then compared with the conventional incremental conductance technique. Lastly, the effectiveness of the intended techniques is proven using real data obtained form previous literature. With the change in insolation and temperature portrait, it produces exceptional MPPT maximization. This shows that optimum performance is achieved using the intended method compared to the typical method.

Performance analysis of ‘Perturb and Observe’ and ‘Incremental Conductance’ MPPT algorithms for PV system

Science.gov (United States)

Lodhi, Ehtisham; Lodhi, Zeeshan; Noman Shafqat, Rana; Chen, Fieda

2017-07-01

Photovoltaic (PV) system usually employed The Maximum power point tracking (MPPT) techniques for increasing its efficiency. The performance of the PV system perhaps boosts by controlling at its apex point of power, in this way maximal power can be given to load. The proficiency of a PV system usually depends upon irradiance, temperature and array architecture. PV array shows a non-linear style for V-I curve and maximal power point on V-P curve also varies with changing environmental conditions. MPPT methods grantees that a PV module is regulated at reference voltage and to produce entire usage of the maximal output power. This paper gives analysis between two widely employed Perturb and Observe (P&O) and Incremental Conductance (INC) MPPT techniques. Their performance is evaluated and compared through theoretical analysis and digital simulation on the basis of response time and efficiency under varying irradiance and temperature condition using Matlab/Simulink.

Comparative analysis of distributed MPPT controllers for partially shaded stand alone photovoltaic systems

International Nuclear Information System (INIS)

Muthuramalingam, M.; Manoharan, P.S.

2014-01-01

Highlights: • Analyzes the performance of ANN and ANFIS MPPT algorithms by stand alone PV system. • ISSBC with ANFIS can provide the overall efficiency higher than ANN. • CHBMLI integrate with SHE ANN modulation technique improve output voltage quality. • Simulation and hardware results show the ANFIS algorithm efficient than ANN algorithm. - Abstract: This paper presents a unique combination of an interleaved soft switched boost converter (ISSBC) run by a set of two photovoltaic panel (PV) with a distributed MPPT, suitable to guarantee MPPT even under partial shadowed conditions, managed by an adaptive neuro fuzzy inference system trained by the training data derived from a particle swarm optimization (PSO–ANFIS) unit. The ISSBC is followed by a, single phase cascaded H bridge five-level inverter (CHI) driven by the individual DC outputs of the ISSBC, with selective harmonic elimination scheme to eliminate typically the seventh order harmonics. A comparison of different intelligent distributed maximum power point tracking (MPPT) algorithms for photovoltaic (PV) system under partial shadow conditions is carried out. The use of the ISSBC guarantees mitigation of ripple and it is meant to handle higher currents with minimal switching losses. Simulation was carried out in the Matlab Simulink environment and an experimental verification with a scaled down model validated the proposed scheme. It has been thus established, by both simulation and experimental verification, that the PSO–ANFIS model of distributed MPPT scheme of control outperforms other schemes of control for MPPT

Single-stage MPPT control realization for Aalborg inverter in photovoltaic system

DEFF Research Database (Denmark)

Zhang, Shuai; Wu, Weimin; Wang, Houqing

2017-01-01

In this paper, the single-stage Maximum Power Point Tracking (MPPT) control strategy for the Aalborg photovoltaic inverter is presented. Aalborg inverter has many advantages, such as high efficiency, wide range of input voltage, minimum voltage drop of the filtering inductors, etc. Nevertheless......, it is essentially a “half-bridge” inverter with two input sources, where one source works in MPPT mode, the other is out of control. If without the reasonable parameter design and the proper control, the bus-voltage of this inverter may change greatly, resulting in the serious power oscillation around maximum power...

Comparative Analysis of Reduced-Rule Compressed Fuzzy Logic Control and Incremental Conductance MPPT Methods

Science.gov (United States)

Kandemir, Ekrem; Borekci, Selim; Cetin, Numan S.

2018-04-01

Photovoltaic (PV) power generation has been widely used in recent years, with techniques for increasing the power efficiency representing one of the most important issues. The available maximum power of a PV panel is dependent on environmental conditions such as solar irradiance and temperature. To extract the maximum available power from a PV panel, various maximum-power-point tracking (MPPT) methods are used. In this work, two different MPPT methods were implemented for a 150-W PV panel. The first method, known as incremental conductance (Inc. Cond.) MPPT, determines the maximum power by measuring the derivative of the PV voltage and current. The other method is based on reduced-rule compressed fuzzy logic control (RR-FLC), using which it is relatively easier to determine the maximum power because a single input variable is used to reduce computing loads. In this study, a 150-W PV panel system model was realized using these MPPT methods in MATLAB and the results compared. According to the simulation results, the proposed RR-FLC-based MPPT could increase the response rate and tracking accuracy by 4.66% under standard test conditions.

Microprocessor Controlled Maximum Power Point Tracker for Photovoltaic Application

International Nuclear Information System (INIS)

Jiya, J. D.; Tahirou, G.

2002-01-01

This paper presents a microprocessor controlled maximum power point tracker for photovoltaic module. Input current and voltage are measured and multiplied within the microprocessor, which contains an algorithm to seek the maximum power point. The duly cycle of the DC-DC converter, at which the maximum power occurs is obtained, noted and adjusted. The microprocessor constantly seeks for improvement of obtained power by varying the duty cycle

Dynamic Performance of Maximum Power Point Trackers in TEG Systems Under Rapidly Changing Temperature Conditions

DEFF Research Database (Denmark)

Man, E. A.; Sera, D.; Mathe, L.

2016-01-01

of the intermittent operation of the internal combustion engine, the TEG and its MPPT controller are exposed to a cyclic temperature profile. Furthermore, there are no guidelines on how fast the MPPT must be under such dynamic conditions. In the work discussed in this paper, temperature gradients for TEG integrated...

Design of MPPT Controller Monitoring Software Based on QT Framework

Science.gov (United States)

Meng, X. Z.; Lu, P. G.

2017-10-01

The MPPT controller was a hardware device for tracking the maximum power point of solar photovoltaic array. Multiple controllers could be working as networking mode by specific communicating protocol. In this article, based on C++ GUI programming with Qt frame, we designed one sort of desktop application for monitoring and analyzing operational parameter of MPPT controller. The type of communicating protocol for building network was Modbus protocol which using Remote Terminal Unit mode and The desktop application of host computer was connected with all the controllers in the network through RS485 communication or ZigBee wireless communication. Using this application, user could monitor the parameter of controller wherever they were by internet.

Fuzzy Logic Based MPPT Controller for a PV System

Directory of Open Access Journals (Sweden)

Carlos Robles Algarín

2017-12-01

Full Text Available The output power of a photovoltaic (PV module depends on the solar irradiance and the operating temperature; therefore, it is necessary to implement maximum power point tracking controllers (MPPT to obtain the maximum power of a PV system regardless of variations in climatic conditions. The traditional solution for MPPT controllers is the perturbation and observation (P&O algorithm, which presents oscillation problems around the operating point; the reason why improving the results obtained with this algorithm has become an important goal to reach for researchers. This paper presents the design and modeling of a fuzzy controller for tracking the maximum power point of a PV System. Matlab/Simulink (MathWorks, Natick, MA, USA was used for the modeling of the components of a 65 W PV system: PV module, buck converter and fuzzy controller; highlighting as main novelty the use of a mathematical model for the PV module, which, unlike diode based models, only needs to calculate the curve fitting parameter. A P&O controller to compare the results obtained with the fuzzy control was designed. The simulation results demonstrated the superiority of the fuzzy controller in terms of settling time, power loss and oscillations at the operating point.

Fuzzy Controller for a Voltage-Regulated Solar-Powered MPPT System for Hybrid Power System Applications

Directory of Open Access Journals (Sweden)

Jaw-Kuen Shiau

2015-04-01

Full Text Available This paper presents the design of a fuzzy-logic-based voltage-regulated solar power maximum power point tracking (MPPT system for applications involving hybrid power systems. The system contains a solar power system and battery as the primary and secondary power sources, respectively. The solar system alone supplies power to the electric motor and maintains the output voltage at a predetermined level when it has sufficient power. When the solar power is insufficient, the solar system is operated at its maximum power point (MPP and the battery is engaged to compensate for the insufficiency. First, a variant of the incremental conductance MPP condition was established. Under the MPP condition, the voltage-regulated MPPT system was formulated as a feedback control system, where the MPP condition and voltage regulation requirements were used as the system inputs. Next, a fuzzy controller was developed to perform the voltage-regulated MPPT function for the hybrid power system. A simulation model based on Matrix laboratory (MATLAB/SIMULINK (a block diagram environment for multi-domain simulation and model-based design and a piecewise linear electric circuit simulation (PLECS tool for controlling the dc motor velocity was developed to verify the voltage-regulated solar power MPPT system.

Variable frequency iteration MPPT for resonant power converters

Science.gov (United States)

Zhang, Qian; Bataresh, Issa; Chen, Lin

2015-06-30

A method of maximum power point tracking (MPPT) uses an MPPT algorithm to determine a switching frequency for a resonant power converter, including initializing by setting an initial boundary frequency range that is divided into initial frequency sub-ranges bounded by initial frequencies including an initial center frequency and first and second initial bounding frequencies. A first iteration includes measuring initial powers at the initial frequencies to determine a maximum power initial frequency that is used to set a first reduced frequency search range centered or bounded by the maximum power initial frequency including at least a first additional bounding frequency. A second iteration includes calculating first and second center frequencies by averaging adjacent frequent values in the first reduced frequency search range and measuring second power values at the first and second center frequencies. The switching frequency is determined from measured power values including the second power values.

Study of a thermoelectric system equipped with a maximum power point tracker for stand-alone electric generation.

Science.gov (United States)

Favarel, C.; Champier, D.; Bédécarrats, J. P.; Kousksou, T.; Strub, F.

2012-06-01

According to the International Energy Agency, 1.4 billion people are without electricity in the poorest countries and 2.5 billion people rely on biomass to meet their energy needs for cooking in developing countries. The use of cooking stoves equipped with small thermoelectric generator to provide electricity for basic needs (LED, cell phone and radio charging device) is probably a solution for houses far from the power grid. The cost of connecting every house with a landline is a lot higher than dropping thermoelectric generator in each house. Thermoelectric generators have very low efficiency but for isolated houses, they might become really competitive. Our laboratory works in collaboration with plane`te-bois (a non governmental organization) which has developed energy-efficient multifunction (cooking and hot water) stoves based on traditional stoves designs. A prototype of a thermoelectric generator (Bismuth Telluride) has been designed to convert a small part of the energy heating the sanitary water into electricity. This generator can produce up to 10 watts on an adapted load. Storing this energy in a battery is necessary as the cooking stove only works a few hours each day. As the working point of the stove varies a lot during the use it is also necessary to regulate the electrical power. An electric DC DC converter has been developed with a maximum power point tracker (MPPT) in order to have a good efficiency of the electronic part of the thermoelectric generator. The theoretical efficiency of the MMPT converter is discussed. First results obtained with a hot gas generator simulating the exhaust of the combustion chamber of a cooking stove are presented in the paper.

Photovoltaic Cells Mppt Algorithm and Design of Controller Monitoring System

Science.gov (United States)

Meng, X. Z.; Feng, H. B.

2017-10-01

This paper combined the advantages of each maximum power point tracking (MPPT) algorithm, put forward a kind of algorithm with higher speed and higher precision, based on this algorithm designed a maximum power point tracking controller with ARM. The controller, communication technology and PC software formed a control system. Results of the simulation and experiment showed that the process of maximum power tracking was effective, and the system was stable.

A novel maximum power point tracking method for PV systems using fuzzy cognitive networks (FCN)

Energy Technology Data Exchange (ETDEWEB)

Karlis, A.D. [Electrical Machines Laboratory, Department of Electrical & amp; Computer Engineering, Democritus University of Thrace, V. Sofias 12, 67100 Xanthi (Greece); Kottas, T.L.; Boutalis, Y.S. [Automatic Control Systems Laboratory, Department of Electrical & amp; Computer Engineering, Democritus University of Thrace, V. Sofias 12, 67100 Xanthi (Greece)

2007-03-15

Maximum power point trackers (MPPTs) play an important role in photovoltaic (PV) power systems because they maximize the power output from a PV system for a given set of conditions, and therefore maximize the array efficiency. This paper presents a novel MPPT method based on fuzzy cognitive networks (FCN). The new method gives a good maximum power operation of any PV array under different conditions such as changing insolation and temperature. The numerical results show the effectiveness of the proposed algorithm. (author)

All SiC Grid-Connected PV Supply with HF Link MPPT Converter: System Design Methodology and Development of a 20 kHz, 25 kVA Prototype

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Serkan Öztürk

2018-05-01

Full Text Available Design methodology and implementation of an all SiC power semiconductor-based, grid-connected multi-string photovoltaic (PV supply with an isolated high frequency (HF link maximum power point tracker (MPPT have been described. This system configuration makes possible the use of a simple and reliable two-level voltage source inverter (VSI topology for grid connection, owing to the galvanic isolation provided by the HF transformer. This topology provides a viable alternative to the commonly used non-isolated PV supplies equipped with Si-based boost MPPT converters cascaded with relatively more complex inverter topologies, at competitive efficiency figures and a higher power density. A 20 kHz, 25 kVA prototype system was designed based on the dynamic model of the multi-string PV panels obtained from field tests. Design parameters such as input DC link capacitance, switching frequencies of MPPT converter and voltage source inverter, size and performance of HF transformer with nanocrystalline core, DC link voltage, and LCL filter of the VSI were optimized in view of the site dependent parameters such as the variation ranges of solar insolation, module surface temperature, and grid voltage. A modified synchronous reference frame control was implemented in the VSI by applying the grid voltage feedforward to the reference voltages in abc axes directly, so that zero-sequence components of grid voltages are taken into account in the case of an unbalanced grid. The system was implemented and the proposed design methodology verified satisfactorily in the field on a roof-mounted 23.7 kW multi-string PV system.

An Improved Adaptive-Torque-Gain MPPT Control for Direct-Driven PMSG Wind Turbines Considering Wind Farm Turbulences

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Xiaolian Zhang

2016-11-01

Full Text Available Maximum power point tracking (MPPT plays an important role in increasing the efficiency of a wind energy conversion system (WECS. In this paper, three conventional MPPT methods are reviewed: power signal feedback (PSF control, decreased torque gain (DTG control, and adaptive torque gain (ATG control, and their potential challenges are investigated. It is found out that the conventional MPPT method ignores the effect of wind turbine inertia and wind speed fluctuations, which lowers WECS efficiency. Accordingly, an improved adaptive torque gain (IATG method is proposed, which customizes adaptive torque gains and enhances MPPT performances. Specifically, the IATG control considers wind farm turbulences and works out the relationship between the optimal torque gains and the wind speed characteristics, which has not been reported in the literature. The IATG control is promising, especially under the ongoing trend of building wind farms with large-scale wind turbines and at low and medium wind speed sites.

A maximum power point tracker for photovoltaic system using a PIC microcontroller; Controlador de potencia maxima para sistemas fotovoltaicos (SFVs) utilizando un microcontrolador PIC

Energy Technology Data Exchange (ETDEWEB)

Guzman, Eusebio; Mendoza, Victor X; Carrillo, Jose J . A; Galarza, Cristian [Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico)

2000-07-01

A maximum power point tracker MPPT for photovoltaic systems is presented. The equipment can output up to 600 W and its control signals are generated by a PIC microcontroller. The principle of control is based on current and voltage sampling at the output terminals of the photovoltaic generator. From power comparison of two consecutive samples, it is possible to know how far from the optimal point the system is working. Output voltage control is used to force the system to work within the optimal area of operation. The microcontroller program sequence, the DC/DC converter structure and the most relevant results are shown. [Spanish] En este trabajo se presenta el desarrollo de un controlador de potencia maxima para su aplicacion en sistemas fotovoltaicos (SFVs). El diseno alcanza una potencia de 600 W y sus senales de control son generadas con un controlador PIC. El principio de control se basa en el muestreo de la corriente y la tension en las terminadas del generador fotovoltaico GFV. De dos muestreos consecutivos, y por comparacion de las potencias, se determina que tan alejado del punto optimo opera el sistema. La operacion del sistema dentro de la zona de funcionamiento optimo se asegura mediante un control por tension. Se muestra la secuencia de programacion del microcontrolador, la estructura del convertidor CD/CD empleado y algunos resultados relevantes.

A power conditioning system for thermoelectric generator based on interleaved Boost converter with MPPT control

DEFF Research Database (Denmark)

Ni, L.-X; Sun, K.; Zhang, L.

2011-01-01

The thermoelectric generation (TEG) system has its special charactristics of high stablility, low voltage and high current output, which is different from PV modules. The power conditioning system and control schemes used in PV applications cannot be directly applied to TEG applications. A power...... conditioning system for TEG based on interleaved Boost converter with maximum power point tracking (MPPT) control is investigated in this paper. Since an internal resistance exists inside TEG modules, an improved perturbation and observation (P&O) MPPT control scheme with power limit is proposed to extract...... maximum power from TEG by matching the load with internal resistance. Since the battery is usually employed as the load for TEG systems, the interleaved Boost converter operates in two different modes for battery charging: before the battery is fully charged, the system outputs the maximum power (MPPT...

Comparison of Different MPPT Algorithms with a Proposed One Using a Power Estimator for Grid Connected PV Systems

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Manel Hlaili

2016-01-01

Full Text Available Photovoltaic (PV energy is one of the most important energy sources since it is clean and inexhaustible. It is important to operate PV energy conversion systems in the maximum power point (MPP to maximize the output energy of PV arrays. An MPPT control is necessary to extract maximum power from the PV arrays. In recent years, a large number of techniques have been proposed for tracking the maximum power point. This paper presents a comparison of different MPPT methods and proposes one which used a power estimator and also analyses their suitability for systems which experience a wide range of operating conditions. The classic analysed methods, the incremental conductance (IncCond, perturbation and observation (P&O, ripple correlation (RC algorithms, are suitable and practical. Simulation results of a single phase NPC grid connected PV system operating with the aforementioned methods are presented to confirm effectiveness of the scheme and algorithms. Simulation results verify the correct operation of the different MPPT and the proposed algorithm.

Extending the Endurance, Missions and Capabilities of Most UAVs Using Advanced Flexible/Ridged Solar Cells and New High Power Density Batteries Technology

Science.gov (United States)

2011-03-01

Charge Controller is also a DC- to-DC power (boost) converter with MPPT function and was used in the previous thesis [3]. Figure 51. GV26-4 solar...NUMBER OF PAGES 197 14. SUBJECT TERMS Thin-Film Photovoltaics , CIGS, UAV Systems, Solar Array, Maximum Power Point Tracker ( MPPT ), Energy Storage...to a suitable level for charging the battery. The charging process is then optimized by using the MPPT as a power -conditioning unit that

DSP implementation of a PV system with GA-MLP-NN based MPPT controller supplying BLDC motor drive

International Nuclear Information System (INIS)

Akkaya, R.; Kulaksiz, A.A.; Aydogdu, O.

2007-01-01

This paper presents a brushless dc motor drive for heating, ventilating and air conditioning fans, which is utilized as the load of a photovoltaic system with a maximum power point tracking (MPPT) controller. The MPPT controller is based on a genetic assisted, multi-layer perceptron neural network (GA-MLP-NN) structure and includes a DC-DC boost converter. Genetic assistance in the neural network is used to optimize the size of the hidden layer. Also, for training the network, a genetic assisted, Levenberg-Marquardt (GA-LM) algorithm is utilized. The off line GA-MLP-NN, trained by this hybrid algorithm, is utilized for online estimation of the voltage and current values in the maximum power point. A brushless dc (BLDC) motor drive system that incorporates a motor controller with proportional integral (PI) speed control loop is successfully implemented to operate the fans. The digital signal processor (DSP) based unit provides rapid achievement of the MPPT and current control of the BLDC motor drive. The performance results of the system are given, and experimental results are presented for a laboratory prototype of 120 W

Photovoltaic System Equipped with Digital Command Control and Acquisition

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Khalil Kassmi

2013-07-01

Full Text Available In this paper, we present results concerning the design, the realization and the characterization of a photovoltaic system (PV, equipped with a digital controls: Power Point Tracking (MPPT, charge/discharge lead acid batteries, sun tracker and supervision. These different functions are performed with a microcontroller that has capabilities and functions to the reliability of PV systems (signal generation Pulses Width Modulation (PWM, speed etc.. Concerning the MPPT control operation, we improved the accuracy and reliability of research by improving the search algorithm “Hill Climbing” taking into account the optimal operation of PV panels depending on weather conditions (temperature and light.The experiment of each block shows that the MPPT control converges instantly the operating point of the PV panels around the maximum power point, independently of sudden changes of the illumination or the load. The control blocks charge/discharge battery and sun tracking show good control of charge/discharge lead acid batteries and the need of sun tracker to increase the power supplied by the PV panel. By using the improved MPPT control, loss of power supplied by the PV panels are very low (below 5%.

Real-time Modelling, Diagnostics and Optimised MPPT for Residential PV Systems

DEFF Research Database (Denmark)

Sera, Dezso

responsible for yield-reduction of residential photovoltaic systems. Combining the model calculations with measurements, a method to detect changes in the panels’ series resistance based on the slope of the I − V curve in the vicinity of open-circuit conditions and scaled to Standard Test Conditions (STC......The work documented in the thesis has been focused into two main sections. The first part is centred around Maximum Power Point Tracking (MPPT) techniques for photovoltaic arrays, optimised for fast-changing environmental conditions, and is described in Chapter 2. The second part is dedicated...... to diagnostic functions as an additional tool to maximise the energy yield of photovoltaic arrays (Chapter 4). Furthermore, mathematical models of PV panels and arrays have been developed and built (detailed in Chapter 3) for testing MPPT algorithms, and for diagnostic purposes. In Chapter 2 an overview...

Individual Module Maximum Power Point Tracking for a Thermoelectric Generator Systems

DEFF Research Database (Denmark)

Vadstrup, Casper; Chen, Min; Schaltz, Erik

Thermo Electric Generator (TEG) modules are often connected in a series and/or parallel system in order to match the TEG system voltage with the load voltage. However, in order to be able to control the power production of the TEG system a DC/DC converter is inserted between the TEG system...... and the load. The DC/DC converter is under the control of a Maximum Power Point Tracker (MPPT) which insures that the TEG system produces the maximum possible power to the load. However, if the conditions, e.g. temperature, health, etc., of the TEG modules are different each TEG module will not produce its...

Dynamic response evaluation of sensorless MPPT method for hybrid PV-DFIG wind turbine system

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Danvu Nguyen

2016-01-01

Full Text Available This research proposes a sensorless Maximum Power Point Tracking (MPPT method for a hybrid Photovoltaic-Wind system, which consists of Photovoltaic (PV system and Doubly-Fed Induction Generator (DFIG Wind Turbine. In the hybrid system, the DC/DC converter output of the PV system is directly connected to the DC-link of DFIG’s back-to-back converter. Therefore, the PV inverter and its associated circuit can be removed in this structure. Typically, the PV power is monitored by using PV current sensor and PV voltage sensor for MPPT. In this paper, the powers of converters on grid side and rotor side of DFIG are used to estimate the PV power without the PV current sensor. That can efficiently reduce the cost of the hybrid system. The detailed analysis of the sensorless MPPT method, which includes derived equations and operation response, is also presented in this paper. In addition, an overview of PV-DFIG research in literature is stated to supply comprehensive knowledge of related research.

MPPT algorithm for voltage controlled PV inverters

DEFF Research Database (Denmark)

Kerekes, Tamas; Teodorescu, Remus; Liserre, Marco

2008-01-01

This paper presents a novel concept for an MPPT that can be used in case of a voltage controlled grid connected PV inverters. In case of single-phase systems, the 100 Hz ripple in the AC power is also present on the DC side. Depending on the DC link capacitor, this power fluctuation can be used t...... to track the MPP of the PV array, using the information that at MPP the power oscillations are very small. In this way the algorithm can detect the fact that the current working point is at the MPP, for the current atmospheric conditions....

The VSAS approach gives the Best MPPT for Solar Energy Sources

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Nacer Kouider Msirdi

2015-08-01

Full Text Available More and more MPPT (Maximum Power Point Tracking algorithms are in competition to maximize energy extracted from PV systems. This paper shows how to get the best algorithm (the most simple, fast and robust. VSAS (VariableStructure Automatic Systems control methodology is applied to develop the control algorithm, to clarify the rationale behind and get the best optimization algorithm.

A new MATLAB/Simulink model of triple-junction solar cell and MPPT based on artificial neural networks for photovoltaic energy systems

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Hegazy Rezk

2015-09-01

Full Text Available This paper presents a new Matlab/Simulink model of a PV module and a maximum power point tracking (MPPT system for high efficiency InGaP/InGaAs/Ge triple-junction solar cell. The proposed technique is based on Artificial Neural Network. The equivalent circuit model of the triple-junction solar cell includes the parameters of each sub-cell. It is also include the effect of the temperature variations on the energy gap of each sub-cell as well as the diode reverse saturation currents. The implementation of a PV model is based on the triple-junction solar cell in the form of masked block in Matlab/Simulink software package that has a user-friendly icon and dialog. It is fast and accurate technique to follow the maximum power point. The simulation results of the proposed MPPT technique are compared with Perturb and Observe MPPT technique. The output power and energy of the proposed technique are higher than that of the Perturb and Observe MPPT technique. The proposed technique increases the output energy per day for a one PV module from 3.37 kW h to 3.75 kW h, i.e. a percentage of 11.28%.

A Two-Level Sensorless MPPT Strategy Using SRF-PLL on a PMSG Wind Energy Conversion System

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Amina Echchaachouai

2017-01-01

Full Text Available In this paper, a two-level sensorless Maximum Power Point Tracking (MPPT strategy is presented for a variable speed Wind Energy Conversion System (WECS. The proposed system is composed of a wind turbine, a direct-drive Permanent Magnet Synchronous Generator (PMSG and a three phase controlled rectifier connected to a DC load. The realised generator output power maximization analysis justifies the use of the Field Oriented Control (FOC giving the six Pulse Width Modulation (PWM signals to the active rectifier. The generator rotor speed and position required by the FOC and the sensorless MPPT are estimated using a Synchronous Reference Frame Phase Locked Loop (SRF-PLL. The MPPT strategy used consists of two levels, the first level is a power regulation loop and the second level is an extremum seeking bloc generating the coefficient gathering the turbine characteristics. Experimental results validated on a hardware test setup using a DSP digital board (dSPACE 1104 are presented. Figures illustrating the estimated speed and angle confirm that the SRF-PLL is able to give an estimated speed and angle which closely follow the real ones. Also, the power at the DC load and the power at the generator output indicate that the MPPT gives optimum extracted power. Finally, other results show the effectiveness of the adopted approach in real time applications.

Accurate simulation of MPPT methods performance when applied to commercial photovoltaic panels.

Science.gov (United States)

Cubas, Javier; Pindado, Santiago; Sanz-Andrés, Ángel

2015-01-01

A new, simple, and quick-calculation methodology to obtain a solar panel model, based on the manufacturers' datasheet, to perform MPPT simulations, is described. The method takes into account variations on the ambient conditions (sun irradiation and solar cells temperature) and allows fast MPPT methods comparison or their performance prediction when applied to a particular solar panel. The feasibility of the described methodology is checked with four different MPPT methods applied to a commercial solar panel, within a day, and under realistic ambient conditions.

Accurate Simulation of MPPT Methods Performance When Applied to Commercial Photovoltaic Panels

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Javier Cubas

2015-01-01

Full Text Available A new, simple, and quick-calculation methodology to obtain a solar panel model, based on the manufacturers’ datasheet, to perform MPPT simulations, is described. The method takes into account variations on the ambient conditions (sun irradiation and solar cells temperature and allows fast MPPT methods comparison or their performance prediction when applied to a particular solar panel. The feasibility of the described methodology is checked with four different MPPT methods applied to a commercial solar panel, within a day, and under realistic ambient conditions.

Dynamic Performance Comparison for MPPT-PV Systems using Hybrid Pspice/Matlab Simulation

Science.gov (United States)

Aouchiche, N.; Becherif, M.; HadjArab, A.; Aitcheikh, M. S.; Ramadan, H. S.; Cheknane, A.

2016-10-01

The power generated by solar photovoltaic (PV) module depends on the surrounding irradiance and temperature. This paper presents a hybrid Matlab™/Pspice™ simulation model of PV system, combined with Cadence software SLPS. The hybridization is performed in order to gain the advantages of both simulation tools such as accuracy and efficiency in both Pspice electronic circuit and Matlab™ mathematical modelling respectively. For this purpose, the PV panel and the boost converter are developed using Pspice™ and hybridized with the mathematical Matlab™ model of maximum power point method controller (MPPT) through SLPS. The main objective is verify the significance of using the proposed hybrid simulation techniques in comparing the different MPPT algorithms such as the perturbation and observation (P&O), incremental of conductance (Inc-Cond) and counter reaction voltage using pilot cell (Pilot-Cell). Various simulations are performed under different atmospheric conditions in order to evaluate the dynamic behaviour for the system under study in terms of stability, efficiency and rapidity.

MPPT algorithm test on a photovoltaic emulating system constructed by a DC power supply and an indoor solar panel

International Nuclear Information System (INIS)

Zhou, Z.; Holland, P.M.; Igic, P.

2014-01-01

Highlights: • A novel PV emulator is constructed by using conventional solar panels with a DC power supply. • The proposed PV emulator is cost-effectiveness, relatively easy implementation. • The proposed PV emulator avoids the bandwidth problem associated with electronics PV emulators. • Indoor testing of MPPT algorithms and power converters avoids the dependency on solar irradiation. • The PV emulating system has been used for testing a P and O MPPT algorithm and a boost dc converter. - Abstract: In this paper a novel photovoltaic (PV) emulating scheme for testing maximum power point tracking (MPPT) algorithms and PV inverters has been proposed. It is constructed by the parallel connection of conventional solar panels with a DC power supply operating in current source mode. The advantages of the proposed scheme are cost-effectiveness, relatively easy implementation and indoor testing of MPPT algorithms and power converters avoiding weather and time of day dependency on solar irradiation levels. Furthermore, the proposed PV emulator avoids the bandwidth problem associated with the dc converter based PV emulating systems. Detailed circuit connection, parameters, electrical characteristics and mathematical model of the PV emulator are presented and discussed. Proposed PV emulating system has been used to test a boost DC/DC converter controlled by Perturb and Observe (P and O) MPPT algorithm. Test results confirmed the effectiveness of the proposed PV emulation system and all achieved results correspond well to the original designed values

Evaluation of a Distributed Photovoltaic System in Grid-Connected and Standalone Applications by Different MPPT Algorithms

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Ru-Min Chao

2018-06-01

Full Text Available Due to the shortage of fossil fuel and the environmental pollution problem, solar energy applications have drawn a lot of attention worldwide. This paper reports the use of the latest patented distributed photovoltaic (PV power system design, including the two possible maximum power point tracking (MPPT algorithms, a power optimizer, and a PV power controller, in grid-connected and standalone applications. A distributed PV system with four amorphous silicon thin-film solar panels is used to evaluate both the quadratic maximization (QM and the Steepest descent (SD MPPT algorithms. The system’s design is different for the QM or the SD MPPT algorithm being used. The test result for the grid-connected silicon-based PV panels will also be reported. Considering the settling time for the power optimizer to be 20 ms, the test result shows that the tracking time for the QM method is close to 200 ms, which is faster when compared with the SD method whose tracking time is 500 ms. Besides this, the use of the QM method provides a more stable power output since the tracking is restricted by a local power optimizer rather than the global tracking the SD method uses. For a standalone PV application, a solar-powered boat design with 18 PV panels using a cascaded MPPT controller is introduced, and it provides flexibility in system design and the effective use of photovoltaic energy.

Adaptive fuzzy controller based MPPT for photovoltaic systems

International Nuclear Information System (INIS)

Guenounou, Ouahib; Dahhou, Boutaib; Chabour, Ferhat

2014-01-01

Highlights: • We propose a fuzzy controller with adaptive output scaling factor as a maximum power point tracker of photovoltaic system. • The proposed controller integrates two different rule bases defined on error and change of error. • Our controller can track the maximum power point with better performances when compared to its conventional counterpart. - Abstract: This paper presents an intelligent approach to optimize the performances of photovoltaic systems. The system consists of a PV panel, a DC–DC boost converter, a maximum power point tracker controller and a resistive load. The key idea of the proposed approach is the use of a fuzzy controller with an adaptive gain as a maximum power point tracker. The proposed controller integrates two different rule bases. The first is used to adjust the duty cycle of the boost converter as in the case of a conventional fuzzy controller while the second rule base is designed for an online adjusting of the controller’s gain. The performances of the adaptive fuzzy controller are compared with those obtained using a conventional fuzzy controllers with different gains and in each case, the proposed controller outperforms its conventional counterpart

Grid Connected Solar PV System with SEPIC Converter Compared with Parallel Boost Converter Based MPPT

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T. Ajith Bosco Raj

2014-01-01

Full Text Available The main objective of this work is to study the behaviour of the solar PV systems and model the efficient Grid-connected solar power system. The DC-DC MPPT circuit using chaotic pulse width modulation has been designed to track maximum power from solar PV module. The conversion efficiency of the proposed MPPT system is increased when CPWM is used as a control scheme. This paper also proposes a simplified multilevel (seven level inverter for a grid-connected photovoltaic system. The primary goal of these systems is to increase the energy injected to the grid by keeping track of the maximum power point of the panel, by reducing the switching frequency, and by providing high reliability. The maximum power has been tracked experimentally. It is compared with parallel boost converter. Also this model is based on mathematical equations and is described through an equivalent circuit including a PV source with MPPT, a diode, a series resistor, a shunt resistor, and dual boost converter with active snubber circuit. This model can extract PV power and boost by using dual boost converter with active snubber. By using this method the overall system efficiency is improved thereby reducing the switching losses and cost.

New current control based MPPT technique for single stage grid connected PV systems

International Nuclear Information System (INIS)

Jain, Sachin; Agarwal, Vivek

2007-01-01

This paper presents a new maximum power point tracking algorithm based on current control for a single stage grid connected photovoltaic system. The main advantage of this algorithm comes from its ability to predict the approximate amplitude of the reference current waveform or power that can be derived from the PV array with the help of an intermediate variable β. A variable step size for the change in reference amplitude during initial tracking helps in fast tracking. It is observed that if the reference current amplitude is greater than the array capacity, the system gets unstable (i.e. moves into the positive slope region of the p-v characteristics of the array). The proposed algorithm prevents the PV system from entering the positive slope region of the p-v characteristics. It is also capable of restoring stability if the system goes unstable due to a sudden environmental change. The proposed algorithm has been tested on a new single stage grid connected PV configuration recently developed by the authors to feed sinusoidal current into the grid. The system is operated in a continuous conduction mode to realize advantages such as low device current stress, high efficiency and low EMI. A fast MPPT tracker with single stage inverter topology operating in CCM makes the overall system highly efficient. Specific cases of the system, operating in just discontinuous current mode and discontinuous current mode and their relative merits and demerits are also discussed

Improvement of maximum power point tracking perturb and observe algorithm for a standalone solar photovoltaic system

International Nuclear Information System (INIS)

Awan, M.M.A.; Awan, F.G.

2017-01-01

Extraction of maximum power from PV (Photovoltaic) cell is necessary to make the PV system efficient. Maximum power can be achieved by operating the system at MPP (Maximum Power Point) (taking the operating point of PV panel to MPP) and for this purpose MPPT (Maximum Power Point Trackers) are used. There are many tracking algorithms/methods used by these trackers which includes incremental conductance, constant voltage method, constant current method, short circuit current method, PAO (Perturb and Observe) method, and open circuit voltage method but PAO is the mostly used algorithm because it is simple and easy to implement. PAO algorithm has some drawbacks, one is low tracking speed under rapid changing weather conditions and second is oscillations of PV systems operating point around MPP. Little improvement is achieved in past papers regarding these issues. In this paper, a new method named 'Decrease and Fix' method is successfully introduced as improvement in PAO algorithm to overcome these issues of tracking speed and oscillations. Decrease and fix method is the first successful attempt with PAO algorithm for stability achievement and speeding up of tracking process in photovoltaic system. Complete standalone photovoltaic system's model with improved perturb and observe algorithm is simulated in MATLAB Simulink. (author)

Conception and realization of a PV system provided with a sun tracker operating at dual axis

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Khalil Kassmi

2016-06-01

Full Text Available In this paper, we present the conception, the realization and the experimentation of  a photovoltaic (PV system provided with a sun tracker reliable and low cost operating at dual axis. The tracker's role is to orient the PV generator, whose weight may reach 9 Kg, perpendicular to the sun with very good accuracy. This tracking  based on the use of four LDR sensors, which detect the intensity of light scattered by the sun a processing unit, from  command and control (UTCC, which manages all of the sun tracking tasks (the end detection of parcours, regulation of the power supplied by the PV panels (Command MPPT, ... . The results obtained show a significant improvement of the energy produced, compared to conventional PV installations where generators are fixed and oriented south at a  tilt 45°. During a day of operation, improvement could reach 41% and consumption of the tracking does not exceed 0.55% of the energy production produced by the PV generator (an improvement of 5 % compared to existing trackers.

Impact of modified perturb and observe control on MPPT of PV/battery fed three - port DC‐DC converter

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Venmathi Mahendran

2017-07-01

Full Text Available This paper presents the modified perturb and observe (P&O maximum power point tracking (MPPT method for photovoltaic (PV fed three-port DC‐DC converter in PV/battery hybrid system. The proposed MPPT technique reduces the drift problem which occurs in the conventional MPPT methods by including the data of change in current (ΔI in addition to the data used in the conventional P&O algorithm. The drift phenomenon and its effects are clearly demonstrated in this paper. The ability of the proposed P&O method to address this issue is proved by comparing the conventional P&O algorithm in different modes of operation. The performance assessment includes peak overshoot, settling time, MPP ratio and stability. The experimental validation was implemented using DSPIC30F4011 microcontroller. From the analysis and results, it could be seen that the modified P&O showed better performance in terms of accuracy in tracking the maximum power, less tracking time, high MPP ratio and reduced drift in the changing weather conditions.

Maximum power point tracking for photovoltaic solar pump based on ANFIS tuning system

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S. Shabaan

2018-05-01

Full Text Available Solar photovoltaic (PV systems are a clean and naturally replenished energy source. PV panels have a unique point which represents the maximum available power and this point depend on the environmental conditions such as temperature and irradiance. A maximum power point tracking (MPPT is therefore necessary for maximum efficiency. In this paper, a study of MPPT for PV water pumping system based on adaptive neuro-fuzzy inference system (ANFIS is discussed. A comparison between the performance of the system with and without MPPT is carried out under varying irradiation and temperature conditions. ANFIS based controller shows fast response with high efficiency at all irradiance and temperature levels making it a powerful technique for non-linear systems as PV modules. Keywords: MPPT, ANFIS, Boost converter, PMDC pump

Star Tracker Based ATP System Conceptual Design and Pointing Accuracy Estimation

Science.gov (United States)

Orfiz, Gerardo G.; Lee, Shinhak

2006-01-01

A star tracker based beaconless (a.k.a. non-cooperative beacon) acquisition, tracking and pointing concept for precisely pointing an optical communication beam is presented as an innovative approach to extend the range of high bandwidth (> 100 Mbps) deep space optical communication links throughout the solar system and to remove the need for a ground based high power laser as a beacon source. The basic approach for executing the ATP functions involves the use of stars as the reference sources from which the attitude knowledge is obtained and combined with high bandwidth gyroscopes for propagating the pointing knowledge to the beam pointing mechanism. Details of the conceptual design are presented including selection of an orthogonal telescope configuration and the introduction of an optical metering scheme to reduce misalignment error. Also, estimates are presented that demonstrate that aiming of the communications beam to the Earth based receive terminal can be achieved with a total system pointing accuracy of better than 850 nanoradians (3 sigma) from anywhere in the solar system.

Operational characteristic analysis of PV generation system for grid connection by using a senseless MPPT control

Energy Technology Data Exchange (ETDEWEB)

Lee, S.-J.; Kim, K.-H.; Park, H.-Y.; Seo, H.-R.; Park, M.; Yu, I.-K. [Changwon National Univ., SarimDong (Korea, Republic of). Dept. of Electrical Engineering

2007-07-01

In photovoltaics, the sun's light energy is captured to create electricity. One of the key issues about a photovoltaic (PV) generation system is to keep the output power of photovoltaic cells maximized under any weather conditions. In a conventional maximum power point tracking (MPPT) control method, both voltage and current coming out from PV array require feedback. The system may fail to track the MPP of a PV array when unexpected weather conditions happen. This paper proposed a novel PV output senseless (POS) control method to solve the problem. The proposed POS MPPT control method only had one factor to consider, the load current. To verify this theory, a POS MPPT control was applied to a manufactured PV generation system, and the results of the the simulated and experimental data under real weather conditions were compared and analyzed. Several tables and diagrams were presented, including the circuit diagram of a manufactured PV generation system connected to grid as well as the the specifications of the PV array and PCS used for the experiment. Reasonable results were obtained in this study. In addition, the scheme was found to be very useful in maximizing power from PV array to load with feedback of only the load current. 8 refs., 3 tabs., 15 figs.

MPPT Algorithm for Small Wind Systems based on Speed Control Strategy

Directory of Open Access Journals (Sweden)

Ciprian VLAD

2008-07-01

Full Text Available This paper presents experimental results of an autonomous low-power wind energy conversion system (WECS, based on a permanent-magnet synchronous generator (PMSG connected directly to the wind turbine. The purpose of this paper is to present an improving method for MPPT (Maximum Power Point Tracking algorithm based shaft rotational speed optimal control. The proposed method concern the variable delay compensation between measured wind speed from anemometer and wind shaft rotational speed proportional signal. Experimental results aiming to prove the efficiency of the proposed method are presented.

SPICE Modeling and Simulation of a MPPT Algorithm

Directory of Open Access Journals (Sweden)

Miona Andrejević Stošović

2014-06-01

Full Text Available One among several equally important subsystems of a standalone photovoltaic (PV system is the circuit for maximum power point tracking (MPPT. There are several algorithms that may be used for it. In this paper we choose such an algorithm based on the maximum simplicity criteria. Then we make some small modifications to it in order to make it more robust. We synthesize a circuit built out of elements from the list of elements recognized by SPICE. The inputs are the voltage and the current at the PV panel to DC-DC converter interface. Its task is to generate a pulse width modulated pulse train whose duty ratio is defined to keep the input impedance of the DC-DC converter at the optimal value.

Photovoltaic System with Smart Tracking of the Optimal Working Point

Directory of Open Access Journals (Sweden)

PATARAU, T.

2010-08-01

Full Text Available A photovoltaic (PV system, based on a Maximum Power Point Tracking (MPPT controller that extracts the maximum possible output power from the solar panel is described. Output efficiency of a PV energy system can be achieved only if the system working point is brought near the maximum power point (MPP. The proposed system, making use of several MPPT control algorithms (Perturb and Observe, Incremental conductance, Fuzzy Logic, demonstrates in simulations as well as in real experiments good tracking of the optimal working point.

Efficiency of Photovoltaic Maximum Power Point Tracking Controller Based on a Fuzzy Logic

Directory of Open Access Journals (Sweden)

Ammar Al-Gizi

2017-07-01

Full Text Available This paper examines the efficiency of a fuzzy logic control (FLC based maximum power point tracking (MPPT of a photovoltaic (PV system under variable climate conditions and connected load requirements. The PV system including a PV module BP SX150S, buck-boost DC-DC converter, MPPT, and a resistive load is modeled and simulated using Matlab/Simulink package. In order to compare the performance of FLC-based MPPT controller with the conventional perturb and observe (P&O method at different irradiation (G, temperature (T and connected load (RL variations – rising time (tr, recovering time, total average power and MPPT efficiency topics are calculated. The simulation results show that the FLC-based MPPT method can quickly track the maximum power point (MPP of the PV module at the transient state and effectively eliminates the power oscillation around the MPP of the PV module at steady state, hence more average power can be extracted, in comparison with the conventional P&O method.

Modeling, analysis and comparison of TSR and OTC methods for MPPT and power smoothing in permanent magnet synchronous generator-based wind turbines

International Nuclear Information System (INIS)

Nasiri, M.; Milimonfared, J.; Fathi, S.H.

2014-01-01

Highlights: • Small signal modeling of PMSG wind turbine with two controllers are introduced. • Poles and zeroes analyzing of OTC and TSR methods is performed. • Generator output power with varying wind speed in PMSG wind turbine is studied. • MPPT capability of OTC and TSR methods to wind speed variations are compared. • Power smoothing capability and reducing mechanical stress of both methods are studied. - Abstract: This paper presents a small signal modeling of a direct-driven permanent magnet synchronous generator (PMSG) based on wind turbine which is connected to the grid via back-to-back converters. The proposed small signal model includes two maximum power point tracking (MPPT) controllers: tip speed ratio (TSR) control and optimal torque control (OTC). These methods are analytically compared to illustrate MPPT and power smoothing capability. Then, to compare the MPPT and power smoothing operation of the mentioned methods, simulations are performed in MATLAB/Simulink software. From the simulation results, OTC is highly efficient in power smoothing enhancement and has clearly good performance to extract maximum power from wind; however, TSR control has definitely fast responses to wind speed variations with the expense of higher fluctuations due to its non-minimum phase characteristic

Development and Analysis of a Novel Multi-Mode MPPT Technique with Fast and Efficient Performance for PMSG-Based Wind Energy Conversion Systems

Directory of Open Access Journals (Sweden)

S. Heshmatian

2018-03-01

Full Text Available Wind energy is one of the most promising renewable energy resources. Due to instantaneous variations of the wind speed, an appropriate Maximum Power Point Tracking (MPPT method is necessary for maximizing the captured energy from the wind at different speeds. The most commonly used MPPT algorithms are Tip Speed Ratio (TSR, Power Signal Feedback (PSF, Optimal Torque Control (OTC and Hill Climbing Search (HCS. Each of these algorithms has some advantages and also some major drawbacks. In this paper, a novel hybrid MPPT algorithm is proposed which modifies the conventional methods in a way that eliminates their drawbacks and yields an improved performance. This proposed algorithm is faster in tracking the maximum power point and provides a more accurate response with lower steady state error. Moreover, it presents a great performance under conditions with intensive wind speed variations. The studied Wind Energy Conversion System (WECS consists of a Permanent Magnet Synchronous Generator (PMSG connected to the dc link through a Pulse-Width Modulated (PWM rectifier. The proposed algorithm and the conventional methods are applied to this WECS and their performances are compared using the simulation results. These results approve the satisfactory performance of the proposed algorithm and its notable advantages over the conventional methods.

Maximum Power Point Tracking of Photovoltaic System for Traffic Light Application

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Riza Muhida

2013-07-01

Full Text Available Photovoltaic traffic light system is a significant application of renewable energy source. The development of the system is an alternative effort of local authority to reduce expenditure for paying fees to power supplier which the power comes from conventional energy source. Since photovoltaic (PV modules still have relatively low conversion efficiency, an alternative control of maximum power point tracking (MPPT method is applied to the traffic light system. MPPT is intended to catch up the maximum power at daytime in order to charge the battery at the maximum rate in which the power from the battery is intended to be used at night time or cloudy day. MPPT is actually a DC-DC converter that can step up or down voltage in order to achieve the maximum power using Pulse Width Modulation (PWM control. From experiment, we obtained the voltage of operation using MPPT is at 16.454 V, this value has error of 2.6%, if we compared with maximum power point voltage of PV module that is 16.9 V. Based on this result it can be said that this MPPT control works successfully to deliver the power from PV module to battery maximally.

Fuzzy Controller Design Using FPGA for Photovoltaic Maximum Power Point Tracking

OpenAIRE

Basil M Hamed; Mohammed S. El-Moghany

2012-01-01

The cell has optimum operating point to be able to get maximum power. To obtain Maximum Power from photovoltaic array, photovoltaic power system usually requires Maximum Power Point Tracking (MPPT) controller. This paper provides a small power photovoltaic control system based on fuzzy control with FPGA technology design and implementation for MPPT. The system composed of photovoltaic module, buck converter and the fuzzy logic controller implemented on FPGA for controlling on/off time of MOSF...

Optical model and calibration of a sun tracker

International Nuclear Information System (INIS)

Volkov, Sergei N.; Samokhvalov, Ignatii V.; Cheong, Hai Du; Kim, Dukhyeon

2016-01-01

Sun trackers are widely used to investigate scattering and absorption of solar radiation in the Earth's atmosphere. We present a method for optimization of the optical altazimuth sun tracker model with output radiation direction aligned with the axis of a stationary spectrometer. The method solves the problem of stability loss in tracker pointing at the Sun near the zenith. An optimal method for tracker calibration at the measurement site is proposed in the present work. A method of moving calibration is suggested for mobile applications in the presence of large temperature differences and errors in the alignment of the optical system of the tracker. - Highlights: • We present an optimal optical sun tracker model for atmospheric spectroscopy. • The problem of loss of stability of tracker pointing at the Sun has been solved. • We propose an optimal method for tracker calibration at a measurement site. • Test results demonstrate the efficiency of the proposed optimization methods.

FPGA-based implementation of a fuzzy controller (MPPT) for photovoltaic module

International Nuclear Information System (INIS)

Messai, A.; Mellit, A.; Massi Pavan, A.; Guessoum, A.; Mekki, H.

2011-01-01

Research highlights: → FL-MPPT controller is implemented on FPGA. → Results obtained with ModelSim show a satisfactory performance. → Results will be useful for future development in PV. -- Abstract: This paper describes the hardware implementation of a two-inputs one-output digital Fuzzy Logic Controller (FLC) on a Xilinx reconfigurable Field-Programmable Gate Array (FPGA) using VHDL Hardware Description Language. The FLC is designed for seeking the maximum power point deliverable by a photovoltaic module using the measures of the photovoltaic current and voltage. The simulation results obtained with ModelSim Xilinx Edition-III show a satisfactory performance with a good agreement between the expected and the obtained values.

FPGA-based implementation of a fuzzy controller (MPPT) for photovoltaic module

Energy Technology Data Exchange (ETDEWEB)

Messai, A. [CRNB Ain Oussera, P.O. Box 180, 17200, Djelfa (Algeria); Department of Electronics, Faculty of Sciences Engineering, Blida University, Blida 90000 (Algeria); Mellit, A., E-mail: a.mellit@yahoo.co.u [Department of Electronics, Faculty of Sciences and Technology, Jijel University, Ouled-aissa, P.O. Box 98, Jijel 18000 (Algeria); Department of Electronics, Faculty of Sciences Engineering, Blida University, Blida 90000 (Algeria); Massi Pavan, A. [Department of Materials and Natural Resources, University of Trieste, Via A. Valerio, 2 - 34127 Trieste (Italy); Guessoum, A. [Department of Electronics, Faculty of Sciences Engineering, Blida University, Blida 90000 (Algeria); Mekki, H. [CRNB Ain Oussera, P.O. Box 180, 17200, Djelfa (Algeria); Department of Electronics, Faculty of Sciences Engineering, Blida University, Blida 90000 (Algeria)

2011-07-15

Research highlights: {yields} FL-MPPT controller is implemented on FPGA. {yields} Results obtained with ModelSim show a satisfactory performance. {yields} Results will be useful for future development in PV. -- Abstract: This paper describes the hardware implementation of a two-inputs one-output digital Fuzzy Logic Controller (FLC) on a Xilinx reconfigurable Field-Programmable Gate Array (FPGA) using VHDL Hardware Description Language. The FLC is designed for seeking the maximum power point deliverable by a photovoltaic module using the measures of the photovoltaic current and voltage. The simulation results obtained with ModelSim Xilinx Edition-III show a satisfactory performance with a good agreement between the expected and the obtained values.

Single Stage String Inverter for Gridconnected Photovoltaic System with Modified Perturb and Observe (P&O Fuzzy Logic Control(FLC-based MPPT Technique

Directory of Open Access Journals (Sweden)

S.Z.Mohammad Noor

2016-06-01

Full Text Available This paper presents an implementation of Single-phase Single stage String inverter for Grid connected Photovoltaic (PV system. The proposed system uses Modified Perturb and Observe (P&O algorithm implemented using Fuzzy Logic Control (FLC as Maximum Power Point Tracking (MPPT. The inverter is designed for 340W system using two series of STP170s24/Ac PV modules. The MPPT unit keeps tracking the maximum power from the PV array by changing the modulation index and the phase angle of inverter’s output voltage. The simulation model is developed using Matlab/Simulink to evaluate the performance of the converter. Selected experimental results are also presented in this paper.

Adaptive Fuzzy Logic based MPPT Control for PV System Under Partial Shading Condition

OpenAIRE

Choudhury, Subhashree; Rout, Pravat Kumar

2016-01-01

Partial shading causes power loss, hotspots and threatens the reliability of the Photovoltaic generation system. Moreover characteristic curves exhibit multiple peaks. Conventional MPPT techniques under this condition often fail to give optimum MPP. Focusing on the afore mentioned problem an attempt has been made to design an Adaptive Takagi-Sugeno Fuzzy Inference System based Fuzzy Logic Control MPPT.The mathematical model of PV array is simulated using in MATLAB/Simulink environment.Various...

Optimization of PV-based energy production by dynamic PV-panel/inverter configuration

DEFF Research Database (Denmark)

Paasch, Kasper; Nymand, Morten; Haase, Frerk

This paper investigates the possible increase in annual energy production of a PV system with more than one MPPT (maximum power point tracker) input channels under Nordic illumination conditions, in case a concept of dynamic switching of the PV panels is used at the inputs of the inverters....

Modeling and Control of DC/DC Boost Converter using K-Factor Control for MPPT of Solar PV System

DEFF Research Database (Denmark)

Vangari, Adithya; Haribabu, Divyanagalakshmi; Sakamuri, Jayachandra N.

2015-01-01

This paper is focused on the design of a controller for the DC/DC boost converter using K factor control, which is based on modified PI control method, for maximum power point tracking (MPPT) of solar PV system. A mathematical model for boost converter based on small signal averaging approach...... is presented. Design of the passive elements of the boost converter as per the system specifications is also illustrated. The performance of the proposed K factor control method is verified with the simulations for MPPT on solar PV system at different atmospheric conditions. A new circuit based model for solar...... PV array, which includes the effect of solar insolation and temperature on PV array output, for the application in power system transient simulations, is also presented. The performance of the PV array model is verified with simulations at different atmospheric conditions. A 160W PV module from BP...

Design of Solar Street Lamp Control System Based on MPPT

Science.gov (United States)

Cui, Fengying

This paper proposes a new solar street lamp control system which is composed of photovoltaic cell, controller, battery and load. In this system controller as the key part applies the microchip to achieve many functions. According to the nonlinear output characteristics of solar cell and the influence of environment, it uses the perturbation and observation (P&O) method to realize the maximum power point tracking (MPPT) and promotes the efficiency. In order to prolong the battery life the pulse width modulation (PWM) charge mode is selected to control the battery capacity and provent the battery from the state of over-charge and over-discharge. Meanwhile the function of temperature compensation, charge and discharge protection are set to improve the running safety and stability.

Microwatt power consumption maximum power point tracking circuit using an analogue differentiator for piezoelectric energy harvesting

Science.gov (United States)

Chew, Z. J.; Zhu, M.

2015-12-01

A maximum power point tracking (MPPT) scheme by tracking the open-circuit voltage from a piezoelectric energy harvester using a differentiator is presented in this paper. The MPPT controller is implemented by using a low-power analogue differentiator and comparators without the need of a sensing circuitry and a power hungry controller. This proposed MPPT circuit is used to control a buck converter which serves as a power management module in conjunction with a full-wave bridge diode rectifier. Performance of this MPPT control scheme is verified by using the prototyped circuit to track the maximum power point of a macro-fiber composite (MFC) as the piezoelectric energy harvester. The MFC was bonded on a composite material and the whole specimen was subjected to various strain levels at frequency from 10 to 100 Hz. Experimental results showed that the implemented full analogue MPPT controller has a tracking efficiency between 81% and 98.66% independent of the load, and consumes an average power of 3.187 μW at 3 V during operation.

Comparative Analysis of Maximum Power Point Tracking Controllers under Partial Shaded Conditions in a Photovoltaic System

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R. Ramaprabha

2015-06-01

Full Text Available Mismatching effects due to partial shaded conditions are the major drawbacks existing in today’s photovoltaic (PV systems. These mismatch effects are greatly reduced in distributed PV system architecture where each panel is effectively decoupled from its neighboring panel. To obtain the optimal operation of the PV panels, maximum power point tracking (MPPT techniques are used. In partial shaded conditions, detecting the maximum operating point is difficult as the characteristic curves are complex with multiple peaks. In this paper, a neural network control technique is employed for MPPT. Detailed analyses were carried out on MPPT controllers in centralized and distributed architecture under partial shaded environments. The efficiency of the MPPT controllers and the effectiveness of the proposed control technique under partial shaded environments was examined using MATLAB software. The results were validated through experimentation.

A reliable, fast and low cost maximum power point tracker for photovoltaic applications

Energy Technology Data Exchange (ETDEWEB)

Enrique, J.M.; Andujar, J.M.; Bohorquez, M.A. [Departamento de Ingenieria Electronica, de Sistemas Informaticos y Automatica, Universidad de Huelva (Spain)

2010-01-15

This work presents a new maximum power point tracker system for photovoltaic applications. The developed system is an analog version of the ''P and O-oriented'' algorithm. It maintains its main advantages: simplicity, reliability and easy practical implementation, and avoids its main disadvantages: inaccurateness and relatively slow response. Additionally, the developed system can be implemented in a practical way at a low cost, which means an added value. The system also shows an excellent behavior for very fast variables in incident radiation levels. (author)

A Single-Phase Multilevel PV Generation System with an Improved Ripple Correlation Control MPPT Algorithm

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Manel Hammami

2017-12-01

Full Text Available The implementation of maximum power point tracking (MPPT schemes by the ripple correlation control (RCC algorithm is presented in this paper. A reference is made to single-phase single-stage multilevel photovoltaic (PV generation systems, when the inverter input variables (PV voltage and PV current have multiple low-frequency (ripple harmonics. The harmonic analysis is carried out with reference to a multilevel configuration consisting of an H-bridge inverter and level doubling network (LDN cell, leading to the multilevel inverter having double the output voltage levels as compared to the basic H-bridge inverter topology (i.e., five levels vs. three levels. The LDN cell is basically a half-bridge fed by a floating capacitor, with self-balancing voltage capability. The multilevel configuration introduces additional PV voltage and current low-frequency harmonics, perturbing the basic implementation of the RCC scheme (based on the second harmonic component, leading to malfunctioning. The proposed RCC algorithm employs the PV current and voltage harmonics at a specific frequency for the estimation of the voltage derivative of power dP/dV (or dI/dV, driving the PV operating point toward the maximum power point (MPP in a faster and more precise manner. The steady-state and transient performances of the proposed RCC-MPPT schemes have been preliminarily tested and compared using MATLAB/Simulink. Results have been verified by experimental tests considering the whole multilevel PV generation system, including real PV modules, multilevel insulated-gate bipolar transistor (IGBT inverters, and utility grids.

A Comparison Study between Two MPPT Control Methods for a Large Variable-Speed Wind Turbine under Different Wind Speed Characteristics

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Dongran Song

2017-05-01

Full Text Available Variable speed wind turbines (VSWTs usually adopt a maximum power point tracking (MPPT method to optimize energy capture performance. Nevertheless, obtained performance offered by different MPPT methods may be affected by the impact of wind turbine (WT’s inertia and wind speed characteristics and it needs to be clarified. In this paper, the tip speed ratio (TSR and optimal torque (OT methods are investigated in terms of their performance under different wind speed characteristics on a 1.5 MW wind turbine model. To this end, the TSR control method based on an effective wind speed estimator and the OT control method are firstly presented. Then, their performance is investigated and compared through simulation test results under different wind speeds using Bladed software. Comparison results show that the TSR control method can capture slightly more wind energy at the cost of high component loads than the other one under all wind conditions. Furthermore, it is found that both control methods present similar trends of power reduction that is relevant to mean wind speed and turbulence intensity. From the obtained results, we demonstrate that, to further improve MPPT capability of large VSWTs, other advanced control methods using wind speed prediction information need to be addressed.

A CONCEPT OF SOLAR TRACKER SYSTEM DESIGN

OpenAIRE

Meita Rumbayan *, Muhamad Dwisnanto Putro

2017-01-01

Improvement of solar panel efficiency is an ongoing research work recently. Maximizing the output power by integrating with the solar tracker system becomes a interest point of the research. This paper presents the concept in designing a solar tracker system applied to solar panel. The development of solar panel tracker system design that consist of system display prototype design, hardware design, and algorithm design. This concept is useful as the control system for solar tracker to improve...

High Step-Up DC—DC Converter for AC Photovoltaic Module with MPPT Control

Science.gov (United States)

Sundar, Govindasamy; Karthick, Narashiman; Rama Reddy, Sasi

2014-08-01

This paper presents the high gain step-up BOOST converter which is essential to step up the low output voltage from PV panel to the high voltage according to the requirement of the application. In this paper a high gain BOOST converter with coupled inductor technique is proposed with the MPPT control. Without extreme duty ratios and the numerous turns-ratios of a coupled inductor this converter achieves a high step-up voltage-conversion ratio and the leakage energy of the coupled inductor is efficiently recycled to the load. MPPT control used to extract the maximum power from PV panel by controlling the Duty ratio of the converter. The PV panel, BOOST converter and the MPPT are modeled using Sim Power System blocks in MATLAB/SIMULINK environment. The prototype model of the proposed converter has been implemented with the maximum measured efficiency is up to 95.4% and full-load efficiency is 93.1%.

Improved double integral sliding mode MPPT controller based parameter estimation for a stand-alone photovoltaic system

International Nuclear Information System (INIS)

Chatrenour, Nasrin; Razmi, Hadi; Doagou-Mojarrad, Hasan

2017-01-01

Highlights: • IDISMC based MPPT algorithm is introduced. • Hurwitz stability theorem is used for switching surface coefficients computation. • GA approach is presented for parameter estimation of the stand-alone PV system. - Abstract: In this paper, an Improved Double Integral Sliding Mode MPPT Controller (IDISMC) for a stand-alone photovoltaic (PV) system is proposed. Performance of a sliding mode controller (SMC) is greatly influenced by the choice of the sliding surface. Switching surface coefficients were selected by the use of Hurwitz stability theorem. The IDISMC not only is robust against parametric and non-parametric uncertainties, but also has a very small steady-state error, thanks to the use of double integral of tracking voltage error in the definition of its sliding surface. For realistic simulation, Genetic Algorithm (GA) method was used to estimate parameters of solar panels model. The validity of the proposed double integral SMC in maximum power point tracking was approved by comparing the simulation results obtained for a sample PV system with the results of other methods.

Genetic algorithms optimized fuzzy logic control for the maximum power point tracking in photovoltaic system

Energy Technology Data Exchange (ETDEWEB)

Larbes, C.; Ait Cheikh, S.M.; Obeidi, T.; Zerguerras, A. [Laboratoire des Dispositifs de Communication et de Conversion Photovoltaique, Departement d' Electronique, Ecole Nationale Polytechnique, 10, Avenue Hassen Badi, El Harrach, Alger 16200 (Algeria)

2009-10-15

This paper presents an intelligent control method for the maximum power point tracking (MPPT) of a photovoltaic system under variable temperature and irradiance conditions. First, for the purpose of comparison and because of its proven and good performances, the perturbation and observation (P and O) technique is briefly introduced. A fuzzy logic controller based MPPT (FLC) is then proposed which has shown better performances compared to the P and O MPPT based approach. The proposed FLC has been also improved using genetic algorithms (GA) for optimisation. Different development stages are presented and the optimized fuzzy logic MPPT controller (OFLC) is then simulated and evaluated, which has shown better performances. (author)

Tracking the global maximum power point of PV arrays under partial shading conditions

Science.gov (United States)

Fennich, Meryem

This thesis presents the theoretical and simulation studies of the global maximum power point tracking (MPPT) for photovoltaic systems under partial shading. The main goal is to track the maximum power point of the photovoltaic module so that the maximum possible power can be extracted from the photovoltaic panels. When several panels are connected in series with some of them shaded partially either due to clouds or shadows from neighboring buildings, several local maxima appear in the power vs. voltage curve. A power increment based MPPT algorithm is effective in identifying the global maximum from the several local maxima. Several existing MPPT algorithms are explored and the state-of-the-art power increment method is simulated and tested for various partial shading conditions. The current-voltage and power-voltage characteristics of the PV model are studied under different partial shading conditions, along with five different cases demonstrating how the MPPT algorithm performs when shading switches from one state to another. Each case is supplemented with simulation results. The method of tracking the Global MPP is based on controlling the DC-DC converter connected to the output of the PV array. A complete system simulation including the PV array, the direct current to direct current (DC-DC) converter and the MPPT is presented and tested using MATLAB software. The simulation results show that the MPPT algorithm works very well with the buck converter, while the boost converter needs further changes and implementation.

Maximum Power Point Tracking Control of a Thermoelectric Generation System Using the Extremum Seeking Control Method

Directory of Open Access Journals (Sweden)

Ssennoga Twaha

2017-12-01

Full Text Available This study proposes and implements maximum power Point Tracking (MPPT control on thermoelectric generation system using an extremum seeking control (ESC algorithm. The MPPT is applied to guarantee maximum power extraction from the TEG system. The work has been carried out through modelling of thermoelectric generator/dc-dc converter system using Matlab/Simulink. The effectiveness of ESC technique has been assessed by comparing the results with those of the Perturb and Observe (P&O MPPT method under the same operating conditions. Results indicate that ESC MPPT method extracts more power than the P&O technique, where the output power of ESC technique is higher than that of P&O by 0.47 W or 6.1% at a hot side temperature of 200 °C. It is also noted that the ESC MPPT based model is almost fourfold faster than the P&O method. This is attributed to smaller MPPT circuit of ESC compared to that of P&O, hence we conclude that the ESC MPPT method outperforms the P&O technique.

Performance enhancement of photovoltaic array through string and central based MPPT system under non-uniform irradiance conditions

International Nuclear Information System (INIS)

Syafaruddin; Karatepe, Engin; Hiyama, Takashi

2012-01-01

Highlights: ► We propose MPPT method for tracking global MPP of PV arrays under non-uniform irradiance conditions. ► We compare the performance of string and central based MPPT. ► Intelligent control method is utilized to identify the global operating voltage in string and central based MPPT system. ► The performance of proposed method is tested on different size of PV. - Abstract: Mismatching losses reduction of photovoltaic (PV) array has been intensively discussed through the increasing penetration of residential and commercial PV systems. Many causes of mismatching losses have been identified and plenty of proposed methods to solve this problem have been recently proposed. This paper deals with reducing method of mismatching losses due to the non-uniform irradiance conditions. It is well-known that a certain number of multiple peaks occur on the power–voltage curve as the number of PV modules in one-string increases under non-uniform operating conditions. Since the conventional control method only drives the operating points of PV system to the local maxima close to open circuit voltage, only small portion of power can be extracted from the PV system. In this study, a radial basis function neural network (RBF-ANN) based intelligent control method is utilized to map the global operating voltage and non-irradiance operating condition in string and central based MPPT systems. The proposed method has been tested on 10 × 3 (2.2 kW), 15 × 3 (2.5 kW) and 20 × 3 (3.3 kW) of series–parallel PV array configuration under random-shaded and continuous-shaded patterns. The proposed method is compared with the ideal case and conventional method through a simple power–voltage curve of PV arrays. The simulation results show that there are significant increases of about 30–60% of the extracted power in one operating condition when the proposed method is able to shift the operating voltage of modules to their optimum voltages.

Interferometric Star Tracker for High Precision Pointing, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Optical Physics Company (OPC) proposes to adapt the precision star tracker it is currently developing under several DoD contracts for deep space lasercom beam...

A modified P&O MPPT algorithm for single-phase PV systems based on deadbeat control

DEFF Research Database (Denmark)

Yang, Yongheng; Blaabjerg, Frede

2012-01-01

A modified perturb and observe (P&O) algorithm is presented to improve maximum power point tracking (MPPT) performance of photovoltaic (PV) systems. This modified algorithm is applied to a single-phase PV system based on deadbeat control in order to test the tracking accuracy and its impact...... on the reliability of the whole system. Both simulations and experimental results show that the proposed algorithm offers a fast response as well as smaller steady-state oscillations even under low irradiance condition compared with classical methods....

Circuit Simulation for Solar Power Maximum Power Point Tracking with Different Buck-Boost Converter Topologies

Directory of Open Access Journals (Sweden)

Jaw-Kuen Shiau

2014-08-01

Full Text Available The power converter is one of the essential elements for effective use of renewable power sources. This paper focuses on the development of a circuit simulation model for maximum power point tracking (MPPT evaluation of solar power that involves using different buck-boost power converter topologies; including SEPIC, Zeta, and four-switch type buck-boost DC/DC converters. The circuit simulation model mainly includes three subsystems: a PV model; a buck-boost converter-based MPPT system; and a fuzzy logic MPPT controller. Dynamic analyses of the current-fed buck-boost converter systems are conducted and results are presented in the paper. The maximum power point tracking function is achieved through appropriate control of the power switches of the power converter. A fuzzy logic controller is developed to perform the MPPT function for obtaining maximum power from the PV panel. The MATLAB-based Simulink piecewise linear electric circuit simulation tool is used to verify the complete circuit simulation model.

A Novel Maximum Power Point Tracking Control for Permanent Magnet Direct Drive Wind Energy Conversion Systems

Directory of Open Access Journals (Sweden)

Wei Wang

2012-05-01

Full Text Available This paper proposes a novel optimal current given (OCG maximum power point tracking (MPPT control strategy based on the theory of power feedback and hill climb searching (HCS for a permanent magnet direct drive wind energy conversion system (WECS. The presented strategy not only has the advantages of not needing the wind speed and wind turbine characteristics of the traditional HCS method, but it also improves the stability and accuracy of MPPT by estimating the exact loss torque. The OCG MPPT control strategy is first carried out by simulation, then an experimental platform based on the dSPACE1103 controller is built and a 5.5 kW permanent magnet synchronous generator (PMSG is tested. Furthermore, the proposed method is compared experimentally with the traditional optimum tip speed ratio (TSR MPPT control. The experiments verify the effectiveness of the proposed OCG MPPT strategy and demonstrate its better performance than the traditional TSR MPPT control.

A new maximum power point method based on a sliding mode approach for solar energy harvesting

International Nuclear Information System (INIS)

Farhat, Maissa; Barambones, Oscar; Sbita, Lassaad

2017-01-01

Highlights: • Create a simple, easy of implement and accurate V_M_P_P estimator. • Stability analysis of the proposed system based on the Lyapunov’s theory. • A comparative study versus P&O, highlight SMC good performances. • Construct a new PS-SMC algorithm to include the partial shadow case. • Experimental validation of the SMC MPP tracker. - Abstract: This paper presents a photovoltaic (PV) system with a maximum power point tracking (MPPT) facility. The goal of this work is to maximize power extraction from the photovoltaic generator (PVG). This goal is achieved using a sliding mode controller (SMC) that drives a boost converter connected between the PVG and the load. The system is modeled and tested under MATLAB/SIMULINK environment. In simulation, the sliding mode controller offers fast and accurate convergence to the maximum power operating point that outperforms the well-known perturbation and observation method (P&O). The sliding mode controller performance is evaluated during steady-state, against load varying and panel partial shadow (PS) disturbances. To confirm the above conclusion, a practical implementation of the maximum power point tracker based sliding mode controller on a hardware setup is performed on a dSPACE real time digital control platform. The data acquisition and the control system are conducted all around dSPACE 1104 controller board and its RTI environment. The experimental results demonstrate the validity of the proposed control scheme over a stand-alone real photovoltaic system.

A Study of a Two Stage Maximum Power Point Tracking Control of a Photovoltaic System under Partially Shaded Insolation Conditions

Science.gov (United States)

Kobayashi, Kenji; Takano, Ichiro; Sawada, Yoshio

A photovoltaic array shows relatively low output power density, and has a greatly drooping Current-Voltage (I-V) characteristic. Therefore, Maximum Power Point Tracking (MPPT) control is used to maximize the output power of the array. Many papers have been reported in relation to MPPT. However, the Current-Power (I-P) curve sometimes shows multi-local maximum points mode under non-uniform insolation conditions. The operating point of the PV system tends to converge to a local maximum output point which is not the real maximal output point on the I-P curve. Some papers have been also reported, trying to avoid this difficulty. However most of those control systems become rather complicated. Then, the two stage MPPT control method is proposed in this paper to realize a relatively simple control system which can track the real maximum power point even under non-uniform insolation conditions. The feasibility of this control concept is confirmed for steady insolation as well as for rapidly changing insolation by simulation study using software PSIM and LabVIEW. In addition, simulated experiment confirms fundament al operation of the two stage MPPT control.

DSPACE Real-Time Implementation of MPPT-Based FLC Method

OpenAIRE

Noman, Abdullah M.; Addoweesh, Khaled E.; Mashaly, Hussein M.

2013-01-01

Maximum power point trackers are so important in photovoltaic systems to improve their overall efficiency. This paper presents a photovoltaic system with maximum power point tracking facility. An intelligent fuzzy logic controller method is proposed in this paper to achieve the maximum power point tracking of PV modules. The system consists of a photovoltaic solar module connected to a DC-DC buck-boost converter. The system is modeled using MATLAB/SIMULINK. The system has been experienced und...

Modeling of Maximum Power Point Tracking Controller for Solar Power System

Directory of Open Access Journals (Sweden)

Aryuanto Soetedjo

2012-09-01

Full Text Available In this paper, a Maximum Power Point Tracking (MPPT controller for solar power system is modeled using MATLAB Simulink. The model consists of PV module, buck converter, and MPPT controller. The contribution of the work is in the modeling of buck converter that allowing the input voltage of the converter, i.e. output voltage of PV is changed by varying the duty cycle, so that the maximum power point could be tracked when the environmental changes. The simulation results show that the developed model performs well in tracking the maximum power point (MPP of the PV module using Perturb and Observe (P&O Algorithm.

MPPT Algorithm Development for Laser Powered Surveillance Camera Power Supply Unit

Science.gov (United States)

Zhang, Yungui; Dushantha Chaminda, P. R.; Zhao, Kun; Cheng, Lin; Jiang, Yi; Peng, Kai

2018-03-01

Photovoltaics (PV) cells, modules which are semiconducting materials, convert light energy into electricity. Operation of a PV cell requires 3 basic features. When the light is absorbed it generate pairs of electron holes or excitons. An external circuit carrier opposite types of electrons irrespective of the source (sunlight or LASER light). The PV arrays have photovoltaic effect and the PV cells are defined as a device which has electrical characteristics: such as current, voltage and resistance. It varies when exposed to light, that the power output is depend on direct Laser-light. In this paper Laser-light to electricity by direct conversion with the use of PV cells and its concept of Band gap Energy, Series Resistance, Conversion Efficiency and Maximum Power Point Tracking (MPPT) methods [1].

¬MPPT Pada Sistem PV Menggunakan Algoritma Firefly dan Modified P&O dengan Konverter Hybrid Cuk terkoneksi ke Grid Satu Phasa di Bawah Kondisi Partial Shaded

Directory of Open Access Journals (Sweden)

Dhuhari Chalis Bani

2017-01-01

Full Text Available Abstrak— Photovoltaic (PV merupakan sumber energi terbarukan yang paling banyak dijumpai di alam serta merupakn energi alternatif yang sangat pesat perkembangannya. Untuk mengahasilkan daya, sebuah PV dipengaruhi sebuah nilai intensitas cahaya matahari yang mengenainya. Sebuah sistem PV membutuhkan sebuah kontrol yang bertujuan untuk meningkatkan efisien daya PV tersebut. Kontrol ini adalah Maximum Power Point Tracking (MPPT yang dapat mengoptimalkan daya yang dihasilkan oleh PV.  Sebuah PV hanya menghasilkan nilai tegangan yang rendah, untuk itu perlu menggunakan koverter DC-DC step up untuk menaikan rasio tegangan DC tadi. Untuk mengoptimalkan sistem ini, diperlukan sebuah konverter yang efisien dan dapat menghasilkan rasio konversi tegangan yang tinggi. Pada penelitian menggunakan firefly algoritm (FFA dan modified perturb and observe (P&O sebagai MPPT untuk mendapatkan nilai daya optimal pada keluaran PV.  Konverter DC-DC yang digunakan adalah hybrid cuk converter boost mode yang memiliki rasio tegangan yang tinggi. Dari DC-link kemudian masuk ke inverter (VSI yang diinterkoneksi dengan grid menggunakan current control. Hasil analisis simulasi menunjukan bahwa FFA dan P&O mampu menghasilkan daya PV yang optimum dengan riak yang kecil dan konverter hybrid cuk converter boost mode dapat menghasilkan rasio tegangan yang lebih besar dibandingkan konverter cuk biasa.   Kata Kunci — PV, MPPT FFA, MPPT P&O, Hybrid Cuk Converter, DC-Link, Inverter Grid Connected

FPGA-based real time implementation of MPPT-controller for photovoltaic systems

Energy Technology Data Exchange (ETDEWEB)

Mellit, A.; Rezzouk, H.; Medjahed, B. [Faculty of Sciences and Technology, Jijel University, Ouled-aissa, P.O. Box 98, Jijel 18000 (Algeria); Messai, A. [CRNB Ain Oussera, P.O. Box 180, 17200 Djelfa (Algeria)

2011-05-15

In this paper an FPGA-based implementation of a real time perturb and observe (P and O) algorithm for tracking the Maximum Power Point (MPP) of a photovoltaic (PV) generator is presented. The P and O algorithm has been designed using the very high-speed description language (VHDL) and implemented on Xilinx Virtex-II-Pro(xc2v1000-4fg456) - Field Programmable Gate Array (FPGA). The algorithm and the hardware have been simulated and tested by conditioning the power produced by the PV-modules installed on the rooftop of the ''Hall of Technology Laboratory'' at Jijel University. The main advantages of the developed MPPT are low cost, good velocity, acceptable reliability, and easy implementation. However, its main disadvantage is related to the fact that for fast changes in irradiance it may fail to track the maximum power point. The efficiency of the implemented P and O controller is about 96%. (author)

Adaptive smart simulator for characterization and MPPT construction of PV array

International Nuclear Information System (INIS)

Ouada, Mehdi; Meridjet, Mohamed Salah; Dib, Djalel

2016-01-01

Partial shading conditions are among the most important problems in large photovoltaic array. Many works of literature are interested in modeling, control and optimization of photovoltaic conversion of solar energy under partial shading conditions, The aim of this study is to build a software simulator similar to hard simulator and to produce a shading pattern of the proposed photovoltaic array in order to use the delivered information to obtain an optimal configuration of the PV array and construct MPPT algorithm. Graphical user interfaces (Matlab GUI) are built using a developed script, this tool is easy to use, simple, and has a rapid of responsiveness, the simulator supports large array simulations that can be interfaced with MPPT and power electronic converters.

Adaptive smart simulator for characterization and MPPT construction of PV array

Science.gov (United States)

Ouada, Mehdi; Meridjet, Mohamed Salah; Dib, Djalel

2016-07-01

Partial shading conditions are among the most important problems in large photovoltaic array. Many works of literature are interested in modeling, control and optimization of photovoltaic conversion of solar energy under partial shading conditions, The aim of this study is to build a software simulator similar to hard simulator and to produce a shading pattern of the proposed photovoltaic array in order to use the delivered information to obtain an optimal configuration of the PV array and construct MPPT algorithm. Graphical user interfaces (Matlab GUI) are built using a developed script, this tool is easy to use, simple, and has a rapid of responsiveness, the simulator supports large array simulations that can be interfaced with MPPT and power electronic converters.

Adaptive smart simulator for characterization and MPPT construction of PV array

Energy Technology Data Exchange (ETDEWEB)

Ouada, Mehdi, E-mail: mehdi.ouada@univ-annaba.org; Meridjet, Mohamed Salah [Electromechanical engineering department, Electromechanical engineering laboratory, Badji Mokhtar University, B.P. 12, Annaba (Algeria); Dib, Djalel [Department of Electrical Engineering, University of Tebessa, Tebessa (Algeria)

2016-07-25

Partial shading conditions are among the most important problems in large photovoltaic array. Many works of literature are interested in modeling, control and optimization of photovoltaic conversion of solar energy under partial shading conditions, The aim of this study is to build a software simulator similar to hard simulator and to produce a shading pattern of the proposed photovoltaic array in order to use the delivered information to obtain an optimal configuration of the PV array and construct MPPT algorithm. Graphical user interfaces (Matlab GUI) are built using a developed script, this tool is easy to use, simple, and has a rapid of responsiveness, the simulator supports large array simulations that can be interfaced with MPPT and power electronic converters.

Maximum Power Point Tracking menggunakan Buck Converter dengan Algoritma P & O untuk Turbin Angin

Directory of Open Access Journals (Sweden)

Erik Tridianto

2016-12-01

Full Text Available Energi terbarukan adalah salah satu energi alternatif sebagai pengganti bahan bakar untuk pembangkit listrik. Dari berbagai energi terbarukan,yang ada energi angin adalah yang paling mudah dicari. Indonesia merupakan negara kepulauan dengan ratusan pantai dan dengan kecepatan angin yang besar dan berfluktuasi 3-5 m / s. Dan solusi dari masalah angin yang berfluktuasi ini adalah dengan menggunakan kontrol MPPT (Maximum Power Point Tracking dengan lm2596 dc-dc buck converter. Ketika daya yang dihasilkan kurang dari yang diharapkan, maka kontrol MPPT akan menurunkan tegangan untuk mendapatkan daya maksimum. Penelitian ini dilakukan dengan menggunakan lm2596 buck dc-dc converter menggunakan kontrol MPPT dengan tujuan mendapatkan daya maksimum pada kondisi kecepatan angin yang bervariasi, dan jenis MPPT yang digunakan adalah Perturb and Observation (P & O. Untuk membaca daya yang dihasilkan menggunakan Voltage dan Current sensor. Hasil tes menunjukkan bahwa, dengan penambahan kontrol MPPT dapat meningkatkan output daya dari generator sebesar 23%-49%.

A Multi-Point Method Considering the Maximum Power Point Tracking Dynamic Process for Aerodynamic Optimization of Variable-Speed Wind Turbine Blades

Directory of Open Access Journals (Sweden)

Zhiqiang Yang

2016-05-01

Full Text Available Due to the dynamic process of maximum power point tracking (MPPT caused by turbulence and large rotor inertia, variable-speed wind turbines (VSWTs cannot maintain the optimal tip speed ratio (TSR from cut-in wind speed up to the rated speed. Therefore, in order to increase the total captured wind energy, the existing aerodynamic design for VSWT blades, which only focuses on performance improvement at a single TSR, needs to be improved to a multi-point design. In this paper, based on a closed-loop system of VSWTs, including turbulent wind, rotor, drive train and MPPT controller, the distribution of operational TSR and its description based on inflow wind energy are investigated. Moreover, a multi-point method considering the MPPT dynamic process for the aerodynamic optimization of VSWT blades is proposed. In the proposed method, the distribution of operational TSR is obtained through a dynamic simulation of the closed-loop system under a specific turbulent wind, and accordingly the multiple design TSRs and the corresponding weighting coefficients in the objective function are determined. Finally, using the blade of a National Renewable Energy Laboratory (NREL 1.5 MW wind turbine as the baseline, the proposed method is compared with the conventional single-point optimization method using the commercial software Bladed. Simulation results verify the effectiveness of the proposed method.

Evaluation of a photovoltaic energy mechatronics system with a built-in quadratic maximum power point tracking algorithm

Energy Technology Data Exchange (ETDEWEB)

Chao, R.M.; Ko, S.H.; Lin, I.H. [Department of Systems and Naval Mechatronics Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China); Pai, F.S. [Department of Electronic Engineering, National University of Tainan (China); Chang, C.C. [Department of Environment and Energy, National University of Tainan (China)

2009-12-15

The historically high cost of crude oil price is stimulating research into solar (green) energy as an alternative energy source. In general, applications with large solar energy output require a maximum power point tracking (MPPT) algorithm to optimize the power generated by the photovoltaic effect. This work aims to provide a stand-alone solution for solar energy applications by integrating a DC/DC buck converter to a newly developed quadratic MPPT algorithm along with its appropriate software and hardware. The quadratic MPPT method utilizes three previously used duty cycles with their corresponding power outputs. It approaches the maximum value by using a second order polynomial formula, which converges faster than the existing MPPT algorithm. The hardware implementation takes advantage of the real-time controller system from National Instruments, USA. Experimental results have shown that the proposed solar mechatronics system can correctly and effectively track the maximum power point without any difficulties. (author)

A Maximum Power Point Tracking Control Method of a Photovoltaic Power Generator with Consideration of Dynamic Characteristics of Solar Cells

Science.gov (United States)

Watanabe, Takashi; Yoshida, Toshiya; Ohniwa, Katsumi

This paper discusses a new control strategy for photovoltaic power generation systems with consideration of dynamic characteristics of the photovoltaic cells. The controller estimates internal currents of an equivalent circuit for the cells. This estimated, or the virtual current and the actual voltage of the cells are fed to a conventional Maximum-Power-Point-Tracking (MPPT) controller. Consequently, this MPPT controller still tracks the optimum point even though it is so designed that the seeking speed of the operating point is extremely high. This system may suit for applications, which are installed in rapidly changeable insolation and temperature-conditions e.g. automobiles, trains, and airplanes. The proposed method is verified by experiment with a combination of this estimating function and the modified Boehringer's MPPT algorithm.

Brushless DC motor drives supplied by PV power system based on Z-source inverter and FL-IC MPPT controller

International Nuclear Information System (INIS)

Mozaffari Niapour, S.A.KH.; Danyali, S.; Sharifian, M.B.B.; Feyzi, M.R.

2011-01-01

Highlights: → Employing the BLDC motor in water pumping systems. → Utilizing the ZSI as a single-stage power converter in the PV water pumping systems based on BLDC motor. → Improvement of the conventional IC MPPT method with the fuzzy logic control scheme to save more energy from the PV array. → Taking the advantages of the DTC drive of the BLDC motor. → Optimizing the water pumping system speed response characteristic by PSO. - Abstract: This paper discusses operation performance of a water pumping system consist of a brushless dc (BLDC) motor coupled a centrifugal pump and accompanying a Z-source inverter (ZSI) fed by a photovoltaic (PV) array, to be improved. Despite conventional double-stage power converters, this paper proposes utilizing a single-stage ZSI to extract the maximum power of the PV array and supply the BLDC motor simultaneously. Utilizing the ZSI provides some inherent advantages such as high efficiency and low cost, which is very promising for PV systems due to its novel voltage buck/boost capability. In addition, in order to precisely perform the maximum power point tracking (MPPT) of the PV array the fuzzy logic-incremental conductance (FL-IC) MPPT scheme is proposed. The proposed FL-IC MPPT scheme provides enough modification to the conventional IC method to enjoy an appropriate variable step size MPPT control signal for the ZSI. Moreover, direct torque control (DTC) is found more effective in comparison with hysteresis current control with current shaping to drive the BLDC motor, because it benefits from faster torque response, reduced torque ripple, less sensitivity to parameters variations, and simple implementation. In the mean time, due to the frequently variations of the PV power generation; delivered mechanical power to the centrifugal pump is variable. Thus, the BLDC motor should be driven with variable reference speed. In order to improve the speed transient response of the BLDC motor and enhance the energy saving aspect of

Maximum Power Point Tracking of Photovoltaic System for Traffic Light Application

OpenAIRE

Muhida, Riza; Mohamad, Nor Hilmi; Legowo, Ari; Irawan, Rudi; Astuti, Winda

2013-01-01

Photovoltaic traffic light system is a significant application of renewable energy source. The development of the system is an alternative effort of local authority to reduce expenditure for paying fees to power supplier which the power comes from conventional energy source. Since photovoltaic (PV) modules still have relatively low conversion efficiency, an alternative control of maximum power point tracking (MPPT) method is applied to the traffic light system. MPPT is intended to catch up th...

A novel multi-model neuro-fuzzy-based MPPT for three-phase grid-connected photovoltaic system

Energy Technology Data Exchange (ETDEWEB)

Chaouachi, Aymen; Kamel, Rashad M.; Nagasaka, Ken [Department of Electronic and Information Engineering, Tokyo University of Agriculture and Technology, Nakamachi (Japan)

2010-12-15

This paper presents a novel methodology for Maximum Power Point Tracking (MPPT) of a grid-connected 20 kW photovoltaic (PV) system using neuro-fuzzy network. The proposed method predicts the reference PV voltage guarantying optimal power transfer between the PV generator and the main utility grid. The neuro-fuzzy network is composed of a fuzzy rule-based classifier and three multi-layered feed forwarded Artificial Neural Networks (ANN). Inputs of the network (irradiance and temperature) are classified before they are fed into the appropriated ANN for either training or estimation process while the output is the reference voltage. The main advantage of the proposed methodology, comparing to a conventional single neural network-based approach, is the distinct generalization ability regarding to the nonlinear and dynamic behavior of a PV generator. In fact, the neuro-fuzzy network is a neural network based multi-model machine learning that defines a set of local models emulating the complex and nonlinear behavior of a PV generator under a wide range of operating conditions. Simulation results under several rapid irradiance variations proved that the proposed MPPT method fulfilled the highest efficiency comparing to a conventional single neural network and the Perturb and Observe (P and O) algorithm dispositive. (author)

Grid Connected Solar PV System with SEPIC Converter Compared with Parallel Boost Converter Based MPPT

OpenAIRE

Bosco Raj, T. Ajith; Ramesh, R.; Maglin, J. R.; Vaigundamoorthi, M.; William Christopher, I.; Gopinath, C.; Yaashuwanth, C.

2014-01-01

The main objective of this work is to study the behaviour of the solar PV systems and model the efficient Grid-connected solar power system. The DC-DC MPPT circuit using chaotic pulse width modulation has been designed to track maximum power from solar PV module. The conversion efficiency of the proposed MPPT system is increased when CPWM is used as a control scheme. This paper also proposes a simplified multilevel (seven level) inverter for a grid-connected photovoltaic system. The primary g...

Optical Airborne Tracker System

Data.gov (United States)

National Aeronautics and Space Administration — The Optical Airborne Tracker System (OATS) is an airborne dual-axis optical tracking system capable of pointing at any sky location or ground target.  The objectives...

Maximum Power Point Tracking Control of Photovoltaic Systems: A Polynomial Fuzzy Model-Based Approach

DEFF Research Database (Denmark)

Rakhshan, Mohsen; Vafamand, Navid; Khooban, Mohammad Hassan

2018-01-01

This paper introduces a polynomial fuzzy model (PFM)-based maximum power point tracking (MPPT) control approach to increase the performance and efficiency of the solar photovoltaic (PV) electricity generation. The proposed method relies on a polynomial fuzzy modeling, a polynomial parallel......, a direct maximum power (DMP)-based control structure is considered for MPPT. Using the PFM representation, the DMP-based control structure is formulated in terms of SOS conditions. Unlike the conventional approaches, the proposed approach does not require exploring the maximum power operational point...

Star trackers for attitude determination

DEFF Research Database (Denmark)

Liebe, Carl Christian

1995-01-01

One problem comes to all spacecrafts using vector information. That is the problem of determining the attitude. This paper describes how the area of attitude determination instruments has evolved from simple pointing devices into the latest technology, which determines the attitude by utilizing...... a CCD camera and a powerful microcomputer. The instruments are called star trackers and they are capable of determining the attitude with an accuracy better than 1 arcsecond. The concept of the star tracker is explained. The obtainable accuracy is calculated, the numbers of stars to be included...... in the star catalogue are discussed and the acquisition of the initial attitude is explained. Finally the commercial market for star trackers is discussed...

Rancang Bangun Maximum Power Point Tracking pada Panel Photovoltaic Berbasis Logika Fuzzy di Buoy Weather Station

Directory of Open Access Journals (Sweden)

Bayu Prima Juliansyah Putra

2013-09-01

Full Text Available Salah satu aplikasi yang sering digunakan dalam bidang energi terbarukan adalah panel photovoltaic. Panel ini memiliki prinsip kerja berdasarkan efek photovoltaic dimana lempengan logam akan menghasilkan energi listrik apabila diberi intensitas cahaya. Untuk menghasilkan daya keluaran panel yang maksimal, maka diperlukan suatu algoritma yang biasa disebut Maximum Power Point Tracking (MPPT.MPPT yang diterapkan pada sistem photovoltaic berfungsi untuk mengatur nilai tegangan keluaran panel sehingga titik ker-janya beroperasi pada kondisi maksimal. Algoritma MPPT pada panel ini telah dilakukan dengan menggunakan logika fuzzy melalui mikrokontroler Arduino Uno sebagai pem-bangkit sinyal Pulse Width Modulation (PWM yang akan dikirimkan menuju DC-DC Buck Boost Converter. Keluaran dari buck boost converterakan dihubungkan secara langsung dengan buoy weather station untuk menyuplai energi listrik tiap komponen yang berada di dalamnya. Untuk menguji performansi dari algoritma MPPT yang telah dirancang, maka sistem akan diuji menggunakan variasi beban antara metode direct-coupled dengan MPPT menggunakan logika fuzzy. Hasil pengujian menunjukkan bahwa MPPT dengan logika fuzzy dapat menghasilkan daya maksimum daripada direct-coupled. Pada sistem panel photovoltaic ini memiliki range efisiensi 33.07589 % hingga 74.25743 %. Daya mak-simal dapat dicapai oleh sistem untuk tiap variasi beban dan efisiensi maksimal dapat dicapai pada beban 20 Ohm dari hasil pengujian sistem MPPT.

A novel MPPT method for enhancing energy conversion efficiency taking power smoothing into account

International Nuclear Information System (INIS)

Liu, Jizhen; Meng, Hongmin; Hu, Yang; Lin, Zhongwei; Wang, Wei

2015-01-01

Highlights: • We discuss the disadvantages of conventional OTC MPPT method. • We study the relationship between enhancing efficiency and power smoothing. • The conversion efficiency is enhanced and the volatility of power is suppressed. • Small signal analysis is used to verify the effectiveness of proposed method. - Abstract: With the increasing capacity of wind energy conversion system (WECS), the rotational inertia of wind turbine is becoming larger. And the efficiency of energy conversion is significantly reduced by the large inertia. This paper proposes a novel maximum power point tracking (MPPT) method to enhance the efficiency of energy conversion for large-scale wind turbine. Since improving the efficiency may increase the fluctuations of output power, power smoothing is considered as the second control objective. A T-S fuzzy inference system (FIS) is adapted to reduce the fluctuations according to the volatility of wind speed and accelerated rotor speed by regulating the compensation gain. To verify the effectiveness, stability and good dynamic performance of the new method, mechanism analyses, small signal analyses, and simulation studies are carried out based on doubly-fed induction generator (DFIG) wind turbine, respectively. Study results show that both the response speed and the efficiency of proposed method are increased. In addition, the extra fluctuations of output power caused by the high efficiency are reduced effectively by the proposed method with FIS

Intelligent Photovoltaic Maximum Power Point Tracking Controller for Energy Enhancement in Renewable Energy System

Directory of Open Access Journals (Sweden)

Subiyanto

2013-01-01

Full Text Available Photovoltaic (PV system is one of the promising renewable energy technologies. Although the energy conversion efficiency of the system is still low, but it has the advantage that the operating cost is free, very low maintenance and pollution-free. Maximum power point tracking (MPPT is a significant part of PV systems. This paper presents a novel intelligent MPPT controller for PV systems. For the MPPT algorithm, an optimized fuzzy logic controller (FLC using the Hopfield neural network is proposed. It utilizes an automatically tuned FLC membership function instead of the trial-and-error approach. The MPPT algorithm is implemented in a new variant of coupled inductor soft switching boost converter with high voltage gain to increase the converter output from the PV panel. The applied switching technique, which includes passive and active regenerative snubber circuits, reduces the insulated gate bipolar transistor switching losses. The proposed MPPT algorithm is implemented using the dSPACE DS1104 platform software on a DS1104 board controller. The prototype MPPT controller is tested using an agilent solar array simulator together with a 3 kW real PV panel. Experimental test results show that the proposed boost converter produces higher output voltages and gives better efficiency (90% than the conventional boost converter with an RCD snubber, which gives 81% efficiency. The prototype MPPT controller is also found to be capable of tracking power from the 3 kW PV array about 2.4 times more than that without using the MPPT controller.

Photovoltaic High-Frequency Pulse Charger for Lead-Acid Battery under Maximum Power Point Tracking

Directory of Open Access Journals (Sweden)

Hung-I. Hsieh

2013-01-01

Full Text Available A photovoltaic pulse charger (PV-PC using high-frequency pulse train for charging lead-acid battery (LAB is proposed not only to explore the charging behavior with maximum power point tracking (MPPT but also to delay sulfating crystallization on the electrode pores of the LAB to prolong the battery life, which is achieved due to a brief pulse break between adjacent pulses that refreshes the discharging of LAB. Maximum energy transfer between the PV module and a boost current converter (BCC is modeled to maximize the charging energy for LAB under different solar insolation. A duty control, guided by a power-increment-aided incremental-conductance MPPT (PI-INC MPPT, is implemented to the BCC that operates at maximum power point (MPP against the random insolation. A 250 W PV-PC system for charging a four-in-series LAB (48 Vdc is examined. The charging behavior of the PV-PC system in comparison with that of CC-CV charger is studied. Four scenarios of charging statuses of PV-BC system under different solar insolation changes are investigated and compared with that using INC MPPT.

Efficiency improvement of the maximum power point tracking for PV systems using support vector machine technique

International Nuclear Information System (INIS)

Kareim, Ameer A; Mansor, Muhamad Bin

2013-01-01

The aim of this paper is to improve efficiency of maximum power point tracking (MPPT) for PV systems. The Support Vector Machine (SVM) was proposed to achieve the MPPT controller. The theoretical, the perturbation and observation (P and O), and incremental conductance (IC) algorithms were used to compare with proposed SVM algorithm. MATLAB models for PV module, theoretical, SVM, P and O, and IC algorithms are implemented. The improved MPPT uses the SVM method to predict the optimum voltage of the PV system in order to extract the maximum power point (MPP). The SVM technique used two inputs which are solar radiation and ambient temperature of the modeled PV module. The results show that the proposed SVM technique has less Root Mean Square Error (RMSE) and higher efficiency than P and O and IC methods.

Design of Incremental Conductance Sliding Mode MPPT Control Applied by Integrated Photovoltaic and Proton Exchange Membrane Fuel Cell System under Various Operating Conditions for BLDC Motor

Directory of Open Access Journals (Sweden)

Jehun Hahm

2015-01-01

Full Text Available This paper proposes an integrated photovoltaic (PV and proton exchange membrane fuel cell (PEMFC system for continuous energy harvesting under various operating conditions for use with a brushless DC motor. The proposed scheme is based on the incremental conductance (IncCond algorithm combined with the sliding mode technique. Under changing atmospheric conditions, the energy conversion efficiency of a PV array is very low, leading to significant power losses. Consequently, increasing efficiency by means of maximum power point tracking (MPPT is particularly important. To manage such a hybrid system, control strategies need to be established to achieve the aim of the distributed system. Firstly, a Matlab/Simulink based model of the PV and PEMFC is developed and validated, as well as the incremental conductance sliding (ICS MPPT technique; then, different MPPT algorithms are employed to control the PV array under nonuniform temperature and insolation conditions, to study these algorithms effectiveness under various operating conditions. Conventional techniques are easy to implement but produce oscillations at MPP. Compared to these techniques, the proposed technique is more efficient; it produces less oscillation at MPP in the steady state and provides more precise tracking.

Optimal Design of MPPT Controllers for Grid Connected Photovoltaic Array System

Science.gov (United States)

Ebrahim, M. A.; AbdelHadi, H. A.; Mahmoud, H. M.; Saied, E. M.; Salama, M. M.

2016-10-01

Integrating photovoltaic (PV) plants into electric power system exhibits challenges to power system dynamic performance. These challenges stem primarily from the natural characteristics of PV plants, which differ in some respects from the conventional plants. The most significant challenge is how to extract and regulate the maximum power from the sun. This paper presents the optimal design for the most commonly used Maximum Power Point Tracking (MPPT) techniques based on Proportional Integral tuned by Particle Swarm Optimization (PI-PSO). These suggested techniques are, (1) the incremental conductance, (2) perturb and observe, (3) fractional short circuit current and (4) fractional open circuit voltage techniques. This research work provides a comprehensive comparative study with the energy availability ratio from photovoltaic panels. The simulation results proved that the proposed controllers have an impressive tracking response. The system dynamic performance improved greatly using the proposed controllers.

TRACKER

CERN Document Server

Bora Akgun

2013-01-01

Pixel Tracker Maintenance of the Pixel Tracker has been ongoing since it was extracted from inside CMS and safely stored at low temperatures in Pixel laboratory at Point 5 (see previous Bulletin).    All four half cylinders of the forward Pixel detector (FPIX) have been repaired and the failures have been understood. In October, a team of technicians from Fermilab replaced a total of three panels that were not repairable in place. The replacement of panels is a delicate operation that involves removing the half disks that hold the panels from the half cylinders, removing the damaged panels from the half disks, installing the new panels on the half disks, and finally putting the half disks back into the half cylinders and hooking up the cooling connections. The work was completed successfully. The same team also prepared the installation of the Phase 1 Pixel pilot blade system, installing a third half disk mechanics in the half cylinders; these half disks will host new Phase 1 P...

Analysis on the MPPT control of PV generation system using SPRW

Energy Technology Data Exchange (ETDEWEB)

Park, Min Won [Osaka University (Japan); Kim, Bong Tae; Lee, Jae Deuk; Yu, In Keun [Changwon National University (Korea)

2001-07-01

Photovoltaic (PV) system has been studied and watch with keen interest due to a clean and renewable power source. But, because the output power of PV system is not only unstable but also uncontrollable, the MPPT control of PV power system is still hard to be optimized with the tracking failure under the sudden fluctuation of irradiance. Authors proposed a novel transient phenomenon simulation method for PV power generation system under the real field weather condition(SPRW), and the research and development of PV power generation system is expected to be able to analyze easily and cheaply under various conditions with considering the sort of cell, the capacity of system and the used converter system. In this paper, a PV array was simulated to confirm the availability of SPRW. And, several real weather conditions were used with various MPPT controls. (author). 6 refs., 9 figs., 3 tabs.

Magnet Test Setup of the CMS Tracker ready for installation

CERN Multimedia

Maximilien Brice

2006-01-01

The pieces of the Tracker that will be operated in the forthcoming Magnet Test and Cosmic Challenge (MTCC) have been transported inside the dummy tracker support tube to the CMS experimental hall (Point 5, Cessy). The operation took place during the night of 12th May, covering the ~15km distance in about three hours. The transport was monitored for shocks, temperature and humidity with the help of the CERN TS-IC section. The Tracker setup comprises segments of the Tracker Inner Barrel (TIB), the Tracker Outer Barrel (TOB) and Tracker EndCaps (TEC) detectors. It represents roughly 1% of the final CMS Tracker. Installation into the solenoid is foreseen to take place on Wednesday 17th May.

Intelligent approach to maximum power point tracking control strategy for variable-speed wind turbine generation system

Energy Technology Data Exchange (ETDEWEB)

Lin, Whei-Min; Hong, Chih-Ming [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 80424 (China)

2010-06-15

To achieve maximum power point tracking (MPPT) for wind power generation systems, the rotational speed of wind turbines should be adjusted in real time according to wind speed. In this paper, a Wilcoxon radial basis function network (WRBFN) with hill-climb searching (HCS) MPPT strategy is proposed for a permanent magnet synchronous generator (PMSG) with a variable-speed wind turbine. A high-performance online training WRBFN using a back-propagation learning algorithm with modified particle swarm optimization (MPSO) regulating controller is designed for a PMSG. The MPSO is adopted in this study to adapt to the learning rates in the back-propagation process of the WRBFN to improve the learning capability. The MPPT strategy locates the system operation points along the maximum power curves based on the dc-link voltage of the inverter, thus avoiding the generator speed detection. (author)

Comparative study of the reliability of MPPT algorithms for the crystalline silicon photovoltaic modules in variable weather conditions

Directory of Open Access Journals (Sweden)

Abraham Dandoussou

2017-05-01

Full Text Available The crystalline silicon photovoltaic modules are widely used as power supply sources in the tropical areas where the weather conditions change abruptly. Fortunately, many MPPT algorithms are implemented to improve their performance. In the other hand, it is well known that these power supply sources are nonlinear dipoles and so, their intrinsic parameters may vary with the irradiance and the temperature. In this paper, the MPPT algorithms widely used, i.e. Perturb and Observe (P&O, Incremental Conductance (INC, Hill-Climbing (HC, are implemented using Matlab®/Simulink® model of a crystalline silicon photovoltaic module whose intrinsic parameters were extracted by fitting the I(V characteristic to experimental points. Comparing the simulation results, it is obvious that the variable step size INC algorithm has the best reliability than both HC and P&O algorithms for the near to real Simulink® model of photovoltaic modules. With a 60 Wp photovoltaic module, the daily maximum power reaches 50.76 W against 34.40 W when the photovoltaic parameters are fixed. Meanwhile, the daily average energy is 263 Wh/day against 195 Wh/day.

CMS tracker slides into centre stage

CERN Document Server

2006-01-01

As preparations for the magnet test and cosmic challenge get underway, a prototype tracker has been carefully inserted into the centre of CMS. The tracker, in its special platform, is slowly inserted into the centre of CMS. The CMS prototype tracker to be used for the magnet test and cosmic challenge coming up this summer has the same dimensions -2.5 m in diameter and 6 m in length- as the real one and tooling exactly like it. However, the support tube is only about 1% equipped, with 2 m2 of silicon detectors installed out of the total 200 m2. This is already more than any LEP experiment ever used and indicates the great care needed to be taken by engineers and technicians as these fragile detectors were installed and transported to Point 5. Sixteen thousand silicon detectors with a total of about 10 million strips will make up the full tracker. So far, 140 modules with about 100 000 strips have been implanted into the prototype tracker. These silicon strips will provide precision tracking for cosmic muon...

A study of a two stage maximum power point tracking control of a photovoltaic system under partially shaded insolation conditions

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Kenji; Takano, Ichiro; Sawada, Yoshio [Kogakuin University, Tokyo 163-8677 (Japan)

2006-11-23

A photovoltaic (PV) array shows relatively low output power density, and has a greatly drooping current-voltage (I-V) characteristic. Therefore, maximum power point tracking (MPPT) control is used to maximize the output power of the PV array. Many papers have been reported in relation to MPPT. However, the current-power (I-P) curve sometimes shows multi-local maximum point mode under non-uniform insolation conditions. The operating point of the PV system tends to converge to a local maximum output point which is not the real maximal output point on the I-P curve. Some papers have been also reported, trying to avoid this difficulty. However, most of those control systems become rather complicated. Then, the two stage MPPT control method is proposed in this paper to realize a relatively simple control system which can track the real maximum power point even under non-uniform insolation conditions. The feasibility of this control concept is confirmed for steady insolation as well as for rapidly changing insolation by simulation study using software PSIM and LabVIEW. (author)

A New Study of Maximum Power Point Tracker Techniques and Comparison for PV Systems

Directory of Open Access Journals (Sweden)

Ahmed M. Atallah

2016-07-01

Full Text Available The maximum power point tracker techniques vary in many aspects as simplicity, digital or analogical implementation, sensor required, convergence speed, range of effectiveness, implementation hardware,popularity, cost and in other aspects. This paper presents in details comparative study between two most popular  algorithm  technique  which  is  incremental  conductance  algorithm  and  perturb  and  observe algorithm.  Two  different  converters  buck  and  cuk  converter  use  for  comparative  in  this  study. Few comparisons such as efficiency, voltage, current and power output for each different combination have been recorded. Multi changes in irradiance, temperature by keeping voltage and current as main sensed parameter been done in the simulation. Matlab simulink tools have been used for performance evaluation on energy point. Simulation will consider different solar irradiance and temperature variations.

Performance Comparison between ĆUK and SEPIC Converters for Maximum Power Point Tracking Using Incremental Conductance Technique in Solar Power Applications

OpenAIRE

James Dunia; Bakari M. M. Mwinyiwiwa

2013-01-01

Photovoltaic (PV) energy is one of the most important energy resources since it is clean, pollution free, and endless. Maximum Power Point Tracking (MPPT) is used in photovoltaic (PV) systems to maximize the photovoltaic output power, irrespective the variations of temperature and radiation conditions. This paper presents a comparison between Ćuk and SEPIC converter in maximum power point tracking (MPPT) of photovoltaic (PV) system. In the paper, advantages and disadvantages of both converter...

Overview of Maximum Power Point Tracking Techniques for Photovoltaic Energy Production Systems

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2017-01-01

production of PV sources, despite the stochastically varying solar irradiation and ambient temperature conditions. Thereby, the overall efficiency of the PV energy production system is increased. Numerous techniques have been presented during the last decades for implementing the MPPT process in a PV system......A substantial growth of the installed photovoltaic (PV) systems capacity has occurred around the world during the last decade, thus enhancing the availability of electric energy in an environmentally friendly way. The maximum power point tracking (MPPT) technique enables to maximize the energy....... This chapter provides an overview of the operating principles of these techniques, which are suited for either uniform or nonuniform solar irradiation conditions. The operational characteristics and implementation requirements of these MPPT methods are also analyzed in order to demonstrate their performance...

A maximum power point tracking for photovoltaic-SPE system using a maximum current controller

Energy Technology Data Exchange (ETDEWEB)

Muhida, Riza [Osaka Univ., Dept. of Physical Science, Toyonaka, Osaka (Japan); Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Park, Minwon; Dakkak, Mohammed; Matsuura, Kenji [Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Tsuyoshi, Akira; Michira, Masakazu [Kobe City College of Technology, Nishi-ku, Kobe (Japan)

2003-02-01

Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented. Based on the characteristics of voltage-current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC-DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously. This method uses a proportional integrator controller to control the duty factor of DC-DC converter with pulse-width modulator (PWM). The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment. (Author)

Single stage three level grid interactive MPPT inverter for PV systems

International Nuclear Information System (INIS)

Ozdemir, Saban; Altin, Necmi; Sefa, Ibrahim

2014-01-01

Highlights: • A three phase three-level NPC inverter for grid interactive PV systems is proposed. • A novel MPPT algorithm is introduced for single stage systems. • The proposed algorithm is robust with respect to parameter variations of PV system. • THD level is measured as 3.45% and it meets the international standards (<5%). • Total system efficiency is measured as 93.08%. - Abstract: In this study, three-phase, single stage neutral point clamped grid interactive inverter is designed and implemented. The reference current of the voltage source inverter is determined by maximum power point tracking sub-program in order to obtain maximum power from photovoltaic modules instantaneously. Proposed control is realized via TMS320F28335 32-bit floating point processor. The modified incremental conductance method is applied for maximum power point tracking; the PI regulator is used to control the inverter output current shape and level. Galvanic isolation is provided by a line frequency transformer that matches inverter output voltage to the grid voltage level and prevents DC current injection into the grid. Experimental results show that the designed inverter imports energy to the grid with unity power factor, total harmonic distortion level is 3.45% and this value is in the limits of the international standards. In addition, the total efficiency of the system is measured as 93.08%. The proposed system gets the maximum power from photovoltaic module and dispatches into the grid without using additional DC/DC converter

TRACKER

CERN Multimedia

C. Barth

2012-01-01

  Strip Tracker In the end of 2011, the Silicon Strip Tracker participated in the very successful heavy-ion collision data-taking. With zero downtime attributed to the Strip Tracker, CMS could achieve the excellent efficiency of 96%. Thus we were able to improve on the already good uptime during pp collisions, and completed an excellent year for the Strip Tracker. The shift of responsibility to raise the high voltages at the declaration of Stable Beams from the Tracker DOC to the central crew went smoothly. The new scheme is working reliably and we improved our automatic DQM and DCS SMS services. With this further improvement we plan to discontinue calling the TK DOC at each Stable Beam; so far the TK DOC personally checked all systems. The biggest effort of this Year-End Technical Stop was a comprehensive evaluation of the C6F14 cooling system performance with respect to future cold operation. The analysis allows a dedicated planning of system refurbishments to be executed during 2012 and LS1....

Study of a photovoltaic system with MPPT using Matlab

Directory of Open Access Journals (Sweden)

Dumitru Pop

2012-12-01

Full Text Available In this paper a photovoltaic (PV system is analyzed using Matlab. First, a Matlab code is written in order to obtain the I-V and P-V curves at different values of solar irradiation and cell temperature. The results were compared with the experimental data of a commercial PV module, USP 150. Then, the code was implemented in Simulink and, along with a MPPT algorithm and a DC-DC converter, the whole system was simulated.

Star Tracker Performance Estimate with IMU

Science.gov (United States)

Aretskin-Hariton, Eliot D.; Swank, Aaron J.

2015-01-01

A software tool for estimating cross-boresight error of a star tracker combined with an inertial measurement unit (IMU) was developed to support trade studies for the Integrated Radio and Optical Communication project (iROC) at the National Aeronautics and Space Administration Glenn Research Center. Typical laser communication systems, such as the Lunar Laser Communication Demonstration (LLCD) and the Laser Communication Relay Demonstration (LCRD), use a beacon to locate ground stations. iROC is investigating the use of beaconless precision laser pointing to enable laser communication at Mars orbits and beyond. Precision attitude knowledge is essential to the iROC mission to enable high-speed steering of the optical link. The preliminary concept to achieve this precision attitude knowledge is to use star trackers combined with an IMU. The Star Tracker Accuracy (STAcc) software was developed to rapidly assess the capabilities of star tracker and IMU configurations. STAcc determines the overall cross-boresight error of a star tracker with an IMU given the characteristic parameters: quantum efficiency, aperture, apparent star magnitude, exposure time, field of view, photon spread, detector pixels, spacecraft slew rate, maximum stars used for quaternion estimation, and IMU angular random walk. This paper discusses the supporting theory used to construct STAcc, verification of the program and sample results.

Four-cell solar tracker

Science.gov (United States)

Berdahl, C. M.

1981-01-01

Forty cm Sun tracker, consisting of optical telescope and four solar cells, stays pointed at Sun throughout day for maximum energy collection. Each solar cell generates voltage proportional to part of solar image it receives; voltages drive servomotors that keep image centered. Mirrored portion of cylinder extends acquisition angle of device by reflecting Sun image back onto solar cells.

Novel TPPO Based Maximum Power Point Method for Photovoltaic System

Directory of Open Access Journals (Sweden)

ABBASI, M. A.

2017-08-01

Full Text Available Photovoltaic (PV system has a great potential and it is installed more when compared with other renewable energy sources nowadays. However, the PV system cannot perform optimally due to its solid reliance on climate conditions. Due to this dependency, PV system does not operate at its maximum power point (MPP. Many MPP tracking methods have been proposed for this purpose. One of these is the Perturb and Observe Method (P&O which is the most famous due to its simplicity, less cost and fast track. But it deviates from MPP in continuously changing weather conditions, especially in rapidly changing irradiance conditions. A new Maximum Power Point Tracking (MPPT method, Tetra Point Perturb and Observe (TPPO, has been proposed to improve PV system performance in changing irradiance conditions and the effects on characteristic curves of PV array module due to varying irradiance are delineated. The Proposed MPPT method has shown better results in increasing the efficiency of a PV system.

Analysis and MPPT control of a wind-driven three-phase induction generator feeding single-phase utility grid

Directory of Open Access Journals (Sweden)

Krishnan Arthishri

2017-05-01

Full Text Available In this study, a three-phase diode bridge rectifier and a single-phase voltage source inverter topology has been proposed for feeding single-phase utility grid employing a three-phase induction generator fed from wind energy. A self-excited induction generator configuration has been chosen for wide speed operation of wind turbine system, which gives the scope for extracting maximum power available in the wind. In addition to maximum power point tracking (MPPT, the generator can be loaded to its rated capacity for feeding single-phase utility grid using a three-phase induction machine, whereas it is not possible with existing configurations because of the absence of power converters. For the proposed system, MPPT algorithm has been devised by continuously monitoring the grid current and a proportional resonant controller has been employed for grid synchronisation of voltage source inverter with single-phase grid. A MATLAB/Simulink model of the proposed system has been developed to ascertain its successful working by predetermining the overall performance characteristics. The present proposal has also been tested with sag, swell and distortion in the grid voltage. The control strategy has been implemented using field programmable gate array (FPGA controller with modularised programming approach. The efficacy of the system has been demonstrated with the results obtained from an experimental set-up in the laboratory.

Modeling and simulation of stand-alone hybrid power system with fuzzy MPPT for remote load application

Directory of Open Access Journals (Sweden)

Bogaraj T.

2015-09-01

Full Text Available Many parts of remote locations in the world are not electrified even in this Advanced Technology Era. To provide electricity in such remote places renewable hybrid energy systems are very much suitable. In this paper PV/Wind/Battery Hybrid Power System (HPS is considered to provide an economical and sustainable power to a remote load. HPS can supply the maximum power to the load at a particular operating point which is generally called as Maximum Power Point (MPP. Fuzzy Logic based MPPT (FLMPPT control method has been implemented for both Solar and Wind Power Systems. FLMPPT control technique is implemented to generate the optimal reference voltage for the first stage of DC-DC Boost converter in both the PV and Wind energy system. The HPS is tested with variable solar irradiation, temperature, and wind speed. The FLMPPT method is compared with P&O MPPT method. The proposed method provides a good maximum power operation of the hybrid system at all operating conditions. In order to combine both sources, the DC bus voltage is made constant by employing PI Controllers for the second stage of DC-DC Buck-Boost converter in both Solar and Wind Power Systems. Battery Bank is used to store excess power from Renewable Energy Sources (RES and to provide continuous power to load when the RES power is less than load power. A SPWM inverter is designed to convert DC power into AC to supply three phase load. An LC filter is also used at the output of inverter to get sinusoidal current from the PWM inverter. The entire system was modeled and simulated in Matlab/Simulink Environment. The results presented show the validation of the HPS design.

Application Research on Variable Universe FuzzyController in PV MPPT System%变论域模糊控制器在光伏系统MPPT中的应用研究

Institute of Scientific and Technical Information of China (English)

王苏洲; 舒志兵; 李照

2017-01-01

In order to solve the problem of the nonlinear characteristics of photovoltaic power generation system and the steady state error of the general fuzzy control,the variable universe fuzzy control was applied to the photovoltaic MPPT system and the selection of the expansion factor of variable universe fuzzy control and the design of the controller were introduced,MATLAB/Simulink was used to establish the MPPT system simulation model based on BOOST conversion circuit.Adjusting the duty ratio of the Boost circuit switch tube,the method was made to work at maximum power point of photovoltaic cells.The work had been carried on with simulation.Finally simulation was used to prove the efficiency of this method.The simulation results showed that the variable universe fuzzy control can improve the stability of MPPT,reduce the static error and fluctuation,improve the utilization rate of solar energy.%为了解决光伏发电系统非线性特点及一般模糊控制存在稳态误差的问题,将变论域模糊控制应用到光伏发电系统的MPPT(Maximum Power Point Tracking)中,介绍了变论域模糊控制伸缩因子的选取及控制器的设计,运用MATLAB/Simulink建立基于BOOST转换电路的MPPT系统仿真模型.通过调节Boost电路开关管的占空比使光伏电池工作在最大功率点,并对该方法进行了仿真验证.仿真结果表明,变论域模糊控制能够改善光伏发电系统MPPT的稳定性,减小稳态误差与波动,提高太阳能的利用率.

Maximum Power Point Tracking for Brushless DC Motor-Driven Photovoltaic Pumping Systems Using a Hybrid ANFIS-FLOWER Pollination Optimization Algorithm

Directory of Open Access Journals (Sweden)

Neeraj Priyadarshi

2018-04-01

Full Text Available In this research paper, a hybrid Artificial Neural Network (ANN-Fuzzy Logic Control (FLC tuned Flower Pollination Algorithm (FPA as a Maximum Power Point Tracker (MPPT is employed to amend root mean square error (RMSE of photovoltaic (PV modeling. Moreover, Gaussian membership functions have been considered for fuzzy controller design. This paper interprets the Luo converter occupied brushless DC motor (BLDC-directed PV water pump application. Experimental responses certify the effectiveness of the suggested motor-pump system supporting diverse operating states. The Luo converter, a newly developed DC-DC converter, has high power density, better voltage gain transfer and superior output waveform and can track optimal power from PV modules. For BLDC speed control there is no extra circuitry, and phase current sensors are enforced for this scheme. The most recent attempt using adaptive neuro-fuzzy inference system (ANFIS-FPA-operated BLDC directed PV pump with advanced Luo converter, has not been formerly conferred.

Maximum-power-point tracking control of solar heating system

KAUST Repository

Huang, Bin-Juine

2012-11-01

The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

Eye Tracker Accuracy: Quantitative Evaluation of the Invisible Eye Center Location

OpenAIRE

Wyder, Stephan; Cattin, Philippe C.

2017-01-01

Purpose. We present a new method to evaluate the accuracy of an eye tracker based eye localization system. Measuring the accuracy of an eye tracker's primary intention, the estimated point of gaze, is usually done with volunteers and a set of fixation points used as ground truth. However, verifying the accuracy of the location estimate of a volunteer's eye center in 3D space is not easily possible. This is because the eye center is an intangible point hidden by the iris. Methods. We evaluate ...

A Method of MPPT Control Based on Power Variable Step-size in Photovoltaic Converter System

Directory of Open Access Journals (Sweden)

Xu Hui-xiang

2016-01-01

Full Text Available Since the disadvantage of traditional MPPT algorithms of variable step-size, proposed power tracking based on variable step-size with the advantage method of the constant-voltage and the perturb-observe (P&O[1-3]. The control strategy modify the problem of voltage fluctuation caused by perturb-observe method, at the same time, introducing the advantage of constant-voltage method and simplify the circuit topology. With the theoretical derivation, control the output power of photovoltaic modules to change the duty cycle of main switch. Achieve the maximum power stabilization output, reduce the volatility of energy loss effectively, and improve the inversion efficiency[3,4]. Given the result of experimental test based theoretical derivation and the curve of MPPT when the prototype work.

Software and mathematical support of Kazakhstani star tracker

Science.gov (United States)

Akhmedov, D.; Yelubayev, S.; Ten, V.; Bopeyev, T.; Alipbayev, K.; Sukhenko, A.

2016-10-01

Currently the specialists of Kazakhstan have been developing the star tracker that is further planned to use on Kazakhstani satellites of various purposes. At the first stage it has been developed the experimental model of star tracker that has following characteristics: field of view 20°, update frequency 2 Hz, exclusion angle 40°, accuracy of attitude determination of optical axis/around optical axis 15/50 arcsec. Software and mathematical support are the most high technology parts of star tracker. The results of software and mathematical support development of experimental model of Kazakhstani star tracker are represented in this article. In particular, there are described the main mathematical models and algorithms that have been used as a basis for program units of preliminary image processing of starry sky, stars identification and star tracker attitude determination. The results of software and mathematical support testing with the help of program simulation complex using various configurations of defects including image sensor noises, point spread function modeling, optical system distortion up to 2% are presented. Analysis of testing results has shown that accuracy of attitude determination of star tracker is within the permissible range

Application results for an augmented video tracker

Science.gov (United States)

Pierce, Bill

1991-08-01

The Relay Mirror Experiment (RME) is a research program to determine the pointing accuracy and stability levels achieved when a laser beam is reflected by the RME satellite from one ground station to another. This paper reports the results of using a video tracker augmented with a quad cell signal to improve the RME ground station tracking system performance. The video tracker controls a mirror to acquire the RME satellite, and provides a robust low bandwidth tracking loop to remove line of sight (LOS) jitter. The high-passed, high-gain quad cell signal is added to the low bandwidth, low-gain video tracker signal to increase the effective tracking loop bandwidth, and significantly improves LOS disturbance rejection. The quad cell augmented video tracking system is analyzed, and the math model for the tracker is developed. A MATLAB model is then developed from this, and performance as a function of bandwidth and disturbances is given. Improvements in performance due to the addition of the video tracker and the augmentation with the quad cell are provided. Actual satellite test results are then presented and compared with the simulated results.

Modeling photovoltaic systems for AC appliances

Directory of Open Access Journals (Sweden)

Andreea Maria Neaca

2009-10-01

Full Text Available In this paper is described the development of a model which can simulate the performance of a photovoltaic (PV system under specific meteorological conditions and transforming the DC current into AC current. In this model, the accent stands on the design of a series charge regulator. It is treated also the benefit of creating a circuit, with different methods, that can test the maximum power point trackers (MPPT for different photovoltaic applications.

NPS-SCAT: Systems Engineering and Payload Subsystem Design, Integration, and Testing of NPS’ First CubeSat

Science.gov (United States)

2010-06-01

uses the photovoltaic (PV) effect to produce electrical power . Discovered in 1839, the PV effect “is the direct conversion of light into electricity...electrical power subsystem (EPS) of the NPS-SCAT satellite is used to provide, store, distribute, and control the spacecraft electrical power [52]. The...current not to exceed 0.5 A; the solar panels must be designed to meet this specification. The BCRs use a maximum power point tracker ( MPPT ) to

Uninterrupted thermoelectric energy harvesting using temperature-sensor-based maximum power point tracking system

International Nuclear Information System (INIS)

Park, Jae-Do; Lee, Hohyun; Bond, Matthew

2014-01-01

Highlights: • Feedforward MPPT scheme for uninterrupted TEG energy harvesting is suggested. • Temperature sensors are used to avoid current measurement or source disconnection. • MPP voltage reference is generated based on OCV vs. temperature differential model. • Optimal operating condition is maintained using hysteresis controller. • Any type of power converter can be used in the proposed scheme. - Abstract: In this paper, a thermoelectric generator (TEG) energy harvesting system with a temperature-sensor-based maximum power point tracking (MPPT) method is presented. Conventional MPPT algorithms for photovoltaic cells may not be suitable for thermoelectric power generation because a significant amount of time is required for TEG systems to reach a steady state. Moreover, complexity and additional power consumption in conventional circuits and periodic disconnection of power source are not desirable for low-power energy harvesting applications. The proposed system can track the varying maximum power point (MPP) with a simple and inexpensive temperature-sensor-based circuit without instantaneous power measurement or TEG disconnection. This system uses TEG’s open circuit voltage (OCV) characteristic with respect to temperature gradient to generate a proper reference voltage signal, i.e., half of the TEG’s OCV. The power converter controller maintains the TEG output voltage at the reference level so that the maximum power can be extracted for the given temperature condition. This feedforward MPPT scheme is inherently stable and can be implemented without any complex microcontroller circuit. The proposed system has been validated analytically and experimentally, and shows a maximum power tracking error of 1.15%

Forecasting method in multilateration accuracy based on laser tracker measurement

International Nuclear Information System (INIS)

Aguado, Sergio; Santolaria, Jorge; Samper, David; José Aguilar, Juan

2017-01-01

Multilateration based on a laser tracker (LT) requires the measurement of a set of points from three or more positions. Although the LTs’ angular information is not used, multilateration produces a volume of measurement uncertainty. This paper presents two new coefficients from which to determine whether the measurement of a set of points, before performing the necessary measurements, will improve or worsen the accuracy of the multilateration results, avoiding unnecessary measurement, and reducing the time and economic cost required. The first specific coefficient measurement coefficient (MC LT ) is unique for each laser tracker. It determines the relationship between the radial and angular laser tracker measurement noise. Similarly, the second coefficient is related with specific conditions of measurement β . It is related with the spatial angle between the laser tracker positions α and its effect on error reduction. Both parameters MC LT and β are linked in error reduction limits. Beside these, a new methodology to determine the multilateration reduction limit according to the multilateration technique of an ideal laser tracker distribution and a random one are presented. It provides general rules and advice from synthetic tests that are validated through a real test carried out in a coordinate measurement machine. (paper)

Maximum power point tracking for photovoltaic applications by using two-level DC/DC boost converter

Science.gov (United States)

Moamaei, Parvin

Recently, photovoltaic (PV) generation is becoming increasingly popular in industrial applications. As a renewable and alternative source of energy they feature superior characteristics such as being clean and silent along with less maintenance problems compared to other sources of the energy. In PV generation, employing a Maximum Power Point Tracking (MPPT) method is essential to obtain the maximum available solar energy. Among several proposed MPPT techniques, the Perturbation and Observation (P&O;) and Model Predictive Control (MPC) methods are adopted in this work. The components of the MPPT control system which are P&O; and MPC algorithms, PV module and high gain DC-DC boost converter are simulated in MATLAB Simulink. They are evaluated theoretically under rapidly and slowly changing of solar irradiation and temperature and their performance is shown by the simulation results, finally a comprehensive comparison is presented.

Dynamic modeling and performance evaluation of axial flux PMSG based wind turbine system with MPPT control

Directory of Open Access Journals (Sweden)

Vahid Behjat

2014-12-01

Full Text Available This research work develops dynamic model of a gearless small scale wind power generation system based on a direct driven single sided outer rotor AFPMSG with coreless armature winding. Dynamic modeling of the AFPMSG based wind turbine requires machine parameters. To this end, a 3D FEM model of the generator is developed and from magnetostatic and transient analysis of the FEM model, machine parameters are calculated and utilized in dynamic modeling of the system. A maximum power point tracking (MPPT-based FOC control approach is used to obtain maximum power from the variable wind speed. The simulation results show the proper performance of the developed dynamic model of the AFPMSG, control approach and power generation system.

INNER TRACKER

CERN Multimedia

Karl Gill

A series of important milestones have been passed during the last 3 months. With the delivery of refurbished cooling systems, pixels and strip systems have been brought back into operation after long shutdowns. Pixels has been operating since reinsertion of FPIX in April, and has been running at 4°C since May 16 when the bulkhead thermal screen was commissioned. More recently, on June 10 the Strip Tracker was powered up in its entirety, with cooling fluid circulating at 4°C, allowing commissioning of the Strip Tracker to proceed at full speed. The full Tracker is well on course to be ready for CRAFT, with Strip Tracker readout operation in ‘peak’ mode remaining also on track to be ready for beam operations in the Autumn in ‘deconvolution’ readout mode. The main Tracker activity during the shutdown was the cooling plant refurbishment for Strips and Pixels systems. The objectives were to reduce the serious leaks observed in 2008 and improve the longevity...

A Robust MPP Tracker Based on Sliding Mode Control for a Photovoltaic Based Pumping System

Institute of Scientific and Technical Information of China (English)

Farhat Maissa; Oscar Barambones; Sbita Lassad; Aymen Fleh

2017-01-01

In this paper,a mathematical model of the photovoltaic (PV) pumping system's main components is firstly established.Then,the design of maximum power point tracking (MPPT) stage that ensures battery charging is described.This work is motivated by the need of photovoltaic generator (PVG) that efficiently extracts maximum power.The PVG is a special source of energy which has nonlinear current-voltage characteristics depending on variations in temperature and solar irradiance.In order to achieve the MPPT operating goals,a special interest is focused on the variable structure sliding mode (SM) control strategy and the classic perturb and observe (P&O) algorithm.The permanent magnet synchronous motor (PMSM) is selected as a pump driver.The field oriented control is performed as the motor drive strategy.Simulation results show a high level of efficiency,obtained with the proposed PV based pumping system.The performance comparison between SM controller and P&O controller has been carried out to demonstrate the effectiveness of the former in drawing more energy and a fast response against irradiation disturbances.

A Differential Evolution Based MPPT Method for Photovoltaic Modules under Partial Shading Conditions

Directory of Open Access Journals (Sweden)

Kok Soon Tey

2014-01-01

Full Text Available Partially shaded photovoltaic (PV modules have multiple peaks in the power-voltage (P-V characteristic curve and conventional maximum power point tracking (MPPT algorithm, such as perturbation and observation (P&O, which is unable to track the global maximum power point (GMPP accurately due to its localized search space. Therefore, this paper proposes a differential evolution (DE based optimization algorithm to provide the globalized search space to track the GMPP. The direction of mutation in the DE algorithm is modified to ensure that the mutation always converges to the best solution among all the particles in the generation. This helps to provide the rapid convergence of the algorithm. Simulation of the proposed PV system is carried out in PSIM and the results are compared to P&O algorithm. In the hardware implementation, a high step-up DC-DC converter is employed to verify the proposed algorithm experimentally on partial shading conditions, load variation, and solar intensity variation. The experimental results show that the proposed algorithm is able to converge to the GMPP within 1.2 seconds with higher efficiency than P&O.

Maximum power point tracking-based control algorithm for PMSG wind generation system without mechanical sensors

International Nuclear Information System (INIS)

Hong, Chih-Ming; Chen, Chiung-Hsing; Tu, Chia-Sheng

2013-01-01

Highlights: ► This paper presents MPPT based control for optimal wind energy capture using RBFN. ► MPSO is adopted to adjust the learning rates to improve the learning capability. ► This technique can maintain the system stability and reach the desired performance. ► The EMF in the rotating reference frame is utilized in order to estimate speed. - Abstract: This paper presents maximum-power-point-tracking (MPPT) based control algorithms for optimal wind energy capture using radial basis function network (RBFN) and a proposed torque observer MPPT algorithm. The design of a high-performance on-line training RBFN using back-propagation learning algorithm with modified particle swarm optimization (MPSO) regulating controller for the sensorless control of a permanent magnet synchronous generator (PMSG). The MPSO is adopted in this study to adapt the learning rates in the back-propagation process of the RBFN to improve the learning capability. The PMSG is controlled by the loss-minimization control with MPPT below the base speed, which corresponds to low and high wind speed, and the maximum energy can be captured from the wind. Then the observed disturbance torque is feed-forward to increase the robustness of the PMSG system

INNER TRACKER

CERN Multimedia

P. Sharp

The CMS Inner Tracking Detector continues to make good progress. The Objective for 2007 is to deliver to CMS a completed, installed, commissioned and calibrated Tracking System (Silicon Strip and Pixels) aligned to < 100µ in April 2008 ready for the first physics collisions at LHC. On 21 March 2007, the integration of the CMS Silicon Strip Tracker was completed with the successful integration of TEC- into the Tracker Support Tube (TST). Since then ~25% of the complete Tracker Systems has been commission at the TIF at both room temperature and operating temperature (-100 C), and the Tracker Community has gained very valuable experience in operating, calibrating and aligning the Tracker at the TIF before it is prepared for transportation to P5 in July 2007. The CMS Pixel System continues to make good progress. Module and Plaquette production is very well advanced. The first 25% of the Forward Pixel detector (Fpix) was delivered to CERN in April and the second 25% will shipped to CERN on 19 ...

INNER TRACKER

CERN Multimedia

K. Gill.

The clear highlight of recent months was switching on the Tracker to capture the first LHC collisions with 450GeV beams. This was during the first trial run of the LHC on 23rd November. On that day, the Tracker Outer Barrel (TOB) was powered and the detector performance was excellent, in accord with our expectations. Since then, the full Tracker, strips and pixels, has been powered up during “quiet” beam periods when there was judged to be little risk of damage due to sudden beam losses. All Tracker systems performed very well, considering the beam and trigger conditions in place, and we now eagerly anticipate the first collisions with stable beams. Besides this very intense and exciting recent period there has been a lot of other activity in the last 6 months. The full Tracker participated in CRAFT09 and operations of all systems went very smoothly for both pixels and strips, validating all the meticulous work that had taking place during the long shutdown, the subsequent re-commissionin...

MAXIMUM POWEWR POINT TRACKING SYSTEM FOR PHOTOVOLTAIC STATION: A REVIEW

Directory of Open Access Journals (Sweden)

I. Elzein

2015-01-01

Full Text Available In recent years there has been a growing attention towards the use of renewable energy sources. Among them solar energy is one of the most promising green energy resources due to its environment sustainability and inexhaustibility. However photovoltaic systems (PhV suffer from big cost of equipment and low efficiency. Moreover, the solar cell V-I characteristic is nonlinear and varies with irradiation and temperature. In general, there is a unique point of PhV operation, called the Maximum Power Point (MPP, in which the PV system operates with maximum efficiency and produces its maximum output power. The location of the MPP is not known in advance, but can be located, either through calculation models or by search algorithms. Therefore MPPT techniques are important to maintain the PV array’s high efficiency. Many different techniques for MPPT are discussed. This review paper hopefully will serve as a convenient tool for future work in PhV power conversion.

Matlab-Based Modeling and Simulations to Study the Performance of Different MPPT Techniques Used for Photovoltaic Systems under Partially Shaded Conditions

Directory of Open Access Journals (Sweden)

Jehun Hahm

2015-01-01

Full Text Available A pulse-width-modulator- (PWM- based sliding mode controller is developed to study the effects of partial shade, temperature, and insolation on the performance of maximum power point tracking (MPPT used in photovoltaic (PV systems. Under partially shaded conditions and temperature, PV array characteristics become more complex, with multiple power-voltage maxima. MPPT is an automatic control technique to adjust power interfaces and deliver power for a diverse range of insolation values, temperatures, and partially shaded modules. The PV system is tested using two conventional algorithms: the Perturb and Observe (P&O algorithm and the Incremental Conductance (IncCond algorithm, which are simple to implement for a PV array. The proposed method applied a model to simulate the performance of the PV system for solar energy usage, which is compared to the conventional methods under nonuniform insolation improving the PV system utilization efficiency and allowing optimization of the system performance. The PWM-based sliding mode controller successfully overcomes the issues presented by nonuniform conditions and tracks the global MPP. In this paper, the PV system consists of a solar module under shade connected to a boost converter that is controlled by three different algorithms and is generated using Matlab/Simulink.

TRACKER INSERTED INTO YB0 & HEAVY LOWERING COMPLETED

CERN Multimedia

      The Tracker travelled very smoothly from Meyrin to Point 5 during the early hours of December 13th. Lowered later the same day, insertion was completed 18th December. The intense campaign of Tracker connections, involving 980 pipes, 2330 cables and 3623 fibre ribbons, has since begun and is making good progress. The final large element of CMS YE-1 was lowered gently into the cavern on January 22nd. This marks the end of fourteen months of heavy lowering operations.  

Application of a DC–DC boost converter with maximum power point tracking for low power thermoelectric generators

International Nuclear Information System (INIS)

Mamur, Hayati; Ahiska, Rasit

2015-01-01

Highlights: • Charges with direct and MPPT conditions have been compared. • Perturb and observation method has been practically tested on a new TEG. • Matched load condition has been experimentally investigated. • To increase the efficiency of a TEG, the charge with MPPT should be used. • The charge with MPPT provides twice-fold increase in efficiency. - Abstract: Thermoelectric generators (TEGs) directly generate electrical power from the geothermal/waste heat as well as contribute to efficient usage of the energy. TEGs cannot be operated at full capacity without additional electronic equipments, since the internal resistances of TEGs are not equal to the device resistances connected across TEGs. For this reason, in this paper, the application of a DC–DC boost converter with maximum power point tracking (MPPT) based on microcontroller embedded in perturb and observe (P&O) algorithm has been proposed to obtain maximum power from a newly designed portable TEG (pTEG) in a real TEG system. The matched condition load for the pTEG has been experimentally investigated. Firstly, the pTEG has been directly charged to the battery pack, secondly it has been charged through the improved convertor with MPPT. In the first one, the pTEG operated with less efficiency than half of its full capacity, whereas, in the second, the pTEG operated efficiency near its full capacity

Near-maximum-power-point-operation (nMPPO) design of photovoltaic power generation system

Energy Technology Data Exchange (ETDEWEB)

Huang, B.J.; Sun, F.S.; Ho, R.W. [Department of Mechanical Engineering, National Taiwan University, Taipei 106, Taiwan (China)

2006-08-15

The present study proposes a PV system design, called 'near-maximum power-point-operation' (nMPPO) that can maintain the performance very close to PV system with MPPT (maximum-power-point tracking) but eliminate hardware of the MPPT. The concept of nMPPO is to match the design of battery bank voltage V{sub set} with the MPP (maximum-power point) of the PV module based on an analysis using meteorological data. Three design methods are used in the present study to determine the optimal V{sub set}. The analytical results show that nMPPO is feasible and the optimal V{sub set} falls in the range 13.2-15.0V for MSX60 PV module. The long-term performance simulation shows that the overall nMPPO efficiency {eta}{sub nMPPO} is higher than 94%. Two outdoor field tests were carried out in the present study to verify the design of nMPPO. The test results for a single PV module (60Wp) indicate that the nMPPO efficiency {eta}{sub nMPPO} is mostly higher than 93% at various PV temperature T{sub pv}. Another long-term field test of 1kWp PV array using nMPPO shows that the power generation using nMPPO is almost identical with MPPT at various weather conditions and T{sub pv} variation from 24{sup o}C to 70{sup o}C. (author)

A Sliding Mode Control for a Sensorless Tracker: Application on a Photovoltaic System

OpenAIRE

Rhif, Ahmed

2012-01-01

The photovoltaic sun tracker allows us to increase the energy production. The sun tracker considered in this study has two degrees of freedom (2-DOF) and especially specified by the lack of sensors. In this way, the tracker will have as a set point the sun position at every second during the day for a period of five years. After sunset, the tracker goes back to the initial position (which of sunrise). The sliding mode control (SMC) will be applied to ensure at best the tracking mechanism and,...

Starting characteristics of direct current motors powered by solar cells

Science.gov (United States)

Singer, S.; Appelbaum, J.

1989-01-01

Direct current motors are used in photovoltaic systems. Important characteristics of electric motors are the starting to rated current and torque ratios. These ratios are dictated by the size of the solar cell array and are different for the various dc motor types. Discussed here is the calculation of the starting to rated current ratio and starting to rated torque ratio of the permanent magnet, and series and shunt excited motors when powered by solar cells for two cases: with and without a maximum-power-point-tracker (MPPT) included in the system. Comparing these two cases, one gets a torque magnification of about 3 for the permanent magnet motor and about 7 for other motor types. The calculation of the torques may assist the PV system designer to determine whether or not to include an MPPT in the system.

Variable Parameter Nonlinear Control for Maximum Power Point Tracking Considering Mitigation of Drive-train Load

Institute of Scientific and Technical Information of China (English)

Zaiyu; Chen; Minghui; Yin; Lianjun; Zhou; Yaping; Xia; Jiankun; Liu; Yun; Zou

2017-01-01

Since mechanical loads exert a significant influence on the life span of wind turbines, the reduction of transient load on drive-train shaft has received more attention when implementing a maximum power point tracking(MPPT) controller.Moreover, a trade-off between the efficiency of wind energy extraction and the load level of drive-train shaft becomes a key issue. However, for the existing control strategies based on nonlinear model of wind turbines, the MPPT efficiencies are improved at the cost of the intensive fluctuation of generator torque and significant increase of transient load on drive train shaft. Hence, in this paper, a nonlinear controller with variable parameter is proposed for improving MPPT efficiency and mitigating transient load on drive-train simultaneously. Then,simulations on FAST(Fatigue, Aerodynamics, Structures, and Turbulence) code and experiments on the wind turbine simulator(WTS) based test bench are presented to verify the efficiency improvement of the proposed control strategy with less cost of drive-train load.

Variable Parameter Nonlinear Control for Maximum Power Point Tracking Considering Mitigation of Drive-train Load

Institute of Scientific and Technical Information of China (English)

Zaiyu Chen; Minghui Yin; Lianjun Zhou; Yaping Xia; Jiankun Liu; Yun Zou

2017-01-01

Since mechanical loads exert a significant influence on the life span of wind turbines,the reduction of transient load on drive-train shaft has received more attention when implementing a maximum power point tracking (MPPT) controller.Moreover,a trade-off between the efficiency of wind energy extraction and the load level of drive-train shaft becomes a key issue.However,for the existing control strategies based on nonlinear model of wind turbines,the MPPT efficiencies are improved at the cost of the intensive fluctuation of generator torque and significant increase of transient load on drive train shaft.Hence,in this paper,a nonlinear controller with variable parameter is proposed for improving MPPT efficiency and mitigating transient load on drive-train simultaneously.Then,simulations on FAST (Fatigue,Aerodynamics,Structures,and Turbulence) code and experiments on the wind turbine simulator (WTS) based test bench are presented to verify the efficiency improvement of the proposed control strategy with less cost of drive-train load.

Maximum power point tracking techniques for wind energy systems using three levels boost converter

Science.gov (United States)

Tran, Cuong Hung; Nollet, Frédéric; Essounbouli, Najib; Hamzaoui, Abdelaziz

2018-05-01

This paper presents modeling and simulation of three level Boost DC-DC converter in Wind Energy Conversion System (WECS). Three-level Boost converter has significant advantage compared to conventional Boost. A maximum power point tracking (MPPT) method for a variable speed wind turbine using permanent magnet synchronous generator (PMSG) is also presented. Simulation of three-level Boost converter topology with Perturb and Observe algorithm and Fuzzy Logic Control is implemented in MATLAB/SIMULINK. Results of this simulation show that the system with MPPT using fuzzy logic controller has better performance to the Perturb and Observe algorithm: fast response under changing conditions and small oscillation.

Autonomous Star Tracker Algorithms

DEFF Research Database (Denmark)

Betto, Maurizio; Jørgensen, John Leif; Kilsgaard, Søren

1998-01-01

Proposal, in response to an ESA R.f.P., to design algorithms for autonomous star tracker operations.The proposal also included the development of a star tracker breadboard to test the algorithms performances.......Proposal, in response to an ESA R.f.P., to design algorithms for autonomous star tracker operations.The proposal also included the development of a star tracker breadboard to test the algorithms performances....

Synchronous Buck Converter with Perturb and Observe Maximum Power Point Tracking Implemented on a Low-Cost Arduino-microcontroller

Directory of Open Access Journals (Sweden)

Emad Talib Hashim

2018-02-01

Full Text Available Maximum power point tracking (MPPT is used in photovoltaic (PV systems to enhance efficiency and maximize the output power of PV module, regardless the variation of temperature, irradiation, and the electrical characteristics of the load. A new MPPT system has been presented in this research, consisting of a synchronous DC-DC step-down Buck converter controlled by an Arduino microcontroller based unit. The MPPT process with Perturb and Observe method is performed with a DC-DC converter circuit to overcome the problem of voltage mismatch between the PV modules and the loads. The proposing system has high efficiency, lower cost and can be easily modified to handle more energy sources. The test results indicate that the use of the proposed MPPT control with the designed synchronous Buck converter increases the PV output power; hence increases the overall solar system efficiency. The synchronous Buck converter test results used in this design showed high converter efficiency up to 95% of the power produced from the solar module, leading to reduce power loss caused by the power transfer process from PV module to the loads.

L1 Adaptive Speed Control of a Small Wind Energy Conversion System for Maximum Power Point Tracking

DEFF Research Database (Denmark)

Zhao, Haoran; Wu, Qiuwei; Rasmussen, Claus Nygaard

2014-01-01

This paper presents the design of an L1 adaptive controller for maximum power point tracking (MPPT) of a small variable speed Wind Energy Conversion System (WECS). The proposed controller generates the optimal torque command for the vector controlled generator side converter (GSC) based on the wi......) is used to carry out case studies using Matlab/Simulink. The case study results show that the designed L1 adaptive controller has good tracking performance even with unmodeled dynamics and in the presence of parameter uncertainties and unknown disturbances.......This paper presents the design of an L1 adaptive controller for maximum power point tracking (MPPT) of a small variable speed Wind Energy Conversion System (WECS). The proposed controller generates the optimal torque command for the vector controlled generator side converter (GSC) based on the wind...

Independent control strategy of two DC-link voltages for separate MPPTs in transformerless photovoltaic systems using neutral-point-clamped inverters

DEFF Research Database (Denmark)

Choi, Uimin; Blaabjerg, Frede; Lee, Kyo-Beum

2014-01-01

To improve the efficiency of the photovoltaic (PV) system, the centralized topology using three-level inverters are widely used. In this system, PV modules are separately connected to the split DC-links. This causes a decrease of maximum power point tracking (MPPT) efficiency under the partial...... shading condition. This paper proposes an independent control of two DC-link voltages for separate MPPT of each PV module in three-level inverters. The proposed method is simply implemented by adding or subtracting the time-offset to the three-phase turn-on times and modifying the reference voltages...

Two ATLAS trackers become one

CERN Multimedia

2006-01-01

The ATLAS inner detector barrel comes one step closer to completion as the semiconductor tracker is merged with the transition radiation tracker. ATLAS collaborators prepare for the insertion of the semiconductor tracker (SCT, behind) into the transition radiation tracker (TRT, in front). Some had hoped it would fall on Valentine's Day. But despite the slight delay, Friday 17 February was lovingly embraced as 'Conception Day,' when dozens of physicists and engineers from the international collaboration gathered to witness the insertion of the ATLAS semiconductor tracker into the transition radiation tracker, a major milestone in the assembly of the experiment's inner detector. With just millimeters of room for error, the cylindrical trackers were slid into each other as inner detector integration coordinator Heinz Pernegger issued commands and scientists held out flashlights, lay on their backs and stood on ladders to take careful measurements. Each tracker is the result of about 10 years of international ...

TRACKER

CERN Multimedia

L. Demaria

2011-01-01

Strip Tracker The Silicon Strip Tracker has maintained excellent operational performance during the 2011 data-taking period. The increase of instantaneous luminosity up to 1033 cm-2s-1 did not introduce any new issues in the detector. The detector has collected high-quality physics data with an uptime greater than 98%. Sources of downtime have been identified and problems were properly addressed. Improved firmware in the Front-End Driver (FED) firmware was deployed to increase the robustness of the readout against spurious extra frames coming from the detector. When a FED detects bad data, it goes into Out-Of-Sync (OOS) status, waits for a L1 resynchronisation command (resync) to clean up the culprit data and restarts. Resync commands are now sent automatically to the Strip Tracker when it signals OOS and, as a result, this source of downtime has been reduced significantly. The dead-time, caused by recoveries from OOS, accounts for less than 0.1%. Downtime was also found to be caused by a FED occasionally ge...

TRACKER

CERN Multimedia

G. Dirkes

2010-01-01

The strip system has generally exhibited stable and high performance operation during the last six months of pp and heavy ion collisions. The up-time during pp collision from June onwards was 99.0% and during the first weeks of heavy-ion running we reached 99.7%. Most of the down-time during the proton runs came from Tracker DAQ problems. Spurious extra events from individual front-end channels caused ‘sync loss draining’ errors at the central DAQ system downstream of the Tracker FEDs. Once the problem was understood, new firmware that detects this error condition was installed on the FEDs. This has reduced the recovery procedure from this particular condition from a full reconfiguration requiring 170 s, to a simple re-synchronisation taking only ~1 s. We have also streamlined the instructions for the central DAQ shifters in order to minimise the time needed to decide the proper reaction to a given problem. The average down-time for problems triggered by the strip tracker DAQ is 395 s. Th...

TRACKER

CERN Multimedia

D. Strom

2011-01-01

Strip Tracker Since the June CMS Week, the Silicon Strip Tracker has had another period of excellent detector operation with more than 97% system uptime. The focus on stable proton physics collection was fruitful, as CMS recorded greater than 5 fb–1 by the completion of the 2011 pp run. Following the November machine development and technical stop, the Strip Tracker now aims to provide the highest quality data during the heavy-ion run. The detector health, measured by the fraction of alive channels, is largely stable at around 97.8%. Recent failures include a TOB control ring, which now requires redundancy, and a TEC control ring with intermittent failures. These will be investigated during the Year-End Technical Stop. Critical services are very stable. The cooling system has a low total leak rate of less than 1 kg per day, and the power supply exchange rate is less than 1 unit per month. Two operational changes recently went into effect to optimise data-taking efficiency: (1) a tripped power su...

TRACKER

CERN Multimedia

Frank Hartmann

2012-01-01

  Strip Tracker In general, the Strip Tracker is operating smoothly with the current peak instantaneous luminosity beyond 6.5E33, high L1 rate and large pile-up. With several improvements in automatic DQM checks and an enhanced SMS and e-mail service system plus additional audio alarms, we have reduced the work-load of our TK DOC and stopped the calls made at the beginning of each fill. We successfully collected more than two million cosmic tracks in peak mode during inter-fill periods before June, fulfilling the request from the Tracker alignment group. Around 500k cosmic tracks were also collected at zero Tesla. All planned special measurements, namely DCU calibration and I-V scans, have been taken during the YETS and other technical stops. A peak-mode run, a delay run and two HV scans have also been taken during early collisions at the initial low-lumi runs as well as during the fill where CMS had a problem with the magnet. The largest source of downtime comes from TIB-2.8.1 a.k.a. FED 101, ...

A Simple Checking Algorithm with Perturb and Observe Maximum Power Point Tracking for Partially Shaded Photovoltaic System

Directory of Open Access Journals (Sweden)

Rozana Alik

2016-03-01

Full Text Available This paper presents a simple checking algorithm for maximum power point tracking (MPPT technique for Photovoltaic (PV system using Perturb and Observe (P&O algorithm. The main benefit of this checking algorithm is the simplicity and efficiency of the system whose duty cycle produced by the MPPT is smoother and changes faster according to maximum power point (MPP. This checking algorithm can determine the maximum power first before the P&O algorithm takes place to identify the voltage at MPP (VMPP, which is needed to calculate the duty cycle for the boost converter. To test the effectiveness of the algorithm, a simulation model of PV system has been carried out using MATLAB/Simulink under different level of irradiation; or in other words partially shaded condition of PV array. The results from the system using the proposed approach prove to have faster response and low ripple. Besides, the results are close to the desired outputs and exhibit an approximately 98.25% of the system efficiency. On the other hand, the system with conventional P&O MPPT seems to be unstable and has higher percentage of error. In summary, the proposed method is useful under varying level of irradiation with higher efficiency of the system.

Multi-Input Converter with MPPT Feature for Wind-PV Power Generation System

Directory of Open Access Journals (Sweden)

Chih-Lung Shen

2013-01-01

Full Text Available A multi-input converter (MIC to process wind-PV power is proposed, designed, analyzed, simulated, and implemented. The MIC cannot only process solar energy but deal with wind power, of which structure is derived from forward-type DC/DC converter to step-down/up voltage for charger systems, DC distribution applications, or grid connection. The MIC comprises an upper modified double-ended forward, a lower modified double-ended forward, a common output inductor, and a DSP-based system controller. The two modified double-ended forwards can operate individually or simultaneously so as to accommodate the variation of the hybrid renewable energy under different atmospheric conditions. While the MIC operates at interleaving mode, better performance can be achieved and volume also is reduced. The proposed MIC is capable of recycling the energy stored in the leakage inductance and obtaining high step-up output voltage. In order to draw maximum power from wind turbine and PV panel, perturb-and-observe method is adopted to achieve maximum power point tracking (MPPT feature. The MIC is constructed, analyzed, simulated, and tested. Simulations and hardware measurements have demonstrated the feasibility and functionality of the proposed multi-input converter.

Two-Stage Chaos Optimization Search Application in Maximum Power Point Tracking of PV Array

Directory of Open Access Journals (Sweden)

Lihua Wang

2014-01-01

Full Text Available In order to deliver the maximum available power to the load under the condition of varying solar irradiation and environment temperature, maximum power point tracking (MPPT technologies have been used widely in PV systems. Among all the MPPT schemes, the chaos method is one of the hot topics in recent years. In this paper, a novel two-stage chaos optimization method is presented which can make search faster and more effective. In the process of proposed chaos search, the improved logistic mapping with the better ergodic is used as the first carrier process. After finding the current optimal solution in a certain guarantee, the power function carrier as the secondary carrier process is used to reduce the search space of optimized variables and eventually find the maximum power point. Comparing with the traditional chaos search method, the proposed method can track the change quickly and accurately and also has better optimization results. The proposed method provides a new efficient way to track the maximum power point of PV array.

Performance optimization of a hybrid micro-grid based on double-loop MPPT and SVC-MERS

Science.gov (United States)

Wei, Yewen; Hou, Xilun; Zhang, Xiang; Xiong, Shengnan; Peng, Fei

2018-02-01

With ever-increasing concerns on environmental pollution and energy shortage, the development of renewable resource has attracted a lot of attention. This paper first reviews both the wind and photovoltaic (PV) generation techniques and approaches of micro-grid voltage control. Then, a novel islanded micro-grid, which consists of wind & PV generation and hybrid-energy storage device, is built for application to remote and isolated areas. For the PV power generation branch, a double- maximum power point tracking (MPPT) technique is developed to trace the sunlight and regulate the tilt angle of PV panels. For wind-power generation branch, squirrel cage induction generator (SCIG) is used as its simple structure, robustness and less cost. In order to stabilize the output voltage of SCIGs, a new Static Var Compensator named magnetic energy recovery switch (SVC-MERS) is applied. Finally, experimental results confirm that both of the proposed methods can improve the efficiency of PV power generation and voltage stability of the micro-grid, respectively.

CosmoQuest Transient Tracker: Opensource Photometry & Astrometry software

Science.gov (United States)

Myers, Joseph L.; Lehan, Cory; Gay, Pamela; Richardson, Matthew; CosmoQuest Team

2018-01-01

CosmoQuest is moving from online citizen science, to observational astronomy with the creation of Transient Trackers. This open source software is designed to identify asteroids and other transient/variable objects in image sets. Transient Tracker’s features in final form will include: astrometric and photometric solutions, identification of moving/transient objects, identification of variable objects, and lightcurve analysis. In this poster we present our initial, v0.1 release and seek community input.This software builds on the existing NIH funded ImageJ libraries. Creation of this suite of opensource image manipulation routines is lead by Wayne Rasband and is released primarily under the MIT license. In this release, we are building on these libraries to add source identification for point / point-like sources, and to do astrometry. Our materials released under the Apache 2.0 license on github (http://github.com/CosmoQuestTeam) and documentation can be found at http://cosmoquest.org/TransientTracker.

Comparative Study of Maximum Power Point Tracking Techniques for Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Fernando Lessa Tofoli

2015-01-01

Full Text Available The generation of electricity from photovoltaic (PV arrays has been increasingly considered as a prominent alternative to fossil fuels. However, the conversion efficiency is typically low and the initial cost is still appreciable. A required feature of a PV system is the ability to track the maximum power point (MPP of the PV array. Besides, MPP tracking (MPPT is desirable in both grid-connected and stand-alone photovoltaic systems because the solar irradiance and temperature change throughout the day, as well as along seasons and geographical conditions, also leading to the modification of the I×V (current versus voltage and P×V (power versus voltage curves of the PV module. MPPT is also justified by the relatively high cost of the energy generated by PV systems if compared with other sources. Since there are various MPPT approaches available in the literature, this work presents a comparative study among four popular techniques, which are the fixed duty cycle method, constant voltage (CV, perturb and observe (P&O, and incremental conductance (IC. It considers different operational climatic conditions (i.e., irradiance and temperature, since the MPP is nonlinear with the environment status. PSIM software is used to validate the assumptions, while relevant results are discussed in detail.

Camtracker: a new camera controlled high precision solar tracker system for FTIR-spectrometers

Directory of Open Access Journals (Sweden)

M. Gisi

2011-01-01

Full Text Available A new system to very precisely couple radiation of a moving source into a Fourier Transform Infrared (FTIR Spectrometer is presented. The Camtracker consists of a homemade altazimuthal solar tracker, a digital camera and a homemade program to process the camera data and to control the motion of the tracker. The key idea is to evaluate the image of the radiation source on the entrance field stop of the spectrometer. We prove that the system reaches tracking accuracies of about 10 arc s for a ground-based solar absorption FTIR spectrometer, which is significantly better than current solar trackers. Moreover, due to the incorporation of a camera, the new system allows to document residual pointing errors and to point onto the solar disk center even in case of variable intensity distributions across the source due to cirrus or haze.

Photovoltaic System Modeling with Fuzzy Logic Based Maximum Power Point Tracking Algorithm

Directory of Open Access Journals (Sweden)

Hasan Mahamudul

2013-01-01

Full Text Available This paper represents a novel modeling technique of PV module with a fuzzy logic based MPPT algorithm and boost converter in Simulink environment. The prime contributions of this work are simplification of PV modeling technique and implementation of fuzzy based MPPT system to track maximum power efficiently. The main highlighted points of this paper are to demonstrate the precise control of the duty cycle with respect to various atmospheric conditions, illustration of PV characteristic curves, and operation analysis of the converter. The proposed system has been applied for three different PV modules SOLKAR 36 W, BP MSX 60 W, and KC85T 87 W. Finally the resultant data has been compared with the theoretical prediction and company specified value to ensure the validity of the system.

TRACKER

CERN Multimedia

M. Dinardo and G. Benelli

2013-01-01

Pixel Tracker At the beginning of May, the Pixel detector was successfully extracted from inside CMS. The operation lasted one and a half days each for the forward and barrel Pixel detectors. Everything went smoothly: new people were trained during the exercise and care was taken to minimise radiation exposure – see Image 3.  Lessons learned were noted in an updated written extraction procedure.  Care was also taken to prepare for reinsertion around the new beam pipe next year, with new alignment targets placed on the barrel Pixel detector. All pieces were lifted to the surface and are now safely stored at low temperatures in the dedicated Pixel laboratory at Point 5 (see Image 4 and previous Bulletin). Image 3 (a) and (b): Extracted FPIX and BPIX detector The subsequent maintenance of the forward Pixel detector started on 27 May.  Since then one of four half cylinders has been repaired and, even more importantly, most of the failures have been fully understood. ...

Optimization of partially shaded PV array using a modified P&O MPPT algorithm

Directory of Open Access Journals (Sweden)

Abdelaziz YOUCEF

2016-07-01

Full Text Available A photovoltaic (PV array generated power is directly affected by temperature, solar irradiation, shading, and array configuration. In practice, PV arrays could be partially shaded by could, buildings, trees and other utilities. In this case, multiple maximums appear in the P-V curve, a global maximum and one or several local maximums. The “perturb and observe“ (P&O maximum power point tracking (MPPT algorithm cannot differentiate between a global and a local maximum and it is therefore ineffective when partial shading occurs. First, this paper presents an original mathematical model of the P-V curve of a partially shaded PV array, that was used to perform a simulation study in order to show the P&O algorithm inability to track the global MPP of a PV array solar system under partial shading for low shading irradiation levels, then an adaptation sub algorithm is proposed to be added to the P&O algorithm in order to give it the ability to track the global MPP. This sub algorithm moves the operating point imposed by the partial shading configuration to a point in the vicinity of the global MPP in order to be easily tracked by the P&O algorithm. In the simulation, a PV array with a hundred modules has been considered by using a light, a medium then a severe shading configuration. The results obtained indicate that the proposed modified P&O algorithm is able to track the global MPP for the considered shading configurations and for any shading irradiation level.

Use of a Remote Eye-Tracker for the Analysis of Gaze during Treadmill Walking and Visual Stimuli Exposition

Directory of Open Access Journals (Sweden)

V. Serchi

2016-01-01

Full Text Available The knowledge of the visual strategies adopted while walking in cognitively engaging environments is extremely valuable. Analyzing gaze when a treadmill and a virtual reality environment are used as motor rehabilitation tools is therefore critical. Being completely unobtrusive, remote eye-trackers are the most appropriate way to measure the point of gaze. Still, the point of gaze measurements are affected by experimental conditions such as head range of motion and visual stimuli. This study assesses the usability limits and measurement reliability of a remote eye-tracker during treadmill walking while visual stimuli are projected. During treadmill walking, the head remained within the remote eye-tracker workspace. Generally, the quality of the point of gaze measurements declined as the distance from the remote eye-tracker increased and data loss occurred for large gaze angles. The stimulus location (a dot-target did not influence the point of gaze accuracy, precision, and trackability during both standing and walking. Similar results were obtained when the dot-target was replaced by a static or moving 2D target and “region of interest” analysis was applied. These findings foster the feasibility of the use of a remote eye-tracker for the analysis of gaze during treadmill walking in virtual reality environments.

A reduced switch count UPF power conditioner for grid connected variable speed wind energy conversion system employing PM generators: a simulation study

Energy Technology Data Exchange (ETDEWEB)

Raju, A.B.; Fernandes, B.G.; Chatterjee, K. [Indian Institute of Technology, Mumbai (India). Dept. of Electrical Engineering

2004-07-01

In this paper, modelling and simulation of a grid connected variable speed wind energy conversion system (VSWECS) with reduced switch count power converter is presented. The system consists of a permanent magnet synchronous generator (PMSG), two-pulse width modulated B-4 power converters and a maximum power point tracker (MPPT). Mathematical models of each element of the system are developed separately and are then integrated to simulate the whole system for various wind velocities. The complete system is simulated using MATLAB/SIMULINK and simulation results are presented. (author)

Improving efficiency of two-type maximum power point tracking methods of tip-speed ratio and optimum torque in wind turbine system using a quantum neural network

International Nuclear Information System (INIS)

Ganjefar, Soheil; Ghassemi, Ali Akbar; Ahmadi, Mohamad Mehdi

2014-01-01

In this paper, a quantum neural network (QNN) is used as controller in the adaptive control structures to improve efficiency of the maximum power point tracking (MPPT) methods in the wind turbine system. For this purpose, direct and indirect adaptive control structures equipped with QNN are used in tip-speed ratio (TSR) and optimum torque (OT) MPPT methods. The proposed control schemes are evaluated through a battery-charging windmill system equipped with PMSG (permanent magnet synchronous generator) at a random wind speed to demonstrate transcendence of their effectiveness as compared to PID controller and conventional neural network controller (CNNC). - Highlights: • Using a new control method to harvest the maximum power from wind energy system. • Using an adaptive control scheme based on quantum neural network (QNN). • Improving of MPPT-TSR method by direct adaptive control scheme based on QNN. • Improving of MPPT-OT method by indirect adaptive control scheme based on QNN. • Using a windmill system based on PMSG to evaluate proposed control schemes

Which Eye Tracker is Right for Your Research Performance Evaluation of Several Cost Variant Eye Trackers

Science.gov (United States)

2016-09-19

utilized to study a diverse number of topics such as the patterns of fixations and saccades while reading text (e.g., Rayner, 1998), the workload of...of their accessibility to our laboratory and because they represent a diverse set of relative price points, from low (Eye Tribe Tracker, Tobii EyeX...see Figure 1 for the layout of those systems). At both workstations, task stimuli were presented to observers on 48.26 cm Samsung SyncMaster 940Bx

3D Silicon Tracker for AFP - From Qualification to Operation

CERN Document Server

F\\"orster, Fabian Alexander; The ATLAS collaboration

2017-01-01

The ATLAS Forward Proton (AFP) experiment is a detector located ~210 m away from the ATLAS interaction point on both sides. Its aim is to tag and measure forward protons produced in diffractive events. The detector consists of a 3D silicon pixel tracker, to measure the proton trajectory, as well as a time-of-flight system to suppress pileup-related backgrounds. Each tracker and the ToF system are placed inside a Roman Pot, allowing operation in the vicinity of the LHC beam, up to 2-3 mm. AFP was installed in 2 stages during the LHC technical shutdowns of 2015-2016 and 2016-2017. This presentation will give an overview of the silicon sensor qualification as well as the production, assembly and quality assurance of the tracker modules. The installation, commissioning and operation of the full detector will also be discussed.

Maximum Power Point Tracking Control of Hydrokinetic Turbine and Low-speed High-Thrust Permanent Magnet Generator Design

Science.gov (United States)

2012-01-01

MPPT control method is similar to hill-climbing used as MPPT control in photovoltaic ...climbing method used as MPPT control in photovoltaic systems. In addition, the proposed MPPT control strategy is generic to all the hydrokinetic...convert AC power from the generator into DC power and a boost converter is used to implement energy flow control . On the load side, an electronic

INNER TRACKER

CERN Multimedia

K. Gill

During the winter shutdown several parts of the Tracker system are undergoing maintenance, revision or upgrade. The main items are the revision of the strips and pixels cooling plants, removal and maintenance of FPIX, sealing of Tracker patch-panels and the bulkhead, integration of strips and pixels DCS, and further development of the DAQ, Online and commissioning software and firmware. The revision of the cooling system involves the complete replacement of the tanks, distribution lines, valves and manifolds on the SS1 and SS2 strip tracker (182 circuits) and pixels (36 circuits) cooling plants. The objectives are to eliminate the large leaks experienced during 2008 operations and to assure the long-term reliability of the cooling systems. Additional instrumentation is being added to provide more detailed monitoring of the performance of the cooling system. This work is proceeding smoothly under close supervision. Procurements are almost completed and the quality of delivered parts and the subsequent assembl...

Motion-blurred star acquisition method of the star tracker under high dynamic conditions.

Science.gov (United States)

Sun, Ting; Xing, Fei; You, Zheng; Wei, Minsong

2013-08-26

The star tracker is one of the most promising attitude measurement devices used in spacecraft due to its extremely high accuracy. However, high dynamic performance is still one of its constraints. Smearing appears, making it more difficult to distinguish the energy dispersive star point from the noise. An effective star acquisition approach for motion-blurred star image is proposed in this work. The correlation filter and mathematical morphology algorithm is combined to enhance the signal energy and evaluate slowly varying background noise. The star point can be separated from most types of noise in this manner, making extraction and recognition easier. Partial image differentiation is then utilized to obtain the motion parameters from only one image of the star tracker based on the above process. Considering the motion model, the reference window is adopted to perform centroid determination. Star acquisition results of real on-orbit star images and laboratory validation experiments demonstrate that the method described in this work is effective and the dynamic performance of the star tracker could be improved along with more identified stars and guaranteed position accuracy of the star point.

Development of a Two-Dimensional Tracker with Plasma Panel Detector

CERN Document Server

AUTHOR|(CDS)2233132

Plasma panel sensors are micropattern gaseous radiation detectors which are based on the technology of plasma display panels. This thesis summarizes the research that had been done on commercially available plasma display panels that were converted to plasma panel sensor prototypes and describes the construction of a two-dimensional tracker consisting of four of those prototypes, with one-dimensional readout on each, used to detect tracks of cosmic muons. A large amount of 2-point as well as 3 and 4-point tracks were detected. Qualitative analyses as well as Pearson’s χ2 tests are performed on the track angular distribution and on a histogram of the linearity measure of 3-point tracks to reject the hypothesis that these tracks result from completely random panel hits. Some RF noise effects contributing to false positives are ruled out, while it is shown that other effects can be ruled out only with a high-intensity minimum ionizing particle source. A significant part of the tracker construction was the dev...

A Novel Technique for Maximum Power Point Tracking of a Photovoltaic Based on Sensing of Array Current Using Adaptive Neuro-Fuzzy Inference System (ANFIS)

Science.gov (United States)

El-Zoghby, Helmy M.; Bendary, Ahmed F.

2016-10-01

Maximum Power Point Tracking (MPPT) is now widely used method in increasing the photovoltaic (PV) efficiency. The conventional MPPT methods have many problems concerning the accuracy, flexibility and efficiency. The MPP depends on the PV temperature and solar irradiation that randomly varied. In this paper an artificial intelligence based controller is presented through implementing of an Adaptive Neuro-Fuzzy Inference System (ANFIS) to obtain maximum power from PV. The ANFIS inputs are the temperature and cell current, and the output is optimal voltage at maximum power. During operation the trained ANFIS senses the PV current using suitable sensor and also senses the temperature to determine the optimal operating voltage that corresponds to the current at MPP. This voltage is used to control the boost converter duty cycle. The MATLAB simulation results shows the effectiveness of the ANFIS with sensing the PV current in obtaining the MPPT from the PV.

PV inverter test setup for European efficiency, static and dynamic MPPT efficiency evaluation

DEFF Research Database (Denmark)

Sera, Dezso; Teodorescu, Remus; Valentini, Massimo

2008-01-01

This paper concerns the evaluation of performance of grid-connected PV inverters in terms of conversion efficiency, European efficiency, static and dynamic MPP efficiency. Semi-automated tests were performed in the PV laboratory of the Institute of Energy Technology at the Aalborg University...... (Denmark) on a commercial transformerless PV inverter. Thanks to the available experimental test setups, that provide the required high measuring accuracy, and the developed PV simulator, which is required for MPPT performance evaluation, PV Inverters can be pretested before being tested by accredited...

Vertex and Tracker Research and Development for CLIC

CERN Document Server

Munker, M

2017-01-01

Challenging detector requirements are imposed by the physics goals at the future multi-TeV e+e− Compact Linear Collider (CLIC). A single point resolution of 3 μm for the vertex detector and 7 μm for the tracker is required. Moreover, the CLIC vertex detector and tracker need to be extremely light weighted with a material budget of 0.2%X0 per layer in the vertex detector and 1 - 2%X0 in the tracker. A fast time slicing of 10 ns is further required to suppress background from beam-beam interactions. A wide range of sensor and readout ASIC technologies are investigated within the CLIC silicon pixel R&D; effort. Various hybrid planar sensor assemblies with a pixel size of 25 × 25 μm2 and 55 × 55 μm2 have been produced and characterised by laboratory measurements and during test-beam campaigns. Experimental and simulation results for thin (50 μm- 500 μm) slim edge and active-edge planar, and High-Voltage CMOS sensors hybridised to various readout ASICs (Timepix, Timepix3, CLICpix) are presented.

Experimental predictions drawn from a computational model of sign-trackers and goal-trackers.

Science.gov (United States)

Lesaint, Florian; Sigaud, Olivier; Clark, Jeremy J; Flagel, Shelly B; Khamassi, Mehdi

2015-01-01

Gaining a better understanding of the biological mechanisms underlying the individual variation observed in response to rewards and reward cues could help to identify and treat individuals more prone to disorders of impulsive control, such as addiction. Variation in response to reward cues is captured in rats undergoing autoshaping experiments where the appearance of a lever precedes food delivery. Although no response is required for food to be delivered, some rats (goal-trackers) learn to approach and avidly engage the magazine until food delivery, whereas other rats (sign-trackers) come to approach and engage avidly the lever. The impulsive and often maladaptive characteristics of the latter response are reminiscent of addictive behaviour in humans. In a previous article, we developed a computational model accounting for a set of experimental data regarding sign-trackers and goal-trackers. Here we show new simulations of the model to draw experimental predictions that could help further validate or refute the model. In particular, we apply the model to new experimental protocols such as injecting flupentixol locally into the core of the nucleus accumbens rather than systemically, and lesioning of the core of the nucleus accumbens before or after conditioning. In addition, we discuss the possibility of removing the food magazine during the inter-trial interval. The predictions from this revised model will help us better understand the role of different brain regions in the behaviours expressed by sign-trackers and goal-trackers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Intelligent robotic tracker

Science.gov (United States)

Otaguro, W. S.; Kesler, L. O.; Land, K. C.; Rhoades, D. E.

1987-01-01

An intelligent tracker capable of robotic applications requiring guidance and control of platforms, robotic arms, and end effectors has been developed. This packaged system capable of supervised autonomous robotic functions is partitioned into a multiple processor/parallel processing configuration. The system currently interfaces to cameras but has the capability to also use three-dimensional inputs from scanning laser rangers. The inputs are fed into an image processing and tracking section where the camera inputs are conditioned for the multiple tracker algorithms. An executive section monitors the image processing and tracker outputs and performs all the control and decision processes. The present architecture of the system is presented with discussion of its evolutionary growth for space applications. An autonomous rendezvous demonstration of this system was performed last year. More realistic demonstrations in planning are discussed.

Chaos Quantum-Behaved Cat Swarm Optimization Algorithm and Its Application in the PV MPPT

Directory of Open Access Journals (Sweden)

Xiaohua Nie

2017-01-01

Full Text Available Cat Swarm Optimization (CSO algorithm was put forward in 2006. Despite a faster convergence speed compared with Particle Swarm Optimization (PSO algorithm, the application of CSO is greatly limited by the drawback of “premature convergence,” that is, the possibility of trapping in local optimum when dealing with nonlinear optimization problem with a large number of local extreme values. In order to surmount the shortcomings of CSO, Chaos Quantum-behaved Cat Swarm Optimization (CQCSO algorithm is proposed in this paper. Firstly, Quantum-behaved Cat Swarm Optimization (QCSO algorithm improves the accuracy of the CSO algorithm, because it is easy to fall into the local optimum in the later stage. Chaos Quantum-behaved Cat Swarm Optimization (CQCSO algorithm is proposed by introducing tent map for jumping out of local optimum in this paper. Secondly, CQCSO has been applied in the simulation of five different test functions, showing higher accuracy and less time consumption than CSO and QCSO. Finally, photovoltaic MPPT model and experimental platform are established and global maximum power point tracking control strategy is achieved by CQCSO algorithm, the effectiveness and efficiency of which have been verified by both simulation and experiment.

Chaos Quantum-Behaved Cat Swarm Optimization Algorithm and Its Application in the PV MPPT.

Science.gov (United States)

Nie, Xiaohua; Wang, Wei; Nie, Haoyao

2017-01-01

Cat Swarm Optimization (CSO) algorithm was put forward in 2006. Despite a faster convergence speed compared with Particle Swarm Optimization (PSO) algorithm, the application of CSO is greatly limited by the drawback of "premature convergence," that is, the possibility of trapping in local optimum when dealing with nonlinear optimization problem with a large number of local extreme values. In order to surmount the shortcomings of CSO, Chaos Quantum-behaved Cat Swarm Optimization (CQCSO) algorithm is proposed in this paper. Firstly, Quantum-behaved Cat Swarm Optimization (QCSO) algorithm improves the accuracy of the CSO algorithm, because it is easy to fall into the local optimum in the later stage. Chaos Quantum-behaved Cat Swarm Optimization (CQCSO) algorithm is proposed by introducing tent map for jumping out of local optimum in this paper. Secondly, CQCSO has been applied in the simulation of five different test functions, showing higher accuracy and less time consumption than CSO and QCSO. Finally, photovoltaic MPPT model and experimental platform are established and global maximum power point tracking control strategy is achieved by CQCSO algorithm, the effectiveness and efficiency of which have been verified by both simulation and experiment.

Sliding Mode Extremum Seeking Control Scheme Based on PSO for Maximum Power Point Tracking in Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Her-Terng Yau

2013-01-01

Full Text Available An extremum seeking control (ESC scheme is proposed for maximum power point tracking (MPPT in photovoltaic power generation systems. The robustness of the proposed scheme toward irradiance changes is enhanced by implementing the ESC scheme using a sliding mode control (SMC law. In the proposed approach, the chattering phenomenon caused by high frequency switching is suppressed by means of a sliding layer concept. Moreover, in implementing the proposed controller, the optimal value of the gain constant is determined using a particle swarm optimization (PSO algorithm. The experimental and simulation results show that the proposed PSO-based sliding mode ESC (SMESC control scheme yields a better transient response, steady-state stability, and robustness than traditional MPPT schemes based on gradient detection methods.

Control Strategy of Two Capacitor Voltages for Separate MPPTs in Photovoltaic Systems Using Neutral-Point-Clamped Inverters

DEFF Research Database (Denmark)

Choi, Ui-Min; Blaabjerg, Frede; Lee, Kyo-Beum

2015-01-01

The centralized topology with three-level inverters are widely used in photovoltaic (PV) systems due to their less installation costs and complexity. However, the common maximum power point tracking (MPPT) is a disadvantage of the centralized topology particularly under the partial shading...... and panel mismatch conditions. In this system, if PV modules are separately connected to the split capacitor voltage, the MPPT efficiency can be improved by the proposed control strategy. By the proposed method, the two capacitor voltages can be controlled asymmetrically to perform the separate MPPTs...... of each PV module connected to separate capacitors. The outputs can be generated without distortion even if two capacitors are asymmetrically regulated. Simulation and experimental results verify the validity and feasibility of the proposed methods....

A silicon tracker for Christmas

CERN Multimedia

2008-01-01

The CMS experiment installed the world’s largest silicon tracker just before Christmas. Marcello Mannelli: physicist and deputy CMS project leader, and Alan Honma, physicist, compare two generations of tracker: OPAL for the LEP (at the front) and CMS for the LHC (behind). There is quite a difference between 1m2 and 205m2.. CMS received an early Christmas present on 18 December when the silicon tracker was installed in the heart of the CMS magnet. The CMS tracker team couldn’t have hoped for a better present. Carefully wrapped in shiny plastic, the world’s largest silicon tracker arrived at Cessy ready for installation inside the CMS magnet on 18 December. This rounded off the year for CMS with a major event, the crowning touch to ten years of work on the project by over five hundred scientists and engineers. "Building a scientific instrument of this size and complexity is a huge technical a...

First half of CMS inner tracker barrel

CERN Multimedia

Maximilien Brice

2006-01-01

The first half of the CMS inner tracker barrel is seen in this image consisting of three layers of silicon modules which will be placed at the centre of the CMS experiment at the LHC in CERN. Laying close to the interaction point of the 14 TeV proton-proton collisions, the silicon used here must be able to survive high doses of radiation and a 4 T magnetic field without damage.

The CMS Silicon Tracker Alignment

CERN Document Server

Castello, R

2008-01-01

The alignment of the Strip and Pixel Tracker of the Compact Muon Solenoid experiment, with its large number of independent silicon sensors and its excellent spatial resolution, is a complex and challenging task. Besides high precision mounting, survey measurements and the Laser Alignment System, track-based alignment is needed to reach the envisaged precision.\\\\ Three different algorithms for track-based alignment were successfully tested on a sample of cosmic-ray data collected at the Tracker Integration Facility, where 15\\% of the Tracker was tested. These results, together with those coming from the CMS global run, will provide the basis for the full-scale alignment of the Tracker, which will be carried out with the first \\emph{p-p} collisions.

MediaTracker system

Energy Technology Data Exchange (ETDEWEB)

Sandoval, D. M. (Dana M.); Strittmatter, R. B. (Richard B.); Abeyta, J. D. (Joline D.); Brown, J. (John); Marks, T. (Thomas), Jr.; Martinez, B. J. (Benny J.); Jones, D. B. (Dana Benelli); Hsue, W.

2004-01-01

The initial objectives of this effort were to provide a hardware and software platform that can address the requirements for the accountability of classified removable electronic media and vault access logging. The Media Tracker system software assists classified media custodian in managing vault access logging and Media Tracking to prevent the inadvertent violation of rules or policies for the access to a restricted area and the movement and use of tracked items. The MediaTracker system includes the software tools to track and account for high consequence security assets and high value items. The overall benefits include: (1) real-time access to the disposition of all Classified Removable Electronic Media (CREM), (2) streamlined security procedures and requirements, (3) removal of ambiguity and managerial inconsistencies, (4) prevention of incidents that can and should be prevented, (5) alignment with the DOE's initiative to achieve improvements in security and facility operations through technology deployment, and (6) enhanced individual responsibility by providing a consistent method of dealing with daily responsibilities. In response to initiatives to enhance the control of classified removable electronic media (CREM), the Media Tracker software suite was developed, piloted and implemented at the Los Alamos National Laboratory beginning in July 2000. The Media Tracker software suite assists in the accountability and tracking of CREM and other high-value assets. One component of the MediaTracker software suite provides a Laboratory-approved media tracking system. Using commercial touch screen and bar code technology, the MediaTracker (MT) component of the MediaTracker software suite provides an efficient and effective means to meet current Laboratory requirements and provides new-engineered controls to help assure compliance with those requirements. It also establishes a computer infrastructure at vault entrances for vault access logging, and can

MediaTracker system

International Nuclear Information System (INIS)

Sandoval, D.M.; Strittmatter, R.B.; Abeyta, J.D.; Brown, J.; Marks, T. Jr.; Martinez, B.J.; Jones, D.B.; Hsue, W.

2004-01-01

The initial objectives of this effort were to provide a hardware and software platform that can address the requirements for the accountability of classified removable electronic media and vault access logging. The Media Tracker system software assists classified media custodian in managing vault access logging and Media Tracking to prevent the inadvertent violation of rules or policies for the access to a restricted area and the movement and use of tracked items. The MediaTracker system includes the software tools to track and account for high consequence security assets and high value items. The overall benefits include: (1) real-time access to the disposition of all Classified Removable Electronic Media (CREM), (2) streamlined security procedures and requirements, (3) removal of ambiguity and managerial inconsistencies, (4) prevention of incidents that can and should be prevented, (5) alignment with the DOE's initiative to achieve improvements in security and facility operations through technology deployment, and (6) enhanced individual responsibility by providing a consistent method of dealing with daily responsibilities. In response to initiatives to enhance the control of classified removable electronic media (CREM), the Media Tracker software suite was developed, piloted and implemented at the Los Alamos National Laboratory beginning in July 2000. The Media Tracker software suite assists in the accountability and tracking of CREM and other high-value assets. One component of the MediaTracker software suite provides a Laboratory-approved media tracking system. Using commercial touch screen and bar code technology, the MediaTracker (MT) component of the MediaTracker software suite provides an efficient and effective means to meet current Laboratory requirements and provides new-engineered controls to help assure compliance with those requirements. It also establishes a computer infrastructure at vault entrances for vault access logging, and can accommodate

Neural Network Based Maximum Power Point Tracking Control with Quadratic Boost Converter for PMSG—Wind Energy Conversion System

Directory of Open Access Journals (Sweden)

Ramji Tiwari

2018-02-01

Full Text Available This paper proposes an artificial neural network (ANN based maximum power point tracking (MPPT control strategy for wind energy conversion system (WECS implemented with a DC/DC converter. The proposed topology utilizes a radial basis function network (RBFN based neural network control strategy to extract the maximum available power from the wind velocity. The results are compared with a classical Perturb and Observe (P&O method and Back propagation network (BPN method. In order to achieve a high voltage rating, the system is implemented with a quadratic boost converter and the performance of the converter is validated with a boost and single ended primary inductance converter (SEPIC. The performance of the MPPT technique along with a DC/DC converter is demonstrated using MATLAB/Simulink.

Comparison of Extremum-Seeking Control Techniques for Maximum Power Point Tracking in Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Chen-Han Wu

2011-12-01

Full Text Available Due to Japan’s recent nuclear crisis and petroleum price hikes, the search for renewable energy sources has become an issue of immediate concern. A promising candidate attracting much global attention is solar energy, as it is green and also inexhaustible. A maximum power point tracking (MPPT controller is employed in such a way that the output power provided by a photovoltaic (PV system is boosted to its maximum level. However, in the context of abrupt changes in irradiance, conventional MPPT controller approaches suffer from insufficient robustness against ambient variation, inferior transient response and a loss of output power as a consequence of the long duration required of tracking procedures. Accordingly, in this work the maximum power point tracking is carried out successfully using a sliding mode extremum-seeking control (SMESC method, and the tracking performances of three controllers are compared by simulations, that is, an extremum-seeking controller, a sinusoidal extremum-seeking controller and a sliding mode extremum-seeking controller. Being able to track the maximum power point promptly in the case of an abrupt change in irradiance, the SMESC approach is proven by simulations to be superior in terms of system dynamic and steady state responses, and an excellent robustness along with system stability is demonstrated as well.

An accuracy measurement method for star trackers based on direct astronomic observation.

Science.gov (United States)

Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

2016-03-07

Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.

ATLAS semiconductor tracker installed into its barrel

CERN Multimedia

Maximilien Brice

2005-01-01

The ATLAS silicon tracker is installed in the silicon tracker barrel. Absolute precision was required in this operation to ensure that the tracker was inserted without damage through minimal clearance. The installation was performed in a clean room on the CERN site so that no impurities in the air would contaminate the tracker's systems.

Modeling and Design of MPPT Controller Using Stepped P&O Algorithm in Solar Photovoltaic System

OpenAIRE

R. Prakash; B. Meenakshipriya; R. Kumaravelan

2014-01-01

This paper presents modeling and simulation of Grid Connected Photovoltaic (PV) system by using improved mathematical model. The model is used to study different parameter variations and effects on the PV array including operating temperature and solar irradiation level. In this paper stepped P&O algorithm is proposed for MPPT control. This algorithm will identify the suitable duty ratio in which the DC-DC converter should be operated to maximize the power output. Photo voltaic array with pro...

Comparative analysis of fixed and sun tracking low power PV systems considering energy consumption

International Nuclear Information System (INIS)

Lazaroiu, George Cristian; Longo, Michela; Roscia, Mariacristina; Pagano, Mario

2015-01-01

Highlights: • Photovoltaic system prototype with sun tracking. • Energy analysis of fixed and sun tracking built prototypes. • Experimental tests in different environmental conditions. • Theoretical and experimental validation of the prototype. - Abstract: Photovoltaic technology allows to directly convert solar energy into electrical energy with clear advantages: no environmental impact during operation, reliability and durability of the systems, reduced operating costs and maintenance, ability to both supply remote customers and simply connect to the electrical network. This paper evaluates the performance of two photovoltaic systems: one fixed and one equipped with a sun tracker. The objective of this research is to analyze the increase of daily produced energy by using the sun tracking system. The analysis accounts also the energy consumption of the sun tracker. An analytical approach is proposed. To validate the results through experimental tests, two alternative low power PV systems were built. Each system consists of a PV source, a MPPT (Maximum Power Point Tracker) power converter and a 12 V–40 A h electrochemical battery, which is used as electric load. The sun tracker system evidenced an important growth of power production during morning and evening

TRACKER

CERN Multimedia

K. Gill and G. Bolla

2010-01-01

Silicon strips During the first collisions the strip-Tracker operated with excellent performance and stability. The results obtained were very impressive and this exciting experience marked a fine end to another intense year. Several issues were identified during 2009 operations that could benefit from improvement: to suppress the increased output data volume when in STANDBY state (LV ON, HV OFF), which is due to the larger noise amplitudes when the sensors are unbiased; to reduce the strips configuration time; to increase the stability of the power system, particularly during state transitions, and to decrease the powering up time. The strip-Tracker FEDs now react to changes in the HV conditions of the strips. Upon a transition to STAND-BY, central DAQ starts a PAUSE-RESUME cycle and a flag is issued to the FEDSupervisor. This results in forcing the common mode noise artificially to the maximum value, which effectively suppresses the analogue data output. This forced offset is removed as soon as the strips ...

The CMS tracker calibration workflow: Experience with cosmic ray data

International Nuclear Information System (INIS)

Frosali, Simone

2010-01-01

During the second part of 2008 a CMS commissioning was performed with the acquisition of cosmic events in global runs. Cosmic rays detected in the muon chambers were used to trigger the readout of all CMS subdetectors in the general data acquisition system. A total of about 300M of tracks were collected by the CMS Muon Chambers with a 3.8T magnetic field produced by the CMS superconducting solenoid, 6M of which pointing to the tracker region and reconstructed by the Si-Strip Tracker (SST) detectors. Other 1M of cosmic tracks were collected with the magnetic field off. Using the cosmic data available it was possible to validate the performances of the CMS tracker calibration workflows. In this paper the adopted calibration workflow is described. In particular, the three main calibration workflows requested for the low level reconstruction of the SST, i.e. gain calibration, Lorentz angle calibration and bad components identification, are described. The results obtained using cosmic tracks for these three calibration workflows are also presented.

Intelligent Maximum Power Point Tracking Using Fuzzy Logic for Solar Photovoltaic Systems Under Non-Uniform Irradiation Conditions

OpenAIRE

P. Selvam; S. Senthil Kumar

2016-01-01

Maximum Power Point Tracking (MPPT) has played a vital role to enhance the efficiency of solar photovoltaic (PV) power generation under varying atmospheric temperature and solar irradiation. However, it is hard to track the maximum power point using conventional linear controllers due to the natural inheritance of nonlinear I-V and P-V characteristics of solar PV systems. Fuzzy Logic Controller (FLC) is suitable for nonlinear system control applications and eliminating oscillations, circuit c...

Silicon vertex tracker for RHIC PHENIX experiment

Energy Technology Data Exchange (ETDEWEB)

Taketani, A [RIKEN, Nishina Ctr Accelerator Based Sci, Wako, Saitama, Japan; Cianciolo, Vince [ORNL; Enokizono, Akitomo [Oak Ridge National Laboratory (ORNL); PHENIX, Collaboration [The

2010-01-01

The PHENIX experiment at Relativistic Heavy Ion Collider will be equipped with Silicon Vertex tracker to enhance its physics capability. There are four layers of silicon sensor to reconstruct charged tracks with 50 {micro}m resolution of decay length measurement. The VTX surrounds the collision point. The inner two layers and the outer two layers are composed of 30 pixel ladders and 44 stripixel ladders, respectively. We have been developing these detectors and done a performance test with 120 GeV proton beam.

Maximum Power Point Tracking Using Sliding Mode Control for Photovoltaic Array

Directory of Open Access Journals (Sweden)

J. Ghazanfari

2013-09-01

Full Text Available In this paper, a robust Maximum Power Point Tracking (MPPT for PV array has been proposed using sliding mode control by defining a new formulation for sliding surface which is based on increment conductance (INC method. The stability and robustness of the proposed controller are investigated to load variations and environment changes. Three different types of DC-DC converter are used in Maximum Power Point (MPP system and the results obtained are given. The simulation results confirm the effectiveness of the proposed method in the presence of load variations and environment changes for different types of DC-DC converter topologies.

Mechanical stability of the CMS Tracker

CERN Document Server

CMS Collaboration

2015-01-01

reconstructs the absolute position of individual detector modules with a similar accuracy but after days of data taking. During the long term operation at fixed temperature of +4$^o$C in years 2011--2013 the alignment of tracker components was stable within 10 microns. Temperature variations in the Tracker volume are found to cause the displacements of tracker structures of abou...

Time-Of-Flight Camera, Optical Tracker and Computed Tomography in Pairwise Data Registration.

Directory of Open Access Journals (Sweden)

Bartlomiej Pycinski

Full Text Available A growing number of medical applications, including minimal invasive surgery, depends on multi-modal or multi-sensors data processing. Fast and accurate 3D scene analysis, comprising data registration, seems to be crucial for the development of computer aided diagnosis and therapy. The advancement of surface tracking system based on optical trackers already plays an important role in surgical procedures planning. However, new modalities, like the time-of-flight (ToF sensors, widely explored in non-medical fields are powerful and have the potential to become a part of computer aided surgery set-up. Connection of different acquisition systems promises to provide a valuable support for operating room procedures. Therefore, the detailed analysis of the accuracy of such multi-sensors positioning systems is needed.We present the system combining pre-operative CT series with intra-operative ToF-sensor and optical tracker point clouds. The methodology contains: optical sensor set-up and the ToF-camera calibration procedures, data pre-processing algorithms, and registration technique. The data pre-processing yields a surface, in case of CT, and point clouds for ToF-sensor and marker-driven optical tracker representation of an object of interest. An applied registration technique is based on Iterative Closest Point algorithm.The experiments validate the registration of each pair of modalities/sensors involving phantoms of four various human organs in terms of Hausdorff distance and mean absolute distance metrics. The best surface alignment was obtained for CT and optical tracker combination, whereas the worst for experiments involving ToF-camera.The obtained accuracies encourage to further develop the multi-sensors systems. The presented substantive discussion concerning the system limitations and possible improvements mainly related to the depth information produced by the ToF-sensor is useful for computer aided surgery developers.

Small star trackers for modern space vehicles

Science.gov (United States)

Kouzmin, Vladimir; Jushkov, Vladimir; Zaikin, Vladimir

2017-11-01

Based on experience of many years creation of spacecrafts' star trackers with diversified detectors (from the first star trackers of 60's to tens versions of star trackers in the following years), using technological achievements in the field of optics and electronics the NPP "Geofizika-Cosmos" has provided celestial orientation for all the space vehicles created in Russia and now has developed a series of new star trackers with CCD matrix and special processors, which are able to meet needs in celestial orientation of the modern spacecrafts for the nearest 10-15 years. In the given article the main characteristics and description of some star trackers' versions are presented. The star trackers have various levels of technical characteristics and use both combined (Russian and foreign) procurement parts, and only national (Russian) procurement parts for the main units.

Study of Stand-Alone Microgrid under Condition of Faults on Distribution Line

Science.gov (United States)

Malla, S. G.; Bhende, C. N.

2014-10-01

The behavior of stand-alone microgrid is analyzed under the condition of faults on distribution feeders. During fault since battery is not able to maintain dc-link voltage within limit, the resistive dump load control is presented to do so. An inverter control is proposed to maintain balanced voltages at PCC under the unbalanced load condition and to reduce voltage unbalance factor (VUF) at load points. The proposed inverter control also has facility to protect itself from high fault current. Existing maximum power point tracker (MPPT) algorithm is modified to limit the speed of generator during fault. Extensive simulation results using MATLAB/SIMULINK established that the performance of the controllers is quite satisfactory under different fault conditions as well as unbalanced load conditions.

Biaxial Solar Tracking System Based on the MPPT Approach Integrating ICTs for Photovoltaic Applications

Directory of Open Access Journals (Sweden)

Raúl Gregor

2015-01-01

Full Text Available The smart grid and distributed generation based on renewable energy applications often involve the use of information and communication technology (ICT coupled with advanced control and monitoring algorithms to improve the efficiency and reliability of the electrical grid and renewable generation systems. Photovoltaic (PV systems have been recently applied with success in the fields of distributed generation due to their lower environmental impact where the electrical energy generation is related to the amount of solar irradiation and thus the angle of incident ray of the sun on the surface of the modules. This paper introduces an integration of ICTs in order to achieve the maximum power point tracking (MPPT using a biaxial solar tracking system for PV power applications. To generate the references for the digital control of azimuth and elevation angles a Global Positioning System (GPS by satellites is used which enables acquiring the geographic coordinates of the sun in real-time. As a total integration of the system a communication platform based on the 802.15.4 protocol for the wireless sensor networks (WSNs is adopted for supervising and monitoring the PV plant. A 2.4 kW prototype system is implemented to validate the proposed control scheme performance.

Status of the KLOE-2 Inner Tracker

Directory of Open Access Journals (Sweden)

De Lucia Erika

2018-01-01

Full Text Available KLOE-2 at the DAΦNE Φ-factory is the main experiment of the INFN Laboratori Nazionali di Frascati (LNF and is the first high-energy experiment using the GEM technology with a cylindrical geometry, a novel idea developed at LNF. Four concentric cylindrical triple-GEM detectors compose the Inner Tracker, inserted around the interaction region and before the inner wall of the pre-existing KLOE Drift Chamber to improve the resolution on decay vertices close to the interaction point. State-of-the-art solutions have been expressly developed or tuned for this project: single-mask GEM etching, multi-layer XV patterned readout, PEEK spacer grid, GASTONE front-end board, a custom 64-channel ASIC with digital output, and the Global Interface Board for data collection, with a configurable FPGA architecture and Gigabit Ethernet. Alignment and calibration of a cylindrical GEM detector was never done before and represents one of the challenging activities of the experiment. The Inner Tracker detector construction, operation, calibration and performance obtained with cosmic-ray muons and Bhabha scattering events will be reported.

Status of the KLOE-2 Inner Tracker

Science.gov (United States)

De Lucia, Erika

2018-01-01

KLOE-2 at the DAΦNE Φ-factory is the main experiment of the INFN Laboratori Nazionali di Frascati (LNF) and is the first high-energy experiment using the GEM technology with a cylindrical geometry, a novel idea developed at LNF. Four concentric cylindrical triple-GEM detectors compose the Inner Tracker, inserted around the interaction region and before the inner wall of the pre-existing KLOE Drift Chamber to improve the resolution on decay vertices close to the interaction point. State-of-the-art solutions have been expressly developed or tuned for this project: single-mask GEM etching, multi-layer XV patterned readout, PEEK spacer grid, GASTONE front-end board, a custom 64-channel ASIC with digital output, and the Global Interface Board for data collection, with a configurable FPGA architecture and Gigabit Ethernet. Alignment and calibration of a cylindrical GEM detector was never done before and represents one of the challenging activities of the experiment. The Inner Tracker detector construction, operation, calibration and performance obtained with cosmic-ray muons and Bhabha scattering events will be reported.

LHCb: The LHCb Silicon Tracker: Running experience

CERN Multimedia

Saornil Gamarra, S

2012-01-01

The LHCb Silicon Tracker is part of the main tracking system of the LHCb detector at the LHC. It measures very precisely the particle trajectories coming from the interaction point in the region of high occupancies around the beam axis. After presenting our production and comissioning issues in TWEPP 2008, we report on our running experience. Focusing on electronic and hardware issues as well as operation and maintenance adversities, we describe the lessons learned and the pitfalls encountered after three years of successful operation.

TRACKER

CERN Multimedia

K. Gill

2010-01-01

The Tracker has continued to operate with excellent performance during this first period with 7 TeV collisions. Strips operations have been very smooth. The up-time during collisions was 98.5%, up to end of May, with a large fraction of the down-time coming during the planned fine-timing scan with early 7 TeV collisions. Pixels operations are also going very well, besides problems related to background beam-gas collisions where the particles produced generate very large clusters in the barrel modules. When CMS triggers on these events, the FEDs affected overflow and then timeout. Effort was mobilised very quickly to understand and mitigate this problem, with modifications made to the pixel FED firmware in order to provide automatic recovery. With operations becoming more and more routine at P5, Pixels have begun the transition to centrally attended operation, which means that the P5 shifters will no longer be required to be on duty. The strip-Tracker is also planning to make this transition at the end of Ju...

Scintillating fibre (SciFi) tracker

CERN Multimedia

Caraban Gonzalez, Noemi

2017-01-01

128 modules – containing 11 000 km of scintillating fibres – will make up the new SciFi tracker, which will replace the outer and inner trackers of the LHCb detector as part of the experiment’s major upgrade during Long Shutdown 2 (LS2)

The MICE scintillating-fibre tracker

Energy Technology Data Exchange (ETDEWEB)

Matsushita, T [Imperial College London (United Kingdom)], E-mail: T.Matsushita@imperial.ac.uk

2008-06-15

The international Muon Ionization Cooling Experiment (MICE) collaboration will carry out a systematic investigation of the ionization cooling of a muon beam. An ionization cooling channel is required to compress the phase-space volume occupied by the muon beam prior to acceleration in the baseline conceptual designs for both the Neutrino Factory and the Muon Collider. Muons entering and leaving the cooling channel will be measured in two solenoidal spectrometers, each of which is instrumented with a scintillating-fibre tracker. Each tracker is composed of five planar scintillating fibre stations, each station being composed of three planar layers of 350 micron scintillating fibres. The devices will be read out using the Visible Light Photon Counters (VLPCs) developed for use in the D0 experiment at the Tevatron. The design of the system will be presented along with the status of the tracker-construction project. The expected performance of prototypes of the full tracker will be summarised.

Different types of maximum power point tracking techniques for renewable energy systems: A survey

Science.gov (United States)

Khan, Mohammad Junaid; Shukla, Praveen; Mustafa, Rashid; Chatterji, S.; Mathew, Lini

2016-03-01

Global demand for electricity is increasing while production of energy from fossil fuels is declining and therefore the obvious choice of the clean energy source that is abundant and could provide security for development future is energy from the sun. In this paper, the characteristic of the supply voltage of the photovoltaic generator is nonlinear and exhibits multiple peaks, including many local peaks and a global peak in non-uniform irradiance. To keep global peak, MPPT is the important component of photovoltaic systems. Although many review articles discussed conventional techniques such as P & O, incremental conductance, the correlation ripple control and very few attempts have been made with intelligent MPPT techniques. This document also discusses different algorithms based on fuzzy logic, Ant Colony Optimization, Genetic Algorithm, artificial neural networks, Particle Swarm Optimization Algorithm Firefly, Extremum seeking control method and hybrid methods applied to the monitoring of maximum value of power at point in systems of photovoltaic under changing conditions of irradiance.

Control strategy of grid-connected photovoltaic generation system based on GMPPT method

Science.gov (United States)

Wang, Zhongfeng; Zhang, Xuyang; Hu, Bo; Liu, Jun; Li, Ligang; Gu, Yongqiang; Zhou, Bowen

2018-02-01

There are multiple local maximum power points when photovoltaic (PV) array runs under partial shading condition (PSC).However, the traditional maximum power point tracking (MPPT) algorithm might be easily trapped in local maximum power points (MPPs) and cannot find the global maximum power point (GMPP). To solve such problem, a global maximum power point tracking method (GMPPT) is improved, combined with traditional MPPT method and particle swarm optimization (PSO) algorithm. Under different operating conditions of PV cells, different tracking algorithms are used. When the environment changes, the improved PSO algorithm is adopted to realize the global optimal search, and the variable step incremental conductance (INC) method is adopted to achieve MPPT in optimal local location. Based on the simulation model of the PV grid system built in Matlab/Simulink, comparative analysis of the tracking effect of MPPT by the proposed control algorithm and the traditional MPPT method under the uniform solar condition and PSC, validate the correctness, feasibility and effectiveness of the proposed control strategy.

Sizing modelling and simulation of PV generation system feeding a 6 MW induction motor dedicated to pumping applications

Directory of Open Access Journals (Sweden)

Samir HADJERI

2017-06-01

Full Text Available This paper proposes an autonomous photovoltaic (PV pumping system for rural/remote applications especially in the large desert in northern Africa where the sun radiation is abundant. Since PV generators exhibit nonlinear I-V characteristics and their maximum power point varies with solar radiation. For this reason, the MPPT controller is used to optimize the solar energy conversion by guaranteeing fast maximum power point tracking (MPPT. This feature has an essential role in dynamic response and efficiency of the photovoltaic system, thus it maximizes the amount of extracted natural gas to be conveyed to another site for an ulterior utilization. Here a robust maximum power point tracker (MPPT using incremental conductance algorithm is applied to the duty cycle value of the DC-DC converter which acts directly on the drive speed. A DC/DC boost is used to enhance voltage up to the favourite level and the SVPWM inverter connects it to a powerful induction motor for a pumping of natural gas application, these systems are at the heart of many industrial sectors such as the oil industry, the production of thermal and nuclear energy etc. An understanding of how these systems operate is essential to increase their performance and reduce their operating costs. Furthermore, three phase voltage-fed PWM inverters are recently showing growing popularity for multi-megawatt industrial drive applications, the main purpose of these topologies is to provide a three-phase voltage source, where the amplitude, phase, and frequency of the voltages should always be controllable. The model of a three-phase voltage source inverter is modelled and discussed based on space vector modulation theory. Simulation results are obtained using MATLAB/Simulink environment for effectiveness of the proposed system.

Silicon Tracker Design for the ILC

International Nuclear Information System (INIS)

Nelson, T.; SLAC

2005-01-01

The task of tracking charged particles in energy frontier collider experiments has been largely taken over by solid-state detectors. While silicon microstrip trackers offer many advantages in this environment, large silicon trackers are generally much more massive than their gaseous counterparts. Because of the properties of the machine itself, much of the material that comprises a typical silicon microstrip tracker can be eliminated from a design for the ILC. This realization is the inspiration for a tracker design using lightweight, short, mass-producible modules to tile closed, nested cylinders with silicon microstrips. This design relies upon a few key technologies to provide excellent performance with low cost and complexity. The details of this concept are discussed, along with the performance and status of the design effort

Extended Kalman Filtering to estimate temperature and irradiation for maximum power point tracking of a photovoltaic module

International Nuclear Information System (INIS)

Docimo, D.J.; Ghanaatpishe, M.; Mamun, A.

2017-01-01

This paper develops an algorithm for estimating photovoltaic (PV) module temperature and effective irradiation level. The power output of a PV system depends directly on both of these states. Estimating the temperature and irradiation allows for improved state-based control methods while eliminating the need of additional sensors. Thermal models and irradiation estimators have been developed in the literature, but none incorporate feedback for estimation. This paper outlines an Extended Kalman Filter for temperature and irradiation estimation. These estimates are, in turn, used within a novel state-based controller that tracks the maximum power point of the PV system. Simulation results indicate this state-based controller provides up to an 8.5% increase in energy produced per day as compared to an impedance matching controller. A sensitivity analysis is provided to examine the impact state estimate errors have on the ability to find the optimal operating point of the PV system. - Highlights: • Developed a temperature and irradiation estimator for photovoltaic systems. • Designed an Extended Kalman Filter to handle model and measurement uncertainty. • Developed a state-based controller for maximum power point tracking (MPPT). • Validated combined estimator/controller algorithm for different weather conditions. • Algorithm increases energy captured up to 8.5% over traditional MPPT algorithms.

Uncertainty estimation and multi sensor fusion for kinematic laser tracker measurements

Science.gov (United States)

Ulrich, Thomas

2013-08-01

Laser trackers are widely used to measure kinematic tasks such as tracking robot movements. Common methods to evaluate the uncertainty in the kinematic measurement include approximations specified by the manufacturers, various analytical adjustment methods and the Kalman filter. In this paper a new, real-time technique is proposed, which estimates the 4D-path (3D-position + time) uncertainty of an arbitrary path in space. Here a hybrid system estimator is applied in conjunction with the kinematic measurement model. This method can be applied to processes, which include various types of kinematic behaviour, constant velocity, variable acceleration or variable turn rates. The new approach is compared with the Kalman filter and a manufacturer's approximations. The comparison was made using data obtained by tracking an industrial robot's tool centre point with a Leica laser tracker AT901 and a Leica laser tracker LTD500. It shows that the new approach is more appropriate to analysing kinematic processes than the Kalman filter, as it reduces overshoots and decreases the estimated variance. In comparison with the manufacturer's approximations, the new approach takes account of kinematic behaviour with an improved description of the real measurement process and a reduction in estimated variance. This approach is therefore well suited to the analysis of kinematic processes with unknown changes in kinematic behaviour as well as the fusion among laser trackers.

30 March 2009 - Representatives of the Danish Council for Independent Research Natural Sciences visiting the LHC tunnel at Point 1 with Collaboration Spokesperson F. Gianotti, Former Spokesperson P. Jenni and Transition Radiation Tracker Project Leader C. Rembser.

CERN Document Server

Maximilien Brice

2009-01-01

30 March 2009 - Representatives of the Danish Council for Independent Research Natural Sciences visiting the LHC tunnel at Point 1 with Collaboration Spokesperson F. Gianotti, Former Spokesperson P. Jenni and Transition Radiation Tracker Project Leader C. Rembser.

On-Orbit Solar Dynamics Observatory (SDO) Star Tracker Warm Pixel Analysis

Science.gov (United States)

Felikson, Denis; Ekinci, Matthew; Hashmall, Joseph A.; Vess, Melissa

2011-01-01

This paper describes the process of identification and analysis of warm pixels in two autonomous star trackers on the Solar Dynamics Observatory (SDO) mission. A brief description of the mission orbit and attitude regimes is discussed and pertinent star tracker hardware specifications are given. Warm pixels are defined and the Quality Index parameter is introduced, which can be explained qualitatively as a manifestation of a possible warm pixel event. A description of the algorithm used to identify warm pixel candidates is given. Finally, analysis of dumps of on-orbit star tracker charge coupled devices (CCD) images is presented and an operational plan going forward is discussed. SDO, launched on February 11, 2010, is operated from the NASA Goddard Space Flight Center (GSFC). SDO is in a geosynchronous orbit with a 28.5 inclination. The nominal mission attitude points the spacecraft X-axis at the Sun, with the spacecraft Z-axis roughly aligned with the Solar North Pole. The spacecraft Y-axis completes the triad. In attitude, SDO moves approximately 0.04 per hour, mostly about the spacecraft Z-axis. The SDO star trackers, manufactured by Galileo Avionica, project the images of stars in their 16.4deg x 16.4deg fields-of-view onto CCD detectors consisting of 512 x 512 pixels. The trackers autonomously identify the star patterns and provide an attitude estimate. Each unit is able to track up to 9 stars. Additionally, each tracker calculates a parameter called the Quality Index, which is a measure of the quality of the attitude solution. Each pixel in the CCD measures the intensity of light and a warns pixel is defined as having a measurement consistently and significantly higher than the mean background intensity level. A warns pixel should also have lower intensity than a pixel containing a star image and will not move across the field of view as the attitude changes (as would a dim star image). It should be noted that the maximum error introduced in the star tracker

Star point centroid algorithm based on background forecast

Science.gov (United States)

Wang, Jin; Zhao, Rujin; Zhu, Nan

2014-09-01

The calculation of star point centroid is a key step of improving star tracker measuring error. A star map photoed by APS detector includes several noises which have a great impact on veracity of calculation of star point centroid. Through analysis of characteristic of star map noise, an algorithm of calculation of star point centroid based on background forecast is presented in this paper. The experiment proves the validity of the algorithm. Comparing with classic algorithm, this algorithm not only improves veracity of calculation of star point centroid, but also does not need calibration data memory. This algorithm is applied successfully in a certain star tracker.

LHCb upstream tracker

CERN Multimedia

Artuso, Marina

2016-01-01

The detector for the LHCb upgrade is designed for 40MHz readout, allowing the experiment to run at an instantaneous luminosity of 2x10^33 cm$^2$s$^-1$. The upgrade of the tracker subsystem in front of the dipole magnet, the Upstream Tracker, is crucial for charged track reconstruction and fast trigger decisions based on a tracking algorithm involving also vertex detector information. The detector consists of 4 planes with a total area of about 8.5m$^2$, made of single sided silicon strip sensors read-out by a novel custom-made ASIC (SALT). Details on the performance of prototype sensors, front-end electronics, near-detector electronics and mechanical components are presented.

CMS Tracker Visualisation

CERN Document Server

Mennea, Maria Santa; Zito, Giuseppe

2004-01-01

To provide improvements in the performance of existing tracker data visualization tools in IGUANA, a 2D visualisation software has been developed, using the object oriented paradigm and software engineering techniques. We have designed 2D graphics objects and some of them have been implemented. The access to the new objects is made in ORCA plugin of IGUANA CMS. A new tracker object oriented model has been designed for developing these 2D graphics objects. The model consists of new classes which represent all its components (layers, modules, rings, petals, rods).The new classes are described here. The last part of this document contains a user manual of the software and will be updated with new releases.

CMS silicon tracker developments

International Nuclear Information System (INIS)

Civinini, C.; Albergo, S.; Angarano, M.; Azzi, P.; Babucci, E.; Bacchetta, N.; Bader, A.; Bagliesi, G.; Basti, A.; Biggeri, U.; Bilei, G.M.; Bisello, D.; Boemi, D.; Bosi, F.; Borrello, L.; Bozzi, C.; Braibant, S.; Breuker, H.; Bruzzi, M.; Buffini, A.; Busoni, S.; Candelori, A.; Caner, A.; Castaldi, R.; Castro, A.; Catacchini, E.; Checcucci, B.; Ciampolini, P.; Creanza, D.; D'Alessandro, R.; Da Rold, M.; Demaria, N.; De Palma, M.; Dell'Orso, R.; Della Marina, R.D.R.; Dutta, S.; Eklund, C.; Feld, L.; Fiore, L.; Focardi, E.; French, M.; Freudenreich, K.; Frey, A.; Fuertjes, A.; Giassi, A.; Giorgi, M.; Giraldo, A.; Glessing, B.; Gu, W.H.; Hall, G.; Hammarstrom, R.; Hebbeker, T.; Honma, A.; Hrubec, J.; Huhtinen, M.; Kaminsky, A.; Karimaki, V.; Koenig, St.; Krammer, M.; Lariccia, P.; Lenzi, M.; Loreti, M.; Luebelsmeyer, K.; Lustermann, W.; Maettig, P.; Maggi, G.; Mannelli, M.; Mantovani, G.; Marchioro, A.; Mariotti, C.; Martignon, G.; Evoy, B. Mc; Meschini, M.; Messineo, A.; Migliore, E.; My, S.; Paccagnella, A.; Palla, F.; Pandoulas, D.; Papi, A.; Parrini, G.; Passeri, D.; Pieri, M.; Piperov, S.; Potenza, R.; Radicci, V.; Raffaelli, F.; Raymond, M.; Santocchia, A.; Schmitt, B.; Selvaggi, G.; Servoli, L.; Sguazzoni, G.; Siedling, R.; Silvestris, L.; Starodumov, A.; Stavitski, I.; Stefanini, G.; Surrow, B.; Tempesta, P.; Tonelli, G.; Tricomi, A.; Tuuva, T.; Vannini, C.; Verdini, P.G.; Viertel, G.; Xie, Z.; Yahong, Li; Watts, S.; Wittmer, B.

2002-01-01

The CMS Silicon tracker consists of 70 m 2 of microstrip sensors which design will be finalized at the end of 1999 on the basis of systematic studies of device characteristics as function of the most important parameters. A fundamental constraint comes from the fact that the detector has to be operated in a very hostile radiation environment with full efficiency. We present an overview of the current results and prospects for converging on a final set of parameters for the silicon tracker sensors

Model of CMS Tracker

CERN Multimedia

Breuker

1999-01-01

A full scale CMS tracker mock-up exposed temporarily in the hall of building 40. The purpose of the mock-up is to study the routing of services, assembly and installation. The people in front are only a small fraction of the CMS tracker collaboration. Left to right : M. Atac, R. Castaldi, H. Breuker, D. Pandoulas,P. Petagna, A. Caner, A. Carraro, H. Postema, M. Oriunno, S. da Mota Silva, L. Van Lancker, W. Glessing, G. Benefice, A. Onnela, M. Gaspar, G. M. Bilei

ColorTracker

NARCIS (Netherlands)

Holzheu, Stefanie; Lee, S.; Herneoja, Aulikki; Österlund, Toni; Markkanen, Piia

2016-01-01

With the work-in-progress research project ColorTracker we explore color as a formal design tool. This project-based paper describes a novel software application that processes color composition of a place and transcribes the data into three-dimensional geometries for architectural design. The

Laser tracker error determination using a network measurement

International Nuclear Information System (INIS)

Hughes, Ben; Forbes, Alistair; Lewis, Andrew; Sun, Wenjuan; Veal, Dan; Nasr, Karim

2011-01-01

We report on a fast, easily implemented method to determine all the geometrical alignment errors of a laser tracker, to high precision. The technique requires no specialist equipment and can be performed in less than an hour. The technique is based on the determination of parameters of a geometric model of the laser tracker, using measurements of a set of fixed target locations, from multiple locations of the tracker. After fitting of the model parameters to the observed data, the model can be used to perform error correction of the raw laser tracker data or to derive correction parameters in the format of the tracker manufacturer's internal error map. In addition to determination of the model parameters, the method also determines the uncertainties and correlations associated with the parameters. We have tested the technique on a commercial laser tracker in the following way. We disabled the tracker's internal error compensation, and used a five-position, fifteen-target network to estimate all the geometric errors of the instrument. Using the error map generated from this network test, the tracker was able to pass a full performance validation test, conducted according to a recognized specification standard (ASME B89.4.19-2006). We conclude that the error correction determined from the network test is as effective as the manufacturer's own error correction methodologies

The CMS Tracker upgrade for HL-LHC

CERN Document Server

Ahuja, Sudha

2017-01-01

The LHC machine is planning an upgrade program which will smoothly bring the luminosity to about 5 $\\times$ $10^{34} $cm$^{-2}$s$^{-1}$ in 2028, to possibly reach an integrated luminosity of 3000 fb$^{-1}$ by the end of 2037. This High Luminosity LHC scenario, HL-LHC, will require a preparation program of the LHC detectors known as Phase-2 upgrade. The current CMS Outer Tracker, already running beyond design specifications, and CMS Phase1 Pixel Detector will not be able to survive HL-LHC radiation conditions and CMS will need completely new devices, in order to fully exploit the high-demanding operating conditions and the delivered luminosity. The new Outer Tracker should have also trigger capabilities. To achieve such goals, R$\\&$D activities are ongoing to explore options both for the Outer Tracker, and for the pixel Inner Tracker. Solutions are being developed that would allow including tracking information at Level-1. The design choices for the Tracker upgrades are discussed along with some highlights...

The LHCb Silicon Tracker, first operational results

CERN Document Server

Esperante, D; Adeva, B; Gallas, A; Pérez Trigo, E; Rodríguez Pérez, P; Pazos Álvarez, A; Saborido, J; Vàzquez, P; Bay, A; Bettler, M O; Blanc, F; Bressieux, J; Conti, G; Dupertuis, F; Fave, V; Frei, R; Gauvin, N; Haefeli, G; Keune, A; Luisier, J; Muresan, R; Nakada, T; Needham, M; Nicolas, L; Knecht, M; Potterat, C; Schneider, O; Tran, M; Aquines Gutierrez, O; Bauer, C; Britsch, M; Hofmann, W; Maciuc, F; Schmelling, M; Voss, H; Anderson, J; Buechler, A; Bursche, A; Chiapolini, N; de Cian, M; Elsaesser, C; Hangartner, V; Salzmann, C; Steiner, S; Steinkamp, O; Straumann, U; van Tilburg, J; Tobin, M; Vollhardt, A; Iakovenko, V; Okhrimenko, O; Pugatch, V

2010-01-01

The Large Hadron Collider beauty (LHCb) experiment at CERN (Conseil Européen pour la Recherche Nucléaire) is designed to perform precision measurements of b quark decays. The LHCb Silicon Tracker consists of two sub-detectors, the Tracker Turicensis and the Inner Tracker, which are built from silicon micro-strip technology. First performance results of both detectors using data from Large Hadron Collider synchronization tests are presented.

Design and implementation of a microcontroller-based maximum power point tracking fuzzy solar-charge controller

Energy Technology Data Exchange (ETDEWEB)

Qazalbash, A.A.; Iqbal, T.; Shafiq, M.Z. [National Univ. of Sciences and Technology, Rawalpindi (Pakistan). Dept. of Electrical Engineering

2007-07-01

Photovoltaic (PV) solar arrays are particularly useful for electrical power generation in remote, off-grid areas in developing countries. However, PV arrays offer a small power to area ratio, resulting in the need for more PV arrays which increases the cost of the system. In order to improve the profitability of PV arrays, the power extraction from available PV array systems must be maximized. This paper presented an analysis, modeling and implementation of an efficient solar charge controller. It was shown that the maximum power of a photovoltaic system depends largely on temperature and insolation. A perturb and observe algorithm was used for maximum power point tracking (MPPT). MPPT maximizes the efficiency of a solar PV system. A solar charge controller determines the optimal values of output current and voltage of converters to maximize power output for battery charging. In order to improve performance and implement the perturb and observe algorithm, the authors designed a fuzzy rule-based system in which a solar charge controller worked with a PWM controlled DC-DC converter for battery charging. The system was implemented on a low-cost PIC microcontroller. Results were better than conventional techniques in power efficiency. Swift maximum power point tracking was obtained. 13 refs., 1 tab., 11 figs.

Application of virtual distances methodology to laser tracker verification with an indexed metrology platform

International Nuclear Information System (INIS)

Acero, R; Pueo, M; Santolaria, J; Aguilar, J J; Brau, A

2015-01-01

High-range measuring equipment like laser trackers need large dimension calibrated reference artifacts in their calibration and verification procedures. In this paper, a new verification procedure for portable coordinate measuring instruments based on the generation and evaluation of virtual distances with an indexed metrology platform is developed. This methodology enables the definition of an unlimited number of reference distances without materializing them in a physical gauge to be used as a reference. The generation of the virtual points and reference lengths derived is linked to the concept of the indexed metrology platform and the knowledge of the relative position and orientation of its upper and lower platforms with high accuracy. It is the measuring instrument together with the indexed metrology platform one that remains still, rotating the virtual mesh around them. As a first step, the virtual distances technique is applied to a laser tracker in this work. The experimental verification procedure of the laser tracker with virtual distances is simulated and further compared with the conventional verification procedure of the laser tracker with the indexed metrology platform. The results obtained in terms of volumetric performance of the laser tracker proved the suitability of the virtual distances methodology in calibration and verification procedures for portable coordinate measuring instruments, broadening and expanding the possibilities for the definition of reference distances in these procedures. (paper)

Application of virtual distances methodology to laser tracker verification with an indexed metrology platform

Science.gov (United States)

Acero, R.; Santolaria, J.; Pueo, M.; Aguilar, J. J.; Brau, A.

2015-11-01

High-range measuring equipment like laser trackers need large dimension calibrated reference artifacts in their calibration and verification procedures. In this paper, a new verification procedure for portable coordinate measuring instruments based on the generation and evaluation of virtual distances with an indexed metrology platform is developed. This methodology enables the definition of an unlimited number of reference distances without materializing them in a physical gauge to be used as a reference. The generation of the virtual points and reference lengths derived is linked to the concept of the indexed metrology platform and the knowledge of the relative position and orientation of its upper and lower platforms with high accuracy. It is the measuring instrument together with the indexed metrology platform one that remains still, rotating the virtual mesh around them. As a first step, the virtual distances technique is applied to a laser tracker in this work. The experimental verification procedure of the laser tracker with virtual distances is simulated and further compared with the conventional verification procedure of the laser tracker with the indexed metrology platform. The results obtained in terms of volumetric performance of the laser tracker proved the suitability of the virtual distances methodology in calibration and verification procedures for portable coordinate measuring instruments, broadening and expanding the possibilities for the definition of reference distances in these procedures.

Simulation studies for the ATLAS upgrade Strip tracker

CERN Document Server

Wang, Jike; The ATLAS collaboration

2017-01-01

ATLAS is making extensive efforts towards preparing a detector upgrade for the High luminosity operations of the LHC (HL-LHC), which will commence operation in ~10 years. The current ATLAS Inner Detector will be replaced by a all-silicon tracker (comprising an inner Pixel tracker and outer Strip tracker). The software currently used for the new silicon tracker is broadly inherited from that used for the LHC Run 1 and 2, but many new developments have been made to better fulfil the future detector and operation requirements. One aspect in particular which will be highlighted is the simulation software for the Strip tracker. The available geometry description software (including the detailed description for all the sensitive elements, the services, etc.) did not allow for accurate modeling of the planned detector design. A range of sensors/layouts for the Strip tracker are being considered and must be studied in detailed simulations in order to assess the performance and ascertain that requirements are met. For...

Analyzing Virtual Physics Simulations with Tracker

Science.gov (United States)

Claessens, Tom

2017-12-01

In the physics teaching community, Tracker is well known as a user-friendly open source video analysis software, authored by Douglas Brown. With this tool, the user can trace markers indicated on a video or on stroboscopic photos and perform kinematic analyses. Tracker also includes a data modeling tool that allows one to fit some theoretical equations of motion onto experimentally obtained data. In the field of particle mechanics, Tracker has been effectively used for learning and teaching about projectile motion, "toss up" and free-fall vertical motion, and to explain the principle of mechanical energy conservation. Also, Tracker has been successfully used in rigid body mechanics to interpret the results of experiments with rolling/slipping cylinders and moving rods. In this work, I propose an original method in which Tracker is used to analyze virtual computer simulations created with a physics-based motion solver, instead of analyzing video recording or stroboscopic photos. This could be an interesting approach to study kinematics and dynamics problems in physics education, in particular when there is no or limited access to physical labs. I demonstrate the working method with a typical (but quite challenging) problem in classical mechanics: a slipping/rolling cylinder on a rough surface.

Clementine Star Tracker Stellar Compass: Final report part 1

Energy Technology Data Exchange (ETDEWEB)

Priest, R.E.; Kordas, J.F.; Lewis, I.T. [and others

1995-07-01

The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. Two star stracker stellar compasses (star tracker camera + stellar compass software) were included on the spacecraft, serving a primary function of providing angle updates to the guidance and navigation system. These cameras served a secondary function by providing a wide field of view imaging capability for lunar horizon glow and other dark-side imaging data. This 290 g camera using a 576 x 384 focal plane array and a 17 mm entrance pupil, detected and centroided stars as dim and dimmer than 4.5 m{sub v}, providing rms pointing accuracy of better than 100 {mu}rad pitch and yaw and 450 {mu}rad roll. A description of this light-weight, low power star tracker camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights. Documentation generated during the design, analysis, build, test and characterization of the star tracker cameras are presented. Collectively, this documentation represents a small library of information for this camera, and may be used as a framework for producing copy units by commercial enterprises, and therefore satisfies a Department of Defense and Department of Energy goal to transfer technology to industry. However, the considerable knowledge gained from the experience of the individuals involved in the system trades, design, analysis, production, testing and characterization of the star tracker stellar compass is not contained in this documentation.

The LHCb Silicon Inner Tracker

International Nuclear Information System (INIS)

Sievers, P.

2002-01-01

A silicon strip detector has been adopted as baseline technology for the LHCb Inner Tracker system. It consists of nine planar stations covering a cross-shaped area around the LHCb beam pipe. Depending on the final layout of the stations the sensitive surface of the Inner Tracker will be of the order of 14 m 2 . Ladders have to be 22 cm long and the pitch of the sensors should be as large as possible in order to reduce costs of the readout electronics. Major design criteria are material budget, short shaping time and a moderate spatial resolution of about 80 μm. After an introduction on the requirements of the LHCb Inner Tracker we present a description and characterization of silicon prototype sensors. First, laboratory and test beam results are discussed

The CMS all silicon Tracker simulation

CERN Document Server

Biasini, Maurizio

2009-01-01

The Compact Muon Solenoid (CMS) tracker detector is the world's largest silicon detector with about 201 m$^2$ of silicon strips detectors and 1 m$^2$ of silicon pixel detectors. It contains 66 millions pixels and 10 million individual sensing strips. The quality of the physics analysis is highly correlated with the precision of the Tracker detector simulation which is written on top of the GEANT4 and the CMS object-oriented framework. The hit position resolution in the Tracker detector depends on the ability to correctly model the CMS tracker geometry, the signal digitization and Lorentz drift, the calibration and inefficiency. In order to ensure high performance in track and vertex reconstruction, an accurate knowledge of the material budget is therefore necessary since the passive materials, involved in the readout, cooling or power systems, will create unwanted effects during the particle detection, such as multiple scattering, electron bremsstrahlung and photon conversion. In this paper, we present the CM...

Evaluation of a remote webcam-based eye tracker

DEFF Research Database (Denmark)

Skovsgaard, Henrik; Agustin, Javier San; Johansen, Sune Alstrup

2011-01-01

In this paper we assess the performance of an open-source gaze tracker in a remote (i.e. table-mounted) setup, and compare it with two other commercial eye trackers. An experiment with 5 subjects showed the open-source eye tracker to have a significantly higher level of accuracy than one...

Novel high efficient speed sensorless controller for maximum power extraction from wind energy conversion systems

International Nuclear Information System (INIS)

Fathabadi, Hassan

2016-01-01

Highlights: • Novel sensorless MPPT technique without drawbacks of other sensor/sensorless methods. • Tracking the actual MPP of WECSs, no tracking the MPP of their wind turbines. • Actually extracting the highest output power from WECSs. • Novel MPPT technique having the MPPT efficiency more than 98.5% for WECSs. • Novel MPPT technique having short convergence time for WECSs. - Abstract: In this study, a novel high accurate sensorless maximum power point tracking (MPPT) method is proposed. The technique tracks the actual maximum power point of a wind energy conversion system (WECS) at which maximum output power is extracted from the system, not the maximum power point of its wind turbine at which maximum mechanical power is obtained from the turbine, so it actually extracts the highest output power from the system. The technique only uses input voltage and current of the converter used in the system, and neither needs any speed sensors (anemometer and tachometer) nor has the drawbacks of other sensor/sensorless based MPPT methods. The technique has been implemented as a MPPT controller by constructing a WECS. Theoretical results, the technique performance, and its advantages are validated by presenting real experimental results. The real static-dynamic response of the MPPT controller is experimentally obtained that verifies the proposed MPPT technique high accurately extracts the highest instant power from wind energy conversion systems with the MPPT efficiency of more than 98.5% and a short convergence time that is only 25 s for the constructed system having a total inertia and friction coefficient of 3.93 kg m 2 and 0.014 N m s, respectively.

Tracker Performance Metric

National Research Council Canada - National Science Library

Olson, Teresa; Lee, Harry; Sanders, Johnnie

2002-01-01

.... We have developed the Tracker Performance Metric (TPM) specifically for this purpose. It was designed to measure the output performance, on a frame-by-frame basis, using its output position and quality...

Autonomous star tracker based on active pixel sensors (APS)

Science.gov (United States)

Schmidt, U.

2017-11-01

Star trackers are opto-electronic sensors used onboard of satellites for the autonomous inertial attitude determination. During the last years, star trackers became more and more important in the field of the attitude and orbit control system (AOCS) sensors. High performance star trackers are based up today on charge coupled device (CCD) optical camera heads. The Jena-Optronik GmbH is active in the field of opto-electronic sensors like star trackers since the early 80-ties. Today, with the product family ASTRO5, ASTRO10 and ASTRO15, all marked segments like earth observation, scientific applications and geo-telecom are supplied to European and Overseas customers. A new generation of star trackers can be designed based on the APS detector technical features. The measurement performance of the current CCD based star trackers can be maintained, the star tracker functionality, reliability and robustness can be increased while the unit costs are saved.

The Detector Control System of the ATLAS SemiCondutor Tracker during Macro-Assembly and Integration

CERN Document Server

Abdesselam, A; Basiladze, S; Bates, R L; Bell, P; Bingefors, N; Böhm, J; Brenner, R; Chamizo-Llatas, M; Clark, A; Codispoti, G; Colijn, A P; D'Auria, S; Dorholt, O; Doherty, F; Ferrari, P; Ferrère, D; Górnicki, E; Koperny, S; Lefèvre, R; Lindquist, L-E; Malecki, P; Mikulec, B; Mohn, B; Pater, J; Pernegger, H; Phillips, P; Robichaud-Véronneau, A; Robinson, D; Roe, S; Sandaker, H; Sfyrla, A; Stanecka, E; Stastny, J; Viehhauser, G; Vossebeld, J; Wells, P

2008-01-01

The ATLAS SemiConductor Tracker (SCT) is one of the largest existing semiconductor detectors. It is situated between the Pixel detector and the Transition Radiation Tracker at one of the four interaction points of the Large Hadron Collider (LHC). During 2006-2007 the detector was lowered into the ATLAS cavern and installed in its final position. For the assembly, integration and commissioning phase, a complete Detector Control System (DCS) was developed to ensure the safe operation of the tracker. This included control of the individual powering of the silicon modules, a bi-phase cooling system and various types of sensors monitoring the SCT environment and the surrounding test enclosure. The DCS software architecture, performance and operational experience will be presented in the view of a validation of the DCS for the final SCT installation and operation phase.

An automated tool for solar power systems

International Nuclear Information System (INIS)

Natsheh, E.M.; Natsheh, A.R.; Albarbar, AH

2014-01-01

In this paper a novel model of smart grid-connected solar power system is developed. The model is implemented using MatLab/SIMULINK software package. Artificial neural network (ANN) algorithm is used for maximizing the generated power based on maximum power point tracker (MPPT) implementation. The dynamic behavior of the proposed model is examined under different operating conditions. Solar irradiance, and temperature data are gathered from a grid connected, 28.8 kW solar power system located in central Manchester. The developed system and its control strategy exhibit excellent performance with tracking efficiency exceed 94.5%. The proposed model and its control strategy offer a proper tool for smart grid performance optimization. (author)

Rosetta Star Tracker and Navigation Camera

DEFF Research Database (Denmark)

Thuesen, Gøsta

1998-01-01

Proposal in response to the Invitation to Tender (ITT) issued by Matra Marconi Space (MSS) for the procurement of the ROSETTA Star Tracker and Navigation Camera.......Proposal in response to the Invitation to Tender (ITT) issued by Matra Marconi Space (MSS) for the procurement of the ROSETTA Star Tracker and Navigation Camera....

LHCb Upstream Tracker

CERN Multimedia

Gandini, Paolo

2014-01-01

The LHCb upgrade requires replacing the silicon strip tracker between the vertex locator (VELO) and the magnet. A new design has been developed and tested based on the "stave" concept planned for the ATLAS upgrade.

LHCb Upstream Tracker

CERN Multimedia

Gandini, P

2014-01-01

The LHCb upgrade requires replacing the silicon strip tracker between the vertex locator (VELO) and the magnet. A new design has been developed and tested based on the "stave" concept planned for the ATLAS upgrade

Multi-Layer Artificial Neural Networks Based MPPT-Pitch Angle Control of a Tidal Stream Generator

Directory of Open Access Journals (Sweden)

Khaoula Ghefiri

2018-04-01

Full Text Available Artificial intelligence technologies are widely investigated as a promising technique for tackling complex and ill-defined problems. In this context, artificial neural networks methodology has been considered as an effective tool to handle renewable energy systems. Thereby, the use of Tidal Stream Generator (TSG systems aim to provide clean and reliable electrical power. However, the power captured from tidal currents is highly disturbed due to the swell effect and the periodicity of the tidal current phenomenon. In order to improve the quality of the generated power, this paper focuses on the power smoothing control. For this purpose, a novel Artificial Neural Network (ANN is investigated and implemented to provide the proper rotational speed reference and the blade pitch angle. The ANN supervisor adequately switches the system in variable speed and power limitation modes. In order to recover the maximum power from the tides, a rotational speed control is applied to the rotor side converter following the Maximum Power Point Tracking (MPPT generated from the ANN block. In case of strong tidal currents, a pitch angle control is set based on the ANN approach to keep the system operating within safe limits. Two study cases were performed to test the performance of the output power. Simulation results demonstrate that the implemented control strategies achieve a smoothed generated power in the case of swell disturbances.

INNER TRACKER

CERN Multimedia

Peter Sharp

In March the Silicon Strip Detector had been successfully connected to the PP1 patch panels on the CMS Cryostat, and every thing had been prepared to check out the Tracker and commission it with CMS with the ambition of joining the CMS Global Cosmic Run in April.  There followed serious problems with the cooling plant which through tremendous effort have been overcome and recently allowed commissioning of the tracker to proceed. In November 2007 there had been a failure of the heat exchanger in one of the seven cooling plants in the UXC cavern. After an analysis of the failure it was decided to replace this heat exchanger with a well-proven commercial heat exchanger and to re-commission the system. Re-commissioning the system proved to be more difficult than anticipated as on May 8 there was a second failure of a heat exchanger, in the main chiller plant in the USC service cavern. The analysis of the failure showed it was very similar to the previous failure. It was decided to replace all the heat ...

Developments for the TOF Straw Tracker

Energy Technology Data Exchange (ETDEWEB)

Ucar, A.

2006-07-01

COSY-TOF is a very large acceptance spectrometer for charged particles using precise information on track geometry and time of flight of reaction products. It is an external detector system at the Cooler Synchrotron and storage ring COSY in Juelich. In order to improve the performance of the COSY-TOF, a new tracking detector ''Straw Tracker'' is being constructed which combines very low mass, operation in vacuum, very good resolution, high sampling density and very high acceptance. A comparison of pp{yields}d{pi}{sup +} data and a simulation using the straw tracker with geometry alone indicates big improvements with the new tracker. In order to investigate the straw tracker properties a small tracking hodoscope ''cosmic ray test facility'' was constructed in advance. It is made of two crossed hodoscopes consisting of 128 straw tubes arranged in 4 double planes. For the first time Juelich straws have been used for 3 dimensional reconstruction of cosmic ray tracks. In this illuminating field the space dependent response of scintillators and a straw tube were studied. (orig.)

Developments for the TOF Straw Tracker

International Nuclear Information System (INIS)

Ucar, A.

2006-01-01

COSY-TOF is a very large acceptance spectrometer for charged particles using precise information on track geometry and time of flight of reaction products. It is an external detector system at the Cooler Synchrotron and storage ring COSY in Juelich. In order to improve the performance of the COSY-TOF, a new tracking detector ''Straw Tracker'' is being constructed which combines very low mass, operation in vacuum, very good resolution, high sampling density and very high acceptance. A comparison of pp→dπ + data and a simulation using the straw tracker with geometry alone indicates big improvements with the new tracker. In order to investigate the straw tracker properties a small tracking hodoscope ''cosmic ray test facility'' was constructed in advance. It is made of two crossed hodoscopes consisting of 128 straw tubes arranged in 4 double planes. For the first time Juelich straws have been used for 3 dimensional reconstruction of cosmic ray tracks. In this illuminating field the space dependent response of scintillators and a straw tube were studied. (orig.)

2D/3D Visual Tracker for Rover Mast

Science.gov (United States)

Bajracharya, Max; Madison, Richard W.; Nesnas, Issa A.; Bandari, Esfandiar; Kunz, Clayton; Deans, Matt; Bualat, Maria

2006-01-01

A visual-tracker computer program controls an articulated mast on a Mars rover to keep a designated feature (a target) in view while the rover drives toward the target, avoiding obstacles. Several prior visual-tracker programs have been tested on rover platforms; most require very small and well-estimated motion between consecutive image frames a requirement that is not realistic for a rover on rough terrain. The present visual-tracker program is designed to handle large image motions that lead to significant changes in feature geometry and photometry between frames. When a point is selected in one of the images acquired from stereoscopic cameras on the mast, a stereo triangulation algorithm computes a three-dimensional (3D) location for the target. As the rover moves, its body-mounted cameras feed images to a visual-odometry algorithm, which tracks two-dimensional (2D) corner features and computes their old and new 3D locations. The algorithm rejects points, the 3D motions of which are inconsistent with a rigid-world constraint, and then computes the apparent change in the rover pose (i.e., translation and rotation). The mast pan and tilt angles needed to keep the target centered in the field-of-view of the cameras (thereby minimizing the area over which the 2D-tracking algorithm must operate) are computed from the estimated change in the rover pose, the 3D position of the target feature, and a model of kinematics of the mast. If the motion between the consecutive frames is still large (i.e., 3D tracking was unsuccessful), an adaptive view-based matching technique is applied to the new image. This technique uses correlation-based template matching, in which a feature template is scaled by the ratio between the depth in the original template and the depth of pixels in the new image. This is repeated over the entire search window and the best correlation results indicate the appropriate match. The program could be a core for building application programs for systems

Fuzzy logic control of stand-alone photovoltaic system with battery storage

Science.gov (United States)

Lalouni, S.; Rekioua, D.; Rekioua, T.; Matagne, E.

Photovoltaic energy has nowadays an increased importance in electrical power applications, since it is considered as an essentially inexhaustible and broadly available energy resource. However, the output power provided via the photovoltaic conversion process depends on solar irradiation and temperature. Therefore, to maximize the efficiency of the photovoltaic energy system, it is necessary to track the maximum power point of the PV array. The present paper proposes a maximum power point tracker (MPPT) method, based on fuzzy logic controller (FLC), applied to a stand-alone photovoltaic system. It uses a sampling measure of the PV array power and voltage then determines an optimal increment required to have the optimal operating voltage which permits maximum power tracking. This method carries high accuracy around the optimum point when compared to the conventional one. The stand-alone photovoltaic system used in this paper includes two bi-directional DC/DC converters and a lead-acid battery bank to overcome the scare periods. One converter works as an MPP tracker, while the other regulates the batteries state of charge and compensates the power deficit to provide a continuous delivery of energy to the load. The Obtained simulation results show the effectiveness of the proposed fuzzy logic controller.

Performance of the RASNIK Optical Alignment Monitoring System for the LHCb Outer Tracker Detector

CERN Document Server

Szczekowski, Marek; Ukleja, Artur; Pellegrino, Antonio; Hart, Robert; Syryczynski, Krzysztof

2017-01-01

We present the results collected by an optical system for position control of the Outer Tracker detector stations in the LHCb experiment. This system has been constructed using the RASNIK three-point alignment monitors. The measurements are based on data taken in Run 2 of LHC.

The control system for the CMS tracker front-end

CERN Document Server

Drouhin, F; Ljuslin, C; Maazouzi, C; Marchiero, A; Marinelli, N; Paillard, C; Siegrist, P; Tsirou, A L; Verdini, P G; Walsham, P; Zghiche, A

2002-01-01

The CMS Tracker uses complex, programmable embedded electronics for the readout of the Silicon sensors, for the control of the working point of the optical transmitters, for the phase adjustment of the 40 MHz LHC clock and for the monitoring of the voltages, currents and temperatures. In order to establish reliable, noise-free communication with the outside world the control chain has been designed to operate over a ribbon of optical fibers. The optical links, the Front End Controller board that carries their support electronics, the Clocking and Control Unit module receiving the signals over the high-speed link and fanning them out to the front- ends have recently become available. A multi-layered software architecture to handle these devices, and the front-ends, in a way transparent to the end-user, interfaced to an Oracle database for the retrieval of the parameters to be downloaded with the intent of building and operating a small-scale prototype of the control system for the CMS Tracker. The paper descri...

The Laser Alignment System for the CMS silicon strip tracker

CERN Document Server

Olzem, Jan

2009-01-01

The Laser Alignment System (LAS) of the CMS silicon strip Tracker has been designed for surveying the geometry of the large-scale Tracker support structures. It uses 40 laser beams ($\\lambda$ = 1075 nm) that induce signals on a subset of the Tracker silicon sensors. The positions in space of the laser spots on the sensors are reconstructed with a resolution of 30 $\\mu$m. From this, the LAS is capable of permanent in-time monitoring of the different Tracker components relative to each other with better than 30 $\\mu$m precision. Additionally, it can provide an absolute measurement of the Tracker mechanical structure with an accuracy better than 70 $\\mu$m, thereby supplying additional input to the track based alignment at detector startup. 31 out of the 40 LAS beams have been successfully operated during the CMS cosmic muon data taking campaign in autumn 2008. The alignment of the Tracker Endcap Discs and of the discs with respect to the Tracker Inner Barrel and Tracker Outer Barrel subdetectors was measured w...

The Design Parameters for the MICE Tracker Solenoid

International Nuclear Information System (INIS)

Green, Michael A.; Chen, C.Y.; Juang, Tiki; Lau, Wing W.; Taylor, Clyde; Virostek, Steve P.; Wahrer, Robert; Wang, S.T.; Witte, Holger; Yang, Stephanie Q.

2006-01-01

The first superconducting magnets to be installed in the muon ionization cooling experiment (MICE) will be the tracker solenoids. The tracker solenoid module is a five coil superconducting solenoid with a 400 mm diameter warm bore that is used to provide a 4 T magnetic field for the experiment tracker module. Three of the coils are used to produce a uniform field (up to 4 T with better than 1 percent uniformity) in a region that is 300 mm in diameter and 1000 mm long. The other two coils are used to match the muon beam into the MICE cooling channel. Two 2.94-meter long superconducting tracker solenoid modules have been ordered for MICE. The tracker solenoid will be cooled using two-coolers that produce 1.5 W each at 4.2 K. The magnet system is described. The decisions that drive the magnet design will be discussed in this report

Development of Star Tracker System for Accurate Estimation of Spacecraft Attitude

Science.gov (United States)

2009-12-01

For a high- cost spacecraft with accurate pointing requirements, the use of a star tracker is the preferred method for attitude determination. The...solutions, however there are certain costs with using this algorithm. There are significantly more features a triangle can provide when compared to an...to the other. The non-rotating geocentric equatorial frame provides an inertial frame for the two-body problem of a satellite in orbit. In this

Operation and Performance of the ATLAS Semiconductor Tracker

International Nuclear Information System (INIS)

Barlow, Nick

2013-06-01

The ATLAS detector is the largest of the four main particle detectors at the Large Hadron Collider at CERN, Switzerland. A crucial requirement for it to accomplish its physics goals is efficient and precise tracking of charged particles in the region around the point where proton-proton collisions take place. This role is performed by the ATLAS Inner Detector, of which the Semiconductor Tracker (SCT) is a key component. I will briefly describe the design and layout of the SCT, before discussing the commissioning of the detector and its operation over the course of LHC Run 1. (authors)

Operation and Performance of the ATLAS Semiconductor Tracker

CERN Document Server

Barlow, N; The ATLAS collaboration

2013-01-01

The ATLAS detector is the largest of the four main particle detectors at the Large Hadron Collider at CERN, Switzerland. A crucial requirement for it to accomplish its physics goals is efficient and precise tracking of charged particles in the region around the point where proton-proton collisions take place. This role is performed by the ATLAS Inner Detector, of which the Semiconductor Tracker (SCT) is a key component. I will briefly describe the design and layout of the SCT, before discussing the commissioning of the detector and its operation over the course of LHC Run 1.

An improved maximum power point tracking method for a photovoltaic system

Science.gov (United States)

Ouoba, David; Fakkar, Abderrahim; El Kouari, Youssef; Dkhichi, Fayrouz; Oukarfi, Benyounes

2016-06-01

In this paper, an improved auto-scaling variable step-size Maximum Power Point Tracking (MPPT) method for photovoltaic (PV) system was proposed. To achieve simultaneously a fast dynamic response and stable steady-state power, a first improvement was made on the step-size scaling function of the duty cycle that controls the converter. An algorithm was secondly proposed to address wrong decision that may be made at an abrupt change of the irradiation. The proposed auto-scaling variable step-size approach was compared to some various other approaches from the literature such as: classical fixed step-size, variable step-size and a recent auto-scaling variable step-size maximum power point tracking approaches. The simulation results obtained by MATLAB/SIMULINK were given and discussed for validation.

Sun tracker for clear or cloudy weather

Science.gov (United States)

Scott, D. R.; White, P. R.

1979-01-01

Sun tracker orients solar collector so that they absorb maximum possible sunlight without being fooled by bright clouds, holes in cloud cover, or other atmospheric conditions. Tracker follows sun within 0.25 deg arc and is accurate within + or - 5 deg when sun is hidden.

A Methodology to Analyze Photovoltaic Tracker Uptime

Energy Technology Data Exchange (ETDEWEB)

Muller, Matthew T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ruth, Dan [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-17

A metric is developed to analyze the daily performance of single-axis photovoltaic (PV) trackers. The metric relies on comparing correlations between the daily time series of the PV power output and an array of simulated plane-of-array irradiances for the given day. Mathematical thresholds and a logic sequence are presented, so the daily tracking metric can be applied in an automated fashion on large-scale PV systems. The results of applying the metric are visually examined against the time series of the power output data for a large number of days and for various systems. The visual inspection results suggest that overall, the algorithm is accurate in identifying stuck or functioning trackers on clear-sky days. Visual inspection also shows that there are days that are not classified by the metric where the power output data may be sufficient to identify a stuck tracker. Based on the daily tracking metric, uptime results are calculated for 83 different inverters at 34 PV sites. The mean tracker uptime is calculated at 99% based on 2 different calculation methods. The daily tracking metric clearly has limitations, but as there is no existing metrics in the literature, it provides a valuable tool for flagging stuck trackers.

SOLAR TRACKER CERDAS DAN MURAH BERBASIS MIKROKONTROLER 8 BIT ATMega8535

Directory of Open Access Journals (Sweden)

I Wayan Sutaya

2016-08-01

Full Text Available prototipe produk solar tracker cerdas berbasis mikrokontroler AVR 8 bit. Solar tracker ini memasukkan filter digital IIR (Infinite Impulse Response pada bagian program. Memprogram filter ini membutuhkan perkalian 32 bit sedangkan prosesor yang tersedia pada mikrokontroler yang dipakai adalah 8 bit. Proses perkalian ini hanya bisa dilakukan pada mikrokontroler 8 bit dengan menggunakan bahasa assembly yang merupakan bahasa level hardware. Solar tracker cerdas yang menggunakan mikrokontroler 8 bit sebagai otak utama pada penelitian ini menjadikan produk ini berbiaya rendah. Pengujian yang dilakukan menunjukkan bahwa solar tracker cerdas dibandingkan dengan solar tracker biasa mempunyai perbedaan konsumsi daya baterai yang sangat signifikan yaitu terjadi penghematan sebesar 85 %. Besar penghematan konsumsi daya ini tentunya bukan sebuah angka konstan melainkan tergantung seberapa besar noise yang dikenakan pada alat solar tracker. Untuk sebuah perlakuan yang sama, maka semakin besar noise semakin besar pula perbedaan penghematan konsumsi daya pada solar tracker yang cerdas. Kata-kata kunci: solar tracker, filter digital, mikrokontroler 8 bit, konsumsi daya Abstract This research had made a prototype of smart solar tracker product based on microcontroller AVR 8 bit. The solar tracker used digital filter IIR (Infinite Impulse Response on its software. Filter programming needs 32 bit multiplication but the processor inside of the microcontroller that used in this research is 8 bit. This multiplication is only can be solved on microcontroller 8 bit by using assembly language in programming. The language is a hardware level language. The smart solar tracker using the microcontroller 8 bit as a main brain in this research made the product had a low cost. The test results show that the comparison in saving of baterai power consumption between the smart solar tracker and the normal one is 85 %. The percentage of the saving indubitably is not a constant

Power distribution studies for CMS forward tracker

International Nuclear Information System (INIS)

Todri, A.; Turqueti, M.; Rivera, R.; Kwan, S.

2009-01-01

The Electronic Systems Engineering Department of the Computing Division at the Fermi National Accelerator Laboratory is carrying out R and D investigations for the upgrade of the power distribution system of the Compact Muon Solenoid (CMS) Pixel Tracker at the Large Hadron Collider (LHC). Among the goals of this effort is that of analyzing the feasibility of alternative powering schemes for the forward tracker, including DC to DC voltage conversion techniques using commercially available and custom switching regulator circuits. Tests of these approaches are performed using the PSI46 pixel readout chip currently in use at the CMS Tracker. Performance measures of the detector electronics will include pixel noise and threshold dispersion results. Issues related to susceptibility to switching noise will be studied and presented. In this paper, we describe the current power distribution network of the CMS Tracker, study the implications of the proposed upgrade with DC-DC converters powering scheme and perform noise susceptibility analysis.

Evaluation of a proper controller performance for maximum-power point tracking of a stand-alone PV system

Energy Technology Data Exchange (ETDEWEB)

Nafeh, A.E.-S.A.; Fahmy, F.H. [Electronics Research Institute, Cairo (Egypt); El-Zahab, E.M.A. [Cairo University, Giza (Egypt). Faculty of Engineering

2003-02-01

In this paper the implementation of a suggested stand-alone PV system, for maximum-power point tracking (MPPT), is carried out. Also, this paper presents a comparative study, through experimental work, between the conventional PI controller and the fuzzy logic controller (FLC) under different atmospheric conditions. The implemented system with both the PI controller and the FLC gives a good maximum-power operation of the PV array, but the tracking capability for different optimum operating points is better and faster for the case of using the FLC compared to the case of using the PI controller. (author)

Modelling Structural Flexure Effects in CPV Sun Trackers

OpenAIRE

Luque-Heredia, Ignacio; Quéméré, G.; Magalhães, P.H.; Fraile de Lerma, Alberto; Hermanns, Lutz Karl Heinz; Alarcón Álvarez, Enrique; Luque López, Antonio

2006-01-01

Nowadays CPV trends mostly based in lens parqueted flat modules, enable the separate design of the sun tracker. To enable this possibility a set of specifications is to be prescribed for the tracker design team, which take into account fundamental requisites such as the maximum service loads both permanent and variable, the sun tracking accuracy and the tracker structural stiffness required to maintain the CPV array acceptance angle loss below a certain threshold. In its first part this paper...

GigaTracker, a Thin and Fast Silicon Pixels Tracker

CERN Document Server

Velghe, Bob; Bonacini, Sandro; Ceccucci, Augusto; Kaplon, Jan; Kluge, Alexander; Mapelli, Alessandro; Morel, Michel; Noël, Jérôme; Noy, Matthew; Perktold, Lukas; Petagna, Paolo; Poltorak, Karolina; Riedler, Petra; Romagnoli, Giulia; Chiozzi, Stefano; Cotta Ramusino, Angelo; Fiorini, Massimiliano; Gianoli, Alberto; Petrucci, Ferruccio; Wahl, Heinrich; Arcidiacono, Roberta; Jarron, Pierre; Marchetto, Flavio; Gil, Eduardo Cortina; Nuessle, Georg; Szilasi, Nicolas

2014-01-01

GigaTracker, the NA62’s upstream spectrometer, plays a key role in the kinematically constrained background suppression for the study of the K + ! p + n ̄ n decay. It is made of three independent stations, each of which is a six by three cm 2 hybrid silicon pixels detector. To meet the NA62 physics goals, GigaTracker has to address challenging requirements. The hit time resolution must be better than 200 ps while keeping the total thickness of the sensor to less than 0.5 mm silicon equivalent. The 200 μm thick sensor is divided into 18000 300 μm 300 μm pixels bump-bounded to ten independent read-out chips. The chips use an end-of-column architecture and rely on time-over- threshold discriminators. A station can handle a crossing rate of 750 MHz. Microchannel cooling technology will be used to cool the assembly. It allows us to keep the sensor close to 0 C with 130 μm of silicon in the beam area. The sensor and read-out chip performance were validated using a 45 pixel demonstrator with a laser test setu...

The CMS tracker control system

Science.gov (United States)

Dierlamm, A.; Dirkes, G. H.; Fahrer, M.; Frey, M.; Hartmann, F.; Masetti, L.; Militaru, O.; Shah, S. Y.; Stringer, R.; Tsirou, A.

2008-07-01

The Tracker Control System (TCS) is a distributed control software to operate about 2000 power supplies for the silicon modules of the CMS Tracker and monitor its environmental sensors. TCS must thus be able to handle about 104 power supply parameters, about 103 environmental probes from the Programmable Logic Controllers of the Tracker Safety System (TSS), about 105 parameters read via DAQ from the DCUs in all front end hybrids and from CCUs in all control groups. TCS is built on top of an industrial SCADA program (PVSS) extended with a framework developed at CERN (JCOP) and used by all LHC experiments. The logical partitioning of the detector is reflected in the hierarchical structure of the TCS, where commands move down to the individual hardware devices, while states are reported up to the root which is interfaced to the broader CMS control system. The system computes and continuously monitors the mean and maximum values of critical parameters and updates the percentage of currently operating hardware. Automatic procedures switch off selected parts of the detector using detailed granularity and avoiding widespread TSS intervention.

ALAT SOLAR TRACKER BERBASIS MIKROKONTROLER 8 BIT ATMega8535

Directory of Open Access Journals (Sweden)

I Wayan Sutaya

2015-07-01

Full Text Available Penelitian yang telah dilakukan ini adalah membuat prototipe alat solar tracker. Alat ini berfungsi untuk menggerakkan modul sel surya sehingga permukaan sel surya bisa terkena sinar matahari secara maksimal. Saat ini sel surya di Indonesia banyak terpasang secara statis atau tidak dilengkapi alat solar tracker sehingga energi matahari tidak diterima secara maksimal. Hal ini menyebabkan sel surya yang terpasang di beberapa daerah di Indonesia tidak memberikan manfaat yang optimal. Alat solar tracker yang dihasilkan pada penelitian ini diharapkan sebagai solusi dari permasalahan yang ada saat ini. Mikrokontroler 8 bit ATMega8535 yang digunakan sebagai otak utama dari alat solar tracker menjadikan alat ini menjadi berbiaya murah. Serta teknik memprogram dengan bahasa assembly menjadikan alat ini tahan terhadap kegagalan sistem. Solar tracker ini sudah bisa beroperasi dengan baik dan cocok digunakan pada modul sel surya berukuran kecil.

The CMS silicon tracker

International Nuclear Information System (INIS)

Focardi, E.; Albergo, S.; Angarano, M.; Azzi, P.; Babucci, E.; Bacchetta, N.; Bader, A.; Bagliesi, G.; Basti, A.; Biggeri, U.; Bilei, G.M.; Bisello, D.; Boemi, D.; Bosi, F.; Borrello, L.; Bozzi, C.; Braibant, S.; Breuker, H.; Bruzzi, M.; Buffini, A.; Busoni, S.; Candelori, A.; Caner, A.; Castaldi, R.; Castro, A.; Catacchini, E.; Checcucci, B; Ciampolini, P.; Civinini, C.; Creanza, D.; D'Alessandro, R.; Da Rold, M.; Demaria, N.; De Palma, M.; Dell'Orso, R.; Della Marina, R.; Dutta, S.; Eklund, C.; Feld, L.; Fiore, L.; French, M.; Freudenreich, K.; Frey, A.; Fuertjes, A.; Giassi, A.; Giorgi, M.; Giraldo, A.; Glessing, B.; Gu, W.H.; Hall, G.; Hammarstrom, R.; Hebbeker, T.; Honma, A.; Hrubec, J.; Huhtinen, M.; Kaminsky, A.; Karimaki, V.; Koenig, St.; Krammer, M.; Lariccia, P.; Lenzi, M.; Loreti, M.; Leubelsmeyer, K.; Lustermann, W.; Maettig, P.; Maggi, G.; Mannelli, M.; Mantovani, G.; Marchioro, A.; Mariotti, C.; Martignon, G.; Evoy, B.Mc; Meschini, M.; Messineo, A.; Migliore, E.; My, S.; Paccagnella, A.; Palla, F.; Pandoulas, D.; Papi, A.; Parrini, G.; Passeri, D.; Pieri, M.; Piperov, S.; Potenza, R.; Radicci, V.; Raffaelli, F.; Raymond, M.; Rizzo, F.; Santocchia, A.; Schmitt, B.; Selvaggi, G.; Servoli, L.; Sguazzoni, G.; Siedling, R.; Silvestris, L.; Starodumov, A.; Stavitski, I.; Stefanini, G.; Surrow, B.; Tempesta, P.; Tonelli, G.; Tricomi, A.; Tuuva, T.; Vannini, C.; Verdini, P.G.; Viertel, G.; Xie, Z.; Yahong, Li; Watts, S.; Wittmer, B.

2000-01-01

This paper describes the Silicon microstrip Tracker of the CMS experiment at LHC. It consists of a barrel part with 5 layers and two endcaps with 10 disks each. About 10 000 single-sided equivalent modules have to be built, each one carrying two daisy-chained silicon detectors and their front-end electronics. Back-to-back modules are used to read-out the radial coordinate. The tracker will be operated in an environment kept at a temperature of T=-10 deg. C to minimize the Si sensors radiation damage. Heavily irradiated detectors will be safely operated due to the high-voltage capability of the sensors. Full-size mechanical prototypes have been built to check the system aspects before starting the construction

RFP for the Auroral Multiscale Midex (AMM) Mission star tracker

DEFF Research Database (Denmark)

Riis, Troels; Betto, Maurizio; Jørgensen, John Leif

1999-01-01

This document is in response to the John Hopkins University - Applied Physics Laboratory RFP for the Auroral Multiscale Midex Mission star tracker.It describes the functionality, the requirements and the performance of the ASC Star Tracker.......This document is in response to the John Hopkins University - Applied Physics Laboratory RFP for the Auroral Multiscale Midex Mission star tracker.It describes the functionality, the requirements and the performance of the ASC Star Tracker....

A proposal to use microstrip gas counters in a LHC tracker

International Nuclear Information System (INIS)

Geijsberts, M.; Hartjes, F.G.; Pannekoek, J.G.; Schmitz, J.; Udo, F.

1991-06-01

The paper presents an LHC tracker constructed from microstrip gas counters, occupying a cylinder around the beam r=400 mm and r=900 mm. The instrument measures 12 points on track with an accuracy of 30μm. Due to fine granularity and the short charge collection time, the occupancy is below 1 percent at a luminosity of L=10 34 cm -2 . Operating at high magnetic fields and a fast charge collection process are possible using Xe/DME/CO 2 mixtures and reducing the gap width between substrate and drift cathode to 1.6 mm. Hits from low energetic tracks are largely suppressed and hard tracks stand out, which greatly facilitates pattern recognition. By introducing a small stereo angle, the (r,z) coordinate can be measured with an accuracy of 1 mm. A calculation of the collected charge per strip shows that the tracker can withstand the LHC radiation for many years. (author). 9 refs.; 7 figs

Which cue to ‘want’? Opioid stimulation of central amygdala makes goal-trackers show stronger goal-tracking, just as sign-trackers show stronger sign-tracking

Science.gov (United States)

DiFeliceantonio, Alexandra G.; Berridge, Kent C.

2012-01-01

Pavlovian cues that have been paired with reward can gain incentive salience. Drug addicts find drug cues motivationally attractive and binge eaters are attracted by food cues. But the level of incentive salience elicited by a cue re-encounter still varies across time and brain states. In an animal model, cues become attractive and ‘wanted’ in an ‘autoshaping’ paradigm, where different targets of incentive salience emerge for different individuals. Some individuals (sign-trackers) find a predictive discrete cue attractive while others find a reward contiguous and goal cue more attractive (location where reward arrives: goal-trackers). Here we assessed whether central amygdala mu opioid receptor stimulation enhances the phasic incentive salience of the goal-cue for goal-trackers during moments of predictive cue presence (expressed in both approach and consummatory behaviors to goal cue), just as it enhances the attractiveness of the predictive cue target for sign-trackers. Using detailed video analysis we measured the approaches, nibbles, sniffs, and bites directed at their preferred target for both sign-trackers and goal-trackers. We report that DAMGO microinjections in central amygdala made goal-trackers, like sign-trackers, show phasic increases in appetitive nibbles and sniffs directed at the goal-cue expressed selectively whenever the predictive cue was present. This indicates enhancement of incentive salience attributed by both goal trackers and sign-trackers, but attributed in different directions: each to their own target cue. For both phenotypes, amygdala opioid stimulation makes the individual’s prepotent cue into a stronger motivational magnet at phasic moments triggered by a CS that predicts the reward UCS. PMID:22391118

Modeling and analysis of solar distributed generation

Science.gov (United States)

Ortiz Rivera, Eduardo Ivan

Recent changes in the global economy are creating a big impact in our daily life. The price of oil is increasing and the number of reserves are less every day. Also, dramatic demographic changes are impacting the viability of the electric infrastructure and ultimately the economic future of the industry. These are some of the reasons that many countries are looking for alternative energy to produce electric energy. The most common form of green energy in our daily life is solar energy. To convert solar energy into electrical energy is required solar panels, dc-dc converters, power control, sensors, and inverters. In this work, a photovoltaic module, PVM, model using the electrical characteristics provided by the manufacturer data sheet is presented for power system applications. Experimental results from testing are showed, verifying the proposed PVM model. Also in this work, three maximum power point tracker, MPPT, algorithms would be presented to obtain the maximum power from a PVM. The first MPPT algorithm is a method based on the Rolle's and Lagrange's Theorems and can provide at least an approximate answer to a family of transcendental functions that cannot be solved using differential calculus. The second MPPT algorithm is based on the approximation of the proposed PVM model using fractional polynomials where the shape, boundary conditions and performance of the proposed PVM model are satisfied. The third MPPT algorithm is based in the determination of the optimal duty cycle for a dc-dc converter and the previous knowledge of the load or load matching conditions. Also, four algorithms to calculate the effective irradiance level and temperature over a photovoltaic module are presented in this work. The main reasons to develop these algorithms are for monitoring climate conditions, the elimination of temperature and solar irradiance sensors, reductions in cost for a photovoltaic inverter system, and development of new algorithms to be integrated with maximum

PageRank tracker: from ranking to tracking.

Science.gov (United States)

Gong, Chen; Fu, Keren; Loza, Artur; Wu, Qiang; Liu, Jia; Yang, Jie

2014-06-01

Video object tracking is widely used in many real-world applications, and it has been extensively studied for over two decades. However, tracking robustness is still an issue in most existing methods, due to the difficulties with adaptation to environmental or target changes. In order to improve adaptability, this paper formulates the tracking process as a ranking problem, and the PageRank algorithm, which is a well-known webpage ranking algorithm used by Google, is applied. Labeled and unlabeled samples in tracking application are analogous to query webpages and the webpages to be ranked, respectively. Therefore, determining the target is equivalent to finding the unlabeled sample that is the most associated with existing labeled set. We modify the conventional PageRank algorithm in three aspects for tracking application, including graph construction, PageRank vector acquisition and target filtering. Our simulations with the use of various challenging public-domain video sequences reveal that the proposed PageRank tracker outperforms mean-shift tracker, co-tracker, semiboosting and beyond semiboosting trackers in terms of accuracy, robustness and stability.

The CMS Outer Tracker for HL-LHC

CERN Document Server

Dierlamm, Alexander Hermann

2018-01-01

The LHC is planning an upgrade program, which will bring the luminosity to about $5-7\\times10^{34}$~cm$^{-2}$s$^{-1}$ in 2026, with a goal of an integrated luminosity of 3000 fb$^{-1}$ by the end of 2037. This High Luminosity LHC scenario, HL-LHC, will require a preparation program of the LHC detectors known as Phase-2 Upgrade. The current CMS Tracker is already running beyond design specifications and will not be able to cope with the HL-LHC radiation conditions. CMS will need a completely new Tracker in order to fully exploit the highly demanding operating conditions and the delivered luminosity. The new Outer Tracker system is designed to provide robust tracking as well as Level-1 trigger capabilities using closely spaced modules composed of silicon macro-pixel and/or strip sensors. Research and development activities are ongoing to explore options and develop module components and designs for the HL-LHC environment. The design choices for the CMS Outer Tracker Upgrade are discussed along with some highlig...

A Heavy Flavor Tracker for STAR

International Nuclear Information System (INIS)

Chasman, C.; Beavis, D.; Debbe, R.; Lee, J.H.; Levine, M.J.; Videbaek, F.; Xu, Z.; Kleinfelder, S.; Li, S.; Cendejas, R.; Huang, H.; Sakai, S.; Whitten, C.; Joseph, J.; Keane, D.; Margetis, S.; Rykov, V.; Zhang, W.M.; Bystersky, M.; Kapitan, J.; Kushpil, V.; Sumbera, M.; Baudot, J.; Hu-Guo, C.; Shabetai, A.; Szelezniak, M.; Winter, M.; Kelsey, J.; Milner, R.; Plesko, M.; Redwine, R.; Simon, F.; Surrow, B.; Van Nieuwenhuizen, G.; Anderssen, E.; Dong, X.; Greiner, L.; Matis, H.S.; Morgan, S.; Ritter, H.G.; Rose, A.; Sichtermann, E.; Singh, R.P.; Stezelberger, T.; Sun, X.; Thomas, J.H.; Tram, V.; Vu, C.; Wieman, H.H.; Xu, N.; Hirsch, A.; Srivastava, B.; Wang, F.; Xie, W.; Bichsel, H.

2008-01-01

The STAR Collaboration proposes to construct a state-of-the-art microvertex detector, the Heavy Flavor Tracker (HFT), utilizing active pixel sensors and silicon strip technology. The HFT will significantly extend the physics reach of the STAR experiment for precision measurement of the yields and spectra of particles containing heavy quarks. This will be accomplished through topological identification of D mesons by reconstruction of their displaced decay vertices with a precision of approximately 50 mu m in p+p, d+A, and A+A collisions. The HFT consists of 4 layers of silicon detectors grouped into two sub-systems with different technologies, guaranteeing increasing resolution when tracking from the TPC and the Silicon Strip Detector (SSD) towards the vertex of the collision. The Intermediate Silicon Tracker (IST), consisting of two layers of single-sided strips, is located inside the SSD. Two layers of Silicon Pixel Detector (PIXEL) are inside the IST. The PIXEL detectors have the resolution necessary for a precision measurement of the displaced vertex. The PIXEL detector will use CMOS Active Pixel Sensors (APS), an innovative technology never used before in a collider experiment. The APS sensors are only 50 mu m thick and at a distance of only 2.5 cm from the interaction point. This opens up a new realm of possibilities for physics measurements. In particular, a thin detector (0.28percent radiation length per layer) in STAR makes it possible to do the direct topological reconstruction of open charm hadrons down to very low pT by the identification of the charged daughters of the hadronic decay

A Heavy Flavor Tracker for STAR

Energy Technology Data Exchange (ETDEWEB)

Chasman, C.; Beavis, D.; Debbe, R.; Lee, J.H.; Levine, M.J.; Videbaek, F.; Xu, Z.; Kleinfelder, S.; Li, S.; Cendejas, R.; Huang, H.; Sakai, S.; Whitten, C.; Joseph, J.; Keane, D.; Margetis, S.; Rykov, V.; Zhang, W.M.; Bystersky, M.; Kapitan, J.; Kushpil, V.; Sumbera, M.; Baudot, J.; Hu-Guo, C.; Shabetai, A.; Szelezniak, M.; Winter, M.; Kelsey, J.; Milner, R.; Plesko, M.; Redwine, R.; Simon, F.; Surrow, B.; Van Nieuwenhuizen, G.; Anderssen, E.; Dong, X.; Greiner, L.; Matis, H.S.; Morgan, S.; Ritter, H.G.; Rose, A.; Sichtermann, E.; Singh, R.P.; Stezelberger, T.; Sun, X.; Thomas, J.H.; Tram, V.; Vu, C.; Wieman, H.H.; Xu, N.; Hirsch, A.; Srivastava, B.; Wang, F.; Xie, W.; Bichsel, H.

2008-02-25

The STAR Collaboration proposes to construct a state-of-the-art microvertex detector,the Heavy Flavor Tracker (HFT), utilizing active pixel sensors and silicon strip technology. The HFT will significantly extend the physics reach of the STAR experiment for precision measurement of the yields and spectra of particles containing heavy quarks. This will be accomplished through topological identification of D mesons by reconstruction of their displaced decay vertices with a precision of approximately 50 mu m in p+p, d+A, and A+A collisions. The HFT consists of 4 layers of silicon detectors grouped into two sub-systems with different technologies, guaranteeing increasing resolution when tracking from the TPC and the Silicon Strip Detector (SSD) towards the vertex of the collision. The Intermediate Silicon Tracker (IST), consisting of two layers of single-sided strips, is located inside the SSD. Two layers of Silicon Pixel Detector (PIXEL) are inside the IST. The PIXEL detectors have the resolution necessary for a precision measurement of the displaced vertex. The PIXEL detector will use CMOS Active Pixel Sensors (APS), an innovative technology never used before in a collider experiment. The APSsensors are only 50 mu m thick and at a distance of only 2.5 cm from the interaction point. This opens up a new realm of possibilities for physics measurements. In particular, a thin detector (0.28percent radiation length per layer) in STAR makes it possible to do the direct topological reconstruction of open charm hadrons down to very low pT by the identification of the charged daughters of the hadronic decay.

A New MPPT Control for Photovoltaic Panels by Instantaneous Maximum Power Point Tracking

Science.gov (United States)

Tokushima, Daiki; Uchida, Masato; Kanbei, Satoshi; Ishikawa, Hiroki; Naitoh, Haruo

This paper presents a new maximum power point tracking control for photovoltaic (PV) panels. The control can be categorized into the Perturb and Observe (P & O) method. It utilizes instantaneous voltage ripples at PV panel output terminals caused by the switching of a chopper connected to the panel in order to identify the direction for the maximum power point (MPP). The tracking for the MPP is achieved by a feedback control of the average terminal voltage of the panel. Appropriate use of the instantaneous and the average values of the PV voltage for the separate purposes enables both the quick transient response and the good convergence with almost no ripples simultaneously. The tracking capability is verified experimentally with a 2.8 W PV panel under a controlled experimental setup. A numerical comparison with a conventional P & O confirms that the proposed control extracts much more power from the PV panel.

Data acquisition software for the CMS strip tracker

International Nuclear Information System (INIS)

Bainbridge, R; Cripps, N; Fulcher, J; Radicci, V; Wingham, M; Baulieu, G; Bel, S; Delaere, C; Drouhin, F; Gill, K; Mirabito, L; Cole, J; Jesus, A C A; Giassi, A; Giordano, D; Gross, L; Hahn, K; Mersi, S; Nikolic, M; Tkaczyk, S

2008-01-01

The CMS silicon strip tracker, providing a sensitive area of approximately 200 m 2 and comprising 10 million readout channels, has recently been completed at the tracker integration facility at CERN. The strip tracker community is currently working to develop and integrate the online and offline software frameworks, known as XDAQ and CMSSW respectively, for the purposes of data acquisition and detector commissioning and monitoring. Recent developments have seen the integration of many new services and tools within the online data acquisition system, such as event building, online distributed analysis, an online monitoring framework, and data storage management. We review the various software components that comprise the strip tracker data acquisition system, the software architectures used for stand-alone and global data-taking modes. Our experiences in commissioning and operating one of the largest ever silicon micro-strip tracking systems are also reviewed

Maximum Power Point Tracking for Cascaded PV-Converter Modules Using Two-Stage Particle Swarm Optimization.

Science.gov (United States)

Mao, Mingxuan; Duan, Qichang; Zhang, Li; Chen, Hao; Hu, Bei; Duan, Pan

2017-08-24

The paper presents a novel two-stage particle swarm optimization (PSO) for the maximum power point tracking (MPPT) control of a PV system consisting of cascaded PV-converter modules, under partial shading conditions (PSCs). In this scheme, the grouping method of the shuffled frog leaping algorithm (SFLA) is incorporated with the basic PSO algorithm, ensuring fast and accurate searching of the global extremum. An adaptive speed factor is also introduced to improve its convergence speed. A PWM algorithm enabling permuted switching of the PV sources is applied. The method enables this PV system to achieve the maximum power generation for any number of PV and converter modules. Simulation studies of the proposed MPPT scheme are performed on a system having two chained PV buck-converter modules and a dc-ac H-bridge connected at its terminals for supplying an AC load. The results show that this type of PV system allows each module to achieve the maximum power generation according its illumination level without affecting the others, and the proposed new control method gives significantly higher power output compared with the conventional P&O and PSO methods.

Activity trackers: a critical review.

Science.gov (United States)

Lee, Jeon; Finkelstein, Joseph

2014-01-01

The wearable consumer health devices can be mainly divided into activity trackers, sleep trackers, and stress management devices. These devices are widely advertised to provide positive effects on the user's daily behaviours and overall heath. However, objective evidence supporting these claims appears to be missing. The goal of this study was to review available evidence pertaining to performance of activity trackers. A comprehensive review of available information has been conducted for seven representative devices and the validity of marketing claims was assessed. The device assessment was based on availability of verified output metrics, theoretical frameworks, systematic evaluation, and FDA clearance. The review identified critical absence of supporting evidence of advertised functions and benefits for the majority of the devices. Six out of seven devices did not provide any information on sensor accuracy and output validity at all. Possible underestimation or overestimation of specific health indicators reported to consumers was not clearly disclosed to the public. Furthermore, significant limitations of these devices which can be categorized into user restrictions, user responsibilities and company disclaimers could not be easily found or comprehended by unsophisticated users and may represent a serious health hazard.

The CMS tracker control system

International Nuclear Information System (INIS)

Dierlamm, A; Dirkes, G H; Fahrer, M; Frey, M; Hartmann, F; Masetti, L; Militaru, O; Shah, S Y; Stringer, R; Tsirou, A

2008-01-01

The Tracker Control System (TCS) is a distributed control software to operate about 2000 power supplies for the silicon modules of the CMS Tracker and monitor its environmental sensors. TCS must thus be able to handle about 10 4 power supply parameters, about 10 3 environmental probes from the Programmable Logic Controllers of the Tracker Safety System (TSS), about 10 5 parameters read via DAQ from the DCUs in all front end hybrids and from CCUs in all control groups. TCS is built on top of an industrial SCADA program (PVSS) extended with a framework developed at CERN (JCOP) and used by all LHC experiments. The logical partitioning of the detector is reflected in the hierarchical structure of the TCS, where commands move down to the individual hardware devices, while states are reported up to the root which is interfaced to the broader CMS control system. The system computes and continuously monitors the mean and maximum values of critical parameters and updates the percentage of currently operating hardware. Automatic procedures switch off selected parts of the detector using detailed granularity and avoiding widespread TSS intervention

Reliability and validity of ten consumer activity trackers

NARCIS (Netherlands)

Kooiman, Thea; Dontje, Manon L.; Sprenger, Siska; Krijnen, Wim; van der Schans, Cees; de Groot, Martijn

2015-01-01

Background: Activity trackers can potentially stimulate users to increase their physical activity behavior. The aim of this study was to examine the reliability and validity of ten consumer activity trackers for measuring step count in both laboratory and free-living conditions. Method: Healthy

Aerodynamical study of a photovoltaic solar tracker

OpenAIRE

Gutiérrez Castillo, José Leonardo

2016-01-01

Investigate the aerodynamic features of ground-mounted solar trackers under atmospheric boundary layer flows. Study and identify the aerodynamical interactions of solar trackers when they are displayed as an array. State of the art. Literature review about CFD applied to solar panels. Analytic approach of the problem. Application of CFD analysis. Validation of the results. Discussion of the results. Improvements proposal.

Laser tracker TSPI uncertainty quantification via centrifuge trajectory

Science.gov (United States)

Romero, Edward; Paez, Thomas; Brown, Timothy; Miller, Timothy

2009-08-01

Sandia National Laboratories currently utilizes two laser tracking systems to provide time-space-position-information (TSPI) and high speed digital imaging of test units under flight. These laser trackers have been in operation for decades under the premise of theoretical accuracies based on system design and operator estimates. Advances in optical imaging and atmospheric tracking technology have enabled opportunities to provide more precise six degree of freedom measurements from these trackers. Applying these technologies to the laser trackers requires quantified understanding of their current errors and uncertainty. It was well understood that an assortment of variables contributed to laser tracker uncertainty but the magnitude of these contributions was not quantified and documented. A series of experiments was performed at Sandia National Laboratories large centrifuge complex to quantify TSPI uncertainties of Sandia National Laboratories laser tracker III. The centrifuge was used to provide repeatable and economical test unit trajectories of a test-unit to use for TSPI comparison and uncertainty analysis. On a centrifuge, testunits undergo a known trajectory continuously with a known angular velocity. Each revolution may represent an independent test, which may be repeated many times over for magnitudes of data practical for statistical analysis. Previously these tests were performed at Sandia's rocket sled track facility but were found to be costly with challenges in the measurement ground truth TSPI. The centrifuge along with on-board measurement equipment was used to provide known ground truth position of test units. This paper discusses the experimental design and techniques used to arrive at measures of laser tracker error and uncertainty.

The research and development of the automatic solar power tracker

OpenAIRE

Li Yan Ping; Yuan Zhong Ying

2016-01-01

The article describes a kind of automatic tracker using solar power. It depends on two important parts which are servo system and adjusting mechanism system to keep the tracker operating normally. The article focuses on describing the characteristics and functions of two systems and the operating details of the automatic solar power tracker.

Maximum Power Point Tracking Based on Sliding Mode Control

Directory of Open Access Journals (Sweden)

Nimrod Vázquez

2015-01-01

Full Text Available Solar panels, which have become a good choice, are used to generate and supply electricity in commercial and residential applications. This generated power starts with the solar cells, which have a complex relationship between solar irradiation, temperature, and output power. For this reason a tracking of the maximum power point is required. Traditionally, this has been made by considering just current and voltage conditions at the photovoltaic panel; however, temperature also influences the process. In this paper the voltage, current, and temperature in the PV system are considered to be a part of a sliding surface for the proposed maximum power point tracking; this means a sliding mode controller is applied. Obtained results gave a good dynamic response, as a difference from traditional schemes, which are only based on computational algorithms. A traditional algorithm based on MPPT was added in order to assure a low steady state error.

Advances in RGB and RGBD Generic Object Trackers

KAUST Repository

Bibi, Adel Aamer

2016-01-01

new state-of-the-art trackers. One of which is 3D based tracker in a particle filter framework where both synchronization and registration of RGB and depth streams are adjusted automatically, and three works in correlation filters that achieve state-of-the-art

A simulator-based approach to evaluating optical trackers

NARCIS (Netherlands)

Smit, F.A.; Liere, van R.

2009-01-01

We describe a software framework to evaluate the performance of model-based optical trackers in virtual environments. The framework can be used to evaluate and compare the performance of different trackers under various conditions, to study the effects of varying intrinsic and extrinsic camera

Advances in RGB and RGBD Generic Object Trackers

KAUST Repository

Bibi, Adel

2016-04-01

Visual object tracking is a classical and very popular problem in computer vision with a plethora of applications such as vehicle navigation, human computer interface, human motion analysis, surveillance, auto-control systems and many more. Given the initial state of a target in the first frame, the goal of tracking is to predict states of the target over time where the states describe a bounding box covering the target. Despite numerous object tracking methods that have been proposed in recent years [1-4], most of these trackers suffer a degradation in performance mainly because of several challenges that include illumination changes, motion blur, complex motion, out of plane rotation, and partial or full occlusion, while occlusion is usually the most contributing factor in degrading the majority of trackers, if not all of them. This thesis is devoted to the advancement of generic object trackers tackling different challenges through different proposed methods. The work presented propose four new state-of-the-art trackers. One of which is 3D based tracker in a particle filter framework where both synchronization and registration of RGB and depth streams are adjusted automatically, and three works in correlation filters that achieve state-of-the-art performance in terms of accuracy while maintaining reasonable speeds.

SOLAR TO AC POWER SOURCE FOR REMOTE AREAS USING SEIG

Directory of Open Access Journals (Sweden)

MEHMET AKBABA

2012-02-01

Full Text Available Photovoltaic generators (PVG are increasingly used to provide electricity in remote areas. However, in many applications the DC generated electricity by a PVG need to be converted to AC. Traditionally DC to AC inverters have been widely used for this purpose. In this paper, a different system is proposed in which a self excited induction generator (SEIG driven by a permanent magnet DC motor (DCM and powered from a PVG through a maximum power point tracker (MPPT are used. A step-up chopper is utilized as an MPPT unit. The proposed system is modelled in time domain, and a detailed transient and steady-state analysis are presented. The main reason behind analyzing the system in the time domain is because of the fact that for unknown speeds, the methods developed for steady-state analysis of SEIGs can not be applied. The presented work shows that the full available power of the PVG can be harnessed by selecting suitable values for the duty cycle and the frequency of the step up chopper and the excitation capacitor of the SEIG. It is also shown that with such a combination power utilization efficiency of more than 83% can be achieved.

Direct tracking error characterization on a single-axis solar tracker

International Nuclear Information System (INIS)

Sallaberry, Fabienne; Pujol-Nadal, Ramon; Larcher, Marco; Rittmann-Frank, Mercedes Hannelore

2015-01-01

Highlights: • The solar tracker of a small-size parabolic trough collector was tested. • A testing procedure for the tracking error characterization of a single-axis tracker was proposed. • A statistical analysis on the tracking error distribution was done regarding different variables. • The optical losses due to the tracking error were calculated based on a ray-tracing simulation. - Abstract: The solar trackers are devices used to orientate solar concentrating systems in order to increase the focusing of the solar radiation on a receiver. A solar concentrator with a medium or high concentration ratio needs to be orientated correctly by an accurate solar tracking mechanism to avoid losing the sunrays out from the receiver. Hence, to obtain an appropriate operation, it is important to know the accuracy of a solar tracker in regard to the required precision of the concentrator in order to maximize the collector optical efficiency. A procedure for the characterization of the accuracy of a solar tracker is presented for a single-axis solar tracker. More precisely, this study focuses on the estimation of the positioning angle error of a parabolic trough collector using a direct procedure. A testing procedure, adapted from the International standard IEC 62817 for photovoltaic trackers, was defined. The results show that the angular tracking error was within ±0.4° for this tracker. The optical losses due to the tracking were calculated using the longitudinal incidence angle modifier obtained by ray-tracing simulation. The acceptance angles for various transversal angles were analyzed, and the average optical loss, due to the tracking, was 0.317% during the whole testing campaign. The procedure presented in this work showed that the tracker precision was adequate for the requirements of the analyzed optical system.

The research and development of the automatic solar power tracker

Directory of Open Access Journals (Sweden)

Li Yan Ping

2016-01-01

Full Text Available The article describes a kind of automatic tracker using solar power. It depends on two important parts which are servo system and adjusting mechanism system to keep the tracker operating normally. The article focuses on describing the characteristics and functions of two systems and the operating details of the automatic solar power tracker.

The LHCb Silicon Tracker Project

International Nuclear Information System (INIS)

Agari, M.; Bauer, C.; Baumeister, D.; Blouw, J.; Hofmann, W.; Knoepfle, K.T.; Loechner, S.; Schmelling, M.; Pugatch, V.; Bay, A.; Carron, B.; Frei, R.; Jiminez-Otero, S.; Tran, M.-T.; Voss, H.; Adeva, B.; Esperante, D.; Lois, C.; Vasquez, P.; Bernhard, R.P.; Bernet, R.; Ermoline, Y.; Gassner, J.; Koestner, S.; Lehner, F.; Needham, M.; Siegler, M.; Steinkamp, O.; Straumann, U.; Vollhardt, A.; Volyanskyy, D.

2006-01-01

Two silicon strip detectors, the Trigger Tracker(TT) and the Inner Tracker(Italy) will be constructed for the LHCb experiment. Transverse momentum information extracted from the TT will be used in the Level 1 trigger. The IT is part of the main tracking system behind the magnet. Both silicon detectors will be read out using a custom-developed chip by the ASIC lab in Heidelberg. The signal-over-noise behavior and performance of various geometrical designs of the silicon sensors, in conjunction with the Beetle read-out chip, have been extensively studied in test beam experiments. Results from those experiments are presented, and have been used in the final choice of sensor geometry

The CMS silicon strip tracker

International Nuclear Information System (INIS)

Focardi, E.; Albergo, S.; Angarano, M.; Azzi, P.; Babucci, E.; Bacchetta, N.; Bader, A.; Bagliesi, G.; Bartalini, P.; Basti, A.; Biggeri, U.; Bilei, G.M.; Bisello, D.; Boemi, D.; Bosi, F.; Borrello, L.; Bozzi, C.; Braibant, S.; Breuker, H.; Bruzzi, M.; Candelori, A.; Caner, A.; Castaldi, R.; Castro, A.; Catacchini, E.; Checcucci, B.; Ciampolini, P.; Civinini, C.; Creanza, D.; D'Alessandro, R.; Da Rold, M.; Demaria, N.; De Palma, M.; Dell'Orso, R.; Marina, R. Della; Dutta, S.; Eklund, C.; Elliott-Peisert, A.; Feld, L.; Fiore, L.; French, M.; Freudenreich, K.; Fuertjes, A.; Giassi, A.; Giraldo, A.; Glessing, B.; Gu, W.H.; Hall, G.; Hammerstrom, R.; Hebbeker, T.; Hrubec, J.; Huhtinen, M.; Kaminsky, A.; Karimaki, V.; Koenig, St.; Krammer, M.; Lariccia, P.; Lenzi, M.; Loreti, M.; Luebelsmeyer, K.; Lustermann, W.; Maettig, P.; Maggi, G.; Mannelli, M.; Mantovani, G.; Marchioro, A.; Mariotti, C.; Martignon, G.; Evoy, B. Mc; Meschini, M.; Messineo, A.; My, S.; Paccagnella, A.; Palla, F.; Pandoulas, D.; Parrini, G.; Passeri, D.; Pieri, M.; Piperov, S.; Potenza, R.; Raffaelli, F.; Raso, G.; Raymond, M.; Santocchia, A.; Schmitt, B.; Selvaggi, G.; Servoli, L.; Sguazzoni, G.; Siedling, R.; Silvestris, L.; Skog, K.; Starodumov, A.; Stavitski, I.; Stefanini, G.; Tempesta, P.; Tonelli, G.; Tricomi, A.; Tuuva, T.; Vannini, C.; Verdini, P.G.; Viertel, G.; Xie, Z.; Wang, Y.; Watts, S.; Wittmer, B.

1999-01-01

The Silicon Strip Tracker (SST) is the intermediate part of the CMS Central Tracker System. SST is based on microstrip silicon devices and in combination with pixel detectors and the Microstrip Gas Chambers aims at performing pattern recognition, track reconstruction and momentum measurements for all tracks with p T ≥2 GeV/c originating from high luminosity interactions at √s=14 TeV at LHC. We aim at exploiting the advantages and the physics potential of the precise tracking performance provided by the microstrip silicon detectors on a large scale apparatus and in a much more difficult environment than ever. In this paper we describe the actual SST layout and the readout system. (author)

A REVIEW OF EXPERIMENTAL STUDY OF POWER QUALITY MEASUREMENT OF PHOTOVOLTAIC CELLS WITH MAXIMUM POWER POINT TRACKING SYSTEM

OpenAIRE

Smriti Dwivedi; Prof. Sunil Kumar Bhatt

2016-01-01

Maximum power point tracking (MPPT) is a technique that charge controllers use for wind turbines and PV solar systems to maximize power output. PV solar systems exist in several different configurations. The most basic version sends power from collector panels directly to the DC-AC inverter and from there directly to the electrical grid. A second version, called a hybrid inverter, might split the power at the inverter, where a percentage of the power goes to the grid and the remainder goes to...

Work on the ATLAS semiconductor tracker barrel

CERN Multimedia

Maximilien Brice

2005-01-01

Precision work is performed on the semiconductor tracker barrel of the ATLAS experiment. All work on these delicate components must be performed in a clean room so that impurities in the air, such as dust, do not contaminate the detector. The semiconductor tracker will be mounted in the barrel close to the heart of the ATLAS experiment to detect the path of particles produced in proton-proton collisions.

A new mapping function in table-mounted eye tracker

Science.gov (United States)

Tong, Qinqin; Hua, Xiao; Qiu, Jian; Luo, Kaiqing; Peng, Li; Han, Peng

2018-01-01

Eye tracker is a new apparatus of human-computer interaction, which has caught much attention in recent years. Eye tracking technology is to obtain the current subject's "visual attention (gaze)" direction by using mechanical, electronic, optical, image processing and other means of detection. While the mapping function is one of the key technology of the image processing, and is also the determination of the accuracy of the whole eye tracker system. In this paper, we present a new mapping model based on the relationship among the eyes, the camera and the screen that the eye gazed. Firstly, according to the geometrical relationship among the eyes, the camera and the screen, the framework of mapping function between the pupil center and the screen coordinate is constructed. Secondly, in order to simplify the vectors inversion of the mapping function, the coordinate of the eyes, the camera and screen was modeled by the coaxial model systems. In order to verify the mapping function, corresponding experiment was implemented. It is also compared with the traditional quadratic polynomial function. And the results show that our approach can improve the accuracy of the determination of the gazing point. Comparing with other methods, this mapping function is simple and valid.

A Hybrid Maximum Power Point Tracking Approach for Photovoltaic Systems under Partial Shading Conditions Using a Modified Genetic Algorithm and the Firefly Algorithm

Directory of Open Access Journals (Sweden)

Yu-Pei Huang

2018-01-01

Full Text Available This paper proposes a modified maximum power point tracking (MPPT algorithm for photovoltaic systems under rapidly changing partial shading conditions (PSCs. The proposed algorithm integrates a genetic algorithm (GA and the firefly algorithm (FA and further improves its calculation process via a differential evolution (DE algorithm. The conventional GA is not advisable for MPPT because of its complicated calculations and low accuracy under PSCs. In this study, we simplified the GA calculations with the integration of the DE mutation process and FA attractive process. Results from both the simulation and evaluation verify that the proposed algorithm provides rapid response time and high accuracy due to the simplified processing. For instance, evaluation results demonstrate that when compared to the conventional GA, the execution time and tracking accuracy of the proposed algorithm can be, respectively, improved around 69.4% and 4.16%. In addition, in comparison to FA, the tracking speed and tracking accuracy of the proposed algorithm can be improved around 42.9% and 1.85%, respectively. Consequently, the major improvement of the proposed method when evaluated against the conventional GA and FA is tracking speed. Moreover, this research provides a framework to integrate multiple nature-inspired algorithms for MPPT. Furthermore, the proposed method is adaptable to different types of solar panels and different system formats with specifically designed equations, the advantages of which are rapid tracking speed with high accuracy under PSCs.

The CMS Tracker Data Quality Monitoring Expert GUI

CERN Document Server

Palmonari, Francesco

2009-01-01

The CMS Tracker data quality monitoring (DQM) is a demanding task due the detector's high granularity. It consists of about 15148 strip and 1440 pixel detector modules. About 350,000 histograms are defined and filled accessing information from different stages of data reconstruction to check the data quality. It is impossible to manage such a large number of histograms by shift personnel and experts. A tracker specific Graphical User Interface (GUI) is developed to simplify the navigation and to spot detector problems efficiently. The GUI is web-based and implemented with Ajax technology. We will describe the framework and the specific features of the expert GUI developed for the CMS Tracker DQM system.

Design of improved controller for thermoelectric generator used in distributed generation

Energy Technology Data Exchange (ETDEWEB)

Molina, M.G. [CONICET, Instituto de Energia Electrica, Universidad Nacional de San Juan, Av. Libertador San Martin Oeste, 1109, J5400ARL, San Juan (Argentina); Juanico, L.E. [CONICET, Centro Atomico Bariloche, 8400 Bariloche (Argentina); Rinalde, G.F.; Taglialavore, E.; Gortari, S. [Centro Atomico Bariloche, 8400 Bariloche (Argentina)

2010-06-15

This paper investigates the application of thermal generation based on solid-state devices such as thermoelectric generators (TEGs) as a novel technological alternative of distributed generation (DG). The full detailed modeling and the dynamic simulation of a three-phase grid-connected TEG used as a dispersed generator is studied. Moreover, a new control scheme of the TEG is proposed, which consists of a multi-level hierarchical structure and incorporates a maximum power point tracker (MPPT) for better use of the thermal resource. In addition, reactive power compensation of the electric grid is included, operating simultaneously and independently of the active power generation. Validation of models and control schemes is performed by using the MATLAB/Simulink environment. Moreover, a small-scale TEG experimental set-up was employed to demonstrate the accuracy of proposed models. (author)

Control Algorithms for Large-scale Single-axis Photovoltaic Trackers

Directory of Open Access Journals (Sweden)

Dorian Schneider

2012-01-01

Full Text Available The electrical yield of large-scale photovoltaic power plants can be greatly improved by employing solar trackers. While fixed-tilt superstructures are stationary and immobile, trackers move the PV-module plane in order to optimize its alignment to the sun. This paper introduces control algorithms for single-axis trackers (SAT, including a discussion for optimal alignment and backtracking. The results are used to simulate and compare the electrical yield of fixed-tilt and SAT systems. The proposed algorithms have been field tested, and are in operation in solar parks worldwide.

The DELPHI Silicon Tracker in the global pattern recognition

CERN Document Server

Elsing, M

2000-01-01

ALEPH and DELPHI were the first experiments operating a silicon vertex detector at LEP. During the past 10 years of data taking the DELPHI Silicon Tracker was upgraded three times to follow the different tracking requirements for LEP 1 and LEP 2 as well as to improve the tracking performance. Several steps in the development of the pattern recognition software were done in order to understand and fully exploit the silicon tracker information. This article gives an overview of the final algorithms and concepts of the track reconstruction using the Silicon Tracker in DELPHI.

The DELPHI Silicon Tracker in the global pattern recognition

International Nuclear Information System (INIS)

Elsing, M.

2000-01-01

ALEPH and DELPHI were the first experiments operating a silicon vertex detector at LEP. During the past 10 years of data taking the DELPHI Silicon Tracker was upgraded three times to follow the different tracking requirements for LEP 1 and LEP 2 as well as to improve the tracking performance. Several steps in the development of the pattern recognition software were done in order to understand and fully exploit the silicon tracker information. This article gives an overview of the final algorithms and concepts of the track reconstruction using the Silicon Tracker in DELPHI

Technical Training Seminar: Laser Trackers: the Local Positioning Technology (LPT)

CERN Document Server

Davide Vitè

2005-01-01

Friday 20 May from 10:00 to 16:00, Training Centre (bldg. 593) Laser Trackers: the Local Positioning Technology (LPT) Simon Moser, Michael Lettau, Achim Lupus, Niklaus Suter, Leica GEOSYSTEMS AG, Switzerland Laser trackers are used at CERN for different applications within the LHC Project. Leica Geosystems AG have been developing during the last four years the revolutionary Local Positioning Technology (LPT). Laser trackers are increasingly used to ensure accuracy of large fabrications, and alignment in the final assembly process. Competing portable Coordinate Measuring Machines (CMM) with articulated arms require a frequent repositioning, known to lead to a loss of accuracy and efficiency. Leica Geosystems developed armless solutions, the T-Probe and T-Scan, for use with its laser trackers. The combination of the tracker technology with photogrammetry is the base of LPT, enabling real time measurements with free hand-held devices, such as the T-Probe and T-Scan. T-Probe and T-Scan overcome the proble...

Documentation for delivery of Star Tracker to CHAMP

DEFF Research Database (Denmark)

Madsen, Peter Buch; Betto, Maurizio; Jørgensen, John Leif

1999-01-01

The documentation EIDP (End Item Data Package) describes all the tests which have been performed on the flight hardware of the Star Tracker for the German satellite CHAMP.......The documentation EIDP (End Item Data Package) describes all the tests which have been performed on the flight hardware of the Star Tracker for the German satellite CHAMP....

The ATLAS Fast Tracker

CERN Document Server

Volpi, Guido; The ATLAS collaboration

2015-01-01

The use of tracking information at the trigger level in the LHC Run II period is crucial for the trigger an data acquisition (TDAQ) system. The tracking precision is in fact important to identify specific decay products of the Higgs boson or new phenomena, a well as to distinguish the contributions coming from many contemporary collisions that occur at every bunch crossing. However, the track reconstruction is among the most demanding tasks performed by the TDAQ computing farm; in fact, full reconstruction at full Level-1 trigger accept rate (100 KHz) is not possible. In order to overcome this limitation, the ATLAS experiment is planning the installation of a specific processor: the Fast Tracker (FTK), which is aimed at achieving this goal. The FTK is a pipeline of high performance electronic, based on custom and commercial devices, which is expected to reconstruct, with high resolution, the trajectories of charged tracks with a transverse momentum above 1 GeV, using the ATLAS inner tracker information. Patte...

EMC Diagnosis and Corrective Actions for Silicon Strip Tracker Detectors

Energy Technology Data Exchange (ETDEWEB)

Arteche, F.; /CERN /Imperial Coll., London; Rivetta, C.; /SLAC

2006-06-06

The tracker sub-system is one of the five sub-detectors of the Compact Muon Solenoid (CMS) experiment under construction at CERN for the Large Hadron Collider (LHC) accelerator. The tracker subdetector is designed to reconstruct tracks of charged sub-atomic particles generated after collisions. The tracker system processes analogue signals from 10 million channels distributed across 14000 silicon micro-strip detectors. It is designed to process signals of a few nA and digitize them at 40 MHz. The overall sub-detector is embedded in a high particle radiation environment and a magnetic field of 4 Tesla. The evaluation of the electromagnetic immunity of the system is very important to optimize the performance of the tracker sub-detector and the whole CMS experiment. This paper presents the EMC diagnosis of the CMS silicon tracker sub-detector. Immunity tests were performed using the final prototype of the Silicon Tracker End-Caps (TEC) system to estimate the sensitivity of the system to conducted noise, evaluate the weakest areas of the system and take corrective actions before the integration of the overall detector. This paper shows the results of one of those tests, that is the measurement and analysis of the immunity to CM external conducted noise perturbations.

The fast tracker processor for hadronic collider triggers

CERN Document Server

Annovi, A; Bardi, A; Carosi, R; Dell'Orso, Mauro; D'Onofrio, M; Giannetti, P; Iannaccone, G; Morsani, F; Pietri, M; Varotto, G

2000-01-01

Perspective for precise and fast track reconstruction in future hadronic collider experiments are addressed. We discuss the feasibility of a pipelined highly parallelized processor dedicated to the implementation of a very fast algorithm. The algorithm is based on the use of a large bank of pre-stored combinations of trajectory points (patterns) for extremely complex tracking systems. The CMS experiment at LHC is used as a benchmark. Tracking data from the events selected by the level-1 trigger are sorted and filtered by the Fast Tracker processor at a rate of 100 kHz. This data organization allows the level-2 trigger logic to reconstruct full resolution traces with transverse momentum above few GeV and search secondary vertexes within typical level-2 times. 15 Refs.

Construction and calibration of the laser alignment system for the CMS tracker

OpenAIRE

Adolphi, Roman

2006-01-01

The CMS detector (Compact Muon Solenoid) is under construction at one of the four proton-proton interaction points of the LHC (Large Hadron Collider) at CERN, the European Organization for Nuclear Research (Geneva, Switzerland). The inner tracking system of the CMS experiment consisting of silicon detectors will have a diameter of 2.4 meter and a length of 5.4 meter representing the largest silicon tracker ever. About 15000 silicon strip modules create an active silicon area of 200 square met...

Simulation Modeling of Intelligent Control Algorithms for Constructing Autonomous Power Supply Systems with Improved Energy Efficiency

Directory of Open Access Journals (Sweden)

Gimazov Ruslan

2018-01-01

Full Text Available The paper considers the issue of supplying autonomous robots by solar batteries. Low efficiency of modern solar batteries is a critical issue for the whole industry of renewable energy. The urgency of solving the problem of improved energy efficiency of solar batteries for supplying the robotic system is linked with the task of maximizing autonomous operation time. Several methods to improve the energy efficiency of solar batteries exist. The use of MPPT charge controller is one these methods. MPPT technology allows increasing the power generated by the solar battery by 15 – 30%. The most common MPPT algorithm is the perturbation and observation algorithm. This algorithm has several disadvantages, such as power fluctuation and the fixed time of the maximum power point tracking. These problems can be solved by using a sufficiently accurate predictive and adaptive algorithm. In order to improve the efficiency of solar batteries, autonomous power supply system was developed, which included an intelligent MPPT charge controller with the fuzzy logic-based perturbation and observation algorithm. To study the implementation of the fuzzy logic apparatus in the MPPT algorithm, in Matlab/Simulink environment, we developed a simulation model of the system, including solar battery, MPPT controller, accumulator and load. Results of the simulation modeling established that the use of MPPT technology had increased energy production by 23%; introduction of the fuzzy logic algorithm to MPPT controller had greatly increased the speed of the maximum power point tracking and neutralized the voltage fluctuations, which in turn reduced the power underproduction by 2%.

Performance studies of the CMS Strip Tracker before installation

CERN Document Server

Adam, Wolfgang; Dragicevic, Marko; Friedl, Markus; Fruhwirth, R; Hansel, S; Hrubec, Josef; Krammer, Manfred; Oberegger, Margit; Pernicka, Manfred; Schmid, Siegfried; Stark, Roland; Steininger, Helmut; Uhl, Dieter; Waltenberger, Wolfgang; Widl, Edmund; Van Mechelen, Pierre; Cardaci, Marco; Beaumont, Willem; de Langhe, Eric; de Wolf, Eddi A; Delmeire, Evelyne; Hashemi, Majid; Bouhali, Othmane; Charaf, Otman; Clerbaux, Barbara; Dewulf, Jean-Paul; Elgammal, Sherif; Hammad, Gregory Habib; de Lentdecker, Gilles; Marage, Pierre Edouard; Vander Velde, Catherine; Vanlaer, Pascal; Wickens, John; Adler, Volker; Devroede, Olivier; De Weirdt, Stijn; D'Hondt, Jorgen; Goorens, Robert; Heyninck, Jan; Maes, Joris; Mozer, Matthias Ulrich; Tavernier, Stefaan; Van Lancker, Luc; Van Mulders, Petra; Villella, Ilaria; Wastiels, C; Bonnet, Jean-Luc; Bruno, Giacomo; De Callatay, Bernard; Florins, Benoit; Giammanco, Andrea; Gregoire, Ghislain; Keutgen, Thomas; Kcira, Dorian; Lemaitre, Vincent; Michotte, Daniel; Militaru, Otilia; Piotrzkowski, Krzysztof; Quertermont, L; Roberfroid, Vincent; Rouby, Xavier; Teyssier, Daniel; Daubie, Evelyne; Anttila, Erkki; Czellar, Sandor; Engstrom, Pauli; Harkonen, J; Karimaki, V; Kostesmaa, J; Kuronen, Auli; Lampen, Tapio; Linden, Tomas; Luukka, Panja-Riina; Maenpaa, T; Michal, Sebastien; Tuominen, Eija; Tuominiemi, Jorma; Ageron, Michel; Baulieu, Guillaume; Bonnevaux, Alain; Boudoul, Gaelle; Chabanat, Eric; Chabert, Eric Christian; Chierici, Roberto; Contardo, Didier; Della Negra, Rodolphe; Dupasquier, Thierry; Gelin, Georges; Giraud, Noël; Guillot, Gérard; Estre, Nicolas; Haroutunian, Roger; Lumb, Nicholas; Perries, Stephane; Schirra, Florent; Trocme, Benjamin; Vanzetto, Sylvain; Agram, Jean-Laurent; Blaes, Reiner; Drouhin, Frédéric; Ernenwein, Jean-Pierre; Fontaine, Jean-Charles; Berst, Jean-Daniel; Brom, Jean-Marie; Didierjean, Francois; Goerlach, Ulrich; Graehling, Philippe; Gross, Laurent; Hosselet, J; Juillot, Pierre; Lounis, Abdenour; Maazouzi, Chaker; Olivetto, Christian; Strub, Roger; Van Hove, Pierre; Anagnostou, Georgios; Brauer, Richard; Esser, Hans; Feld, Lutz; Karpinski, Waclaw; Klein, Katja; Kukulies, Christoph; Olzem, Jan; Ostapchuk, Andrey; Pandoulas, Demetrios; Pierschel, Gerhard; Raupach, Frank; Schael, Stefan; Schwering, Georg; Sprenger, Daniel; Thomas, Maarten; Weber, Markus; Wittmer, Bruno; Wlochal, Michael; Beissel, Franz; Bock, E; Flugge, G; Gillissen, C; Hermanns, Thomas; Heydhausen, Dirk; Jahn, Dieter; Kaussen, Gordon; Linn, Alexander; Perchalla, Lars; Poettgens, Michael; Pooth, Oliver; Stahl, Achim; Zoeller, Marc Henning; Buhmann, Peter; Butz, Erik; Flucke, Gero; Hamdorf, Richard Helmut; Hauk, Johannes; Klanner, Robert; Pein, Uwe; Schleper, Peter; Steinbruck, G; Blum, P; De Boer, Wim; Dierlamm, Alexander; Dirkes, Guido; Fahrer, Manuel; Frey, Martin; Furgeri, Alexander; Hartmann, Frank; Heier, Stefan; Hoffmann, Karl-Heinz; Kaminski, Jochen; Ledermann, Bernhard; Liamsuwan, Thiansin; Muller, S; Muller, Th; Schilling, Frank-Peter; Simonis, Hans-Jürgen; Steck, Pia; Zhukov, Valery; Cariola, P; De Robertis, Giuseppe; Ferorelli, Raffaele; Fiore, Luigi; Preda, M; Sala, Giuliano; Silvestris, Lucia; Tempesta, Paolo; Zito, Giuseppe; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Giordano, Domenico; Maggi, Giorgio; Manna, Norman; My, Salvatore; Selvaggi, Giovanna; Albergo, Sebastiano; Chiorboli, Massimiliano; Costa, Salvatore; Galanti, Mario; Giudice, Nunzio; Guardone, Nunzio; Noto, Francesco; Potenza, Renato; Saizu, Mirela Angela; Sparti, V; Sutera, Concetta; Tricomi, Alessia; Tuve, Cristina; Brianzi, Mirko; Civinini, Carlo; Maletta, Fernando; Manolescu, Florentina; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Broccolo, B; Ciulli, Vitaliano; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Genta, Chiara; Landi, Gregorio; Lenzi, Piergiulio; Macchiolo, Anna; Magini, Nicolo; Parrini, Giuliano; Scarlini, Enrico; Cerati, Giuseppe Benedetto; Azzi, Patrizia; Bacchetta, Nicola; Candelori, Andrea; Dorigo, Tommaso; Kaminsky, A; Karaevski, S; Khomenkov, Volodymyr; Reznikov, Sergey; Tessaro, Mario; Bisello, Dario; De Mattia, Marco; Giubilato, Piero; Loreti, Maurizio; Mattiazzo, Serena; Nigro, Massimo; Paccagnella, Alessandro; Pantano, Devis; Pozzobon, Nicola; Tosi, Mia; Bilei, Gian Mario; Checcucci, Bruno; Fano, Livio; Servoli, Leonello; Ambroglini, Filippo; Babucci, Ezio; Benedetti, Daniele; Biasini, Maurizio; Caponeri, Benedetta; Covarelli, Roberto; Giorgi, Marco; Lariccia, Paolo; Mantovani, Giancarlo; Marcantonini, Marta; Postolache, Vasile; Santocchia, Attilio; Spiga, Daniele; Bagliesi, Giuseppe; Balestri, Gabriele; Berretta, Luca; Bianucci, S; Boccali, Tommaso; Bosi, Filippo; Bracci, Fabrizio; Castaldi, Rino; Ceccanti, Marco; Cecchi, Roberto; Cerri, Claudio; Cucoanes, Andi Sebastian; Dell'Orso, Roberto; Dobur, Didar; Dutta, Suchandra; Giassi, Alessandro; Giusti, Simone; Kartashov, Dmitry; Kraan, Aafke; Lomtadze, Teimuraz; Lungu, George-Adrian; Magazzu, Guido; Mammini, Paolo; Mariani, Filippo; Martinelli, Giovanni; Moggi, Andrea; Palla, Fabrizio; Palmonari, Francesco; Petragnani, Giulio; Profeti, Alessandro; Raffaelli, Fabrizio; Rizzi, Domenico; Sanguinetti, Giulio; Sarkar, Subir; Sentenac, Daniel; Serban, Alin Titus; Slav, Adrian; Soldani, A; Spagnolo, Paolo; Tenchini, Roberto; Tolaini, Sergio; Venturi, Andrea; Verdini, Piero Giorgio; Vos, Marcel; Zaccarelli, Luciano; Avanzini, Carlo; Basti, Andrea; Benucci, Leonardo; Bocci, Andrea; Cazzola, Ugo; Fiori, Francesco; Linari, Stefano; Massa, Maurizio; Messineo, Alberto; Segneri, Gabriele; Tonelli, Guido; Azzurri, Paolo; Bernardini, Jacopo; Borrello, Laura; Calzolari, Federico; Foa, Lorenzo; Gennai, Simone; Ligabue, Franco; Petrucciani, Giovanni; Rizzi, Andrea; Yang, Zong-Chang; Benotto, Franco; Demaria, Natale; Dumitrache, Floarea; Farano, R; Borgia, Maria Assunta; Castello, Roberto; Costa, Marco; Migliore, Ernesto; Romero, Alessandra; Abbaneo, Duccio; Abbas, M; Ahmed, Ijaz; Akhtar, I; Albert, Eric; Bloch, Christoph; Breuker, Horst; Butt, Shahid Aleem; Buchmuller, Oliver; Cattai, Ariella; Delaere, Christophe; Delattre, Michel; Edera, Laura Maria; Engstrom, Pauli; Eppard, Michael; Gateau, Maryline; Gill, Karl; Giolo-Nicollerat, Anne-Sylvie; Grabit, Robert; Honma, Alan; Huhtinen, Mika; Kloukinas, Kostas; Kortesmaa, Jarmo; Kottelat, Luc-Joseph; Kuronen, Auli; Leonardo, Nuno; Ljuslin, Christer; Mannelli, Marcello; Masetti, Lorenzo; Marchioro, Alessandro; Mersi, Stefano; Michal, Sebastien; Mirabito, Laurent; Muffat-Joly, Jeannine; Onnela, Antti; Paillard, Christian; Pal, Imre; Pernot, Jean-Francois; Petagna, Paolo; Petit, Patrick; Piccut, C; Pioppi, Michele; Postema, Hans; Ranieri, Riccardo; Ricci, Daniel; Rolandi, Gigi; Ronga, Frederic Jean; Sigaud, Christophe; Syed, A; Siegrist, Patrice; Tropea, Paola; Troska, Jan; Tsirou, Andromachi; Vander Donckt, Muriel; Vasey, François; Alagoz, Enver; Amsler, Claude; Chiochia, Vincenzo; Regenfus, Christian; Robmann, Peter; Rochet, Jacky; Rommerskirchen, Tanja; Schmidt, Alexander; Steiner, Stefan; Wilke, Lotte; Church, Ivan; Cole, Joanne; Coughlan, John A; Gay, Arnaud; Taghavi, S; Tomalin, Ian R; Bainbridge, Robert; Cripps, Nicholas; Fulcher, Jonathan; Hall, Geoffrey; Noy, Matthew; Pesaresi, Mark; Radicci, Valeria; Raymond, David Mark; Sharp, Peter; Stoye, Markus; Wingham, Matthew; Zorba, Osman; Goitom, Israel; Hobson, Peter R; Reid, Ivan; Teodorescu, Liliana; Hanson, Gail; Jeng, Geng-Yuan; Liu, Haidong; Pasztor, Gabriella; Satpathy, Asish; Stringer, Robert; Mangano, Boris; Affolder, K; Affolder, T; Allen, Andrea; Barge, Derek; Burke, Samuel; Callahan, D; Campagnari, Claudio; Crook, A; D'Alfonso, Mariarosaria; Dietch, J; Garberson, Jeffrey; Hale, David; Incandela, H; Incandela, Joe; Jaditz, Stephen; Kalavase, Puneeth; Kreyer, Steven Lawrence; Kyre, Susanne; Lamb, James; Mc Guinness, C; Mills, C; Nguyen, Harold; Nikolic, Milan; Lowette, Steven; Rebassoo, Finn; Ribnik, Jacob; Richman, Jeffrey; Rubinstein, Noah; Sanhueza, S; Shah, Yousaf Syed; Simms, L; Staszak, D; Stoner, J; Stuart, David; Swain, Sanjay Kumar; Vlimant, Jean-Roch; White, Dean; Ulmer, Keith; Wagner, Stephen Robert; Bagby, Linda; Bhat, Pushpalatha C; Burkett, Kevin; Cihangir, Selcuk; Gutsche, Oliver; Jensen, Hans; Johnson, Mark; Luzhetskiy, Nikolay; Mason, David; Miao, Ting; Moccia, Stefano; Noeding, Carsten; Ronzhin, Anatoly; Skup, Ewa; Spalding, William J; Spiegel, Leonard; Tkaczyk, Slawek; Yumiceva, Francisco; Zatserklyaniy, Andriy; Zerev, E; Anghel, Ioana Maria; Bazterra, Victor Eduardo; Gerber, Cecilia Elena; Khalatian, S; Shabalina, Elizaveta; Baringer, Philip; Bean, Alice; Chen, Jie; Hinchey, Carl Louis; Martin, Christophe; Moulik, Tania; Robinson, Richard; Gritsan, Andrei; Lae, Chung Khim; Tran, Nhan Viet; Everaerts, Pieter; Hahn, Kristan Allan; Harris, Philip; Nahn, Steve; Rudolph, Matthew; Sung, Kevin; Betchart, Burton; Demina, Regina; Gotra, Yury; Korjenevski, Sergey; Miner, Daniel Carl; Orbaker, Douglas; Christofek, Leonard; Hooper, Ryan; Landsberg, Greg; Nguyen, Duong; Narain, Meenakshi; Speer, Thomas; Tsang, Ka Vang

2009-01-01

In March 2007 the assembly of the Silicon Strip Tracker was completed at the Tracker Integration Facility at CERN. Nearly 15% of the detector was instrumented using cables, fiber optics, power supplies, and electronics intended for the operation at the LHC. A local chiller was used to circulate the coolant for low temperature operation. In order to understand the efficiency and alignment of the strip tracker modules, a cosmic ray trigger was implemented. From March through July 4.5 million triggers were recorded. This period, referred to as the Sector Test, provided practical experience with the operation of the Tracker, especially safety, data acquisition, power, and cooling systems. This paper describes the performance of the strip system during the Sector Test, which consisted of five distinct periods defined by the coolant temperature. Significant emphasis is placed on comparisons between the data and results from Monte Carlo studies.

A proposed adaptive step size perturbation and observation maximum power point tracking algorithm based on photovoltaic system modeling

Science.gov (United States)

Huang, Yu

Solar energy becomes one of the major alternative renewable energy options for its huge abundance and accessibility. Due to the intermittent nature, the high demand of Maximum Power Point Tracking (MPPT) techniques exists when a Photovoltaic (PV) system is used to extract energy from the sunlight. This thesis proposed an advanced Perturbation and Observation (P&O) algorithm aiming for relatively practical circumstances. Firstly, a practical PV system model is studied with determining the series and shunt resistances which are neglected in some research. Moreover, in this proposed algorithm, the duty ratio of a boost DC-DC converter is the object of the perturbation deploying input impedance conversion to achieve working voltage adjustment. Based on the control strategy, the adaptive duty ratio step size P&O algorithm is proposed with major modifications made for sharp insolation change as well as low insolation scenarios. Matlab/Simulink simulation for PV model, boost converter control strategy and various MPPT process is conducted step by step. The proposed adaptive P&O algorithm is validated by the simulation results and detail analysis of sharp insolation changes, low insolation condition and continuous insolation variation.

Last ATLAS transition radiation tracker module installed

CERN Multimedia

Maximilien Brice

2005-01-01

The ATLAS transition radiation tracker consists of 96 modules and will join the pixel detector and silicon tracker at the heart of the experiment to map the trajectories of particles and identify electrons produced when proton beams collide. In the last image the team responsible for assembly are shown from left to right: Kirill Egorov (Petersburg Nuclear Physics Institute), Pauline Gagnon (Indiana University), Ben Legeyt (University of Pennsylvania), Chuck Long (Hampton University), John Callahan (Indiana University) and Alex High (University of Pennsylvania).

Electrical properties of various types of straw tubes considered for the LHCb outer tracker

CERN Document Server

Gromov, V

2001-01-01

Because of the appreciable length (up to 3.6 m) of the straw tube modules of the Outer Tracker, transmission line effects will have impact on their operational properties. These effects were clearly observed in a 1.6 m long prototype. A few types of straw tubes have been examined from the point of view of electrical properties, with emphasis on the study of signal transmission and cross-talk.

Radiation hard silicon sensors for the CMS tracker upgrade

CERN Document Server

Pohlsen, Thomas

2013-01-01

At an instantaneous luminosity of $5 \\times 10^{34}$ cm$^{-2}$ s$^{-1}$, the high-luminosity phase of the Large Hadron Collider (HL-LHC) is expected to deliver a total of $3\\,000$ fb$^{-1}$ of collisions, hereby increasing the discovery potential of the LHC experiments significantly. However, the radiation dose of the tracking systems will be severe, requiring new radiation hard sensors for the CMS tracker. The CMS tracker collaboration has initiated a large material investigation and irradiation campaign to identify the silicon material and design that fulfils all requirements for detectors for the HL-LHC. Focussing on the upgrade of the outer tracker region, pad sensors as well as fully functional strip sensors have been implemented on silicon wafers with different material properties and thicknesses. The samples were irradiated with a mixture of neutrons and protons corresponding to fluences as expected for the positions of detector layers in the future tracker. Different proton energies were used for irr...

Software alignment of the LHCb Outer Tracker chambers

Energy Technology Data Exchange (ETDEWEB)

Deissenroth, Marc

2010-04-21

This work presents an alignment algorithm that was developed to precisely determine the positions of the LHCb Outer Tracker detector elements. The algorithm is based on the reconstruction of tracks and exploits that misalignments of the detector change the residual between a measured hit and the reconstructed track. It considers different levels of granularities of the Outer Tracker geometry and fully accounts for correlations of all elements which are imposed by particle trajectories. In extensive tests, simulated shifts and rotations for different levels of the detector granularity have been used as input to the track reconstruction and alignment procedure. With about 260 000 tracks the misalignments are recovered with a statistical precision of O(10 - 100 {mu}m) for the translational degrees of freedom and of O(10{sup -2} - 10{sup -1} mrad) for rotations. A study has been performed to determine the impact of Outer Tracker misalignments on the performance of the track reconstruction algorithms. It shows that the achieved statistical precision does not decrease the track reconstruction performance in a significant way. During the commissioning of the LHCb detector, cosmic ray muon events have been collected. The events have been analysed and used for the first alignment of the 216 Outer Tracker modules. The module positions have been determined within {proportional_to} 90 {mu}m. The developed track based alignment algorithm has demonstrated its reliability and is one of the core algorithms which are used for the precise determination of the positions of the LHCb Outer Tracker elements. (orig.)

Software alignment of the LHCb Outer Tracker chambers

International Nuclear Information System (INIS)

Deissenroth, Marc

2010-01-01

This work presents an alignment algorithm that was developed to precisely determine the positions of the LHCb Outer Tracker detector elements. The algorithm is based on the reconstruction of tracks and exploits that misalignments of the detector change the residual between a measured hit and the reconstructed track. It considers different levels of granularities of the Outer Tracker geometry and fully accounts for correlations of all elements which are imposed by particle trajectories. In extensive tests, simulated shifts and rotations for different levels of the detector granularity have been used as input to the track reconstruction and alignment procedure. With about 260 000 tracks the misalignments are recovered with a statistical precision of O(10 - 100 μm) for the translational degrees of freedom and of O(10 -2 - 10 -1 mrad) for rotations. A study has been performed to determine the impact of Outer Tracker misalignments on the performance of the track reconstruction algorithms. It shows that the achieved statistical precision does not decrease the track reconstruction performance in a significant way. During the commissioning of the LHCb detector, cosmic ray muon events have been collected. The events have been analysed and used for the first alignment of the 216 Outer Tracker modules. The module positions have been determined within ∝ 90 μm. The developed track based alignment algorithm has demonstrated its reliability and is one of the core algorithms which are used for the precise determination of the positions of the LHCb Outer Tracker elements. (orig.)

Construction and Calibration of the Laser Alignment System for the CMS Tracker

CERN Document Server

Adolphi, Roman

2006-01-01

The CMS detector (Compact Muon Solenoid) is under construction at one of the four proton-proton interaction points of the LHC (Large Hadron Collider) at CERN, the European Organization for Nuclear Research (Geneva, Switzerland). The inner tracking system of the CMS experiment consisting of silicon detectors will have a diameter of 2.4 m and a length of 5.4 m representing the largest silicon tracker ever. About 15000 silicon strip modules create an active silicon area of 200 m2 to detect charged particles from proton collisions. They are placed on a rigid carbon fibre structure, providing stability within the working conditions of a 4 T solenoid magnetic field at −10oC. Knowledge of the position of the silicon detectors at the level of 100 μm is needed for an efficient pattern recognition of charged particle tracks. Metrology methods are used to survey tracker subdetectors and the integrated Laser Alignment System (LAS) provides absolute positioning of support structure elements to better than 100 μm. Rela...

LHCb: LHCb Upstream Tracker

CERN Multimedia

Manning Jr, P; Stone, S

2014-01-01

The LHCb upgrade requires replacing the silicon strip tracker between the vertex locator and the magnet. A new design has been developed and tested based on the "stave" concept planned for the ATLAS upgrade. We will describe the new detector being constructed and show its improved performance in charged particle tracking and triggering.

Wearable Gaze Trackers: Mapping Visual Attention in 3D

DEFF Research Database (Denmark)

Jensen, Rasmus Ramsbøl; Stets, Jonathan Dyssel; Suurmets, Seidi

2017-01-01

gaze trackers allows respondents to move freely in any real world 3D environment, removing the previous restrictions. In this paper we propose a novel approach for processing visual attention of respondents using mobile wearable gaze trackers in a 3D environment. The pipeline consists of 3 steps...

FUZZY LOGIC CONTROLLER IMPLEMENTATION FOR PHOTOVOLTAIC STATION

Directory of Open Access Journals (Sweden)

Imad Zein

2014-01-01

Full Text Available Solar panels have a nonlinear voltage-current characteristic, with a distinct maximum power point (MPP, which depends on the environmental factors, such as temperature and irradiation. In order to continuously harvest maximum power from the solar panels, they have to operate at their MPP despite the inevitable changes in the environment. This is why the controllers of all solar power electronic converters employ some method for maximum power point tracking (MPPT . Over the past years many MPPT techniques have been published and based on that the main paper’s objective is to analyze one of the most promising MPPT control algorithms: fuzzy logic controller. 

Alignment of the CMS Silicon Strip Tracker during stand-alone Commissioning

CERN Document Server

Adam, W.; Dragicevic, M.; Friedl, M.; Fruhwirth, R.; Hansel, S.; Hrubec, J.; Krammer, M.; Oberegger, M.; Pernicka, M.; Schmid, S.; Stark, R.; Steininger, H.; Uhl, D.; Waltenberger, W.; Widl, E.; Van Mechelen, P.; Cardaci, M.; Beaumont, W.; de Langhe, E.; de Wolf, E.A.; Delmeire, E.; Hashemi, M.; Bouhali, O.; Charaf, O.; Clerbaux, B.; Dewulf, J.-P.; Elgammal, S.; Hammad, G.; de Lentdecker, G.; Marage, P.; Vander Velde, C.; Vanlaer, P.; Wickens, J.; Adler, V.; Devroede, O.; De Weirdt, S.; D'Hondt, J.; Goorens, R.; Heyninck, J.; Maes, J.; Mozer, Matthias Ulrich; Tavernier, S.; Van Lancker, L.; Van Mulders, P.; Villella, I.; Wastiels, C.; Bonnet, J.-L.; Bruno, G.; De Callatay, B.; Florins, B.; Giammanco, A.; Gregoire, G.; Keutgen, Th.; Kcira, D.; Lemaitre, V.; Michotte, D.; Militaru, O.; Piotrzkowski, K.; Quertermont, L.; Roberfroid, V.; Rouby, X.; Teyssier, D.; daubie, E.; Anttila, E.; Czellar, S.; Engstrom, P.; Harkonen, J.; Karimaki, V.; Kostesmaa, J.; Kuronen, A.; Lampen, T.; Linden, T.; Luukka, P.-R.; Maenaa, T.; Michal, S.; Tuominen, E.; Tuominiemi, J.; Ageron, M.; Baulieu, G.; Bonnevaux, A.; Boudoul, G.; Chabanat, E.; Chabert, E.; Chierici, R.; Contardo, D.; Della Negra, R.; Dupasquier, T.; Gelin, G.; Giraud, N.; Guillot, G.; Estre, N.; Haroutunian, R.; Lumb, N.; Perries, S.; Schirra, F.; Trocme, B.; Vanzetto, S.; Agram, J.-L.; Blaes, R.; Drouhin, F.; Ernenwein, J.-P.; Fontaine, J.-C.; Berst, J.-D.; Brom, J.-M.; Didierjean, F.; Goerlach, U.; Graehling, P.; Gross, L.; Hosselet, J.; Juillot, P.; Lounis, A.; Maazouzi, C.; Olivetto, C.; Strub, R.; Van Hove, P.; Anagnostou, G.; Brauer, R.; Esser, H.; Feld, L.; Karpinski, W.; Klein, K.; Kukulies, C.; Olzem, J.; Ostapchuk, A.; Pandoulas, D.; Pierschel, G.; Raupach, F.; Schael, S.; Schwering, G.; Sprenger, D.; Thomas, M.; Weber, M.; Wittmer, B.; Wlochal, M.; Beissel, F.; Bock, E.; Flugge, G.; Gillissen, C.; Hermanns, T.; Heydhausen, D.; Jahn, D.; Kaussen, G.; Linn, A.; Perchalla, L.; Poettgens, M.; Pooth, O.; Stahl, A.; Zoeller, M.H.; Buhmann, P.; Butz, E.; Flucke, G.; Hamdorf, R.; Hauk, J.; Klanner, R.; Pein, U.; Schleper, P.; Steinbruck, G.; Blum, P.; De Boer, W.; Dierlamm, A.; Dirkes, G.; Fahrer, M.; Frey, M.; Furgeri, A.; Hartmann, F.; Heier, S.; Hoffmann, K.-H.; Kaminski, J.; Ledermann, B.; Liamsuwan, T.; Muller, S.; Muller, Th.; Schilling, F.-P.; Simonis, H.-J.; Steck, P.; Zhukov, V.; Cariola, P.; De Robertis, G.; Ferorelli, R.; Fiore, L.; Preda, M.; Sala, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Creanza, D.; De Filippis, N.; De Palma, M.; Giordano, D.; Maggi, G.; Manna, N.; My, S.; Selvaggi, G.; Albergo, S.; Chiorboli, M.; Costa, S.; Galanti, M.; Giudice, N.; Guardone, N.; Noto, F.; Potenza, R.; Saizu, M.A.; Sparti, V.; Sutera, C.; Tricomi, A.; Tuve, C.; Brianzi, M.; Civinini, C.; Maletta, F.; Manolescu, F.; Meschini, M.; Paoletti, S.; Sguazzoni, G.; Broccolo, B.; Ciulli, V.; D'Alessandro, R.; Focardi, E.; Frosali, S.; Genta, C.; Landi, G.; Lenzi, P.; Macchiolo, A.; Magini, N.; Parrini, G.; Scarlini, E.; Cerati, G.; Azzi, P.; Bacchetta, N.; Candelori, A.; Dorigo, T.; Kaminsky, A.; Karaevski, S.; Khomenkov, V.; Reznikov, S.; Tessaro, M.; Bisello, D.; De Mattia, M.; Giubilato, P.; Loreti, M.; Mattiazzo, S.; Nigro, M.; Paccagnella, A.; Pantano, D.; Pozzobon, N.; Tosi, M.; Bilei, G.M.; Checcucci, B.; Fano, L.; Servoli, L.; Ambroglini, F.; Babucci, E.; Benedetti, D.; Biasini, M.; Caponeri, B.; Covarelli, R.; Giorgi, M.; Lariccia, P.; Mantovani, G.; Marcantonini, M.; Postolache, V.; Santocchia, A.; Spiga, D.; Bagliesi, G.; Balestri, G.; Berretta, L.; Bianucci, S.; Boccali, T.; Bosi, F.; Bracci, F.; Castaldi, R.; Ceccanti, M.; Cecchi, R.; Cerri, C.; Cucoanes, A.S.; Dell'Orso, R.; Dobur, D.; Dutta, S.; Giassi, A.; Giusti, S.; Kartashov, D.; Kraan, A.; Lomtadze, T.; Lungu, G.A.; Magazzu, G.; Mammini, P.; Mariani, F.; Martinelli, G.; Moggi, A.; Palla, F.; Palmonari, F.; Petragnani, G.; Profeti, A.; Raffaelli, F.; Rizzi, D.; Sanguinetti, G.; Sarkar, S.; Sentenac, D.; Serban, A.T.; Slav, A.; Soldani, A.; Spagnolo, P.; Tenchini, R.; Tolaini, S.; Venturi, A.; Verdini, P.G.; Vos, M.; Zaccarelli, L.; Avanzini, C.; Basti, A.; Benucci, L.; Bocci, A.; Cazzola, U.; Fiori, F.; Linari, S.; Massa, M.; Messineo, A.; Segneri, G.; Tonelli, G.; Azzurri, P.; Bernardini, J.; Borrello, L.; Calzolari, F.; Foa, L.; Gennai, S.; Ligabue, F.; Petrucciani, G.; Rizzi, A.; Yang, Z.; Benotto, F.; Demaria, N.; Dumitrache, F.; Farano, R.; Borgia, M.A.; Castello, R.; Costa, M.; Migliore, E.; Romero, A.; Abbaneo, D.; Abbas, M.; Ahmed, I.; Akhtar, I.; Albert, E.; Bloch, C.; Breuker, H.; Butt, S.; Buchmuller, O.; Cattai, A.; Delaere, C.; Delattre, M.; Edera, L.M.; Engstrom, P.; Eppard, M.; Gateau, M.; Gill, K.; Giolo-Nicollerat, A.-S.; Grabit, R.; Honma, A.; Huhtinen, M.; Kloukinas, K.; Kortesmaa, J.; Kottelat, L.J.; Kuronen, A.; Leonardo, N.; Ljuslin, C.; Mannelli, M.; Masetti, L.; Marchioro, A.; Mersi, S.; Michal, S.; Mirabito, L.; Muffat-Joly, J.; Onnela, A.; Paillard, C.; Pal, I.; Pernot, J.F.; Petagna, P.; Petit, P.; Piccut, C.; Pioppi, M.; Postema, H.; Ranieri, R.; Ricci, D.; Rolandi, G.; Ronga, F.; Sigaud, C.; Syed, A.; Siegrist, P.; Tropea, P.; Troska, J.; Tsirou, A.; Vander Donckt, M.; Vasey, F.; Alagoz, E.; Amsler, Claude; Chiochia, V.; Regenfus, Christian; Robmann, P.; Rochet, J.; Rommerskirchen, T.; Schmidt, A.; Steiner, S.; Wilke, L.; Church, I.; Cole, J.; Coughlan, J.; Gay, A.; Taghavi, S.; Tomalin, I.; Bainbridge, R.; Cripps, N.; Fulcher, J.; Hall, G.; Noy, M.; Pesaresi, M.; Radicci, V.; Raymond, D.M.; Sharp, P.; Stoye, M.; Wingham, M.; Zorba, O.; Goitom, I.; Hobson, P.R.; Reid, I.; Teodorescu, L.; Hanson, G.; Jeng, G.-Y.; Liu, H.; Pasztor, G.; Satpathy, A.; Stringer, R.; Mangano, B.; Affolder, K.; Affolder, T.; Allen, A.; Barge, D.; Burke, S.; Callahan, D.; Campagnari, C.; Crook, A.; D'Alfonso, M.; Dietch, J.; Garberson, Jeffrey Ford; Hale, D.; Incandela, H.; Incandela, J.; Jaditz, S.; Kalavase, P.; Kreyer, S.; Kyre, S.; Lamb, J.; Mc Guinnessr, C.; Mills, C.; Nguyen, H.; Nikolic, M.; Lowette, S.; Rebassoo, F.; Ribnik, J.; Richman, J.; Rubinstein, N.; Sanhueza, S.; Shah, Y.; Simms, L.; Staszak, D.; Stoner, J.; Stuart, D.; Swain, S.; Vlimant, J.-R.; White, D.; Ulmer, K.A.; Wagner, S.R.; Bagby, L.; Bhat, P.C.; Burkett, K.; Cihangir, S.; Gutsche, O.; Jensen, H.; Johnson, M.; Luzhetskiy, N.; Mason, D.; Miao, T.; Moccia, S.; Noeding, C.; Ronzhin, A.; Skup, E.; Spalding, W.J.; Spiegel, L.; Tkaczyk, S.; Yumiceva, F.; Zatserklyaniy, A.; Zerev, E.; Anghel, I.; Bazterra, V.E.; Gerber, C.E.; Khalatian, S.; Shabalina, E.; Baringer, Philip S.; Bean, A.; Chen, J.; Hinchey, C.; Martin, C.; Moulik, T.; Robinson, R.; Gritsan, A.V.; Lae, C.K.; Tran, N.V.; Everaerts, P.; Hahn, K.A.; Harris, P.; Nahn, S.; Rudolph, M.; Sung, K.; Betchart, B.; Demina, R.; Gotra, Y.; Korjenevski, S.; Miner, D.; Orbaker, D.; Christofek, L.; Hooper, R.; Landsberg, G.; Nguyen, D.; Narain, M.; Speer, T.; Tsang, K.V.

2009-01-01

The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us to perform first alignment of the active silicon modules with the cosmic tracks using three different statistical approaches; validate the survey and laser alignment system performance; and test the stability of Tracker structures under various stresses and temperatures ranging from +15C to -15C. Comparison with simulation shows that the achieved alignment precision in the barrel part of the tracker leads to residual distributions similar to those obtained with a random misalignment of 50 (80) microns in the outer (inner) part of the barrel.

3D Part-Based Sparse Tracker with Automatic Synchronization and Registration

KAUST Repository

Bibi, Adel Aamer; Zhang, Tianzhu; Ghanem, Bernard

2016-01-01

In this paper, we present a part-based sparse tracker in a particle filter framework where both the motion and appearance model are formulated in 3D. The motion model is adaptive and directed according to a simple yet powerful occlusion handling paradigm, which is intrinsically fused in the motion model. Also, since 3D trackers are sensitive to synchronization and registration noise in the RGB and depth streams, we propose automated methods to solve these two issues. Extensive experiments are conducted on a popular RGBD tracking benchmark, which demonstrate that our tracker can achieve superior results, outperforming many other recent and state-of-the-art RGBD trackers.

3D Part-Based Sparse Tracker with Automatic Synchronization and Registration

KAUST Repository

Bibi, Adel Aamer

2016-12-13

In this paper, we present a part-based sparse tracker in a particle filter framework where both the motion and appearance model are formulated in 3D. The motion model is adaptive and directed according to a simple yet powerful occlusion handling paradigm, which is intrinsically fused in the motion model. Also, since 3D trackers are sensitive to synchronization and registration noise in the RGB and depth streams, we propose automated methods to solve these two issues. Extensive experiments are conducted on a popular RGBD tracking benchmark, which demonstrate that our tracker can achieve superior results, outperforming many other recent and state-of-the-art RGBD trackers.

Teaching Astronomy Using Tracker

Science.gov (United States)

Belloni, Mario; Christian, Wolfgang; Brown, Douglas

2013-01-01

A recent paper in this journal presented a set of innovative uses of video analysis for introductory physics using Tracker. In addition, numerous other papers have described how video analysis can be a meaningful part of introductory courses. Yet despite this, there are few resources for using video analysis in introductory astronomy classes. In…

Prototype ATLAS straw tracker

CERN Multimedia

Laurent Guiraud

1998-01-01

This is an early prototype of the straw tracking device for the ATLAS detector at CERN. This detector will be part of the LHC project, scheduled to start operation in 2008. The straw tracker will consist of thousands of gas-filled straws, each containing a wire, allowing the tracks of particles to be followed.

A state-of-the-art compact SiC photovoltaic inverter with maximum power point tracking function

Science.gov (United States)

Ando, Yuji; Oku, Takeo; Yasuda, Masashi; Ushijima, Kazufumi; Matsuo, Hiroshi; Murozono, Mikio

2018-01-01

We have developed a 150-W SiC-based photovoltaic (PV)-inverter with the maximum power point tracking (MPPT) function. The newly developed inverter achieved a state-of-the-art combination of the weight (0.79 kg) and the volume (790 mm3) as a 150-250 W class PV-inverter. As compared to the original version that we have previously reported, the weight and volume were decreased by 37% and 38%, respectively. This compactness originated from the optimized circuit structure and the increased density of a wiring circuit. Conversion efficiencies of the MPPT charge controller and the direct current (DC)-alternating current (AC) converter reached 96.4% and 87.6%, respectively. These efficiency values are comparable to those for the original version. We have developed a PV power generation system consisting of this inverter, a spherical Si solar cell module, and a 15-V Li-ion laminated battery. The total weight of the system was below 6 kg. The developed system exhibited stable output power characteristics, even when the weather conditions were fluctuated. These compactness, high efficiencies, and excellent stability clearly indicated the feasibility of SiC power devices even for sub-kW class PV power generation systems.

Alignment of Ion Accelerator for Surface Analysis using Theodolite and Laser Tracker

Energy Technology Data Exchange (ETDEWEB)

Ahn, Tae Sung; Seo, Dong Hyuk; Kim, Dae Il; Kim, Han Sung; Kwon, Hyeok Jung; Cho, Yong Sub [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The method of ion accelerator alignment is used two ways which are a theodolite and laser tracker. For the alignment and maintenance of the proton linear accelerator, the laser tracker is typically used at KOMAC. While the device for alignment by using laser tracker is not installed in all ion accelerator components, it was used in parallel in two methods. In this paper, alignment methods are introduced and the result and comparison of each alignment method are presented. The ion accelerator for surface analysis has aligned using theodolite and laser tracker. The two ways for alignment have advantage as well as weakness. But alignment using laser tracker is stronger than using theodolite. Because it is based on alignment and position data and it is more detailed. Also since the beam distribution is smaller than accelerator component that is direction of beam progress, main component (ex. Magnet, Chamber, Pelletron tank, etc.) alignment using laser tracker is enough to align the ion accelerator.

Novel approach to improve the attitude update rate of a star tracker.

Science.gov (United States)

Zhang, Shuo; Xing, Fei; Sun, Ting; You, Zheng; Wei, Minsong

2018-03-05

The star tracker is widely used in attitude control systems of spacecraft for attitude measurement. The attitude update rate of a star tracker is important to guarantee the attitude control performance. In this paper, we propose a novel approach to improve the attitude update rate of a star tracker. The electronic Rolling Shutter (RS) imaging mode of the complementary metal-oxide semiconductor (CMOS) image sensor in the star tracker is applied to acquire star images in which the star spots are exposed with row-to-row time offsets, thereby reflecting the rotation of star tracker at different times. The attitude estimation method with a single star spot is developed to realize the multiple attitude updates by a star image, so as to reach a high update rate. The simulation and experiment are performed to verify the proposed approaches. The test results demonstrate that the proposed approach is effective and the attitude update rate of a star tracker is increased significantly.

SOLAR TRACKER CERDAS DAN MURAH BERBASIS MIKROKONTROLER 8 BIT ATMega8535

OpenAIRE

I Wayan Sutaya; Ketut Udy Ariawan

2016-01-01

prototipe produk solar tracker cerdas berbasis mikrokontroler AVR 8 bit. Solar tracker ini memasukkan filter digital IIR (Infinite Impulse Response) pada bagian program. Memprogram filter ini membutuhkan perkalian 32 bit sedangkan prosesor yang tersedia pada mikrokontroler yang dipakai adalah 8 bit. Proses perkalian ini hanya bisa dilakukan pada mikrokontroler 8 bit dengan menggunakan bahasa assembly yang merupakan bahasa level hardware. Solar tracker cerdas yang menggunakan mikrokontroler 8 ...

CMS tracker observes muons

CERN Multimedia

2006-01-01

A computer image of a cosmic ray traversing the many layers of the TEC+ silicon sensors. The first cosmic muon tracks have been observed in one of the CMS tracker endcaps. On 14 March, a sector on one of the two large tracker endcaps underwent a cosmic muon run. Since then, thousands of tracks have been recorded. These data will be used not only to study the tracking, but also to exercise various track alignment algorithms The endcap tested, called the TEC+, is under construction at RWTH Aachen in Germany. The endcaps have a modular design, with silicon strip modules mounted onto wedge-shaped carbon fibre support plates, so-called petals. Up to 28 modules are arranged in radial rings on both sides of these plates. One eighth of an endcap is populated with 18 petals and called a sector. The next major step is a test of the first sector at CMS operating conditions, with the silicon modules at a temperature below -10°C. Afterwards, the remaining seven sectors have to be integrated. In autumn 2006, TEC+ wil...

ATLAS Silicon Microstrip Tracker

CERN Document Server

Haefner, Petra; The ATLAS collaboration

2010-01-01

The SemiConductor Tracker (SCT), made up from silicon micro-strip detectors is the key precision tracking device in ATLAS, one of the experiments at CERN LHC. The completed SCT is in very good shape: 99.3% of the SCT strips are operational, noise occupancy and hit efficiency exceed the design specifications. In the talk the current status of the SCT will be reviewed. We will report on the operation of the detector and observed problems, with stress on the sensor and electronics performance. TWEPP Summary In December 2009 the ATLAS experiment at the CERN Large Hadron Collider (LHC) recorded the first proton- proton collisions at a centre-of-mass energy of 900 GeV and this was followed by the unprecedented energy of 7 TeV in March 2010. The SemiConductor Tracker (SCT) is the key precision tracking device in ATLAS, made up from silicon micro-strip detectors processed in the planar p-in-n technology. The signal from the strips is processed in the front-end ASICS ABCD3TA, working in the binary readout mode. Data i...

The fast tracker processor for hadron collider triggers

CERN Document Server

Annovi, A; Bardi, A; Carosi, R; Dell'Orso, Mauro; D'Onofrio, M; Giannetti, P; Iannaccone, G; Morsani, E; Pietri, M; Varotto, G

2001-01-01

Perspectives for precise and fast track reconstruction in future hadron collider experiments are addressed. We discuss the feasibility of a pipelined highly parallel processor dedicated to the implementation of a very fast tracking algorithm. The algorithm is based on the use of a large bank of pre-stored combinations of trajectory points, called patterns, for extremely complex tracking systems. The CMS experiment at LHC is used as a benchmark. Tracking data from the events selected by the level-1 trigger are sorted and filtered by the Fast Tracker processor at an input rate of 100 kHz. This data organization allows the level-2 trigger logic to reconstruct full resolution tracks with transverse momentum above a few GeV and search for secondary vertices within typical level-2 times. (15 refs).

CMS tracker towards the HL-LHC

CERN Document Server

Alunni Solestizi, Luisa

2015-01-01

In sight of the incoming new LHC era (High Luminosity - LHC), characterized by a jump forward in the precision boundary and in the event rate, all the CMS sub-detector are developing and studying innovative strategies of trigger, pattern recognition, event timing and so on. A crucial aspect will be the online event selection: a totally new paradigm is needed, given the huge amount of events. In this picture the most granular and innermost sub-detector, the tracker, will play a decisive role. The phase-2 tracker will be involved in the L1 Trigger and, taking advantage of both the Associative Memories and the FPGA, it can ensure a trigger decision in proper time and with satisfactory performances.

Characterization of different options of trackers in OPERA detector

International Nuclear Information System (INIS)

Moret, Guillaume

2002-01-01

Neutrinos were postulated by Pauli during the thirties. These spin-half and massless particles helped to solve the β decay problems. Their study started in the fifties and work is still going on nowadays. This study was lengthy due the difficulty to detect neutrinos and also to a 'strange' phenomenon: we always detect less neutrinos than expected for solar and atmospheric neutrinos. This phenomenon can be explained by oscillation between massive neutrino states. The OPERA project is intended to directly proved this oscillation. To this aim, a ν μ beam is produced at CERN and pointed to Gran-Sasso (Italy), 732 km away. The detector is optimised to reveal the tau neutrino coming from ν μ → ν τ oscillation. This detector of 30 meters length with 2,000 tonnes of target will be built with more than 200,000 bricks of lead and emulsion. Taus are observed after scanning of the emulsions. The bricks must be localized into the wall and this localization is possible with a tracker located downstream of each target wall. The present work was devoted to the determination of the best tracker for OPERA. Three options were studied and a tracker made of plastic scintillator slabs has been chosen. It allows obtaining an efficiency of the localization of the vertex wall of around 80% and an efficiency of the localization of the brick inside the wall of around 80%. As photo detector we have studies HPD with a self-triggerable readout. HPDs have displayed an excellent resolution, a cross talk lower than 2% and a uniformity higher then 98%. A DAQ based on Ethernet was proposed and accepted by the collaboration. In this option, each photon detector is node of the network and can be accessed in a web browser. A prototype with plastic oscillator, a HPD with an self triggerable readout and a DAQ based on Ethernet were built and validated during beam tests. (author)

Development of a new Silicon Tracker at CMS for Super-LHC

CERN Document Server

Pesaresi, Mark

2010-01-01

Tracking is an essential requirement for any high energy particle physics experiment. The Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) employs an all silicon tracker, the largest of its kind, for the precise measurement of track momentum and vertex position. With approximately 10 million detector channels in the strip tracker alone, the analogue non-sparsified readout system has been designed to handle the large data volumes generated at the 100 kHz Level 1 (L1) trigger rate. Fluctuations in the event rate are controlled using buffers whose occupancies are constantly monitored to prevent overflows, otherwise causing loss of synchronisation and data. The status of the tracker is reported by the APV emulator (APVe), which has now been successfully commissioned within the silicon strip tracker readout system. The APVe plays a crucial role in the synchronisation of the tracker by deterministic calculation of the front end buffer occupancy and by monitoring the status of the Front End Dr...

In Defense of Sparse Tracking: Circulant Sparse Tracker

KAUST Repository

Zhang, Tianzhu; Bibi, Adel Aamer; Ghanem, Bernard

2016-01-01

Sparse representation has been introduced to visual tracking by finding the best target candidate with minimal reconstruction error within the particle filter framework. However, most sparse representation based trackers have high computational cost, less than promising tracking performance, and limited feature representation. To deal with the above issues, we propose a novel circulant sparse tracker (CST), which exploits circulant target templates. Because of the circulant structure property, CST has the following advantages: (1) It can refine and reduce particles using circular shifts of target templates. (2) The optimization can be efficiently solved entirely in the Fourier domain. (3) High dimensional features can be embedded into CST to significantly improve tracking performance without sacrificing much computation time. Both qualitative and quantitative evaluations on challenging benchmark sequences demonstrate that CST performs better than all other sparse trackers and favorably against state-of-the-art methods.

In Defense of Sparse Tracking: Circulant Sparse Tracker

KAUST Repository

Zhang, Tianzhu

2016-12-13

Sparse representation has been introduced to visual tracking by finding the best target candidate with minimal reconstruction error within the particle filter framework. However, most sparse representation based trackers have high computational cost, less than promising tracking performance, and limited feature representation. To deal with the above issues, we propose a novel circulant sparse tracker (CST), which exploits circulant target templates. Because of the circulant structure property, CST has the following advantages: (1) It can refine and reduce particles using circular shifts of target templates. (2) The optimization can be efficiently solved entirely in the Fourier domain. (3) High dimensional features can be embedded into CST to significantly improve tracking performance without sacrificing much computation time. Both qualitative and quantitative evaluations on challenging benchmark sequences demonstrate that CST performs better than all other sparse trackers and favorably against state-of-the-art methods.

Star tracker operation in a high density proton field

Science.gov (United States)

Miklus, Kenneth J.; Kissh, Frank; Flynn, David J.

1993-01-01

Algorithms that reject transient signals due to proton effects on charge coupled device (CCD) sensors have been implemented in the HDOS ASTRA-l Star Trackers to be flown on the TOPEX mission scheduled for launch in July 1992. A unique technique for simulating a proton-rich environment to test trackers is described, as well as the test results obtained. Solar flares or an orbit that passes through the South Atlantic Anomaly can subject the vehicle to very high proton flux levels. There are three ways in which spurious proton generated signals can impact tracker performance: the many false signals can prevent or extend the time to acquire a star; a proton-generated signal can compromise the accuracy of the star's reported magnitude and position; and the tracked star can be lost, requiring reacquisition. Tests simulating a proton-rich environment were performed on two ASTRA-1 Star Trackers utilizing these new algorithms. There were no false acquisitions, no lost stars, and a significant reduction in reported position errors due to these improvements.

Upgrading the ATLAS barrel tracker for the super-LHC

International Nuclear Information System (INIS)

Bates, Richard L.

2009-01-01

It has been proposed to increase the luminosity of the large hadron collider (LHC) at CERN by an order of magnitude, with the upgraded machine dubbed super-LHC. The ATLAS experiment will require a new tracker for this high-luminosity operation due to radiation damage and event density. In order to cope with the order of magnitude increase in pile-up backgrounds at the higher luminosity, an all-silicon tracker is being designed. The new strip detector will use significantly shorter strips than the current silicon tracker in order to minimize the occupancy. As the increased luminosity will mean a corresponding increase in radiation dose, a new generation of extremely radiation-hard silicon detectors is required. An R and D program is underway to develop silicon sensors with sufficient radiation hardness. New front-end electronics and readout systems are being designed to cope with the higher data rates. The challenges facing the sensors and the cooling and mechanical support will be discussed. A possible tracker layout will be described.

Maximum power point tracking algorithm based on sliding mode and fuzzy logic for photovoltaic sources under variable environmental conditions

Science.gov (United States)

Atik, L.; Petit, P.; Sawicki, J. P.; Ternifi, Z. T.; Bachir, G.; Della, M.; Aillerie, M.

2017-02-01

Solar panels have a nonlinear voltage-current characteristic, with a distinct maximum power point (MPP), which depends on the environmental factors, such as temperature and irradiation. In order to continuously harvest maximum power from the solar panels, they have to operate at their MPP despite the inevitable changes in the environment. Various methods for maximum power point tracking (MPPT) were developed and finally implemented in solar power electronic controllers to increase the efficiency in the electricity production originate from renewables. In this paper we compare using Matlab tools Simulink, two different MPP tracking methods, which are, fuzzy logic control (FL) and sliding mode control (SMC), considering their efficiency in solar energy production.

Documentation for delivery of Star Tracker to ADEOS II

DEFF Research Database (Denmark)

Madsen, Peter Buch; Betto, Maurizio; Denver, Troelz

1999-01-01

The documentation EIDP (End Item Data Package) describes all the tests which have been performed on the Flight Hardware of the Star Tracker for the Japanese satellite ADEOS II.......The documentation EIDP (End Item Data Package) describes all the tests which have been performed on the Flight Hardware of the Star Tracker for the Japanese satellite ADEOS II....

Prototype Combined Heater/Thermoelectric Power Generator for Remote Applications

Science.gov (United States)

Champier, D.; Favarel, C.; Bédécarrats, J. P.; Kousksou, T.; Rozis, J. F.

2013-07-01

This study presents a prototype thermoelectric generator (TEG) developed for remote applications in villages that are not connected to the electrical power grid. For ecological and economic reasons, there is growing interest in harvesting waste heat from biomass stoves to produce some electricity. Because regular maintenance is not required, TEGs are an attractive choice for small-scale power generation in inaccessible areas. The prototype developed in our laboratory is especially designed to be implemented in stoves that are also used for domestic hot water heating. The aim of this system is to provide a few watts to householders, so they have the ability to charge cellular phones and radios, and to get some light at night. A complete prototype TEG using commercial (bismuth telluride) thermoelectric modules has been built, including system integration with an electric DC/DC converter. The DC/DC converter has a maximum power point tracker (MPPT) driven by an MC9SO8 microcontroller, which optimizes the electrical energy stored in a valve-regulated lead-acid battery. Physical models were used to study the behavior of the thermoelectric system and to optimize the performance of the MPPT. Experiments using a hot gas generator to simulate the exhaust of the combustion chamber of a stove are used to evaluate the system. Additionally, potential uses of such generators are presented.

Tracker: Image-Processing and Object-Tracking System Developed

Science.gov (United States)

Klimek, Robert B.; Wright, Theodore W.

1999-01-01

Tracker is an object-tracking and image-processing program designed and developed at the NASA Lewis Research Center to help with the analysis of images generated by microgravity combustion and fluid physics experiments. Experiments are often recorded on film or videotape for analysis later. Tracker automates the process of examining each frame of the recorded experiment, performing image-processing operations to bring out the desired detail, and recording the positions of the objects of interest. It can load sequences of images from disk files or acquire images (via a frame grabber) from film transports, videotape, laser disks, or a live camera. Tracker controls the image source to automatically advance to the next frame. It can employ a large array of image-processing operations to enhance the detail of the acquired images and can analyze an arbitrarily large number of objects simultaneously. Several different tracking algorithms are available, including conventional threshold and correlation-based techniques, and more esoteric procedures such as "snake" tracking and automated recognition of character data in the image. The Tracker software was written to be operated by researchers, thus every attempt was made to make the software as user friendly and self-explanatory as possible. Tracker is used by most of the microgravity combustion and fluid physics experiments performed by Lewis, and by visiting researchers. This includes experiments performed on the space shuttles, Mir, sounding rockets, zero-g research airplanes, drop towers, and ground-based laboratories. This software automates the analysis of the flame or liquid s physical parameters such as position, velocity, acceleration, size, shape, intensity characteristics, color, and centroid, as well as a number of other measurements. It can perform these operations on multiple objects simultaneously. Another key feature of Tracker is that it performs optical character recognition (OCR). This feature is useful in

A Flexible Maximum Power Point Tracking Control Strategy Considering Both Conversion Efficiency and Power Fluctuation for Large-inertia Wind Turbines

Directory of Open Access Journals (Sweden)

Hongmin Meng

2017-07-01

Full Text Available In wind turbine control, maximum power point tracking (MPPT control is the main control mode for partial-load regimes. Efficiency potentiation of energy conversion and power smoothing are both two important control objectives in partial-load regime. However, on the one hand, low power fluctuation signifies inefficiency of energy conversion. On the other hand, enhancing efficiency may increase output power fluctuation as well. Thus the two objectives are contradictory and difficult to balance. This paper proposes a flexible MPPT control framework to improve the performance of both conversion efficiency and power smoothing, by adaptively compensating the torque reference value. The compensation was determined by a proposed model predictive control (MPC method with dynamic weights in the cost function, which improved control performance. The computational burden of the MPC solver was reduced by transforming the cost function representation. Theoretical analysis proved the good stability and robustness. Simulation results showed that the proposed method not only kept efficiency at a high level, but also reduced power fluctuations as much as possible. Therefore, the proposed method could improve wind farm profits and power grid reliability.

LHCb Upgrade: Scintillating Fibre Tracker

International Nuclear Information System (INIS)

Tobin, Mark

2016-01-01

The LHCb detector will be upgraded during the Long Shutdown 2 (LS2) of the LHC in order to cope with higher instantaneous luminosities and to read out the data at 40 MHz using a trigger-less read-out system. All front-end electronics will be replaced and several sub-detectors must be redesigned to cope with higher occupancy. The current tracking detectors downstream of the LHCb dipole magnet will be replaced by the Scintillating Fibre (SciFi) Tracker. The SciFi Tracker will use scintillating fibres read out by Silicon Photomultipliers (SiPMs). State-of-the-art multi-channel SiPM arrays are being developed to read out the fibres and a custom ASIC will be used to digitise the signals from the SiPMs. The evolution of the design since the Technical Design Report in 2014 and the latest R & D results are presented.

Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

Directory of Open Access Journals (Sweden)

Zheng You

2013-04-01

Full Text Available The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers.

Optical system error analysis and calibration method of high-accuracy star trackers.

Science.gov (United States)

Sun, Ting; Xing, Fei; You, Zheng

2013-04-08

The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers.

Application Of Expert System Techniques To A Visual Tracker

Science.gov (United States)

Myler, Harley R.; Thompson, Wiley E.; Flachs, Gerald M.

1985-04-01

A structure for visual tracking system is presented which relies on information developed from previous tracking scenarios stored in a knowledge base to enhance tracking performance. The system is comprised of a centroid tracker front end which supplies segmented image features to a data reduction algorithm which holds the reduced data in a temporary data base relation. This relation is then classified vio two separate modes, learn and track. Under learn mode, an external teacher-irector operator provides identification and weighting cues for membership in a long-term storage relation within a knowledge base. Track mode operates autonomously from the learn mode where the system determines feature validity by applying fuzzy set membership criteria to previously stored track information in the database. Results determined from the classification generate tracker directives which either enhance or permit current tracking to continue or cause the tracker to search for alternate targets based upon analysis of a global target tracking list. The classification algorithm is based on correlative analysis of the tracker's segmented output presentation after low pass filtering derives lower order harmonics of the feature. The fuzzy set membership criteria is based on size, rotation, Irame location, and past history of the feature. The first three factors are lin-ear operations on the spectra, while the last is generated as a context relation in the knowledge base. The context relation interlinks data between features to facilitate tracker operation during feature occlusion or presence of countermeasures.

Users’ experiences of wearable activity trackers: a cross-sectional study

Directory of Open Access Journals (Sweden)

Carol Maher

2017-11-01

Full Text Available Abstract Background Wearable activity trackers offer considerable promise for helping users to adopt healthier lifestyles. This study aimed to explore users’ experience of activity trackers, including usage patterns, sharing of data to social media, perceived behaviour change (physical activity, diet and sleep, and technical issues/barriers to use. Methods A cross-sectional online survey was developed and administered to Australian adults who were current or former activity tracker users. Results were analysed descriptively, with differences between current and former users and wearable brands explored using independent samples t-tests, Mann-Whitney, and chi square tests. Results Participants included 200 current and 37 former activity tracker users (total N = 237 with a mean age of 33.1 years (SD 12.4, range 18–74 years. Fitbit (67.5% and Garmin devices (16.5% were most commonly reported. Participants typically used their trackers for sustained periods (5–7 months and most intended to continue usage. Participants reported they had improved their physical activity (51–81% more commonly than they had their diet (14–40% or sleep (11–24%, and slightly more participants reported to value the real time feedback (89% compared to the long-term monitoring (78%. Most users (70% reported they had experienced functionality issues with their devices, most commonly related to battery life and technical difficulties. Conclusions Results suggest users find activity trackers appealing and useful tools for increasing perceived physical activity levels over a sustained period.

Performance of the LHCb Outer Tracker

CERN Document Server

Arink, R; Bachmann, S.; Bagaturia, Y.; Band, H.; Bauer, Th.; Berkien, A.; Farber, Ch.; Bien, A.; Blouw, J.; Ceelie, L.; Coco, V.; Deckenhoff, M.; Deng, Z.; Dettori, F.; van Eijk, D.; Ekelhof, R.; Gersabeck, E.; Grillo, L.; Hulsbergen, W.D.; Karbach, T.M.; Koopman, R.; Kozlinskiy, A.; Langenbruch, Ch.; Lavrentyev, V.; Linn, Ch.; Merk, M.; Merkel, J.; Meissner, M.; Michalowski, J.; Morawski, P.; Nawrot, A.; Nedos, M.; Pellegrino, A.; Polok, G.; van Petten, O.; Rovekamp, J.; Schimmel, F.; Schuylenburg, H.; Schwemmer, R.; Seyfert, P.; Serra, N.; Sluijk, T.; Spaan, B.; Spelt, J.; Storaci, B.; Szczekowski, M.; Swientek, S.; Tolk, S.; Tuning, N.; Uwer, U.; Wiedner, D.; Witek, M.; Zeng, M.; Zwart, A.

2014-01-01

The LHCb Outer Tracker is a gaseous detector covering an area of 5x6 m2 with 12 double layers of straw tubes. The detector with its services are described together with the commissioning and calibration procedures. Based on data of the first LHC running period from 2010 to 2012, the performance of the readout electronics and the single hit resolution and efficiency are presented. The efficiency to detect a hit in the central half of the straw is estimated to be 99.2%, and the position resolution is determined to be approximately 200 um. The Outer Tracker received a dose in the hottest region corresponding to 0.12 C/cm, and no signs of gain deterioration or other ageing effects are observed.

The Alpha Magnetic Spectrometer Silicon Tracker

CERN Document Server

Burger, W J

1999-01-01

The Alpha Magnetic Spectrometer (AMS) is designed as a independent module for installation on the International Space Station Alpha (ISSA) in the year 2002 for an operational period of three years. The principal scientific objectives are the searches for antimatter and dark matter in cosmic rays. The AMS uses 5.5 m sup 2 of silicon microstrip sensors to reconstruct charged particle trajectories in the field of a permanent magnet. The detector design and construction covered a 3 yr period which terminated with a test flight on the NASA space shuttle Discovery during June 2-12, 1988. In this contribution, we describe the shuttle version of the AMS silicon tracker, including preliminary results of the tracker performance during the flight. (author)

The CDF online silicon vertex tracker

International Nuclear Information System (INIS)

Ashmanskas, W.

2001-01-01

The CDF Online Silicon Vertex Tracker reconstructs 2-D tracks by linking hit positions measured by the Silicon Vertex Detector to the Central Outer Chamber tracks found by the eXtremely Fast Tracker. The system has been completely built and assembled and it is now being commissioned using the first CDF run II data. The precision measurement of the track impact parameter will allow triggering on B hadron decay vertices and thus investigating important areas in the B sector, like CP violation and B s mixing. In this paper we briefly review the architecture and the tracking algorithms implemented in the SVT and we report on the performance of the system achieved in the early phase of CDF run II

The CDF online Silicon Vertex Tracker

International Nuclear Information System (INIS)

Ashmanskas, W.; Bardi, A.; Bari, M.; Belforte, S.; Berryhill, J.; Bogdan, M.; Carosi, R.; Cerri, A.; Chlachidze, G.; Culbertson, R.; Dell'Orso, M.; Donati, S.; Fiori, I.; Frisch, H.J.; Galeotti, S.; Giannetti, P.; Glagolev, V.; Moneta, L.; Morsani, F.; Nakaya, T.; Passuello, D.; Punzi, G.; Rescigno, M.; Ristori, L.; Sanders, H.; Sarkar, S.; Semenov, A.; Shochet, M.; Speer, T.; Spinella, F.; Wu, X.; Yang, U.; Zanello, L.; Zanetti, A.M.

2002-01-01

The CDF Online Silicon Vertex Tracker (SVT) reconstructs 2D tracks by linking hit positions measured by the Silicon Vertex Detector to the Central Outer Chamber tracks found by the eXtremely Fast Tracker (XFT). The system has been completely built and assembled and it is now being commissioned using the first CDF run II data. The precision measurement of the track impact parameter will allow triggering on B hadron decay vertices and thus investigating important areas in the B sector, like CP violation and B s mixing. In this paper we briefly review the architecture and the tracking algorithms implemented in the SVT and we report on the performance of the system achieved in the early phase of CDF run II

A framework for performance evaluation of model-based optical trackers

NARCIS (Netherlands)

Smit, F.A.; Liere, van R.

2008-01-01

We describe a software framework to evaluate the performance of model-based optical trackers in virtual environments. The framework can be used to evaluate and compare the performance of different trackers under various conditions, to study the effects of varying intrinsic and extrinsic camera

The LHCb Silicon Tracker - Control system specific tools and challenges

CERN Document Server

Adeva, G; Esperante Pereira, D; Gallas, A; Pazos Alvarez, A; Perez Trigo, E; Rodriguez Perez, P; Saborido, J; Amhis, Y; Bay, A; Blanc, F; Bressieux, J; Conti, G; Dupertuis, F; Fave, V; Frei, R; Gauvin, N; Haefeli, G; Keune, A; Luisier, J; Marki, R; Muresan, R; Nakada, T; Needham, M; Knecht, M; Schneider, O; Tran, M; Anderson, J; Buechler, A; Bursche, A; Chiapolini, N; De Cian, M; Elsasser, C; Salzmann, C; Saornil Gamarra, S; Steiner, S; Steinkamp, O; Straumann, U; van Tilburg, J; Tobin, M; Vollhardt, A; Aquines Gutierrez, O; Bauer, C; Britsch, M; Maciuc, F; Schmelling, M; Voss, H; Iakovenko, V; Okhrimenko, O; Pugatch, V

2014-01-01

The Experiment Control System (ECS) of the LHCb Silicon Tracker sub-detectors is built on the integrated LHCb ECS framework. Although all LHCb sub-detectors use the same framework and follow the same guidelines, the Silicon Tracker control system uses some interesting additional features in terms of operation and monitoring. The main details are described in this document. Since its design, the Silicon Tracker control system has been continuously evolving in a quite disorganized way. Some major maintenance activities are required to be able to keep improving. A description of those activities can also be found here.

Determinants for sustained use of an activity tracker : observational study

NARCIS (Netherlands)

Hermsen, Sander; Moons, Jonas; Kerkhof, Peter; Wiekens, Carina; De Groot, Martijn

2017-01-01

BACKGROUND: A lack of physical activity is considered to cause 6% of deaths globally. Feedback from wearables such as activity trackers has the potential to encourage daily physical activity. To date, little research is available on the natural development of adherence to activity trackers or on

Control system design of the CERN/CMS tracker thermal screen

CERN Document Server

Carrone, E

2003-01-01

The Tracker is one of the CMS (Compact Muon Solenoid experiment) subdetectors to be installed at the LHC (Large Hadron Collider) accelerator, scheduled to start data taking in 2007 at CERN (European Organization for Nuclear Research). The tracker will be operated at a temperature of -10 degree C in order to reduce the radiation damage on the silicon detectors; hence, an insulated environment has to be provided by means of a screen that introduces a thermal separation between the Tracker and the neighboring detection systems. The control system design includes a formal description of the process by means of a thermodynamic model; then, the electrical equivalence is derived. The transfer function is inferred by the ratio of the voltage on the outer skin and the voltage input, i.e. the ratio of the temperature outside the tracker and the heat generated (which is the controlled variable). A PID (Proportional Integral Derivative) controller has been designed using MatLab. The results achieved so far prove that thi...

The CMS Tracker Upgrade for HL-LHC\\\\ Sensor R$\\&$D

CERN Document Server

Naseri, Mohsen

2014-01-01

At an instantaneous luminosity of 5~$\\times10^{34}~cm^{-2}~s^{-1}$, the high-luminosity phase of the Large Hadron Collider (HL-LHC) is expected to deliver a total of 3000~fb$^{-1}$ of collisions, hereby increasing the discovery potential of the LHC experiments significantly. However, the radiation environment of the tracking system will be severe, requiring new radiation hard sensors for the CMS tracker. Focusing on the upgrade of the outer tracker region, the CMS tracker collaboration has almost completed a large material investigation and irradiation campaign to identify the silicon material and design that fulfils all requirements of a new tracking detector at HL-LHC. Focusing on the upgrade of the outer tracker region, pad diodes as well as fully functional strip sensors have been implemented on silicon wafers with different material properties and thicknesses. The samples were irradiated with a mixture of neutrons and protons corresponding to fluences as expected for various positions in the future track...

Development and Testing of the AMEGO Silicon Tracker System

Science.gov (United States)

Griffin, Sean; Amego Team

2018-01-01

The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe-class mission in consideration for the 2020 decadal review designed to operate at energies from ˜ 200 keV to > 10 GeV. Operating a detector in this energy regime is challenging due to the crossover in the interaction cross-section for Compton scattering and pair production. AMEGO is made of four major subsystems: a plastic anticoincidence detector for rejecting cosmic-ray events, a silicon tracker for measuring the energies of Compton scattered electrons and pair-production products, a CZT calorimeter for measuring the energy and location of Compton scattered photons, and a CsI calorimeter for measuring the energy of the pair-production products at high energies. The tracker comprises layers of dual-sided silicon strip detectors which provide energy and localization information for Compton scattering and pair-production events. A prototype tracker system is under development at GSFC; in this contribution we provide details on the verification, packaging, and testing of the prototype tracker, as well as present plans for the development of the front-end electronics, beam tests, and a balloon flight.

The AMS silicon tracker readout, performance results with minimum ionizing particles

CERN Document Server

Alpat, B; Battiston, R; Bourquin, Maurice; Burger, W J; Extermann, Pierre; Chang, Y H; Hou, S R; Pauluzzi, M; Produit, N; Qiu, S; Rapin, D; Ribordy, R; Toker, O; Wu, S X

2000-01-01

First results for the AMS silicon tracker readout performance are presented. Small 20.0*20.0*0.300 mm/sup 3/ silicon microstrip detectors were installed in a 50 GeV electron beam at CERN. The detector readout consisted of prototypes of the tracker data reduction card equipped with a 12-bit ADC and the tracker frontend hybrid with VA_hdr readout chips. The system performance is assessed in terms of signal-to-noise, position resolution, and efficiency. (13 refs).

Using an eye tracker for accurate eye movement artifact correction

NARCIS (Netherlands)

Kierkels, J.J.M.; Riani, J.; Bergmans, J.W.M.; Boxtel, van G.J.M.

2007-01-01

We present a new method to correct eye movement artifacts in electroencephalogram (EEG) data. By using an eye tracker, whose data cannot be corrupted by any electrophysiological signals, an accurate method for correction is developed. The eye-tracker data is used in a Kalman filter to estimate which

Field testing of a next generation pointer/tracker for IRCM

Science.gov (United States)

Chapman, Stuart; Wildgoose, Iain; McDonald, Eric; Duncan, Stuart

2008-10-01

SELEX Galileo has been involved in the development, manufacture and support of high performance electro-optic pointing and stabilisation systems for over forty years. The Company currently supplies the pointer/trackers for the AN/AAQ-24(V) NEMESIS DIRCM system, for which over 1,000 combat-proven units have been produced and deployed in the US, the UK and other nations. In 2007, SELEX Galileo embarked on an internally funded programme to develop ECLIPSE, a new advanced, lightweight, low-cost IRCM pointer/tracker, exploiting the extensive knowledge and experience gained from previous targeting and IRCM programmes. The ECLIPSE design is centred on a low inertia, two-axis servo mechanism with a strap-down inertial sensor and advanced sightline control algorithms, allowing effective tracking through the nadir and providing superior sightline performance. The programme involved the production of three demonstrator units in 2007, and two pre-production units in 2008. The demonstrator units were first trialled as part of a NEMESIS DIRCM system in late 2007, and in April 2008 100% success was achieved in jamming live-fire demonstrations. Helicopter installation and ground testing of a UK only trials system is complete, initial flight testing has just begun, and the airborne test and evaluation scheduled for late summer 2008 will bring the ECLIPSE System to technology readiness to level 7 (TRL7). This paper describes the Eclipse performance demonstrated to date.

Monitoring radiation damage in the LHCb Silicon Tracker

CERN Multimedia

Graverini, Elena

2018-01-01

The purpose of LHCb is to search for indirect evidence of new physics in decays of heavy hadrons. The LHCb detector is a single-arm forward spectrometer with precise silicon-strip detectors in the regions with highest particle occupancies. The non-uniform exposure of the LHCb sensors makes it an ideal laboratory to study radiation damage effects in silicon detectors. The LHCb Silicon Tracker is composed of an upstream tracker, the TT, and of the inner part of the downstream tracker (IT). Dedicated scans are regularly taken, which allow a precise measurement of the charge collection efficiency (CCE) and the calibration of the operational voltages. The measured evolution of the effective depletion voltage $V_{depl}$ is shown, and compared with the Hamburg model prediction. The magnitudes of the sensor leakage current are also analysed and compared to their expected evolution according to phenomenological models. Our results prove that both the TT and the IT will withstand normal operation until the end of the L...

Data Quality Monitoring of the CMS Tracker

International Nuclear Information System (INIS)

Dutta, Suchandra

2011-01-01

The Data Quality Monitoring system for the Tracker has been developed within the CMS Software framework. It has been designed to be used during online data taking as well as during offline reconstruction. The main goal of the online system is to monitor detector performance and identify problems very efficiently during data collection so that proper actions can be taken to fix it. On the other hand any issue with data reconstruction or calibration can be detected during offline processing using the same tool. The monitoring is performed using histograms which are filled with information from raw and reconstructed data computed at the level of individual detectors. Furthermore, statistical tests are performed on these histograms to check the quality and flags are generated automatically. Results are visualized with web based graphical user interfaces. Final data certification is done combining these automatic flags and manual inspection. The Tracker DQM system has been successfully used during cosmic data taking and it has been optimised to fulfill the condition of collision data taking. In this paper we describe the functionality of the CMS Tracker DQM system and the experience acquired during proton-proton collision.

CarbonTracker CT2007B release

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — CarbonTracker is an open product of the NOAA Earth System Research Laboratory using data from the Global Monitoring Division greenhouse gas observational network and...

A Hardware Fast Tracker for the ATLAS Trigger: The Fast TracKer (FTK) Project.

CERN Document Server

Asbah, Nedaa; The ATLAS collaboration

2015-01-01

The trigger system of the ATLAS experiment is designed to reduce the event rate from the LHC nominal bunch crossing at 40 MHz to about 1 kHz, at the design luminosity of 10^{34} cm^{-2} s{-1}. After a successful period of data taking from 2010 to early 2013, the LHC is restarting in 2015 with much higher instantaneous luminosity and this will increase the load on High Level Trigger system, the second stage of the selection based on software algorithms. More sophisticated algorithms will be needed to achieve higher background rejection while maintaining good efficiency for interesting physics signals. The Fast TracKer is part of the ATLAS trigger upgrade project; it is a hardware processor that will provide, at every level-1 accept (100 kHz) and within 100 microseconds, full tracking information for tracks with momentum as low as 1 GeV. Providing fast extensive access to tracking information, with resolution comparable to the offline reconstruction, the Fast Tracker will for example help the High Level Trigger...

Tracker: A three-dimensional raytracing program for ionospheric radio propagation

Energy Technology Data Exchange (ETDEWEB)

Argo, P.E.; DeLapp, D.; Sutherland, C.D.; Farrer, R.G.

1994-12-01

TRACKER is an extension of a three-dimensional Hamiltonian raytrace code developed some thirty years ago by R. Michael Jones. Subsequent modifications to this code, which is commonly called the {open_quotes}Jones Code,{close_quotes} were documented by Jones and Stephensen (1975). TRACKER incorporates an interactive user`s interface, modern differential equation integrators, graphical outputs, homing algorithms, and the Ionospheric Conductivity and Electron Density (ICED) ionosphere. TRACKER predicts the three-dimensional paths of radio waves through model ionospheres by numerically integrating Hamilton`s equations, which are a differential expression of Fermat`s principle of least time. By using continuous models, the Hamiltonian method avoids false caustics and discontinuous raypath properties often encountered in other raytracing methods. In addition to computing the raypath, TRACKER also calculates the group path (or pulse travel time), the phase path, the geometrical (or {open_quotes}real{close_quotes}) pathlength, and the Doppler shift (if the time variation of the ionosphere is explicitly included). Computational speed can be traded for accuracy by specifying the maximum allowable integration error per step in the integration. Only geometrical optics are included in the main raytrace code; no partial reflections or diffraction effects are taken into account. In addition, TRACKER does not lend itself to statistical descriptions of propagation -- it requires a deterministic model of the ionosphere.

Simulation model of ANN based maximum power point tracking controller for solar PV system

Energy Technology Data Exchange (ETDEWEB)

Rai, Anil K.; Singh, Bhupal [Department of Electrical and Electronics Engineering, Ajay Kumar Garg Engineering College, Ghaziabad 201009 (India); Kaushika, N.D.; Agarwal, Niti [School of Research and Development, Bharati Vidyapeeth College of Engineering, A-4 Paschim Vihar, New Delhi 110063 (India)

2011-02-15

In this paper the simulation model of an artificial neural network (ANN) based maximum power point tracking controller has been developed. The controller consists of an ANN tracker and the optimal control unit. The ANN tracker estimates the voltages and currents corresponding to a maximum power delivered by solar PV (photovoltaic) array for variable cell temperature and solar radiation. The cell temperature is considered as a function of ambient air temperature, wind speed and solar radiation. The tracker is trained employing a set of 124 patterns using the back propagation algorithm. The mean square error of tracker output and target values is set to be of the order of 10{sup -5} and the successful convergent of learning process takes 1281 epochs. The accuracy of the ANN tracker has been validated by employing different test data sets. The control unit uses the estimates of the ANN tracker to adjust the duty cycle of the chopper to optimum value needed for maximum power transfer to the specified load. (author)

Behavior Change Techniques Present in Wearable Activity Trackers: A Critical Analysis.

Science.gov (United States)

Mercer, Kathryn; Li, Melissa; Giangregorio, Lora; Burns, Catherine; Grindrod, Kelly

2016-04-27

Wearable activity trackers are promising as interventions that offer guidance and support for increasing physical activity and health-focused tracking. Most adults do not meet their recommended daily activity guidelines, and wearable fitness trackers are increasingly cited as having great potential to improve the physical activity levels of adults. The objective of this study was to use the Coventry, Aberdeen, and London-Refined (CALO-RE) taxonomy to examine if the design of wearable activity trackers incorporates behavior change techniques (BCTs). A secondary objective was to critically analyze whether the BCTs present relate to known drivers of behavior change, such as self-efficacy, with the intention of extending applicability to older adults in addition to the overall population. Wearing each device for a period of 1 week, two independent raters used CALO-RE taxonomy to code the BCTs of the seven wearable activity trackers available in Canada as of March 2014. These included Fitbit Flex, Misfit Shine, Withings Pulse, Jawbone UP24, Spark Activity Tracker by SparkPeople, Nike+ FuelBand SE, and Polar Loop. We calculated interrater reliability using Cohen's kappa. The average number of BCTs identified was 16.3/40. Withings Pulse had the highest number of BCTs and Misfit Shine had the lowest. Most techniques centered around self-monitoring and self-regulation, all of which have been associated with improved physical activity in older adults. Techniques related to planning and providing instructions were scarce. Overall, wearable activity trackers contain several BCTs that have been shown to increase physical activity in older adults. Although more research and development must be done to fully understand the potential of wearables as health interventions, the current wearable trackers offer significant potential with regard to BCTs relevant to uptake by all populations, including older adults.

EyeDroid: An Open Source Mobile Gaze Tracker on Android for Eyewear Computers

DEFF Research Database (Denmark)

Jalaliniya, Shahram; Mardanbeigi, Diako; Sintos, Ioannis

2015-01-01

In this paper we report on development and evaluation of a video-based mobile gaze tracker for eyewear computers. Unlike most of the previous work, our system performs all its processing workload on an Android device and sends the coordinates of the gaze point to an eyewear device through wireless...... connection. We propose a lightweight software architecture for Android to increase the efficiency of image processing needed for eye tracking. The evaluation of the system indicated an accuracy of 1:06 and a battery lifetime of approximate 4.5 hours....

Reliability and Validity of Ten Consumer Activity Trackers Depend on Walking Speed.

Science.gov (United States)

Fokkema, Tryntsje; Kooiman, Thea J M; Krijnen, Wim P; VAN DER Schans, Cees P; DE Groot, Martijn

2017-04-01

To examine the test-retest reliability and validity of ten activity trackers for step counting at three different walking speeds. Thirty-one healthy participants walked twice on a treadmill for 30 min while wearing 10 activity trackers (Polar Loop, Garmin Vivosmart, Fitbit Charge HR, Apple Watch Sport, Pebble Smartwatch, Samsung Gear S, Misfit Flash, Jawbone Up Move, Flyfit, and Moves). Participants walked three walking speeds for 10 min each; slow (3.2 km·h), average (4.8 km·h), and vigorous (6.4 km·h). To measure test-retest reliability, intraclass correlations (ICC) were determined between the first and second treadmill test. Validity was determined by comparing the trackers with the gold standard (hand counting), using mean differences, mean absolute percentage errors, and ICC. Statistical differences were calculated by paired-sample t tests, Wilcoxon signed-rank tests, and by constructing Bland-Altman plots. Test-retest reliability varied with ICC ranging from -0.02 to 0.97. Validity varied between trackers and different walking speeds with mean differences between the gold standard and activity trackers ranging from 0.0 to 26.4%. Most trackers showed relatively low ICC and broad limits of agreement of the Bland-Altman plots at the different speeds. For the slow walking speed, the Garmin Vivosmart and Fitbit Charge HR showed the most accurate results. The Garmin Vivosmart and Apple Watch Sport demonstrated the best accuracy at an average walking speed. For vigorous walking, the Apple Watch Sport, Pebble Smartwatch, and Samsung Gear S exhibited the most accurate results. Test-retest reliability and validity of activity trackers depends on walking speed. In general, consumer activity trackers perform better at an average and vigorous walking speed than at a slower walking speed.

Improved incremental conductance method for maximum power point tracking using cuk converter

Directory of Open Access Journals (Sweden)

M. Saad Saoud

2014-03-01

Full Text Available The Algerian government relies on a strategy focused on the development of inexhaustible resources such as solar and uses to diversify energy sources and prepare the Algeria of tomorrow: about 40% of the production of electricity for domestic consumption will be from renewable sources by 2030, Therefore it is necessary to concentrate our forces in order to reduce the application costs and to increment their performances, Their performance is evaluated and compared through theoretical analysis and digital simulation. This paper presents simulation of improved incremental conductance method for maximum power point tracking (MPPT using DC-DC cuk converter. This improved algorithm is used to track MPPs because it performs precise control under rapidly changing Atmospheric conditions, Matlab/ Simulink were employed for simulation studies.

Transient inactivation of the paraventricular nucleus of the thalamus enhances cue-induced reinstatement in goal-trackers, but not sign-trackers.

Science.gov (United States)

Kuhn, Brittany N; Klumpner, Marin S; Covelo, Ignacio R; Campus, Paolo; Flagel, Shelly B

2018-04-01

The paraventricular nucleus of the thalamus (PVT) has been shown to mediate cue-motivated behaviors, such as sign- and goal-tracking, as well as reinstatement of drug-seeking behavior. However, the role of the PVT in mediating individual variation in cue-induced drug-seeking behavior remains unknown. This study aimed to determine if inactivation of the PVT differentially mediates cue-induced drug-seeking behavior in sign-trackers and goal-trackers. Rats were characterized as sign-trackers (STs) or goal-trackers (GTs) based on their Pavlovian conditioned approach behavior. Rats were then exposed to 15 days of cocaine self-administration, followed by a 2-week forced abstinence period and then extinction training. Rats then underwent tests for cue-induced reinstatement and general locomotor activity, prior to which they received an infusion of either saline (control) or baclofen/muscimol (B/M) to inactivate the PVT. Relative to control animals of the same phenotype, GTs show a robust increase in cue-induced drug-seeking behavior following PVT inactivation, whereas the behavior of STs was not affected. PVT inactivation did not affect locomotor activity in either phenotype. In GTs, the PVT appears to inhibit the expression of drug-seeking, presumably by attenuating the incentive value of the drug cue. Thus, inactivation of the PVT releases this inhibition in GTs, resulting in an increase in cue-induced drug-seeking behavior. PVT inactivation did not affect cue-induced drug-seeking behavior in STs, suggesting that the role of the PVT in encoding the incentive motivational value of drug cues differs between STs and GTs.

The effect of latitude on the performance of different solar trackers in Europe and Africa

International Nuclear Information System (INIS)

Bahrami, Arian; Okoye, Chiemeka Onyeka; Atikol, Ugur

2016-01-01

Highlights: • The effect of latitude on the performance of seven solar trackers is analyzed in Europe and Africa. • The performance of the trackers is ranked according to the area location latitude. • The results showed five ranking patterns. • Based on the five patterns and the site latitude, designers can select the best available tracker. - Abstract: In this paper, the effect of latitude on the performance of different solar trackers is examined. The hourly solar radiation data of different locations around Europe and Africa measured on a horizontal surface is collected and utilized. Widely validated Perez anisotropic model is used to predict the diffuse component of the solar radiation on an inclined surface. Different solar trackers namely, Full/dual-axis, East–West (EW), North–South (NS), Inclined East–West (IEW), and Vertical-axis (V) trackers are considered in calculating the available solar potential of the locations. The performance of the solar trackers in terms of the energy gain is ranked according to the area location latitudes. The results show that the tracking performance is highly dependent on the locations, thus changes with the latitude. The percentage variation among the implemented one-axis tracking options relative to dual-axis trackers ranges from 0.42% to 23.4%. Overall, the increase in the energy gain of dual-axis trackers compared to the optimal fixed panel for the locations varies from 17.72% to 31.23%, thus emphasizes the importance of solar trackers. Finally, the study is expected to aid designers in the selection and installation of appropriate solar trackers in the regions.

The CMS silicon strip tracker and its electronic readout

International Nuclear Information System (INIS)

Friedl, M.

2001-05-01

The Large Hadron Collider (LHC) at CERN (Geneva, CH) will be the world's biggest accelerator machine when operation starts in 2006. One of its four detector experiments is the Compact Muon Solenoid (CMS), consisting of a large-scale silicon tracker and electromagnetic and hadron calorimeters, all embedded in a solenoidal magnetic field of 4 T, and a muon system surrounding the magnet coil. The Silicon Strip Tracker has a sensitive area of 206m 2 with 10 million analog channels which are read out at the collider frequency of 40 MHz. The building blocks of the CMS Tracker are the silicon sensors, APV amplifier ASICs, supporting front-end ASICs, analog and digital optical links as well as data processors and control units in the back-end. Radiation tolerance, readout speed and the huge data volume are challenging requirements. The charge collection in silicon detectors was modeled, which is discussed as well as the concepts of readout amplifiers with respect to the LHC requirements, including the deconvolution method of fast pulse shaping, electronic noise constraints and radiation effects. Moreover, extensive measurements on prototype components of the CMS Tracker and different versions of the APV chip in particular were performed. There was a significant contribution to the construction of several detector modules, characterized them in particle beam tests and quantified radiation induced effects on the APV chip and on silicon detectors. In addition, a prototype of the analog optical link and the analog performance of the back-end digitization unit were evaluated. The results are very encouraging, demonstrating the feasibility of the CMS Silicon Strip Tracker system and motivating progress towards the construction phase. (author)

[Reduction of decentration after LASIK using a modified eye tracker ring for the MEL-70 excimer laser].

Science.gov (United States)

Schulze, S; Nietgen, G; Sekundo, W

2004-07-01

The aim of this study was to determine and compare the rate of eccentric laser ablation after LASIK depending on the eye tracker ring used. All LASIK treatments were carried out using the MEL-70 flying spot excimer laser (Zeiss-Meditec, Jena). The flap was produced using a Corneal Shaper trade mark or Hansatome trade mark Microkeratome (B and L Surgical, Heidelberg). Initially we used an 11 mm eye tracker ring without hinge protector. At the end of February 2001 this ring was replaced by a 10 mm and a 9.5 mm ring with built-in hinge protector. An additional modification was introduced by us: at 1 mm separations little teeth-like spikes were engraved into the eyeward side of the ring, thus stabilising the position of the ring on the globe and allowing free liquid to flow through the spaces between each spike. The built-in calibration system of the corneal topography (TMS 3, Tomey, Erlangen) from patients with a follow-up of one month or longer was used to determine the distance between the centre of the ablation zone from the fixation point. In group I patients (old ring) 42 eyes were treated. In 4 eyes ablation was perfect, in 21 eyes the ablation centre was located 0.1 to 0.49 mm from the fixation point, in 11 eyes 0.51 to 0.99 mm and in 5 eyes 1.1 to 1.49 mm whereas one eye showed a decentred ablation of 1.53 mm. In group II (new ring) 42 eyes were investigated also. In 11 eyes ablation was perfect, in 20 eyes the ablation centre was located 0.1 to 0.49 mm from the fixation point, in 10 eyes 0.5 to 0.99 mm and one eye had an eccentric ablation of 1.28 mm from the fixation point. The further development of our eye tracker ring for the MEL-70 laser considerably reduced the rate of decentred ablations. An enhanced grip of the ring onto the globe reduces a slow slide during the laser procedure.

ATLAS Transition Radiation Tracker - large piece

CERN Multimedia

2006-01-01

The ATLAS transition radiation tracker is made of 300'000 straw tubes, up to 144cm long. Filled with a gas mixture and threaded with a wire, each straw is a complete mini-detector in its own right. An electric field is applied between the wire and the outside wall of the straw. As particles pass through, they collide with atoms in the gas, knocking out electrons. The avalanche of electrons is detected as an electrical signal on the wire in the centre. The tracker plays two important roles. Firstly, it makes more position measurements, giving more dots for the computers to join up to recreate the particle tracks. Also, together with the ATLAS calorimeters, it distinguishes between different types of particles depending on whether they emit radiation as they make the transition from the surrounding foil into the straws.

ATLAS Transition Radiation Tracker - small piece

CERN Multimedia

2006-01-01

The ATLAS transition radiation tracker is made of 300'000 straw tubes, up to 144cm long. Filled with a gas mixture and threaded with a wire, each straw is a complete mini-detector in its own right. An electric field is applied between the wire and the outside wall of the straw. As particles pass through, they collide with atoms in the gas, knocking out electrons. The avalanche of electrons is detected as an electrical signal on the wire in the centre. The tracker plays two important roles. Firstly, it makes more position measurements, giving more dots for the computers to join up to recreate the particle tracks. Also, together with the ATLAS calorimeters, it distinguishes between different types of particles depending on whether they emit radiation as they make the transition from the surrounding foil into the straws.

Proposal for the LHCb outer tracker front-end electronics

CERN Document Server

Deppe, H; Feuerstack-Raible, M; Srowig, A; Stange, U; Hommels, B; Sluijk, T

2001-01-01

A market survey on available TDCs for reading out the LHCb Outer Tracker has left over only one TDC, which is not optimal for this purpose. Hence, a new readout architecture which is based on a TDC to be developed anew has been defined. This system fits optimal the requirements of the LHCb Outer Tracker and also should be much cheaper. The system and its main issues are described in this paper.

Muon trackers for imaging a nuclear reactor

Science.gov (United States)

Kume, N.; Miyadera, H.; Morris, C. L.; Bacon, J.; Borozdin, K. N.; Durham, J. M.; Fuzita, K.; Guardincerri, E.; Izumi, M.; Nakayama, K.; Saltus, M.; Sugita, T.; Takakura, K.; Yoshioka, K.

2016-09-01

A detector system for assessing damage to the cores of the Fukushima Daiichi nuclear reactors by using cosmic-ray muon tomography was developed. The system consists of a pair of drift-tube tracking detectors of 7.2× 7.2-m2 area. Each muon tracker consists of 6 x-layer and 6 y-layer drift-tube detectors. Each tracker is capable of measuring muon tracks with 12 mrad angular resolutions, and is capable of operating under 50-μ Sv/h radiation environment by removing gamma induced background with a novel time-coincidence logic. An estimated resolution to observe nuclear fuel debris at Fukushima Daiichi is 0.3 m when the core is imaged from outside the reactor building.

A STRUCTURE APPROACH FOR A PHOTOVOLTAIC STATION CONTROL BASED ON ADAPTIVE FUZZY AGENT

Directory of Open Access Journals (Sweden)

I. A. Elzein

2017-01-01

Full Text Available The solar energy is directly converted into electrical energy by solar PV module. Each type of PV module has its own specific characteristic corresponding to the surrounding condition such as irradiation, and temperature and this makes the tracking of maximum power point (MPP a complicated problem. To overcome this problem, many maximum power point tracking (MPPT control algorithms have been presented. Fuzzy logic (FL has been used for tracking the MPP of PV modules because it has the advantages of being robust, relatively simple to design and does not require the knowledge of an exact model where a mathematical model of the PV module, DC-DC converter, are used in the study of FL based MPPT algorithm. It is suggested to present this problem in the form of two-folds; first to identify the deviation of the power to maximum power point, and secondly, to control the voltage of the DC-DC converter corresponding to maximum power. In this paper, the first discussion approach will stress out the integration of model predictive control in maximum power point tracking MPPT and as progressing a second approach is identified as fuzzy logic controller FLC and perturb & Observe P&O algorithms are analyzed. All are interrelated to MPPT model for a photovoltaic module, PVM, to search for and generate the maximum power; in this case what’s called P-max. As per the first technique the focus is on the optimal duty ratio, D, for a series of multi diverse types of converters and load matching. The design of the MPPT for a stand-alone photovoltaic power generation system is applied where the system will consist of a solar array with nonlinear time varying characteristics, and a converter with appropriate filters. The integration of model predictive control will be addressed first in this paper. The second fold will implement an MPPT system that use the FLC and compare it with a classical MPPT P&O algorithm through the utilization of Simulink. The novel design in

LHCb Silicon Tracker DAQ and DCS Online Systems

CERN Multimedia

Buechler, A; Rodriguez, P

2009-01-01

The LHCb experiment at the Large Hadron Collider (LHC) at CERN in Geneva Switzerland is specialized on precision measurements of b quark decays. The Silicon Tracker (ST) contributes a crucial part in tracking the particle trajectories and consists of two silicon micro-strip detectors, the Tracker Turicensis upstream of the LHCb magnet and the Inner Tracker downstream. The radiation and the magnetic field represent new challenges for the implementation of a Detector Control System (DCS) and the data acquisition (DAQ). The DAQ has to deal with more than 270K analog readout channels, 2K readout chips and real time DAQ at a rate of 1.1 MHz with data processing at TELL1 level. The TELL1 real time algorithms for clustering thresholds and other computations run on dedicated FPGAs that implement 13K configurable parameters per board, in total 1.17 K parameters for the ST. After data processing the total throughput amounts to about 6.4 Gbytes from an input data rate of around ~337 Gbytes per second. A finite state ma...

The construction of the ATLAS semi-conductor tracker

International Nuclear Information System (INIS)

Jones, Tim

2006-01-01

The ATLAS (A Toroidal LHC ApparatuS) experiment at the Large Hadron Collider (LHC) at CERN has been designed to explore physics at the TeV energy scale and will be commissioned in 2007. In the innermost region of the experiment is a charged particle tracker, the Inner Detector of which the Semiconductor Tracker (SCT) is a major component. The SCT comprises a central barrel section enclosed by two endcaps (A and C). The construction of the major components of the ATLAS Semi-conductor tracker (SCT) is now nearing completion. Following a brief description of the design of the SCT, the logistics and organisation of the construction phase of the project are discussed. Central to the delivery of a high quality detector is the testing of large numbers of modules both during assembly and after they are mounted on their final support structures. The results of these tests for endcap C are presented showing that the electrical performance of the 988 modules to be installed in ATLAS is compatible with the specifications required

The CMS silicon tracker

International Nuclear Information System (INIS)

D'Alessandro, R.; Biggeri, U.; Bruzzi, M.; Catacchini, E.; Civinini, C.; Focardi, E.; Lenzi, M.; Loreti, M.; Meschini, M.; Parrini, G.; Pieri, M.; Albergo, S.; Boemi, D.; Potenza, R.; Tricomi, A.; Angarano, M.; Creanza, D.; Palma, M. de; Fiore, L.; Maggi, G.; My, S.; Raso, G.; Selvaggi, G.; Tempesta, P.; Azzi, P.; Bacchetta, N.; Bisello, D.; Candelori, A.; Castro, A.; Da Rold, M.; Giraldo, A.; Martignon, G.; Paccagnella, A.; Stavitsky, I.; Babucci, E.; Bartalini, P.; Bilei, G.M.; Checcucci, B.; Ciampolini, P.; Lariccia, P.; Mantovani, G.; Passeri, D.; Santocchia, A.; Servoli, L.; Wang, Y.; Bagliesi, G.; Basti, A.; Bosi, F.; Borello, L.; Bozzi, C.; Castaldi, R.; Dell'Orso, R.; Giassi, A.; Messineo, A.; Palla, F.; Raffaelli, F.; Sguazzoni, G.; Starodumov, A.; Tonelli, G.; Vannini, C.; Verdini, P.G.; Xie, Z.; Breuker, H.; Caner, A.; Elliott-Peisert, A.; Feld, L.; Glessing, B.; Hammerstrom, R.; Huhtinen, M.; Mannelli, M.; Marchioro, A.; Schmitt, B.; Stefanini, G.; Connotte, J.; Gu, W.H.; Luebelsmeyer, K.; Pandoulas, D.; Siedling, R.; Wittmer, B.; Della Marina, R.; Freudenreich, K.; Lustermann, W.; Viertel, G.; Eklund, C.; Karimaeki, V.; Skog, K.; French, M.; Hall, G.; Mc Evoy, B.; Raymond, M.; Hrubec, J.; Krammer, M.; Piperov, S.; Tuuva, T.; Watts, S.; Silvestris, L.

1998-01-01

The new silicon tracker layout (V4) is presented. The system aspects of the construction are discussed together with the expected tracking performance. Because of the high radiation environment in which the detectors will operate, particular care has been devoted to the study of the characteristics of heavily irradiated detectors. This includes studies on performance (charge collection, cluster size, resolution, efficiency) as a function of the bias voltage, integrated fluence, incidence angle and temperature. (author)

Teaching optical phenomena with Tracker

Science.gov (United States)

Rodrigues, M.; Simeão Carvalho, P.

2014-11-01

Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a relatively complex setup. Fortunately, nowadays it is possible to analyse optical phenomena in a simple and quantitative way using the freeware video analysis software ‘Tracker’. In this paper, we show the advantages of video-based experimental activities for teaching concepts in optics. We intend to show: (a) how easy the study of such phenomena can be, even at home, because only simple materials are needed, and Tracker provides the necessary measuring instruments; and (b) how we can use Tracker to improve students’ understanding of some optical concepts. We give examples using video modelling to study the laws of reflection, Snell’s laws, focal distances in lenses and mirrors, and diffraction phenomena, which we hope will motivate teachers to implement it in their own classes and schools.

The ATLAS semiconductor tracker (SCT)

International Nuclear Information System (INIS)

Jackson, J.N.

2005-01-01

The ATLAS detector (CERN,LHCC,94-43 (1994)) is designed to study a wide range of physics at the CERN Large Hadron Collider (LHC) at luminosities up to 10 34 cm -2 s -1 with a bunch-crossing rate of 40 MHz. The Semiconductor Tracker (SCT) forms a key component of the Inner Detector (vol. 1, ATLAS TDR 4, CERN,LHCC 97-16 (1997); vol. 2, ATLAS TDR 5, CERN,LHCC 97-17 (1997)) which is situated inside a 2 T solenoid field. The ATLAS Semiconductor Tracker (SCT) utilises 4088 silicon modules with binary readout mounted on carbon fibre composite structures arranged in the forms of barrels in the central region and discs in the forward region. The construction of the SCT is now well advanced. The design of the SCT modules, services and support structures will be briefly outlined. A description of the various stages in the construction process will be presented with examples of the performance achieved and the main difficulties encountered. Finally, the current status of the construction is reviewed

Optimized Adaptive Perturb and Observe Maximum Power Point Tracking Control for Photovoltaic Generation

Directory of Open Access Journals (Sweden)

Luigi Piegari

2015-04-01

Full Text Available The power extracted from PV arrays is usually maximized using maximum power point tracking algorithms. One of the most widely used techniques is the perturb & observe algorithm, which periodically perturbs the operating point of the PV array, sometime with an adaptive perturbation step, and compares the PV power before and after the perturbation. This paper analyses the most suitable perturbation step to optimize maximum power point tracking performance and suggests a design criterion to select the parameters of the controller. Using this proposed adaptive step, the MPPT perturb & observe algorithm achieves an excellent dynamic response by adapting the perturbation step to the actual operating conditions of the PV array. The proposed algorithm has been validated and tested in a laboratory using a dual input inductor push-pull converter. This particular converter topology is an efficient interface to boost the low voltage of PV arrays and effectively control the power flow when input or output voltages are variable. The experimental results have proved the superiority of the proposed algorithm in comparison of traditional perturb & observe and incremental conductance techniques.

Large-scale module production for the CMS silicon strip tracker

CERN Document Server

Cattai, A

2005-01-01

The Silicon Strip Tracker (SST) for the CMS experiment at LHC consists of 210 m**2 of silicon strip detectors grouped into four distinct sub-systems. We present a brief description of the CMS Tracker, the industrialised detector module production methods and the current status of the SST with reference to some problems encountered at the factories and in the construction centres.

Quality assurance for CMS Tracker LV and HV Power Supplies

CERN Document Server

Costa, Marco; Sertoli, M; Trapani, P; Periale, L; Isabella, L; Landi, C; Lucchesi, A

2007-01-01

This work describes the quality assurance measurements that have been carried out on about 2000 Power Supply Units produced in CAEN technology for the CMS Silicon Tracker Detector. The automate procedure and the characteristics of the dedicated Test Fixture developed for this activity are described in details. Magnetic field tolerance and radiation hardness of Tracker power supply units is also discussed at length.

SVT: an online silicon vertex tracker for the CDF upgrade

International Nuclear Information System (INIS)

Bardi, A.; Belforte, S.; Berryhill, J.

1997-07-01

The SVT is an online tracker for the CDF upgrade which will reconstruct 2D tracks using information from the Silicon VerteX detector (SVXII) and Central Outer Tracker (COT). The precision measurement of the track impact parameter will then be used to select and record large samples of B hadrons. We discuss the overall architecture, algorithms, and hardware implementation of the system

Dynamic performance of maximum power point tracking circuits using sinusoidal extremum seeking control for photovoltaic generation

Science.gov (United States)

Leyva, R.; Artillan, P.; Cabal, C.; Estibals, B.; Alonso, C.

2011-04-01

The article studies the dynamic performance of a family of maximum power point tracking circuits used for photovoltaic generation. It revisits the sinusoidal extremum seeking control (ESC) technique which can be considered as a particular subgroup of the Perturb and Observe algorithms. The sinusoidal ESC technique consists of adding a small sinusoidal disturbance to the input and processing the perturbed output to drive the operating point at its maximum. The output processing involves a synchronous multiplication and a filtering stage. The filter instance determines the dynamic performance of the MPPT based on sinusoidal ESC principle. The approach uses the well-known root-locus method to give insight about damping degree and settlement time of maximum-seeking waveforms. This article shows the transient waveforms in three different filter instances to illustrate the approach. Finally, an experimental prototype corroborates the dynamic analysis.

The ATLAS Fast Tracker Processing Units - input and output data preparation

CERN Document Server

Bolz, Arthur Eugen; The ATLAS collaboration

2016-01-01

The ATLAS Fast Tracker is a hardware processor built to reconstruct tracks at a rate of up to 100 kHz and provide them to the high level trigger system. The Fast Tracker will allow the trigger to utilize tracking information from the entire detector at an earlier event selection stage than ever before, allowing for more efficient event rejection. The connection of the system from to the detector read-outs and to the high level trigger computing farms are made through custom boards implementing Advanced Telecommunications Computing Technologies standard. The input is processed by the Input Mezzanines and Data Formatter boards, designed to receive and sort the data coming from the Pixel and Semi-conductor Tracker. The Fast Tracker to Level-2 Interface Card connects the system to the computing farm. The Input Mezzanines are 128 boards, performing clustering, placed on the 32 Data Formatter mother boards that sort the information into 64 logical regions required by the downstream processing units. This necessitat...

Studies for the Commissioning of the CERN CMS Silicon Strip Tracker

CERN Document Server

Bloch, Christoph; Abbaneo, Duccio; Fabjan, Christian Wolfgang

2008-01-01

In 2008 the Large Hadron Collider (LHC) at CERN will start producing proton-proton collisions of unprecedented energy. One of its main experiments is the Compact Muon Solenoid (CMS), a general purpose detector, optimized for the search of the Higgs boson and super symmetric particles. The discovery potential of the CMS detector relies on a high precision tracking system, made of a pixel detector and the largest silicon strip Tracker ever built. In order to operate successfully a device as complex as the CMS silicon strip Tracker, and to fully exploit its potential, the properties of the hardware need to be characterized as precisely as possible, and the reconstruction software needs to be commissioned with physics signals. A number of issues were identified and studied to commission the detector, some of which concern the entire Tracker, while some are specific to the Tracker Outer Barrel (TOB): - the time evolution of the signals in the readout electronics need to be precisely measured and correctly simulate...

Design of a cost-effective laser spot tracker

Science.gov (United States)

Artan, Göktuǧ Gencehan; Sari, Hüseyin

2017-05-01

One of the most important aspects of guided systems is detection. The most convenient detection in the sense of precision can be achieved with a laser spot tracker. This study deals with a military grade, high performance and cost-effective laser spot tracker for a guided system. The aim is to develop a high field of view system that will detect a laser spot from a distance of 3 kilometers in which the target is designated from 3 kilometers with a laser. The study basically consists of the system design, modeling, producing and the conducting performance tests of the whole system.

Precision Attitude Determination System (PADS) system design and analysis: Single-axis gimbal star tracker

Science.gov (United States)

1974-01-01

The feasibility is evaluated of an evolutionary development for use of a single-axis gimbal star tracker from prior two-axis gimbal star tracker based system applications. Detailed evaluation of the star tracker gimbal encoder is considered. A brief system description is given including the aspects of tracker evolution and encoder evaluation. System analysis includes evaluation of star availability and mounting constraints for the geosynchronous orbit application, and a covariance simulation analysis to evaluate performance potential. Star availability and covariance analysis digital computer programs are included.

The rad-hard readout system of the BaBar silicon vertex tracker

Science.gov (United States)

Re, V.; DeWitt, J.; Dow, S.; Frey, A.; Johnson, R. P.; Kroeger, W.; Kipnis, I.; Leona, A.; Luo, L.; Mandelli, E.; Manfredi, P. F.; Nyman, M.; Pedrali-Noy, M.; Poplevin, P.; Perazzo, A.; Roe, N.; Spencer, N.

1998-02-01

This paper discusses the behaviour of a prototype rad-hard version of the chip developed for the readout of the BaBar silicon vertex tracker. A previous version of the chip, implemented in the 0.8 μm HP rad-soft version has been thoroughly tested in the recent times. It featured outstanding noise characteristics and showed that the specifications assumed as target for the tracker readout were met to a very good extent. The next step was the realization of a chip prototype in the rad-hard process that will be employed in the actual chip production. Such a prototype is structurally and functionally identical to its rad-soft predecessor. However, the process parameters being different, and not fully mastered at the time of design, some deviations in the behaviour were to be expected. The reasons for such deviations have been identified and some of them were removed by acting on the points that were left accessible on the chip. Other required small circuit modifications that will not affect the production schedule. The tests done so far on the rad-hard chip have shown that the noise behaviour is very close to that of the rad-soft version, that is fully adequate for the vertex detector readout.

Three-level grid-connected photovoltaic inverter with maximum power point tracking

International Nuclear Information System (INIS)

Tsang, K.M.; Chan, W.L.

2013-01-01

Highlight: ► This paper reports a novel 3-level grid connected photovoltaic inverter. ► The inverter features maximum power point tracking and grid current shaping. ► The inverter can be acted as an active filter and a renewable power source. - Abstract: This paper presents a systematic way of designing control scheme for a grid-connected photovoltaic (PV) inverter featuring maximum power point tracking (MPPT) and grid current shaping. Unlike conventional design, only four power switches are required to achieve three output levels and it is not necessary to use any phase-locked-loop circuitry. For the proposed scheme, a simple integral controller has been designed for the tracking of the maximum power point of a PV array based on an improved extremum seeking control method. For the grid-connected inverter, a current loop controller and a voltage loop controller have been designed. The current loop controller is designed to shape the inverter output current while the voltage loop controller can maintain the capacitor voltage at a certain level and provide a reference inverter output current for the PV inverter without affecting the maximum power point of the PV array. Experimental results are included to demonstrate the effectiveness of the tracking and control scheme.

Spacecraft angular velocity estimation algorithm for star tracker based on optical flow techniques

Science.gov (United States)

Tang, Yujie; Li, Jian; Wang, Gangyi

2018-02-01

An integrated navigation system often uses the traditional gyro and star tracker for high precision navigation with the shortcomings of large volume, heavy weight and high-cost. With the development of autonomous navigation for deep space and small spacecraft, star tracker has been gradually used for attitude calculation and angular velocity measurement directly. At the same time, with the dynamic imaging requirements of remote sensing satellites and other imaging satellites, how to measure the angular velocity in the dynamic situation to improve the accuracy of the star tracker is the hotspot of future research. We propose the approach to measure angular rate with a nongyro and improve the dynamic performance of the star tracker. First, the star extraction algorithm based on morphology is used to extract the star region, and the stars in the two images are matched according to the method of angular distance voting. The calculation of the displacement of the star image is measured by the improved optical flow method. Finally, the triaxial angular velocity of the star tracker is calculated by the star vector using the least squares method. The method has the advantages of fast matching speed, strong antinoise ability, and good dynamic performance. The triaxial angular velocity of star tracker can be obtained accurately with these methods. So, the star tracker can achieve better tracking performance and dynamic attitude positioning accuracy to lay a good foundation for the wide application of various satellites and complex space missions.

A Brightness-Referenced Star Identification Algorithm for APS Star Trackers

Science.gov (United States)

Zhang, Peng; Zhao, Qile; Liu, Jingnan; Liu, Ning

2014-01-01

Star trackers are currently the most accurate spacecraft attitude sensors. As a result, they are widely used in remote sensing satellites. Since traditional charge-coupled device (CCD)-based star trackers have a limited sensitivity range and dynamic range, the matching process for a star tracker is typically not very sensitive to star brightness. For active pixel sensor (APS) star trackers, the intensity of an imaged star is valuable information that can be used in star identification process. In this paper an improved brightness referenced star identification algorithm is presented. This algorithm utilizes the k-vector search theory and adds imaged stars' intensities to narrow the search scope and therefore increase the efficiency of the matching process. Based on different imaging conditions (slew, bright bodies, etc.) the developed matching algorithm operates in one of two identification modes: a three-star mode, and a four-star mode. If the reference bright stars (the stars brighter than three magnitude) show up, the algorithm runs the three-star mode and efficiency is further improved. The proposed method was compared with other two distinctive methods the pyramid and geometric voting methods. All three methods were tested with simulation data and actual in orbit data from the APS star tracker of ZY-3. Using a catalog composed of 1500 stars, the results show that without false stars the efficiency of this new method is 4∼5 times that of the pyramid method and 35∼37 times that of the geometric method. PMID:25299950

Automated SmartPrep tracker positioning in liver MRI scans

International Nuclear Information System (INIS)

Goto, Takao; Kabasawa, Hiroyuki

2013-01-01

This paper presents a new method for automated SmartPrep tracker positioning in liver MRI scans. SmartPrep is used to monitor the contrast bolus signal in order to detect the arrival time of the bolus. Accurately placing the tracker in the aorta while viewing three planar scout images is a difficult task for the operator and is an important problem from the workflow standpoint. The development of an automated SmartPrep tracker would therefore help to improve workflow in liver MRI scans. In our proposed method, the aorta is detected using AdaBoost (which is a machine learning technique) by searching around the cerebral spinal fluid (CSF) in the spinal cord. Analysis of scout scan images showed that our detection method functioned properly for a variety of axial MR images without intensity correction. A total of 234 images reconstructed from the datasets of 64 volunteers were analyzed, and the results showed that the detection error for the aorta was approximately 3 mm. (author)

Upgrades of the CMS Outer Tracker for HL-LHC

CERN Document Server

AUTHOR|(CDS)2067159

2016-01-01

The LHC machine is planning an upgrade program which will smoothly bring the luminosity to about 5×1034cm$^{−2}$s$^{−1}$ around 2028, to possibly reach an integrated luminosity of 3000 fb$^{−1}$ in the following decade. This High Luminosity LHC scenario, HL-LHC, will require a preparation program of the LHC detectors known as Phase-2 upgrade. The current CMS Outer Tracker, already running close to its design limits, will not be able to survive HL-LHC radiation conditions and CMS will need a completely new device, in order to fully exploit the highly demanding operating conditions and the delivered luminosity. The new Tracker should have also L1 trigger capabilities. To achieve such goals, R&D; activities are ongoing to explore options and develop solutions that would allow including tracking information at Level-1. The design choices for the CMS Outer Tracker upgrades are discussed along with some highlights of the R&D; activities.

Acquisition, tracking, and pointing IV; Proceedings of the Meeting, Orlando, FL, Apr. 19, 20, 1990

Science.gov (United States)

Gowrinathan, Sankaran

1990-09-01

Various papers on acquisition, tracking, and pointing are presented. Individual topics addressed include: backlash control techniques in geared servo mechanics; optical fiber and photodetector array for robotic seam tracking; star trackers for spacecraft applications; Starfire optical range tracking system for the 1.5 m telescope; real-time video image centroid tracker; optical alignment with a beamwalk system; line-of-sight stabilization requirements for target tracking system; image quality with narrow beam illumination in an active tracking system; IR sensor data fusion for target detection, identification, and tracking; target location and pointing algorithm for a three-axis stabilized line scanner. Also discussed are: adaptive control system techniques applied to inertial stabilization systems; supervisory control of electrooptic tracking and pointing; position loop compensation for flex-pivot-mounted gimbal stabilization systems; advanced testing methods for acquisition, tracking, and pointing; development of kinmatics for gimballed mirror systems.

The ATLAS fast tracker processor design

CERN Document Server

Volpi, Guido; Albicocco, Pietro; Alison, John; Ancu, Lucian Stefan; Anderson, James; Andari, Nansi; Andreani, Alessandro; Andreazza, Attilio; Annovi, Alberto; Antonelli, Mario; Asbah, Needa; Atkinson, Markus; Baines, J; Barberio, Elisabetta; Beccherle, Roberto; Beretta, Matteo; Biesuz, Nicolo Vladi; Blair, R E; Bogdan, Mircea; Boveia, Antonio; Britzger, Daniel; Bryant, Partick; Burghgrave, Blake; Calderini, Giovanni; Camplani, Alessandra; Cavaliere, Viviana; Cavasinni, Vincenzo; Chakraborty, Dhiman; Chang, Philip; Cheng, Yangyang; Citraro, Saverio; Citterio, Mauro; Crescioli, Francesco; Dawe, Noel; Dell'Orso, Mauro; Donati, Simone; Dondero, Paolo; Drake, G; Gadomski, Szymon; Gatta, Mauro; Gentsos, Christos; Giannetti, Paola; Gkaitatzis, Stamatios; Gramling, Johanna; Howarth, James William; Iizawa, Tomoya; Ilic, Nikolina; Jiang, Zihao; Kaji, Toshiaki; Kasten, Michael; Kawaguchi, Yoshimasa; Kim, Young Kee; Kimura, Naoki; Klimkovich, Tatsiana; Kolb, Mathis; Kordas, K; Krizka, Karol; Kubota, T; Lanza, Agostino; Li, Ho Ling; Liberali, Valentino; Lisovyi, Mykhailo; Liu, Lulu; Love, Jeremy; Luciano, Pierluigi; Luongo, Carmela; Magalotti, Daniel; Maznas, Ioannis; Meroni, Chiara; Mitani, Takashi; Nasimi, Hikmat; Negri, Andrea; Neroutsos, Panos; Neubauer, Mark; Nikolaidis, Spiridon; Okumura, Y; Pandini, Carlo; Petridou, Chariclia; Piendibene, Marco; Proudfoot, James; Rados, Petar Kevin; Roda, Chiara; Rossi, Enrico; Sakurai, Yuki; Sampsonidis, Dimitrios; Saxon, James; Schmitt, Stefan; Schoening, Andre; Shochet, Mel; Shoijaii, Jafar; Soltveit, Hans Kristian; Sotiropoulou, Calliope-Louisa; Stabile, Alberto; Swiatlowski, Maximilian J; Tang, Fukun; Taylor, Pierre Thor Elliot; Testa, Marianna; Tompkins, Lauren; Vercesi, V; Wang, Rui; Watari, Ryutaro; Zhang, Jianhong; Zeng, Jian Cong; Zou, Rui; Bertolucci, Federico

2015-01-01

The extended use of tracking information at the trigger level in the LHC is crucial for the trigger and data acquisition (TDAQ) system to fulfill its task. Precise and fast tracking is important to identify specific decay products of the Higgs boson or new phenomena, as well as to distinguish the contributions coming from the many collisions that occur at every bunch crossing. However, track reconstruction is among the most demanding tasks performed by the TDAQ computing farm; in fact, complete reconstruction at full Level-1 trigger accept rate (100 kHz) is not possible. In order to overcome this limitation, the ATLAS experiment is planning the installation of a dedicated processor, the Fast Tracker (FTK), which is aimed at achieving this goal. The FTK is a pipeline of high performance electronics, based on custom and commercial devices, which is expected to reconstruct, with high resolution, the trajectories of charged-particle tracks with a transverse momentum above 1 GeV, using the ATLAS inner tracker info...

CellTracker (not only) for dummies.

Science.gov (United States)

Piccinini, Filippo; Kiss, Alexa; Horvath, Peter

2016-03-15

Time-lapse experiments play a key role in studying the dynamic behavior of cells. Single-cell tracking is one of the fundamental tools for such analyses. The vast majority of the recently introduced cell tracking methods are limited to fluorescently labeled cells. An equally important limitation is that most software cannot be effectively used by biologists without reasonable expertise in image processing. Here we present CellTracker, a user-friendly open-source software tool for tracking cells imaged with various imaging modalities, including fluorescent, phase contrast and differential interference contrast (DIC) techniques. CellTracker is written in MATLAB (The MathWorks, Inc., USA). It works with Windows, Macintosh and UNIX-based systems. Source code and graphical user interface (GUI) are freely available at: http://celltracker.website/ horvath.peter@brc.mta.hu Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

TRACKER

CERN Multimedia

D. Duggan and L. Demaria

2012-01-01

Pixels Tracker With the 2012 proton-proton run almost complete, the pixel detector continues to operate well in an environment with large pile-up and high L1 rate. During this period, the pixel detector has shown excellent stability, with the number of current active channels from each the BPIX and FPIX the same as from the first month of 2012 running, resulting in 96.3% of the detector active. This total includes the recovery of six FPIX channels, temporarily disabled due to an unexpected dependence on the magnetic field. From a dedicated study that identified a small crack in an optical cable connector, a repair was made which restored 120 ROCs in the FPIX. During 2012 there has been a close collaboration of the online operations with the offline studies, resulting in the first dedicated HV bias scans used for the pixel Lorentz Angle measurement. These scans help to better understand this important parameter that changes with temperature, irradiation, and bias voltage. This is in addition to all other s...

TRACKER

CERN Multimedia

R. Yohay and E. Butz

2013-01-01

  Pixel Tracker Preparation of the newly built Pixel clean room in the radioprotection (RP) zone of SX5 has been proceeding at a steady clip since the beginning of 2013. The clean room is designed to provide a cold, dry, dust-free laboratory environment for storage and repairs of the CMS Pixel detector during LS1 and future LHC shutdown periods. To that end, it is required to have robust temperature and humidity control, standalone DAQ and DCS systems, and space for specialised silicon testing and repair equipment. Good progress has been made in delivering each of these items. The ongoing project of commissioning the clean room HVAC system has been a success so far. The clean room will be kept at 10–20 Pa above atmospheric pressure to ensure that contaminants flow out of the room. There are two operating temperatures for the room: 21°C will be used when the Pixel detector components are under cold storage at subzero temperatures in well-sealed “cold boxes,” ...

TRACKER

CERN Multimedia

E. Butz

2011-01-01

The strip tracker took data very efficiently during 2010 with system availabilities of above 97% in the pp running and close to 100% during the heavy-ion running. The number of active channels in the readout is largely stable around 98%. The maintenance and development during the extended technical stop have been focussed on improving the operating conditions of the main silicon strip cooling plants SS1 and SS2, which have been items of concern (see last Bulletin). In order to stabilise and smooth the operation of SS1 and SS2, larger bypass valves and variable frequency drivers (VFDs) have been introduced. Possible noise induced by operation of the VFDs on other parts of CMS has been evaluated and no increased noise has been reported so far. The leak rate of every single line on SS2 was measured with the precise test-rig. Besides the known leaky lines, ten other SS2 lines were measured to leak between 120 g/day and 1200 g/day under the given test conditions, establishin...

リミットサイクル方式MPPT制御による太陽光バッテリ充電器の設計法

OpenAIRE

北野, 達也; 関口, 慎也; Tatsuya, Kitano; Shinya, Sekiguchi; 小山工業高等専門学校電子システム工学専攻科

2007-01-01

In order to track the time varying maximum power point of the solar array depending on its operating conditions of insolation and temperature, the MPPT (maximum power point tracking) control technique plays an important role in the practical PV systems. A variety of MPPT schemes have been proposed so far. However, most of the conventional schemes have been based on the "hill climbing method" using the actual output power information. The authors have been forcusing on the simplification of th...

System-on-a-Chip Based Nano Star Tracker and Its Real-Time Image Processing Approach

OpenAIRE

Wei, Minsong; Bao, Jingyu; Xing, Fei; Liu, Zengyi; Sun, Ting; You, Zheng

2016-01-01

The star tracker is one of the most accurate components for satellite attitude determination. With the development of the nano star tracker, it is compatible for application on small satellites. However, the drawback in dynamic property of nano star tracker has limited its extensive applications. The principal objective of this study is to introduce a system-on-a-chip (SOC) based nano star tracker with enhanced dynamic property. A morphology based image processing approach was realized based ...

A novel algorithm for single-axis maximum power generation sun trackers

International Nuclear Information System (INIS)

Lee, Kung-Yen; Chung, Chi-Yao; Huang, Bin-Juine; Kuo, Ting-Jung; Yang, Huang-Wei; Cheng, Hung-Yen; Hsu, Po-Chien; Li, Kang

2017-01-01

Highlights: • A novel algorithm for a single-axis sun tracker is developed to increase the efficiency. • Photovoltaic module is rotated to find the optimal angle for generating the maximum power. • Electric energy increases up to 8.3%, compared with that of the tracker with three fixed angles. • The rotation range is optimized to reduce energy consumption from the rotation operations. - Abstract: The purpose of this study is to develop a novel algorithm for a single-axis maximum power generation sun tracker in order to identify the optimal stopping angle for generating the maximum amount of daily electric energy. First, the photovoltaic modules of the single-axis maximum power generation sun tracker are automatically rotated from 50° east to 50° west. During the rotation, the instantaneous power generated at different angles is recorded and compared, meaning that the optimal angle for generating the maximum power can be determined. Once the rotation (detection) is completed, the photovoltaic modules are then rotated to the resulting angle for generating the maximum power. The photovoltaic module is rotated once per hour in an attempt to detect the maximum irradiation and overcome the impact of environmental effects such as shading from cloud cover, other photovoltaic modules and surrounding buildings. Furthermore, the detection range is halved so as to reduce the energy consumption from the rotation operations and to improve the reliability of the sun tracker. The results indicate that electric energy production is increased by 3.4% in spring and autumn, 5.4% in summer, and 8.3% in winter, compared with that of the same sun tracker with three fixed angles of 50° east in the morning, 0° at noon and 50° west in the afternoon.

Design and Implementation of PV based Energy Harvester for WSN Node with MAIC algorithm

Directory of Open Access Journals (Sweden)

RAJENDRAN, H.

2015-05-01

Full Text Available Wireless sensor networks (WSNs are hardly in need of an additional source of power other than the normally used batteries, to increase the lifetime considerably. In this paper, mathematical modeling of photovoltaic energy harvesting (PVEH system for the WSN is presented. The system comprises of the solar PV panel, boost converter as maximum power point tracker with moving averaged incremental conductance (MAIC maximum power point (MPP algorithm, Ni-MH battery for energy storage, compensator, buck regulator and the mathematically modeled WSN mote. MAIC algorithm is proposed to avoid the effect of drastic variations in input irradiance, in locking the MPP point. WSN mote is modeled in both active and sleep state based on the power consumption. To maintain the voltage stability, proper compensator has been designed for the proposed system. The performance of the system is tested for dynamic variations of environmental conditions using MATLAB simulation. The proposed system has 50 to 60 percent improved conversion efficiency when compared to the conventional direct coupling method. The parameters of the photovoltaic panel model have been validated through experimentation. Also the practical verification of the operation of MPPT circuit has been performed.

A novel adaptive sun tracker for spacecraft solar panel based on hybrid unsymmetric composite laminates

Science.gov (United States)

Wu, Zhangming; Li, Hao

2017-11-01

This paper proposes a novel adaptive sun tracker which is constructed by hybrid unsymmetric composite laminates. The adaptive sun tracker could be applied on spacecraft solar panels to increase their energy efficiency through decreasing the inclined angle between the sunlight and the solar panel normal. The sun tracker possesses a large rotation freedom and its rotation angle depends on the laminate temperature, which is affected by the light condition in the orbit. Both analytical model and finite element model (FEM) are developed for the sun tracker to predict its rotation angle in different light conditions. In this work, the light condition of the geosynchronous orbit on winter solstice is considered in the numerical prediction of the temperatures of the hybrid laminates. The final inclined angle between the sunlight and the solar panel normal during a solar day is computed using the finite element model. Parametric study of the adaptive sun tracker is conducted to improve its capacity and effectiveness of sun tracking. The improved adaptive sun tracker is lightweight and has a state-of-the-art design. In addition, the adaptive sun tracker does not consume any power of the solar panel, since it has no electrical driving devices. The proposed adaptive sun tracker provides a potential alternative to replace the traditional sophisticated electrical driving mechanisms for spacecraft solar panels.

Maximum power point tracking: a cost saving necessity in solar energy systems

Energy Technology Data Exchange (ETDEWEB)

Enslin, J H.R. [Stellenbosch Univ. (South Africa). Dept. of Electrical and Electronic Engineering

1992-12-01

A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking (MPPT) can improve cost effectiveness, has a higher reliability and can improve the quality of life in remote areas. A high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of between 15 and 25% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply (RAPS) systems. The advantages at large temperature variations and high power rated systems are much higher. Other advantages include optimal sizing and system monitor and control. (author).

Intraoperative magnetic tracker calibration using a magneto-optic hybrid tracker for 3-D ultrasound-based navigation in laparoscopic surgery.

Science.gov (United States)

Nakamoto, Masahiko; Nakada, Kazuhisa; Sato, Yoshinobu; Konishi, Kozo; Hashizume, Makoto; Tamura, Shinichi

2008-02-01

This paper describes a ultrasound (3-D US) system that aims to achieve augmented reality (AR) visualization during laparoscopic surgery, especially for the liver. To acquire 3-D US data of the liver, the tip of a laparoscopic ultrasound probe is tracked inside the abdominal cavity using a magnetic tracker. The accuracy of magnetic trackers, however, is greatly affected by magnetic field distortion that results from the close proximity of metal objects and electronic equipment, which is usually unavoidable in the operating room. In this paper, we describe a calibration method for intraoperative magnetic distortion that can be applied to laparoscopic 3-D US data acquisition; we evaluate the accuracy and feasibility of the method by in vitro and in vivo experiments. Although calibration data can be acquired freehand using a magneto-optic hybrid tracker, there are two problems associated with this method--error caused by the time delay between measurements of the optical and magnetic trackers, and instability of the calibration accuracy that results from the uniformity and density of calibration data. A temporal calibration procedure is developed to estimate the time delay, which is then integrated into the calibration, and a distortion model is formulated by zeroth-degree to fourth-degree polynomial fitting to the calibration data. In the in vivo experiment using a pig, the positional error caused by magnetic distortion was reduced from 44.1 to 2.9 mm. The standard deviation of corrected target positions was less than 1.0 mm. Freehand acquisition of calibration data was performed smoothly using a magneto-optic hybrid sampling tool through a trocar under guidance by realtime 3-D monitoring of the tool trajectory; data acquisition time was less than 2 min. The present study suggests that our proposed method could correct for magnetic field distortion inside the patient's abdomen during a laparoscopic procedure within a clinically permissible period of time, as well as

Beaconless Pointing for Deep-Space Optical Communication

Science.gov (United States)

Swank, Aaron J.; Aretskin-Hariton, Eliot; Le, Dzu K.; Sands, Obed S.; Wroblewski, Adam

2016-01-01

Free space optical communication is of interest to NASA as a complement to existing radio frequency communication methods. The potential for an increase in science data return capability over current radio-frequency communications is the primary objective. Deep space optical communication requires laser beam pointing accuracy on the order of a few microradians. The laser beam pointing approach discussed here operates without the aid of a terrestrial uplink beacon. Precision pointing is obtained from an on-board star tracker in combination with inertial rate sensors and an outgoing beam reference vector. The beaconless optical pointing system presented in this work is the current approach for the Integrated Radio and Optical Communication (iROC) project.

A new star tracker concept for satellite attitude determination based on a multi-purpose panoramic camera

Science.gov (United States)

Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele; Pernechele, Claudio; Dionisio, Cesare

2017-11-01

This paper presents an innovative algorithm developed for attitude determination of a space platform. The algorithm exploits images taken from a multi-purpose panoramic camera equipped with hyper-hemispheric lens and used as star tracker. The sensor architecture is also original since state-of-the-art star trackers accurately image as many stars as possible within a narrow- or medium-size field-of-view, while the considered sensor observes an extremely large portion of the celestial sphere but its observation capabilities are limited by the features of the optical system. The proposed original approach combines algorithmic concepts, like template matching and point cloud registration, inherited from the computer vision and robotic research fields, to carry out star identification. The final aim is to provide a robust and reliable initial attitude solution (lost-in-space mode), with a satisfactory accuracy level in view of the multi-purpose functionality of the sensor and considering its limitations in terms of resolution and sensitivity. Performance evaluation is carried out within a simulation environment in which the panoramic camera operation is realistically reproduced, including perturbations in the imaged star pattern. Results show that the presented algorithm is able to estimate attitude with accuracy better than 1° with a success rate around 98% evaluated by densely covering the entire space of the parameters representing the camera pointing in the inertial space.

Detector production for the R3B Si-tracker

Energy Technology Data Exchange (ETDEWEB)

Borri, M., E-mail: marcello.borri@liverpool.ac.uk [University of Liverpool, Department of Physics, Oxford Street, Liverpool L69 7ZE (United Kingdom); Lemmon, R. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4 CE (United Kingdom); Thornhill, J.; Bate, R.; Chartier, M. [University of Liverpool, Department of Physics, Oxford Street, Liverpool L69 7ZE (United Kingdom); Clague, N. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4 CE (United Kingdom); Herzberg, R.-D. [University of Liverpool, Department of Physics, Oxford Street, Liverpool L69 7ZE (United Kingdom); Labiche, M. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4 CE (United Kingdom); Lindsay, S.; Nolan, P.; Pearce, F.; Powell, W.; Wells, D. [University of Liverpool, Department of Physics, Oxford Street, Liverpool L69 7ZE (United Kingdom)

2016-11-11

R3B is a fixed target experiment which will study reactions with relativistic radioactive beams at FAIR. Its Si-tracker will surround the target volume and it will detect light charged-particles like protons. The detector technology in use consists of double-sided silicon strip sensors wire bonded to the custom made R3B-ASIC. The tracker allows for a maximum of two outer layers and one inner layer. This paper reports on the production of detectors necessary to build the minimum tracking configuration: one inner layer and one outer layer.

Reliability and Validity of Ten Consumer Activity Trackers Depend on Walking Speed

NARCIS (Netherlands)

Fokkema, Tryntsje; Kooiman, Thea J. M.; Krijnen, Wim P.; Van der Schans, Cees P.; De Groot, Martijn

Purpose: To examine the test-retest reliability and validity of ten activity trackers for step counting at three different walking speeds. Methods: Thirty-one healthy participants walked twice on a treadmill for 30 min while wearing 10 activity trackers (Polar Loop, Garmin Vivosmart, Fitbit Charge