WorldWideScience

Sample records for based power quality

  1. Artificial Intelligence Based Three-Phase Unified Power Quality Conditioner

    Directory of Open Access Journals (Sweden)

    Moleykutty George

    2007-01-01

    Full Text Available Power quality is an important measure of the performance of an electrical power system. This paper discusses the topology, control strategies using artificial intelligent (AI based controllers and the performance of a unified power quality conditioner (UPQC for power quality improvement. UPQC is an integration of shunt and series compensation to limit the harmonic contamination within 5 %, the limit imposed by IEEE-519 standard. The novelty of this paper lies in the application of neural network control (NNC algorithms such as model reference control (MRC, and nonlinear autoregressive-moving average (NARMA–L2 control to generate switching signals for the series compensator of the UPQC system. The entire system has been modeled using MATLAB 7.0 toolbox. Simulation results demonstrate the applicability of MRC and NARMA-L2 controllers for the control of UPQC.

  2. Matrix Converter Based Unified Power Quality Conditioner (MUPQC for Power Quality Improvement in a Utility

    Directory of Open Access Journals (Sweden)

    G.L. Valsala

    2014-05-01

    Full Text Available This study proposes a new approach of unified power quality conditioner which is made up of a matrix converter without energy storage devices to mitigate the current harmonics, voltage sags and swell. By connecting the matrix converter output terminals to the load side through series transformer and the input side of matrix converter is connected to the supply side with step up transformer. So a matrix converter injects the compensation voltage on the load-side, so it is possible to mitigate the voltage sag/swell problems, resulting in an efficient solution for mitigating voltage and current related power quality problems. Thus, the proposed topology can mitigate the voltage fluctuations and current harmonics without energy storage elements and the total harmonic distortion produced by the system also very low. It also reduced volume and cost, reduced capacitor power losses, together with higher reliability. The Space-Vector Modulation (SVM is used to control the matrix converter. MATLAB/SIMULINK based simulation results are presented to validate the approach.

  3. Power quality improvement by unified power quality conditioner based on CSC topology using synchronous reference frame theory.

    Science.gov (United States)

    Dharmalingam, Rajasekaran; Dash, Subhransu Sekhar; Senthilnathan, Karthikrajan; Mayilvaganan, Arun Bhaskar; Chinnamuthu, Subramani

    2014-01-01

    This paper deals with the performance of unified power quality conditioner (UPQC) based on current source converter (CSC) topology. UPQC is used to mitigate the power quality problems like harmonics and sag. The shunt and series active filter performs the simultaneous elimination of current and voltage problems. The power fed is linked through common DC link and maintains constant real power exchange. The DC link is connected through the reactor. The real power supply is given by the photovoltaic system for the compensation of power quality problems. The reference current and voltage generation for shunt and series converter is based on phase locked loop and synchronous reference frame theory. The proposed UPQC-CSC design has superior performance for mitigating the power quality problems.

  4. Power Quality Improvement by Unified Power Quality Conditioner Based on CSC Topology Using Synchronous Reference Frame Theory

    Directory of Open Access Journals (Sweden)

    Rajasekaran Dharmalingam

    2014-01-01

    Full Text Available This paper deals with the performance of unified power quality conditioner (UPQC based on current source converter (CSC topology. UPQC is used to mitigate the power quality problems like harmonics and sag. The shunt and series active filter performs the simultaneous elimination of current and voltage problems. The power fed is linked through common DC link and maintains constant real power exchange. The DC link is connected through the reactor. The real power supply is given by the photovoltaic system for the compensation of power quality problems. The reference current and voltage generation for shunt and series converter is based on phase locked loop and synchronous reference frame theory. The proposed UPQC-CSC design has superior performance for mitigating the power quality problems.

  5. Power quality events recognition using a SVM-based method

    Energy Technology Data Exchange (ETDEWEB)

    Cerqueira, Augusto Santiago; Ferreira, Danton Diego; Ribeiro, Moises Vidal; Duque, Carlos Augusto [Department of Electrical Circuits, Federal University of Juiz de Fora, Campus Universitario, 36036 900, Juiz de Fora MG (Brazil)

    2008-09-15

    In this paper, a novel SVM-based method for power quality event classification is proposed. A simple approach for feature extraction is introduced, based on the subtraction of the fundamental component from the acquired voltage signal. The resulting signal is presented to a support vector machine for event classification. Results from simulation are presented and compared with two other methods, the OTFR and the LCEC. The proposed method shown an improved performance followed by a reasonable computational cost. (author)

  6. A New Power Quality Instrument Based on Raspberry-Pi

    Directory of Open Access Journals (Sweden)

    Fabio Leccese

    2016-09-01

    Full Text Available This article describes a new instrument for power quality (PQ measurements based on the Raspberry-Pi. This is the latest step of a long study started by the Electric and Electronic Measurements Laboratory of “Roma Tre” University 12 years ago. During this time, the Laboratory developed and refined instrumentation for high accuracy power quality measurements. Through its own architecture, the new instrument allows the use of the Raspberry instead of a personal computer (PC. The data acquired and locally processed are then sent to a remote server where they can be shown to users. Imagines of the system and of the data prove the activity of the system.

  7. Comparison Of Power Quality Disturbances Classification Based On Neural Network

    Directory of Open Access Journals (Sweden)

    Nway Nway Kyaw Win

    2015-07-01

    Full Text Available Abstract Power quality disturbances PQDs result serious problems in the reliability safety and economy of power system network. In order to improve electric power quality events the detection and classification of PQDs must be made type of transient fault. Software analysis of wavelet transform with multiresolution analysis MRA algorithm and feed forward neural network probabilistic and multilayer feed forward neural network based methodology for automatic classification of eight types of PQ signals flicker harmonics sag swell impulse fluctuation notch and oscillatory will be presented. The wavelet family Db4 is chosen in this system to calculate the values of detailed energy distributions as input features for classification because it can perform well in detecting and localizing various types of PQ disturbances. This technique classifies the types of PQDs problem sevents.The classifiers classify and identify the disturbance type according to the energy distribution. The results show that the PNN can analyze different power disturbance types efficiently. Therefore it can be seen that PNN has better classification accuracy than MLFF.

  8. FLC based adjustable speed drives for power quality enhancement

    Directory of Open Access Journals (Sweden)

    Sukumar Darly

    2010-01-01

    Full Text Available This study describes a new approach based on fuzzy algorithm to suppress the current harmonic contents in the output of an inverter. Inverter system using fuzzy controllers provide ride-through capability during voltage sags, reduces harmonics, improves power factor and high reliability, less electromagnetic interference noise, low common mode noise and extends output voltage range. A feasible test is implemented by building a model of three-phase impedance source inverter, which is designed and controlled on the basis of proposed considerations. It is verified from the practical point of view that these new approaches are more effective and acceptable to minimize the harmonic distortion and improves the quality of power. Due to the complex algorithm, their realization often calls for a compromise between cost and performance. The proposed optimizing strategies may be applied in variable-frequency dc-ac inverters, UPSs, and ac drives.

  9. Power quality control of an autonomous wind-diesel power system based on hybrid intelligent controller.

    Science.gov (United States)

    Ko, Hee-Sang; Lee, Kwang Y; Kang, Min-Jae; Kim, Ho-Chan

    2008-12-01

    Wind power generation is gaining popularity as the power industry in the world is moving toward more liberalized trade of energy along with public concerns of more environmentally friendly mode of electricity generation. The weakness of wind power generation is its dependence on nature-the power output varies in quite a wide range due to the change of wind speed, which is difficult to model and predict. The excess fluctuation of power output and voltages can influence negatively the quality of electricity in the distribution system connected to the wind power generation plant. In this paper, the authors propose an intelligent adaptive system to control the output of a wind power generation plant to maintain the quality of electricity in the distribution system. The target wind generator is a cost-effective induction generator, while the plant is equipped with a small capacity energy storage based on conventional batteries, heater load for co-generation and braking, and a voltage smoothing device such as a static Var compensator (SVC). Fuzzy logic controller provides a flexible controller covering a wide range of energy/voltage compensation. A neural network inverse model is designed to provide compensating control amount for a system. The system can be optimized to cope with the fluctuating market-based electricity price conditions to lower the cost of electricity consumption or to maximize the power sales opportunities from the wind generation plant.

  10. Three-dimensional maps of power quality loss based in the power tensor theory

    Directory of Open Access Journals (Sweden)

    A. J. Ustariz-Farfan

    2012-05-01

    Full Text Available This paper presents the results of a project which was aimed at developing a flexible visualisation tool to be used mainly by power system operators. The project concentrated on a technique for assessing the deterioration of power transfer quality in electrical networks based on the power tensor theory. One of the envisioned tool’s essential goals was to aid system operators by providing images of the system with easily identifiable characteristics related to loss or overall deterioration of power quality. The result was a user-friendly, threedimensional graphic interface. The tool’s effectiveness has been illustrated via different scenarios created using the IEEE 13-bus test feeder as an example.

  11. Improve power quality of coal mine power network based on gray system theory

    Institute of Scientific and Technical Information of China (English)

    ZHU En-guo; YANG Gong-xun; XU Shu-ge; MA Gui-cun

    2007-01-01

    Unified Power Quality Controller(UPQC) was proposed to comprehensively improve power quality of coal mine power network and its basic structure and operation principle was introduced. In order to overcome time lag of Active Power Filter(APF) in compensating harmonic and reactive current, a novel method based on gray system theory was proposed to predict harmonic current and other distortion component. The mathematical model of component to be compensated was constructed by data sequence of distortion component, which could exactly forecast compensation signal of next period.The optimal control strategy was selected according to the principle of output signal approaching component to be compensated as near as possible. Before predicating each time the oldest data was eliminated while the latest data was added to data sequence.Then new predication model was established once again. The results show that the method can always construct mathematical model with variation of system parameters, reflect the latest state of system and not increase calculation quantity. The feasible and effective control strategy can improve power quality of coal mine power network.

  12. Analysis of Power Quality Based on Real Data and Quality Improvement at Campus Distribution System

    Science.gov (United States)

    Kawasaki, Shoji; Matsuki, Junya; Hayashi, Yasuhiro; Ito, Akitoshi

    In recent years, a lot of equipments have been made using the inverter technology from home electric appliances to office automation apparatuses and industrial equipments with the development of power electronics technology. The voltage distortion of a distribution system has increased due to the harmonic currents generated from these apparatuses, and the increase in harmonics continues to be expected. In addition, the distribution system forms the circuit of harmonic distortion expansion by the prevalence of static capacitor without L for power factor improvement. Moreover, the voltage imbalance occurs by diversification of loads or imbalanced connection of single-phase loads. The deterioration of power quality in the distribution system causes various problems such as the overheating of equipments and malfunction of rotating machines. Since the power quality changes according to air temperature and date, it is desirable to measure the voltages and currents continuously for a long time. In this study, the authors focus attention on the distribution system in the University of Fukui campus, and the authors have measured the voltages and currents in the distribution system for a long period with WAMS (Wide Area Measurement System) using NCT (Network Computing Terminal). Based on the obtained data, the authors analyzed the power quality of the campus distribution system from viewpoints of voltage imbalance, current imbalance, voltage THD (Total Harmonic Distortion), and current THD. Furthermore, the improvement effect of power quality of the campus distribution system by exchange of single-phase load connection is described.

  13. Enhanced power quality based single phase photovoltaic distributed generation system

    Science.gov (United States)

    Panda, Aurobinda; Pathak, M. K.; Srivastava, S. P.

    2016-08-01

    This article presents a novel control strategy for a 1-ϕ 2-level grid-tie photovoltaic (PV) inverter to enhance the power quality (PQ) of a PV distributed generation (PVDG) system. The objective is to obtain the maximum benefits from the grid-tie PV inverter by introducing current harmonics as well as reactive power compensation schemes in its control strategy, thereby controlling the PV inverter to achieve multiple functions in the PVDG system such as: (1) active power flow control between the PV inverter and the grid, (2) reactive power compensation, and (3) grid current harmonics compensation. A PQ enhancement controller (PQEC) has been designed to achieve the aforementioned objectives. The issue of underutilisation of the PV inverter in nighttime has also been addressed in this article and for the optimal use of the system; the PV inverter is used as a shunt active power filter in nighttime. A prototype model of the proposed system is developed in the laboratory, to validate the effectiveness of the control scheme, and is tested with the help of the dSPACE DS1104 platform.

  14. The Power Quality Compensation Strategy for Power Distribution System Based on Hybrid Parallel Active Power Filters

    Directory of Open Access Journals (Sweden)

    Rachid DEHINI

    2010-12-01

    Full Text Available In this paper, the main aim is to confront the performance of shunt active power filter (SAPF and the shunt hybrid active power filter (SHAPF to achieve flexibility and reliability of the filter devices. Both of the two devices used the classical proportional-integral controller for pulse generation to trigger the inventers MOSFET’s. In the adopted hybrid active filter there is a passive power filter with high power rating to filter the low order harmonies and one active filter with low power rating to filter the other high order harmonies. In order to investigate the effectiveness of (SHAPF, the studies have been accomplished using simulation with the MATLAB-SIMULINK. The results show That (SHAPF is more effective than (SAPF, and has lower cost.

  15. Power theories for improved power quality

    CERN Document Server

    Pasko, Marian

    2012-01-01

    Power quality describes a set of parameters of electric power and the load’s ability to function properly under specific conditions. It is estimated that problems relating to power quality costs the European industry hundreds of billions of Euros annually. In contrast, financing for the prevention of these problems amount to fragments of these costs. Power Theories for Improved Power Quality addresses this imbalance by presenting and assessing a range of methods and problems related to improving the quality of electric power supply. Focusing particularly on active compensators and the DSP based control algorithms, Power Theories for Improved Power Quality introduces the fundamental problems of electrical power. This introduction is followed by chapters which discuss: •‘Power theories’ including their historical development and application to practical problems, •operational principles of active compensator’s DSP control based algorithms using examples and results from laboratory research, and •t...

  16. Automatic and Intelligent Power Quality Disturbances Monitoring Based on Multi-Agent Systems

    Directory of Open Access Journals (Sweden)

    M. Hajian

    2012-09-01

    Full Text Available Power quality monitoring is the first step in the identification of power quality disturbances and reducing them in order to improve the performance of the power system. The aim of this paper is to propose the architecture of a new intelligent strategy for online and offline power quality monitoring system based on multi-agent systems. In this study, a multi-agent system for solving some problems in power quality monitoring, including computational complexity, low accuracy, change in the data pattern, non adaptive structure of detection system to changing conditions is proposed. In the proposed strategy, the agent characteristics, such as automatic and dynamic performance, intelligent, learning, reasoning ability, objectively and interoperability of agents are used. This paper is presented in two stages. In the one stage, to indicate problems in power quality monitoring, different methods of feature extraction, feature selection and classification for automatic recognition of power quality disturbances have been analyzed. Optimal selection of input feature vector of distinguish system is applied using different methods of data mining. Also, three well-known classifiers are considered. In another stage of the paper, to solve some challenges, the design of investigated structures in the form of a multi-agent system is expressed. The results of the experiments in this paper demonstrate the superiority of agents and multi-agent systems for online and offline power quality monitoring.

  17. A Comprehensive Design Approach of Power Electronic-Based Distributed Generation Units Focused on Power Quality Improvement

    DEFF Research Database (Denmark)

    Esparza, Miguel; Segundo-Ramirez, Juan; Nunez, Ciro

    2017-01-01

    The undesirable harmonic distortion produced by distributed generation units (DGUs) based on power electronic inverters presents operating and power quality challenges in electric systems. ‡e level of distortion depends on the internal elements of the DGUs as well as on the characteristics...... of the grid, loads, controls, among others. ‡is paper presents a comprehensive method, focused on power quality indexes and e�ciency for the design of micro-grids with multiple DGUs interconnected to the AC grid through three phase multi-Megawatt medium-voltage PWM voltage source inverters (PWM-VSI). ‡e...

  18. A DSP based Three Phase Power Quality Analyzer for Motor Drives

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woo Yong; Jung, Young Gook; Lim, Young Cheol [Chonnam National University, Kwangju (Korea)

    2001-02-01

    This paper presents a digital instrument for a DSP based power quality analysis in three phase power system there current waveform is non-sinusoidal. It is based on stand alone type TMS320C31 DSP (digital signal processor) board and on a special high-speed data acquisition system. Power quality of low power motor drives are analyzed and processed by using a simple average power algorithm, and results of power analysis are displayed by LCD in the proposed system. This paper also goes on to discuss the performance of an instrument prototype, both in terms of accuracy and speed of measurement under the transient and steady state condition. (author). 5 refs., 6 figs., 3 tabs.

  19. Control Method for Unified Power Quality Conditioner Using Fuzzy Based Nine-Switch Power Conditioner

    Directory of Open Access Journals (Sweden)

    K.Gowthami

    2015-10-01

    Full Text Available A nine-switch power converter having two sets of out-put terminals was recently proposed in place of the traditional back-to-back power converter that uses 12 switches in total. The nine-switch converter has already been proven to have certain advantages, in addition to its component saving topological feature. Despite these advantages, the nine-switch converter has so far found limited applications due to its many perceived performance tradeoffs like requiring an oversized dc-link capacitor, limited amplitude sharing, and constrained phase shift between its two sets of output terminals. Instead of accepting these tradeoffs as limitations, a nineswitch power conditioner is proposed here that virtually “converts” most of these topological short comings into interesting performance advantages. Aiming further to reduce its switching losses, an appropriate discontinuous modulation scheme is proposed and studied here in detail to doubly ensure that maxi-mal reduction of commutations is achieved. With an appropriately designed control scheme then incorporated, the nine-switch converter is shown to favorably raise the overall power quality in experiment, hence justifying its role as a power conditioner at a reduced semiconductor cost.

  20. An Improved Power Quality Based Sheppard-Taylor Converter Fed BLDC Motor Drive

    Science.gov (United States)

    Singh, Bhim; Bist, Vashist

    2015-12-01

    This paper deals with the design and analysis of a power factor correction based Sheppard-Taylor converter fed brushless dc motor (BLDCM) drive. The speed of the BLDCM is controlled by adjusting the dc link voltage of the voltage source inverter (VSI) feeding BLDCM. Moreover, a low frequency switching of the VSI is used for electronically commutating the BLDCM for reduced switching losses. The Sheppard-Taylor converter is designed to operate in continuous conduction mode to achieve an improved power quality at the ac mains for a wide range of speed control and supply voltage variation. The BLDCM drive is designed and its performance is simulated in a MATLAB/Simulink environment to achieve the power quality indices within the limits of the international power quality standard IEC-61000-3-2.

  1. Area Based Approach for Three Phase Power Quality Assessment in Clarke Plane

    Directory of Open Access Journals (Sweden)

    S. CHATTOPADHYAY

    2008-03-01

    Full Text Available This paper presents an area-based approach for electric power quality analysis. Some specific reference signals have been defined and areas formed by the real power system data with the reference signal have been calculated wherefrom contributions of fundamental waveform and harmonic components have been assessed separately. Active power, reactive power and total harmonic distortion factors have been measured. Clarke transformation technique has been used for analysis in three-phase system, which has reduced the computational effort to a great extent. Distortion factors of individual phase of a three-phase system have also been assessed.

  2. Z-Source-Inverter-Based Flexible Distributed Generation System Solution for Grid Power Quality Improvement

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Vilathgamuwa, D. M.; Loh, Poh Chiang

    2009-01-01

    Distributed generation (DG) systems are usually connected to the grid using power electronic converters. Power delivered from such DG sources depends on factors like energy availability and load demand. The converters used in power conversion do not operate with their full capacity all the time......-stage buck-boost inverter, recently proposed Z-source inverter (ZSI) is a good candidate for future DG systems. This paper presents a controller design for a ZSI-based DG system to improve power quality of distribution systems. The proposed control method is tested with simulation results obtained using...

  3. MATLAB Simulation of UPQC for Power Quality Mitigation Using an Ant Colony Based Fuzzy Control Technique.

    Science.gov (United States)

    Kumarasabapathy, N; Manoharan, P S

    2015-01-01

    This paper proposes a fuzzy logic based new control scheme for the Unified Power Quality Conditioner (UPQC) for minimizing the voltage sag and total harmonic distortion in the distribution system consequently to improve the power quality. UPQC is a recent power electronic module which guarantees better power quality mitigation as it has both series-active and shunt-active power filters (APFs). The fuzzy logic controller has recently attracted a great deal of attention and possesses conceptually the quality of the simplicity by tackling complex systems with vagueness and ambiguity. In this research, the fuzzy logic controller is utilized for the generation of reference signal controlling the UPQC. To enable this, a systematic approach for creating the fuzzy membership functions is carried out by using an ant colony optimization technique for optimal fuzzy logic control. An exhaustive simulation study using the MATLAB/Simulink is carried out to investigate and demonstrate the performance of the proposed fuzzy logic controller and the simulation results are compared with the PI controller in terms of its performance in improving the power quality by minimizing the voltage sag and total harmonic distortion.

  4. MATLAB Simulation of UPQC for Power Quality Mitigation Using an Ant Colony Based Fuzzy Control Technique

    Science.gov (United States)

    Kumarasabapathy, N.; Manoharan, P. S.

    2015-01-01

    This paper proposes a fuzzy logic based new control scheme for the Unified Power Quality Conditioner (UPQC) for minimizing the voltage sag and total harmonic distortion in the distribution system consequently to improve the power quality. UPQC is a recent power electronic module which guarantees better power quality mitigation as it has both series-active and shunt-active power filters (APFs). The fuzzy logic controller has recently attracted a great deal of attention and possesses conceptually the quality of the simplicity by tackling complex systems with vagueness and ambiguity. In this research, the fuzzy logic controller is utilized for the generation of reference signal controlling the UPQC. To enable this, a systematic approach for creating the fuzzy membership functions is carried out by using an ant colony optimization technique for optimal fuzzy logic control. An exhaustive simulation study using the MATLAB/Simulink is carried out to investigate and demonstrate the performance of the proposed fuzzy logic controller and the simulation results are compared with the PI controller in terms of its performance in improving the power quality by minimizing the voltage sag and total harmonic distortion. PMID:26504895

  5. MATLAB Simulation of UPQC for Power Quality Mitigation Using an Ant Colony Based Fuzzy Control Technique

    Directory of Open Access Journals (Sweden)

    N. Kumarasabapathy

    2015-01-01

    Full Text Available This paper proposes a fuzzy logic based new control scheme for the Unified Power Quality Conditioner (UPQC for minimizing the voltage sag and total harmonic distortion in the distribution system consequently to improve the power quality. UPQC is a recent power electronic module which guarantees better power quality mitigation as it has both series-active and shunt-active power filters (APFs. The fuzzy logic controller has recently attracted a great deal of attention and possesses conceptually the quality of the simplicity by tackling complex systems with vagueness and ambiguity. In this research, the fuzzy logic controller is utilized for the generation of reference signal controlling the UPQC. To enable this, a systematic approach for creating the fuzzy membership functions is carried out by using an ant colony optimization technique for optimal fuzzy logic control. An exhaustive simulation study using the MATLAB/Simulink is carried out to investigate and demonstrate the performance of the proposed fuzzy logic controller and the simulation results are compared with the PI controller in terms of its performance in improving the power quality by minimizing the voltage sag and total harmonic distortion.

  6. HOS network-based classification of power quality events via regression algorithms

    Science.gov (United States)

    Palomares Salas, José Carlos; González de la Rosa, Juan José; Sierra Fernández, José María; Pérez, Agustín Agüera

    2015-12-01

    This work compares seven regression algorithms implemented in artificial neural networks (ANNs) supported by 14 power-quality features, which are based in higher-order statistics. Combining time and frequency domain estimators to deal with non-stationary measurement sequences, the final goal of the system is the implementation in the future smart grid to guarantee compatibility between all equipment connected. The principal results are based in spectral kurtosis measurements, which easily adapt to the impulsive nature of the power quality events. These results verify that the proposed technique is capable of offering interesting results for power quality (PQ) disturbance classification. The best results are obtained using radial basis networks, generalized regression, and multilayer perceptron, mainly due to the non-linear nature of data.

  7. A GPS-Based Control Framework for Accurate Current Sharing and Power Quality Improvement in Microgrids

    DEFF Research Database (Denmark)

    Golsorkhi, Mohammad; Savaghebi, Mehdi; Lu, Dylan;

    2016-01-01

    consensus protocol to ensure proportional sharing of average power. The voltage conditioning scheme produces compensation signals at fundamental and dominant harmonics to improve the voltage quality at a sensitive load bus. Experimental results are presented to validate the efficacy of the proposed method.......This paper proposes a novel hierarchical control strategy for improvement of load sharing and power quality in ac microgrids. This control framework is composed of a droop based controller at the primary level, and a combination of distributed power sharing and voltage conditioning schemes...... dynamic response. The droop coefficient, which acts as a virtual resistance is adaptively changed as a function of the peak current. This strategy not only simplifies the control design but also improves the current sharing accuracy at high loading conditions. The distributed power sharing scheme uses...

  8. Power Quality Indices Estimation Platform

    Directory of Open Access Journals (Sweden)

    Eliana I. Arango-Zuluaga

    2013-11-01

    Full Text Available An interactive platform for estimating the quality indices in single phase electric power systems is presented. It meets the IEEE 1459-2010 standard recommendations. The platform was developed in order to support teaching and research activities in electric power quality. The platform estimates the power quality indices from voltage and current signals using three different algorithms based on fast Fourier transform (FFT, wavelet packet transform (WPT and least squares method. The results show that the algorithms implemented are efficient for estimating the quality indices of the power and the platform can be used according to the objectives established. 

  9. An Efficient Feature Extraction Method Based on Entropy for Power Quality Disturbance

    Directory of Open Access Journals (Sweden)

    P. Kailasapathi

    2014-09-01

    Full Text Available This study explores the applicability of entropy defined as thermodynamic state variable introduced by German Physicists Rudolf clausius and also presents the concepts and application of said state variable as a measure of system disorganization. Later an entropy-based feature Analysis method for power quality disturbance analysis has been proposed. Feature extraction of a disturbed power signal provides information that helps to detect the responsible fault for power quality disturbance. A precise and faster feature extraction tool helps power engineers to monitor and maintain power disturbances more efficiently. Firstly, the decomposition coefficients are obtained by applying 10-level wavelet multi resolution analysis to the signals (normal, sag, swell, outage, harmonic and sag with harmonic and swell with harmonic generated by using the parametric equations. Secondly, a combined feature vector is obtained from standard deviation of these features after distinctive features for each signal are extracted by applying the energy, the Shannon entropy and the log-energy entropy methods to decomposition coefficients. Finally the entropy methods detect the different types of power quality disturbance.

  10. An Improved Power Quality BIBRED Converter-Based VSI-Fed BLDC Motor Drive

    Science.gov (United States)

    Singh, Bhim; Bist, Vashist

    2014-01-01

    This paper presents an IHQRR (integrated high-quality rectifier regulator) BIBRED (boost integrated buck rectifier energy storage DC-DC) converter-based VSI (voltage source inverter)-fed BLDC (brushless DC) motor drive. The speed control of BLDC motor is achieved by controlling the DC link voltage of the VSI using a single voltage sensor. This allows VSI to operate in fundamental frequency switching mode for electronic commutation of BLDC motor which reduces the switching losses due to high-frequency switching used in conventional approach of PWM (pulse width modulation)-based VSI-fed BLDC motor drive. A BIBRED converter is operated in a dual-DCM (discontinuous conduction mode) thus using a voltage follower approach for PFC (power factor correction) and DC link voltage control. The performance of the proposed drive is evaluated for improved power quality over a wide range of speed control and supply voltage variation for demonstrating the behavior of proposed drive. The power quality indices thus obtained are within the recommended limits by international PQ (power quality) standards such as IEC 61000-3-2.

  11. Research on De-Noising of Power Quality Disturbance Detection Based on EEMD Threshold

    Directory of Open Access Journals (Sweden)

    Liping Chen

    2013-11-01

    Full Text Available Actual power quality signal which is often affected by noise pollution impacts the analysis results of the disturbance signal. In this paper, EEMD (Ensemble Empirical Mode Decomposition -based threshold de-noising method is proposed for power quality signal with different SNR (Signal-to-Noise Ratio. As a comparison, we use other four thresholds, namely, the heuristic threshold, the self-adaptive threshold, the fixed threshold and the minimax threshold to filter the noises from power quality signal. Through the analysis and comparison of three characteristics of the signal pre-and-post de-noised, including waveforms, SNR and MSE (Mean Square Error, furthermore the instantaneous attribute of corresponding time by HHT (Hilbert Huang Transform. Simulation results show that EEMD threshold de-noising method can make the waveform close to the actual value. The SNR is higher and the MSE is smaller compared with other four thresholds. The instantaneous attribute can reflect the actual disturbance signal more exactly. The optimal threshold EEMD-based algorithm is proposed for power quality disturbance signal de-noising. Meanwhile, EEMD threshold de-noising method with adaptivity is suitable for composite disturbance signal de-noising.

  12. Electric power quality

    CERN Document Server

    Chattopadhyay, Surajit; Sengupta, Samarjit

    2011-01-01

    In the present day deregulated power market electric power quality issues have become great concerns of utilities, end users and manufacturers. Worldwide researches are going on to address those issues. Electric Power Quality has evolved from the researches carried out by the authors. The key features of the book can be highlighted as follows: the contents focuses, on one hand, different power quality issues, their sources and effects and different related standards, which are required for students, researchers and practising engineers and, on the other hand, measurement techniques for differe

  13. Neural Network based Control of SG based Standalone Generating System with Energy Storage for Power Quality Enhancement

    Science.gov (United States)

    Nayar, Priya; Singh, Bhim; Mishra, Sukumar

    2016-09-01

    An artificial intelligence based control algorithm is used in solving power quality problems of a diesel engine driven synchronous generator with automatic voltage regulator and governor based standalone system. A voltage source converter integrated with a battery energy storage system is employed to mitigate the power quality problems. An adaptive neural network based signed regressor control algorithm is used for the estimation of the fundamental component of load currents for control of a standalone system with load leveling as an integral feature. The developed model of the system performs accurately under varying load conditions and provides good dynamic response to the step changes in loads. The real time performance is achieved using MATLAB along with simulink/simpower system toolboxes and results adhere to an IEEE-519 standard for power quality enhancement.

  14. Neural Network based Control of SG based Standalone Generating System with Energy Storage for Power Quality Enhancement

    Science.gov (United States)

    Nayar, Priya; Singh, Bhim; Mishra, Sukumar

    2017-08-01

    An artificial intelligence based control algorithm is used in solving power quality problems of a diesel engine driven synchronous generator with automatic voltage regulator and governor based standalone system. A voltage source converter integrated with a battery energy storage system is employed to mitigate the power quality problems. An adaptive neural network based signed regressor control algorithm is used for the estimation of the fundamental component of load currents for control of a standalone system with load leveling as an integral feature. The developed model of the system performs accurately under varying load conditions and provides good dynamic response to the step changes in loads. The real time performance is achieved using MATLAB along with simulink/simpower system toolboxes and results adhere to an IEEE-519 standard for power quality enhancement.

  15. Power Quality Improvement Using Cascaded H-Bridge Multilevel Inverter Based Dstatcom

    Directory of Open Access Journals (Sweden)

    B. Suryajitt,

    2014-11-01

    Full Text Available Cascaded multilevel configuration of the inverter has the advantage of its simplicity and modularity over the configurations of the diode-clamped and flying capacitor multilevel inverters. This paper presents a threephase, five-level and seven level cascaded multilevel voltage source inverter based active filter for power line conditioning to improve power quality in the distribution network. The DSTATCOM helps to improve the power factor and eliminate the Total Harmonics Distortion (THD drawn from a Non-Liner Diode Rectifier Load (NLDRL. The compensation process is based on concept of p-q theory. A CHB Inverter is considered for shunt compensation of a 11 kV distribution system. Finally a level shifted PWM (LSPWM and phase shifted PWM (PSPWM techniques are adopted to investigate the performance of CHB Inverter. The results are obtained through Matlab/Simulink software package.

  16. New Power Quality Analysis Method Based on Chaos Synchronization and Extension Neural Network

    Directory of Open Access Journals (Sweden)

    Meng-Hui Wang

    2014-10-01

    Full Text Available A hybrid method comprising a chaos synchronization (CS-based detection scheme and an Extension Neural Network (ENN classification algorithm is proposed for power quality monitoring and analysis. The new method can detect minor changes in signals of the power systems. Likewise, prominent characteristics of system signal disturbance can be extracted by this technique. In the proposed approach, the CS-based detection method is used to extract three fundamental characteristics of the power system signal and an ENN-based clustering scheme is then applied to detect the state of the signal, i.e., normal, voltage sag, voltage swell, interruption or harmonics. The validity of the proposed method is demonstrated by means of simulations given the use of three different chaotic systems, namely Lorenz, New Lorenz and Sprott. The simulation results show that the proposed method achieves a high detection accuracy irrespective of the chaotic system used or the presence of noise. The proposed method not only achieves higher detection accuracy than existing methods, but also has low computational cost, an improved robustness toward noise, and improved scalability. As a result, it provides an ideal solution for the future development of hand-held power quality analyzers and real-time detection devices.

  17. Power transformers quality assurance

    CERN Document Server

    Dasgupta, Indrajit

    2009-01-01

    About the Book: With the view to attain higher reliability in power system operation, the quality assurance in the field of distribution and power transformers has claimed growing attention. Besides new developments in the material technology and manufacturing processes of transformers, regular diagnostic testing and maintenance of any engineering product may be ascertained by ensuring: right selection of materials and components and their quality checks. application of correct manufacturing processes any systems engineering. the user`s awareness towards preventive maintenance. The

  18. A New Real Time Lyapunov Based Controller for Power Quality Improvement in Unified Power Flow Controllers Using Direct Matrix Converters

    Directory of Open Access Journals (Sweden)

    Joaquim Monteiro

    2017-06-01

    Full Text Available This paper proposes a Direct Matrix Converter operating as a Unified Power Flow Controller (DMC-UPFC with an advanced control method for UPFC, based on the Lyapunov direct method, presenting good results in power quality assessment. This control method is used for real-time calculation of the appropriate matrix switching state, determining which switching state should be applied in the following sampling period. The control strategy takes into account active and reactive power flow references to choose the vector converter closest to the optimum. Theoretical principles for this new real-time vector modulation and control applied to the DMC-UPFC with input filter are established. The method needs DMC-UPFC dynamic equations to be solved just once in each control cycle, to find the required optimum vector, in contrast to similar control methods that need 27 vector estimations per control cycle. The designed controller’s performance was evaluated using Matlab/Simulink software. Controllers were also implemented using a digital signal processing (DSP system and matrix hardware. Simulation and experimental results show decoupled transmission line active (P and reactive (Q power control with zero theoretical error tracking and fast response. Output currents and voltages show small ripple and low harmonic content.

  19. Hybrid Power Forecasting Model for Photovoltaic Plants Based on Neural Network with Air Quality Index

    Directory of Open Access Journals (Sweden)

    Idris Khan

    2017-01-01

    Full Text Available High concentration of greenhouse gases in the atmosphere has increased dependency on photovoltaic (PV power, but its random nature poses a challenge for system operators to precisely predict and forecast PV power. The conventional forecasting methods were accurate for clean weather. But when the PV plants worked under heavy haze, the radiation is negatively impacted and thus reducing PV power; therefore, to deal with haze weather, Air Quality Index (AQI is introduced as a parameter to predict PV power. AQI, which is an indication of how polluted the air is, has been known to have a strong correlation with power generated by the PV panels. In this paper, a hybrid method based on the model of conventional back propagation (BP neural network for clear weather and BP AQI model for haze weather is used to forecast PV power with conventional parameters like temperature, wind speed, humidity, solar radiation, and an extra parameter of AQI as input. The results show that the proposed method has less error under haze condition as compared to conventional model of neural network.

  20. Power quality on campus

    Energy Technology Data Exchange (ETDEWEB)

    Copper Development Association

    2011-05-15

    The Maria Stata Center on the campus of the Massachusetts Institute of Technology (MIT) is home to the Computer Science and Artificial Intelligence Laboratory (CSAIL), the Laboratory for Information and Decision Systems (LIDS) and the Department of Linguistics and Philosophy. Computers and networks are everywhere on campus and the electrical infrastructure, mainly made of copper, ensures the highest level of power quality. The copper-based grounding system helps stabilize the wiring system and several K-rated transformers help accommodate harmonic currents and improve energy efficiency. Separation from sensitive and non-sensitive branch circuits helps to shield sensitive equipment from electrical noise, and the installation of transient voltage surge suppression equipment assures maximum protection from voltage surges. .

  1. Power Quality Enhancement in Wind Connected Grid System Interface Based On Static Switched Filter Compensator (SSFC

    Directory of Open Access Journals (Sweden)

    Lakshmi Prasanna Vatti

    2014-11-01

    Full Text Available Wind energy has become one of the significant alternative renewable energy resources because of its abundance and the strong drive for its commercialization. Dynamic electric load variations and wind velocity excursions cause excessive changes in the prime mover kinetic energy and the corresponding electrical power injected into the AC grid utility system. In this paper, a scheme based on the low cost static switched filter compensator (SSFC is presented for voltage sag/swell compensation, power factor improvement in distribution grid networks with the dispersed wind energy interface. The SSFC scheme is based on an intermittent switching process between two shunt capacitor banks to be one of them in parallel with the capacitor of a tuned arm filter. Two regulators based on a tri- loop dynamic error driven inter-coupled weighted modified proportional-integralderivative (PID controller which is used to modulate the PWM. The Static Switched Filter Compensation (SSFC compensation scheme which enhances the system power quality has been fully validated using MATLAB–Simulink. The effectiveness of this compensation scheme approach is demonstrated using a study case of 3 bus system. Simulation results show that there is improvement in harmonics reduction, voltage sag/swell compensation, power factor improvement at generator bus, load bus, and infinite bus respectively

  2. A GPS-Based Control Method for Load Sharing and Power Quality Improvement in Microgrids

    DEFF Research Database (Denmark)

    Golsorkhi, Mohammad; Lu, Dylan; Savaghebi, Mehdi;

    2016-01-01

    This paper proposes a novel control method for accurate sharing of load current among the Distributed Energy Resources (DER) and high power quality operating in islanded ac microgrids. This control scheme is based on hierarchical structure comprising of decentralized primary controllers and a cen....... The secondary controller produces compensation signals at fundamental and dominant harmonics to improve the voltage quality at a sensitive load bus. Experimental results are presented to validate the efficacy of the proposed method.......This paper proposes a novel control method for accurate sharing of load current among the Distributed Energy Resources (DER) and high power quality operating in islanded ac microgrids. This control scheme is based on hierarchical structure comprising of decentralized primary controllers......-I) droop characteristic. The droop coefficient, which acts as a virtual resistance, is adaptively changed as a function of peak current. This strategy not only simplifies the control design but also enables faster dynamics and higher accuracy of current sharing especially at high loading conditions...

  3. DSP implementation of Fuzzy based Power Quality enhancement strategy for IPOS converter fed drive

    Directory of Open Access Journals (Sweden)

    N.Radhakrishnan

    2012-03-01

    Full Text Available The paper attempts to develop a Fuzzy based Pulse Width Modulation (PWM scheme through the use of a Digital Signal Processor (DSP with a view to improve the input power factor of a drive system. It corners to exploit the merits of an inherent decision making mechanism to construct a control algorithm and there from articulate a methodology to reshape the input current wave to a sinusoidal form. The procedure forges to facilitate an increase in the fundamental component of the current through the entire operating range. The scheme, investigated using a prototype model envisages to enhance the power quality indices of the AC-DC converter fed drive system, in addition to regulating its speed

  4. Evaluation and classification of power quality disturbances based on discrete Wavelet transform and artificial neural networks

    OpenAIRE

    Alshahrani, S; Abbod, M; Alamri, B; Taylor, G.

    2015-01-01

    In this paper, detection method and classification technique of power quality disturbances is presented. Due to the increase of nonlinear load recently, it becomes an essential requirement to insure high level of power supply and efficient commotional consuming. Wavelet Transform represents a powerful mathematical platform which is needed especially at non-stationary situations. Disturbances are fed into wavelets to filter, detect and extract its features at different frequencies. Training of...

  5. Hybrid Power Forecasting Model for Photovoltaic Plants Based on Neural Network with Air Quality Index

    OpenAIRE

    Idris Khan; Honglu Zhu; Jianxi Yao; Danish Khan; Tahir Iqbal

    2017-01-01

    High concentration of greenhouse gases in the atmosphere has increased dependency on photovoltaic (PV) power, but its random nature poses a challenge for system operators to precisely predict and forecast PV power. The conventional forecasting methods were accurate for clean weather. But when the PV plants worked under heavy haze, the radiation is negatively impacted and thus reducing PV power; therefore, to deal with haze weather, Air Quality Index (AQI) is introduced as a parameter to predi...

  6. A Hilbert Transform-Based Smart Sensor for Detection, Classification, and Quantification of Power Quality Disturbances

    Directory of Open Access Journals (Sweden)

    Roque A. Osornio-Rios

    2013-04-01

    Full Text Available Power quality disturbance (PQD monitoring has become an important issue due to the growing number of disturbing loads connected to the power line and to the susceptibility of certain loads to their presence. In any real power system, there are multiple sources of several disturbances which can have different magnitudes and appear at different times. In order to avoid equipment damage and estimate the damage severity, they have to be detected, classified, and quantified. In this work, a smart sensor for detection, classification, and quantification of PQD is proposed. First, the Hilbert transform (HT is used as detection technique; then, the classification of the envelope of a PQD obtained through HT is carried out by a feed forward neural network (FFNN. Finally, the root mean square voltage (Vrms, peak voltage (Vpeak, crest factor (CF, and total harmonic distortion (THD indices calculated through HT and Parseval’s theorem as well as an instantaneous exponential time constant quantify the PQD according to the disturbance presented. The aforementioned methodology is processed online using digital hardware signal processing based on field programmable gate array (FPGA. Besides, the proposed smart sensor performance is validated and tested through synthetic signals and under real operating conditions, respectively.

  7. Classification of power quality combined disturbances based on phase space reconstruction and support vector machines

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Power Quality (PQ) combined disturbances become common along with ubiquity of voltage flickers and harmonics. This paper presents a novel approach to classify the different patterns of PQ combined disturbances. The classification system consists of two parts, namely the feature extraction and the automatic recognition. In the feature extraction stage, Phase Space Reconstruction (PSR), a time series analysis tool, is utilized to construct disturbance signal trajectories. For these trajectories, several indices are proposed to form the feature vectors. Support Vector Machines (SVMs) are then implemented to recognize the different patterns and to evaluate the efficiencies. The types of disturbances discussed include a combination of short-term disturbances (voltage sags, swells) and long-term disturbances (flickers, harmonics), as well as their homologous single ones. The feasibilities of the proposed approach are verified by simulation with thousands of PQ events. Comparison studies based on Wavelet Transform (WT) and Artificial Neural Network (ANN) are also reported to show its advantages.

  8. Research on improvement of power quality of Micro - grid based on SVG pulse load

    Science.gov (United States)

    Lv, Chuang; Xie, Pu

    2017-05-01

    Pulse load will make the micro-grid public bus power to produce a high peak pulse due to its cyclical pulsation characteristics,, and make the micro-grid voltage fluctuations, frequency fluctuations, voltage and current distortion, power factor reduction and other adverse effects. In order to suppress the adverse effects of the pulse load on the microgrid and improve the power quality of the microgrid, this paper established the SVG simulation model in Matlab / Simulink environment, the superiority of SVG is verified by comparing the improvement of power quality before and after adding the SVG to microgrid system. The results show that the SVG model can suppress the adverse effects effectively of the pulse load on the microgrid, which is of great value and significance to the reactive power compensation and harmonic suppression of the microgrid.

  9. Crystal Quality and Light Output Power of GaN-Based LEDs Grown on Concave Patterned Sapphire Substrate.

    Science.gov (United States)

    Wu, YewChung Sermon; Isabel, A Panimaya Selvi; Zheng, Jian-Hsuan; Lin, Bo-Wen; Li, Jhen-Hong; Lin, Chia-Chen

    2015-04-22

    The crystal quality and light output power of GaN-based light-emitting diodes (LEDs) grown on concave patterned sapphire substrate (CPSS) were investigated. It was found that the crystal quality of GaN-based LEDs grown on CPSS improved with the decrease of the pattern space (percentage of c-plane). However, when the pattern space decreased to 0.41 μm (S0.41-GaN), the GaN crystallinity dropped. On the other hand, the light output power of GaN-based LEDs was increased with the decrease of the pattern space due to the change of the light extraction efficiency.

  10. Z-Source Inverter Based Power Quality Compensator with Enhanced Ride-Through Capability

    DEFF Research Database (Denmark)

    Gajanayake, C.J.; Vilathgamuwa, D.M.; Loh, P.C.;

    2007-01-01

    network. The shunt inverter is controlled to maintain a quality voltage waveform at the load bus. Whereas the series inverter enhances the ride-through capability during grid faults, protects the shunt inverter by limiting the current and also controls the power delivered to the grid. The performance...

  11. Active Power Quality Improvement Strategy for Grid-connected Microgrid Based on Hierarchical Control

    DEFF Research Database (Denmark)

    Wei, Feng; Sun, Kai; Guan, Yajuan

    2017-01-01

    When connected to a distorted grid utility, droop-controlled grid-connected microgrids (DCGC-MG) exhibit low equivalent impedance. The harmonic and unbalanced voltage at the point of common coupling (PCC) deteriorates the power quality of the grid-connected current (GCC) of DCGC-MG. This work...

  12. Detection and analysis of distribution power quality disturbance based on complex wavelet transform and RBF network

    Science.gov (United States)

    Liu, Lin; Shen, Songhua; Liu, Qiang

    2006-11-01

    A novel method to detect power quality disturbance of distribution power system combing complex wavelet transform (WT) with radial basis function (RBF) neural network is presented. The paper tries to explain to design complex supported orthogonal wavelets by Morlet compactly supported orthogonal real wavelets, and then explore the extraction of disturbance signal to obtain the feature information, and finally propose several novel wavelet combined information (CI) to analyze the disturbance signal, superior to real wavelet analysis result. The feature obtained from WT coefficients are inputted into RBF network for power quality disturbance pattern recognition. The power quality disturbance recognition model is established and the synthesized method of recursive orthogonal least squares algorithm (ROLSA) with improved Givens transform is used to fulfill the network structure and parameter identification. By means of choosing enough samples to train the recognition model, the type of disturbance can be obtained when signal representing fault is inputted to the trained network. The results of simulation analysis show that the complex WT combined with RBF network are more sensitive to signal singularity, and found to be significant improvement over current methods in real-time detection and better noise proof ability.

  13. Shunt Active and Series Active Filters-Based Power Quality Conditioner for Matrix Converter

    Directory of Open Access Journals (Sweden)

    P. Jeno Paul

    2011-01-01

    Full Text Available This paper proposes a series active filter and shunt active filter to minimize the power quality impact present in matrix converters instead of passive filter. A matrix converter produces significant harmonics and nonstandard frequency components into load. The proposed system compensates the sag and swell problems efficiently in matrix converter. The proposed system has been tested and validated on the matrix converter using MATLAB/Simulink software. Simulated results confirm that the active power filters can maintain high performance for matrix converter.

  14. Control of PET Based On Fuzzy Logic for Power Quality Improvement

    Directory of Open Access Journals (Sweden)

    P Sravanthi

    2016-06-01

    Full Text Available During the past several years, fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory, especially in the realm of industrial process, which do not lend of quantities data regarding the input-output relations. This paper presents a power electronic transformer with fuzzy controller. In the design process converters and high frequency transformers have been used. One matrix converter operates as AC/AC converter in power electronic transformer. The proposed AC/AC converter can generate desired output voltage from square input voltage. The main point of proposed PET is reduction of the stage and components of the three-part PETs. The reliability and power quality of distribution system can be significantly improved by using proposed PET. To verify the performance of the proposed PET, computer-aided simulations are carried out using MATLAB/SIMULINK

  15. Power Quality Improvement Using DVR

    Directory of Open Access Journals (Sweden)

    C. Benachaiba

    2009-01-01

    Full Text Available Voltage sags and swells in the medium and low voltage distribution grid are considered to be the most frequent type of power quality problems based on recent power quality studies. Their impact on sensitive loads is severe. The impact ranges from load disruptions to substantial economic losses up to millions of dollars. Different solutions have been developed to protect sensitive loads against such disturbances but the DVR is considered to be the most efficient and effective solution. Its appeal includes lower cost, smaller size and its dynamic response to the disturbance. This research described DVR principles and voltage restoration methods for balanced and/or unbalanced voltage sags and swells in a distribution system. Simulation results were presented to illustrate and understand the performances of DVR under voltage sags/swells conditions.

  16. Design and Simulation of Phase-Locked Loop Controller Based Unified Power Quality Conditioner Using Nonlinear Loads

    Directory of Open Access Journals (Sweden)

    N. Suparna

    2012-10-01

    Full Text Available This project presents a power quality improvement of unified power quality conditioner (UPQC to compensate current and voltage quality problems of sensitive loads. The UPQC consists of the series and shunt converter having a common dc link. The series converter mitigates voltage sag from the supply side and shunt converter eliminates current harmonics from the nonlimear load side. The developed controllers for series and shunt converters are based on a reference signal generation method (phase-locked loop. The dc link control strategy is based on the fuzzy-logic controllers. The conventional method using dq transformation to show the superiority of the proposed sag detection method. A fast sag detection method is also is presented. The efficiency of the proposed system is tested through simulation studies using the MATLAB/SIMULINK environment.

  17. PHOTOVOLTAIC BASED SHUNT ACTIVE FILTER FOR POWER QUALITY IMPROVEMENT USING ICOSΦ THEORY

    Directory of Open Access Journals (Sweden)

    VIJAYAKUMAR G.

    2015-11-01

    Full Text Available This paper presents an optimal operation of Photovoltaic based Shunt Active Filter as (PV-SAF for significant energy conservation, harmonic mitigation and reactive power compensation. When the PV system generates excessive or equal power required to the load demand, then the coordinating logic disconnects the service grid from the load and with a consequent reduction of panel tariff and global warming gasses. The PV module is connected to the DC side of SAF through the DC-DC converter. Converter switch is controlled by fuzzy based Perturb & Observe (P&O Maximum Power Point Tracking (MPPT algorithm and it eliminates the drawback in the conventional PV system. The reference currents are extracted by the Fuzzy logic controller based ICosΦ control strategy. This proposed PV-SAF, if connected at the terminals of a small industry or a home or a small enlightening institution can avoid the use of interruptible power supply and individual stabilizer. An emulation using MATLAB Simulink is presented to validate the advantage of the proposed system.

  18. Development of Real Time Implementation of 5/5 Rule based Fuzzy Logic Controller Shunt Active Power Filter for Power Quality Improvement

    Science.gov (United States)

    Puhan, Pratap Sekhar; Ray, Pravat Kumar; Panda, Gayadhar

    2016-12-01

    This paper presents the effectiveness of 5/5 Fuzzy rule implementation in Fuzzy Logic Controller conjunction with indirect control technique to enhance the power quality in single phase system, An indirect current controller in conjunction with Fuzzy Logic Controller is applied to the proposed shunt active power filter to estimate the peak reference current and capacitor voltage. Current Controller based pulse width modulation (CCPWM) is used to generate the switching signals of voltage source inverter. Various simulation results are presented to verify the good behaviour of the Shunt active Power Filter (SAPF) with proposed two levels Hysteresis Current Controller (HCC). For verification of Shunt Active Power Filter in real time, the proposed control algorithm has been implemented in laboratory developed setup in dSPACE platform.

  19. Power quality issues current harmonics

    CERN Document Server

    Mikkili, Suresh

    2015-01-01

    Power Quality Issues: Current Harmonics provides solutions for the mitigation of power quality problems related to harmonics. Focusing on active power filters (APFs) due to their excellent harmonic and reactive power compensation in two-wire (single phase), three-wire (three-phase without neutral), and four-wire (three-phase with neutral) AC power networks with nonlinear loads, the text:Introduces the APF technology, describing various APF configurations and offering guidelines for the selection of APFs for specific application considerationsCompares shunt active filter (SHAF) control strategi

  20. A Novel Approach in Design of a Fuzzy Based Shunt Active Power Filter for the Enhancement of Power Quality

    Directory of Open Access Journals (Sweden)

    Soumya I C

    2014-03-01

    Full Text Available Active power filters most of the times are employed for elimination of the harmonics created by non-linear loads in power system and for reactive power compensation of linear and non-linear loads. Compensating current is sent by shunt active power filter (SAF at Point of Common Coupling (PCC to mitigate current harmonics in the line. Hence sinusoidal nature of current and voltage waveforms are reintroduced. Usually shunt active power filters are connected in parallel with non-linear and reactive loads. Fuzzy logic controller is used as it doesn’t require complex mathematical model. Filter inductor current is shaped by fuzzy controller so that line current is in phase with and of input voltage shape. Simulation of the proposed filter is carried out using MATLAB/SIMULINK.

  1. Application of LMS-Based NN Structure for Power Quality Enhancement in a Distribution Network Under Abnormal Conditions.

    Science.gov (United States)

    Agarwal, Rahul Kumar; Hussain, Ikhlaq; Singh, Bhim

    2017-03-16

    This paper proposes an application of a least mean-square (LMS)-based neural network (NN) structure for the power quality improvement of a three-phase power distribution network under abnormal conditions. It uses a single-layer neuron structure for the control in a distribution static compensator (DSTATCOM) to attenuate the harmonics such as noise, bias, notches, dc offset, and distortion, injected in the grid current due to connection of several nonlinear loads. This admittance LMS-based NN structure has a simple architecture which reduces the computational complexity and burden which makes it easy to implement. A DSTATCOM is a custom power device which performs various functionalities such as harmonics attenuation, reactive power compensation, load balancing, zero voltage regulation, and power factor correction. Other main contribution of this paper involves operation of the system under abnormal conditions of distribution network which means noise and distortion in voltage and imbalance in three-phase voltages at the point of interconnection. For substantiating and demonstrating the performance of proposed control approach, simulations are carried on MATLAB/Simulink software and corresponding experimental tests are conducted on a developed prototype in the laboratory.

  2. E-Learning for Power Quality

    Science.gov (United States)

    Bauer, Pavol; Nagy, Istvan

    E-learning with pre-solved animations can provide a better understanding of the status and different network options, compared to complex simulation or a set of equations. In this paper, examples of such animations for e-learning for power quality are presented. Different network options in a centralized or distributed power system and power electronics based compensators are introduced in the form of a new web-based, software learning tool. Power flow congestion and the impact of power electronic compensators on the system, including detailed operations of power electronic based compensators are presented. These compensators include SVCs, Statcom and UPFC presented in this paper. Using these animated tools, both system level and component level operation of these devices are presented. Further the frequent solutions of power factor correction (PFC) applied on low power level of several hundred watts are treated in the paper.

  3. Cooperative Control of Multi-Master-Slave Islanded Microgrid with Power Quality Enhancement Based on Conservative Power Theory

    DEFF Research Database (Denmark)

    Mortezaei, Ali; Simoes, Marcelo; Savaghebi, Mehdi;

    2017-01-01

    ) interface converters in a three-phase four-wire islanded microgrid using the Conservative Power Theory (CPT) is proposed. Inverters located in close proximity operate as a group in master-salve mode. Slaves inject the available energy and compensate selectively unwanted current components of local loads...... with the secondary effect of having enhanced voltage waveforms while masters share the remaining load power autonomously with distant groups using frequency droop. The close proximity makes it practical for control signals to be communicated between inverters in one group with the potential to provide rapid load...... sharing response for mitigation of undesirable current components. Since each primary source has its own constraints, a supervisory control is considered for each group to determine convenient sharing factors. The CPT decompositions provide decoupled current and power references in abc-frame, resulting...

  4. A New Control Strategy Based Multi Converter UPQC Using Fuzzy Logic Controller to Improve the Power Quality Issues

    Directory of Open Access Journals (Sweden)

    Chandra Babu Paduchuri

    2014-01-01

    Full Text Available A design of multiconverter unified power quality conditioner to improve the power quality issues is presents in this paper. Modified SRF theory and fuzzy logic controller technique are incorporated in this modelling. This newly designed controller is connected to a source in order to compensate voltage and current in the two feeders. The expanded concept of UPQC is multi converter-UPQC; this system has two series voltage source converter (VSC and one shunt VSC connected back to back. In the proposed system, the power can be conveyed from one feeder to another in order to mitigate the voltage sag, swell, interruption and transient response of the system. The control strategies of multi converter-UPQC are designed based on the modified synchronous reference frame theory with fuzzy logic controller. The transient response of the fuzzy logic controller in dc-link voltage controller will be very fast. The relevant simulation and compensation performance analysis of multi converter-UPQC with fuzzy logic controller is performed using MATLAB/Simulink software.

  5. Power Quality Improvement Using UPQC

    Directory of Open Access Journals (Sweden)

    K. Kalaipriya

    2014-05-01

    Full Text Available This paper presents the power quality improvement using UPQC. UPQC consists of series inverter, shunt inverter and capacitance. Every inverter connected with pulse generator for switching on. UPQC is especially obtained to resolve different kind of power quality drawback like reactive power compensation, voltage interruption and harmonics. DVR is connected in series to deliver the active and reactive power to distribution network. DC-link capacitors stay high as a result of the DVR needs a minimum amount of DC-link voltage to compensate sag. So, DC –link voltage is connected with PV module to reduce the cost. Design of UPQC device with multi-bus system obtained using MATLAB/SIMULINK and simulation results are mentioned to support the developed conception.

  6. Power Quality in DC Power Distribution Systems and Microgrids

    Directory of Open Access Journals (Sweden)

    Stephen Whaite

    2015-05-01

    Full Text Available This review paper discusses power quality considerations for direct current (DC electric power distribution systems, particularly DC microgrids. First, four selected sample DC architectures are discussed to provide motivation for the consideration of power quality in DC systems. Second, a brief overview of power quality challenges in conventional alternating current (AC distribution systems is given to establish the field of power quality. Finally, a survey of literature addressing power quality issues in DC systems is presented, and necessary power quality considerations in DC distribution system design and operation are discussed.

  7. A Numerical Matrix-Based Method for Stability and Power Quality Studies Based on Harmonic Transfer Functions

    DEFF Research Database (Denmark)

    Dowlatabadi, Mohammadkazem Bakhshizadeh; Blaabjerg, Frede; Hjerrild, Jesper

    2017-01-01

    Some couplings exist between the positive- and negative-sequence impedances of a voltage sourced power converter especially in the low frequency range due to the nonlinearities and low bandwidth control loops like the PLL. In this paper, a new numerical method based on the Harmonic Transfer...... Function for analysis of the Linear Time Periodic systems is presented, which is able to handle these couplings. In a balanced three-phase system, there is only one coupling term, but in an unbalanced (asymmetrical) system, there are more couplings, and therefore, in order to study the interactions between...

  8. Power Quality and Reliability Project

    Science.gov (United States)

    Attia, John O.

    2001-01-01

    One area where universities and industry can link is in the area of power systems reliability and quality - key concepts in the commercial, industrial and public sector engineering environments. Prairie View A&M University (PVAMU) has established a collaborative relationship with the University of'Texas at Arlington (UTA), NASA/Johnson Space Center (JSC), and EP&C Engineering and Technology Group (EP&C) a small disadvantage business that specializes in power quality and engineering services. The primary goal of this collaboration is to facilitate the development and implementation of a Strategic Integrated power/Systems Reliability and Curriculum Enhancement Program. The objectives of first phase of this work are: (a) to develop a course in power quality and reliability, (b) to use the campus of Prairie View A&M University as a laboratory for the study of systems reliability and quality issues, (c) to provide students with NASA/EPC shadowing and Internship experience. In this work, a course, titled "Reliability Analysis of Electrical Facilities" was developed and taught for two semesters. About thirty seven has benefited directly from this course. A laboratory accompanying the course was also developed. Four facilities at Prairie View A&M University were surveyed. Some tests that were performed are (i) earth-ground testing, (ii) voltage, amperage and harmonics of various panels in the buildings, (iii) checking the wire sizes to see if they were the right size for the load that they were carrying, (iv) vibration tests to test the status of the engines or chillers and water pumps, (v) infrared testing to the test arcing or misfiring of electrical or mechanical systems.

  9. Development of a coal quality analyzer for application to power plants based on laser-induced breakdown spectroscopy

    Science.gov (United States)

    Zhang, Lei; Gong, Yao; Li, Yufang; Wang, Xin; Fan, Juanjuan; Dong, Lei; Ma, Weiguang; Yin, Wangbao; Jia, Suotang

    2015-11-01

    It is vitally important for a power plant to determine the coal property rapidly to optimize the combustion process. In this work, a fully software-controlled laser-induced breakdown spectroscopy (LIBS) based coal quality analyzer comprising a LIBS apparatus, a sampling equipment, and a control module, has been designed for possible application to power plants for offering rapid and precise coal quality analysis results. A closed-loop feedback pulsed laser energy stabilization technology is proposed to stabilize the Nd: YAG laser output energy to a preset interval by using the detected laser energy signal so as to enhance the measurement stability and applied in a month-long monitoring experiment. The results show that the laser energy stability has been greatly reduced from ± 5.2% to ± 1.3%. In order to indicate the complex relationship between the concentrations of the analyte of interest and the corresponding plasma spectra, the support vector regression (SVR) is employed as a non-linear regression method. It is shown that this SVR method combined with principal component analysis (PCA) enables a significant improvement in cross-validation accuracy by using the calibration set of coal samples. The root mean square error for prediction of ash content, volatile matter content, and calorific value decreases from 2.74% to 1.82%, 1.69% to 1.22%, and 1.23 MJ/kg to 0.85 MJ/kg, respectively. Meanwhile, the corresponding average relative error of the predicted samples is reduced from 8.3% to 5.48%, 5.83% to 4.42%, and 5.4% to 3.68%, respectively. The enhanced levels of accuracy obtained with the SVR combined with PCA based calibration models open up avenues for prospective prediction in coal properties.

  10. Simulation and performance evaluation of shunt hybrid power filter using fuzzy logic based non-linear control for power quality improvement

    Indian Academy of Sciences (India)

    R BALASUBRAMANIAN; R SANKARAN; S PALANI

    2017-09-01

    This paper deals with design and simulation of a three-phase shunt hybrid power filter consisting of a pair of 5th and 7th selective harmonic elimination passive power filters connected in series with a conventional active power filter with reduced kVA rating. The objective is to enhance the power quality in a distributionnetwork feeding variety of non-linear, time-varying and unbalanced loads. The theory and modelling of the entire power circuit in terms of synchronously rotating reference frame and leading to a non-linear control scheme is presented. This work involves introduction of individual fuzzy logic controllers for d and q axiscurrent control and for voltage regulation of the DC link capacitor. The simulation schematic covering the power and control circuits have been developed taking into account severe harmonic distortion caused by non-linear and unbalanced loads. The effectiveness of the fuzzy logic controller for the compensation of harmonics and reactive power has been verified by successive simulation runs and analysis of the results. The proposed controller is also able to compensate the distortion generated by the voltage- and current-fed non-linear loads, unbalanced and dynamically varying loads. Further, excellent regulation of the DC link voltage is accomplished, which significantly contributes to improvement of power quality.

  11. ANN based controller for three phase four leg shunt active filter for power quality improvement

    Directory of Open Access Journals (Sweden)

    J. Jayachandran

    2016-03-01

    Full Text Available In this paper, an artificial neural network (ANN based one cycle control (OCC strategy is proposed for the DSTATCOM shunted across the load in three phase four wire distribution system. The proposed control strategy mitigates harmonic/reactive currents, ensures balanced and sinusoidal source current from the supply mains that are nearly in phase with the supply voltage and compensates neutral current under varying source and load conditions. The proposed control strategy is superior over conventional methods as it eliminates, the sensors needed for sensing load current and coupling inductor current, in addition to the multipliers and the calculation of reference currents. ANN controllers are implemented to maintain voltage across the capacitor and as a compensator to compensate neutral current. The DSTATCOM performance is validated for all possible conditions of source and load by simulation using MATLAB software and simulation results prove the efficacy of the proposed control over conventional control strategy.

  12. Management issues power quality in distribution system

    OpenAIRE

    2011-01-01

    In recent years, the number of power quality problems has increased dramatically. This increase in electricity demand of recent years, consecutively with increasing the number of power plants and power, along with changing the structure of energy agents and increasepower receivers, led to deterioration of power quality parameters, with implications serious about working arrangements and consumer networks. Most disputed aspect in terms of power quality standards is the regime's control sizes. ...

  13. Power quality load management for large spacecraft electrical power systems

    Science.gov (United States)

    Lollar, Louis F.

    1988-01-01

    In December, 1986, a Center Director's Discretionary Fund (CDDF) proposal was granted to study power system control techniques in large space electrical power systems. Presented are the accomplishments in the area of power system control by power quality load management. In addition, information concerning the distortion problems in a 20 kHz ac power system is presented.

  14. A Z-source Inverter Based Flexible DG System with P+resonance and Repetitive Controllers for Power Quality Improvement of a Weak Grid

    DEFF Research Database (Denmark)

    Gajanayake, C.J.; Vilathgamuwa, D.M.; Loh, P.C.

    2007-01-01

    are connected to the grid using power electronic converters. The power delivered from these sources depend on many factors like energy availability and load demand etc. In many occasions, the converters used in power conversion can be left with some excess capacity. This could be used to provide some ancillary...... DG systems. Considering these factors, this paper presents the controller design for a Z-source inverter based DG system to improve the power quality of distribution systems. To improve the reference tracking and to eliminate harmonics, a p+resonance and repetitive controller designed using a simple......In the present power systems, nonlinear loads connected at distribution level have increased immensely. This results in reduction of voltage quality for distribution level customers. Significantly, this is an outcome of the concerted action of small loads drawing nonlinear currents. However...

  15. Power quality in power systems and electrical machines

    CERN Document Server

    Fuchs, Ewald

    2015-01-01

    The second edition of this must-have reference covers power quality issues in four parts, including new discussions related to renewable energy systems. The first part of the book provides background on causes, effects, standards, and measurements of power quality and harmonics. Once the basics are established the authors move on to harmonic modeling of power systems, including components and apparatus (electric machines). The final part of the book is devoted to power quality mitigation approaches and devices, and the fourth part extends the analysis to power quality solutions for renewable

  16. Pulse doubling in zigzag-connected autotransformer-based 12-pulse ac-dc converter for power quality improvement

    Science.gov (United States)

    Abdollahi, Rohollah

    2012-12-01

    This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMDs) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse acdc converters each of them consisting of three-phase diode bridge rectifiers. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads.

  17. Measurement Practices for Reliability and Power Quality

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, JD

    2005-05-06

    regulators. The report will also serve to support activities to develop and share information among industry and regulatory participants about critical resources and practices. The toolkit has been developed by investigating the status of indices and definitions, surveying utility organizations on information sharing, and preparing summaries of reliability standards and monitoring requirements--the issues, needs, work under way, existing standards, practices and guidelines--for the following three classifications: (1) terms and definitions of reliability; (2) power quality standards, guidelines, and measurements; and (3) activities and organizations developing and sharing information on distribution reliability. As these synopses of reliability measurement practices are provided, it must be noted that an economic penalty may be associated with requiring too high a reliability level from the distribution system for all customers. It may be appropriate for the distribution system to supply only some base, generally accepted level of reliability. This base level would be adequate for the majority of customers. Users who need a higher level may find it economical to supply using distributed energy resources (DER) and other local solutions to reliability and power quality needs. Local solutions implemented by the customer may be the most cost-effective method for addressing the more stringent needs of a digital economy. These local solutions include energy storage, small distributed generators, and microgrids. This report also considers the market's role in addressing reliability issues and requirements. The customer's needs are discussed in view of issues such as power quality requirements of digital electronic equipment, the cost of outages, the cost of storage and new infrastructure, and natural gas prices. The market role in addressing these issues and requirements is explored. The economic considerations associated with the reliability issues are discussed, as well

  18. High-average-power high-beam-quality vis-UV sources based on kinetically enhanced copper vapor lasers

    Science.gov (United States)

    Brown, Daniel J. W.; Withford, Michael J.; Carman, Robert J.; Mildren, Richard P.; Piper, James A.

    2000-04-01

    Investigations of the factors that limit average power scaling of elemental copper vapor lasers (CVLs) have demonstrated that decay of the electron density in the interpulse period is critical in restricting pulse repetition rate and laser aperture scaling. We have recently developed the 'kinetic enhancement' (or KE) technique to overcome these limitations, whereby optimal plasma conditions are engineered using low concentrations of HCl/H2 additive gases in the Ne buffer. Dissociative electron attachment of HCl and subsequent mutual neutralization of Cl- and Cu+ promote rapid plasma relaxation and fast recovery of Cu densities, permitting operation at elevated Cu densities and pulse rates for given apertures. Using this approach, we have demonstrated increases in output power and efficiency of a factor of 2 or higher over conventional CVLs of the same size. For a 38 mm- bore KE-CVL, output powers up to 150 W have been achieved at 22 kHz, corresponding to record specific powers (80 mW/cm3) for such a 'small/medium-scale' device. In addition, kinetic enhancement significantly extends the gain duration and restores gain on-axis, even for high pulse rates, thereby promoting substantial increases (5 - 10x) in high- beam-quality power levels when operating with unstable resonators. This has enabled us to achieve much higher powers in second-harmonic generation from the visible copper laser output to the ultraviolet (e.g. 5 W at 255 nm from a small- scale KE-CVL). Our approach to developing KE-CVLs including computer modeling and experimental studies will be reviewed, and most recent results in pulse rate scaling and scaling of high-beam-quality power using oscillator-amplifier configurations, will be presented.

  19. Enhanced Power Quality and Minimized Peak Current Control in An Inverter based Microgrid under Unbalanced Grid Faults

    DEFF Research Database (Denmark)

    Liu, Wenzhao; Guo, Xiaoqiang; Sulligoi, Giorgio

    2016-01-01

    ride through control. In order to solve this problem, a novel control strategy is proposed to enhance the output current quality while mitigating the active and reactive output power oscillations. Moreover, a simple current-limited control strategy can be achieved without the necessity of the voltage....../current positive/negative sequence extraction. Finally, the simulation tests of the conventional and proposed control solutions are carried out. The results verify the effectiveness of the proposed strategy....

  20. 基于嵌入ARM和Linux的远程电网监控仪设计%Design of the Power Quality Monitoring based on Embeded ARM-linux

    Institute of Scientific and Technical Information of China (English)

    孙立国

    2011-01-01

    大量电力电子装置及非线性负荷在电力系统中广泛应用,使电能质量问题日益突出。电能质量问题不仅危害电力系统本身的安全及电网的稳定运行,对系统中的用户也造成严重威胁。因此,对电能质量的实时监测具有十分重要的意义。基于ARM—Linux的嵌入式电能质量监测仪,不仅数据处理功能强、人机交互性好、系统升级简单,而且能进行远程监控,并可在此基础上向微型化、高度智能化等方向发展,以满足不同场合的需求,具有较大的使用价值和广阔的应用前景。%Due to a lot of power electronic devices and nonlinear load widely used in the power system,power quality issues have become prominent increasingly.Power quality problems not only endanger the safety of the power system itself and the stable operation of power grids,but also pose a serious threat to the users of the system.Therefore,the real-time monitoring of power quality is of great significance.Power quality monitor based on arm-linux embedded has such advantages as powerful function of data handling,good interface,easy upgrade,remote monitoring.On this basis,it can be further developed to be micro and highly intelligent in order to meet the different needs.It has great value and broad prospects.

  1. Power quality enhancements for IEC 61850

    Energy Technology Data Exchange (ETDEWEB)

    Cumming, D. [Schneider Electric Canada, Toronto, ON (Canada)

    2010-07-01

    The International Electrotechnical Commission (IEC) Standard 61850 has emerged as the dominant global utility substation protocol standard because it is based on solid engineering principles and technology. It can provide valuable information in power quality analysis, compliance reporting and other similar functions. This paper presented IEC 61850 as a valuable tool for providing power quality solutions to the industry while examining concepts for enhancing power quality aspects for improved functionality. IEC 61850 originally focused on automation and protection aspects inside high voltage substations, but has been extended to many electrical infrastructure through the use of its logical node support, time synchronization accuracy, and event sequencing with quality reporting for end users. The standard continues to be extended into substation to substation communications, wind-farms, hydro plants, and device security. IEC 61850 seeks a unified approach, presenting a suite of protocols that are designed to multitask efficiently and provide support for modern engineering workflows in the design, deployment, and operation of electrical utility systems. 6 refs., 2 figs.

  2. Design and implementation of PV-based three-phase four-wire series hybrid active power filter for power quality improvement

    Indian Academy of Sciences (India)

    M Vijayakumar; S Vijayan

    2014-08-01

    This paper proposes a Photovoltaic (PV)-based three-phase four-wire Series Hybrid Active Power Filter (SHAPF), it comprises of a Series Active Power Filter (SAPF) and an LC shunt passive filter. The proposed system eliminates both the current and voltage harmonics and compensates reactive power, neutral current and voltage interruption. A SAPF demands a source of energy for compensating the voltage sag/swell. This system found a new topology for SHAPF which utilizes the PV with DC–DC boost converter as a source of DC power for the series active filter. The compensation current reference evaluation is based on the twin formulation of the vectorial theory of electrical power theorem with Fuzzy Logic Controller (FLC). The PV array/battery managed DC–DC boost converter is employed to step up the voltage to meet the DC bus voltage requirement of the three-leg Voltage Source Inverter (VSI). The foremost benefit of the proposed system is that, it will provide uninterrupted compensation for the whole day. This system utilizes the renewable energy; accordingly saves the energy and provides the uninterruptable power supply to critical/sensitive load, through the PV array/battery bank during both day time and night time. An experimental model was established and results were obtained, which indicated the capability of the proposed control scheme.

  3. Remote power quality monitoring system based on EtherNet%基于ARM的远程电能质量监测系统

    Institute of Scientific and Technical Information of China (English)

    赵燕君; 任卫东

    2012-01-01

    With the rapid development of society and economy, the power quality problems are getting worse, so making efficient power quality monitoring is becoming increasingly important. A power quality monitoring system based on ARM through the request of power monitoring was designed in this paper. By this system, the acquisition of real-time signal was completed, and a WEB server using embedded Linux with the TCP/IP protocol stack was built. In this way, the personnel could visit the system from any WEB browser. It is a new method for the long-distance power quality monitoring.%随着社会的进步和经济的快速发展,电能质量问题不断恶化,高效的电能质量监测变得越来越重要.从电力监测的实际要求出发,设计了基于ARM的电能质量综合监测系统,系统完成实时信号的采集,并利用嵌入式Linux自带的TCP/IP协议栈内建一个WEB服务器,工作人员可以在任何一个WEB浏览器访问这个系统.这对于地域跨越大的电网的远程监测提供了一种新思路.

  4. A Wavelet-Based Unified Power Quality Conditioner to Eliminate Wind Turbine Non-Ideality Consequences on Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Bijan Rahmani

    2016-05-01

    Full Text Available The integration of renewable power sources with power grids presents many challenges, such as synchronization with the grid, power quality problems and so on. The shunt active power filter (SAPF can be a solution to address the issue while suppressing the grid-end current harmonics and distortions. Nonetheless, available SAPFs work somewhat unpredictably in practice. This is attributed to the dependency of the SAPF controller on nonlinear complicated equations and two distorted variables, such as load current and voltage, to produce the current reference. This condition will worsen when the plant includes wind turbines which inherently produce 3rd, 5th, 7th and 11th voltage harmonics. Moreover, the inability of the typical phase locked loop (PLL used to synchronize the SAPF reference with the power grid also disrupts SAPF operation. This paper proposes an improved synchronous reference frame (SRF which is equipped with a wavelet-based PLL to control the SAPF, using one variable such as load current. Firstly the fundamental positive sequence of the source voltage, obtained using a wavelet, is used as the input signal of the PLL through an orthogonal signal generator process. Then, the generated orthogonal signals are applied through the SRF-based compensation algorithm to synchronize the SAPF’s reference with power grid. To further force the remained uncompensated grid current harmonics to pass through the SAPF, an improved series filter (SF equipped with a current harmonic suppression loop is proposed. Concurrent operation of the improved SAPF and SF is coordinated through a unified power quality conditioner (UPQC. The DC-link capacitor of the proposed UPQC, used to interconnect a photovoltaic (PV system to the power grid, is regulated by an adaptive controller. Matlab/Simulink results confirm that the proposed wavelet-based UPQC results in purely sinusoidal grid-end currents with total harmonic distortion (THD = 1.29%, which leads to high

  5. Power Quality Improvement of a Distributed Generation Power System

    Directory of Open Access Journals (Sweden)

    Panga Harish

    2016-06-01

    Full Text Available The aim of this work is to improve the power quality for Distributed Generation (DG with power storage system. Power quality is the combination of voltage quality and current quality. Power quality is the set of limits of electrical properties that allows electrical systems to function in their intended manner without significant loss of performance or life. The electrical power quality is more concerned issue. The main problems are stationery and transient distortions in the line voltage such as harmonics, flicker, swells, sags and voltage asymmetries. Distributed Generation (DG also called as site generation, dispersed generation, embedded generation, decentralized generation, decentralized energy or distributed energy, generates electricity from the many small energy sources. In recent years, micro electric power systems such as photovoltaic generation systems, wind generators and micro gas turbines, etc., have increased with the deregulation and liberalization of the power market. Under such circumstances the environment surrounding the electric power industry has become ever more complicated and provides high-quality power in a stable manner which becomes an important topic. Here DG is assumed to include Wind power Generation (WG and Fuel Cells (FC, etc. Advantages of this system are constant power supply, constant voltage magnitude, absence of harmonics insupply voltage, un-interrupted power supply. In this project the electric power qualities in two cases will be compared. Case I: With the storage battery when it is introduced. Case II: Without the storage battery. The storage battery executes the control that maintains the voltage in the power system. It will be found that the Electric power quality will be improved, when storage battery is introduced. The model system used in this Project work is composed of a Wind Turbine, an Induction Generator, Fuel Cells, An Inverter and a Storage Battery. A miniature Wind Power Generator is

  6. Improving wind power quality with energy storage

    DEFF Research Database (Denmark)

    Rasmussen, Claus Nygaard

    2009-01-01

    The results of simulation of the influence of energy storage on wind power quality are presented. Simulations are done using a mathematical model of energy storage. Results show the relation between storage power and energy, and the obtained increase in minimum available power from the combination...... of wind and storage. The introduction of storage enables smoothening of wind power on a timescale proportional to the storage energy. Storage does not provide availability of wind power at all times, but allows for a certain fraction of average power in a given timeframe to be available with high...... probability. The amount of storage capacity necessary for significant wind power quality improvement in a given period is found to be 20 to 40% of the energy produced in that period. The necessary power is found to be 80 to 100% of the average power of the period....

  7. Power quality problems and mitigation techniques

    CERN Document Server

    Singh, Bhim; Al-Haddad, Kamal

    2014-01-01

    Maintaining a stable level of power quality in the distribution network is a growing challenge due to increased use of power electronics converters in domestic, commercial and industrial sectors. Power quality deterioration is manifested in increased losses; poor utilization of distribution systems; mal-operation of sensitive equipment and disturbances to nearby consumers, protective devices, and communication systems. However, as the energy-saving benefits will result in increased AC power processed through power electronics converters, there is a compelling need for improved understanding o

  8. Control strategy for Single-phase Transformerless Three-leg Unified Power Quality Conditioner Based on Space Vector Modulation

    DEFF Research Database (Denmark)

    Lu, Yong; Xiao, Guochun; Wang, Xiongfei

    2016-01-01

    The unified power quality conditioner (UPQC) is known as an effective compensation device to improve PQ for sensitive end-users. This paper investigates the operation and control of a single-phase three-leg UPQC (TL-UPQC), where a novel space vector modulation method is proposed for naturally...... solving the coupling problem introduced by the common switching leg. The modulation method is similar to the well-known space vector modulation widely used with three-phase voltage source converters, which thus brings extra flexibility to the TL-UPQC system. Two optimized modulation modes with either...... reduced switching loss or harmonic distortion are derived, evaluated, and discussed, in order to demonstrate the flexibility brought by the space vector modulated TL-UPQC. Simulations and experimental results are presented to verify the feasibility and effectiveness of the proposed space vector modulation...

  9. A Survey on Classification of Power Quality Disturbances in a Power System

    Directory of Open Access Journals (Sweden)

    O. Jeba Singh

    2014-08-01

    Full Text Available Nowerdays, due to the penetration of power electronics based loads and microprocessor based controlled loads. We have to give more importance to power Quality problems. In order to improve the power quality, the sources of power quality disturbances should be recognized and classified earlier. So many techniques are proposed so far in many research papers under feature extraction and classification. This paper gives a survey of the various papers and it will be use full for the researchers to know about the various methods discussed and helps to do the further work in this area.

  10. Microgrids and Heterogeneous Power Quality and Reliability

    Energy Technology Data Exchange (ETDEWEB)

    LaCommare, Kristina; Marnay, Chris

    2007-10-01

    This paper describes two stylized alternative visions of how the power system might evolve to meet future requirements for the high quality electricity service that modern digital economies demand, a supergrids paradigm and a dispersed paradigm. Some of the economics of the dispersed vision are explored, and perspectives are presented on both the choice of homogeneous universal power quality upstream in the electricity supply chain and on the extremely heterogeneous requirements of end-use loads. It is argued that meeting the demanding requirements of sensitive loads by local provision of high quality power may be more cost effective than increasing the quality of universal homogeneous supply upstream in the legacy grid. Finally, the potential role of microgrids in delivering heterogeneous power quality is demonstrated by reference to two ongoing microgrid tests in the U.S. and Japan.

  11. A Z-source Inverter Based Flexible DG System with P+resonance and Repetitive Controllers for Power Quality Improvement of a Weak Grid

    DEFF Research Database (Denmark)

    Gajanayake, C.J.; Vilathgamuwa, D.M.; Loh, P.C.

    2007-01-01

    , the utility has an obligation to deliver a quality supply to consumers. Interestingly, with the increase in energy demand and penetration of renewable sources, generation units popularly known as Distributed Generators (DGs) are increasingly connected at the distribution level. Most of these sources...... functions of the power distribution like harmonics and unbalance mitigation etc. Moreover, some of these DG sources have large operating ranges demanding special converters with wide operating range. Being a single stage buck-boost inverter, recently proposed Z-source inverter is a good candidate for future...... DG systems. Considering these factors, this paper presents the controller design for a Z-source inverter based DG system to improve the power quality of distribution systems. To improve the reference tracking and to eliminate harmonics, a p+resonance and repetitive controller designed using a simple...

  12. Power Quality Issues on Wind Power Installations in Denmark

    DEFF Research Database (Denmark)

    Sørensen, Poul Ejnar; Cutululis, Nicolaos Antonio; Lund, Torsten

    2007-01-01

    This paper introduces the power quality issues of wind power installations in a historic perspective, as the development from a few small wind turbines connected directly to the low voltage grid, to the present system with high penetration on the medium voltage distribution grids and two large...

  13. Developing a new power quality analysis software based on LabVIEW%基于LabVIEW的新型电能质量分析软件开发

    Institute of Scientific and Technical Information of China (English)

    韩烨; 刘志刚; 李文帆

    2012-01-01

    传统电能质量检测装置大多采用DSP技术,开发周期长,功能单一.基于LabVIEW虚拟仪器开发平台,开发一种新型的电能质量分析软件,可利用FFT、STFT、WT、HHT等多种现代信号处理方法对电能质量信号进行分析,并利用状态机结构实现人机交互.检测结果表明,软件既能分析电能质量的稳态指标,又能检测电能质量的暂态扰动,操作简单,多种功能,界面友好,具有广泛的使用前景.%DSP technology is used in most of traditional power quality detection devices, with long development cycle and limited functions. Based on Lab VIEW virtual instrument development platform, a new type of power quality analysis software is developed. Transformation-based methods such as FFT, STFT and HHT are adopted to analyze power quality signals, using state machine architecture to achieve human-computer interaction. The test results show that the software can not only analyze the steady-state indexes of power quality, but also detect the transient disturbance signal. There are some advantages such as simple operations, friendly interface, multi-functions and so on, which make the software have an extensive application prospect.

  14. Research in power systems: power quality and electricity market

    OpenAIRE

    Amarís Duarte, Hortensia; Usaola, Julio

    2008-01-01

    The research group REDES from UC3M has experience on electricity market, grid integration of wind energy and power quality. The group may offer consulting activities with a high component of research. We are looking for the collaboration of companies devoted to the consulting related to electricity markets, the integration of wind power in the electricity network, and with power quality. Contrato Programa de Comercialización e Internacionalización. Sistema Regional de Investigación Científ...

  15. Power energy quality; Qualidade da energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Evaldo Serra da; Fernandes, Francisco Alfredo; Bellan, Anderson Aparecido; Brenna, Jose Carlos; Dias, Luis Fernando Souza; Pinheiro, Luiz Eduardo de Oliveira; Bonaparte, Valeria Christina M. [Companhia Energetica de Sao Paulo, SP (Brazil)

    1994-12-31

    This work presents the methods and tools developed by the CESP in the implantation of the total quality process in the its power distribution system and in the attendance of the customer 6 figs., 3 tabs.

  16. Development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, A. [Quebec Univ., Montreal, PQ (Canada). Dept. of Electrical Engineering

    2010-07-01

    Interest in renewable energy sources has grown in recent years in response to concerns of increasing pollution levels and depleting fossil fuels. Among renewable energy sources, wind energy generation is the fastest growing technology and one of the most cost-effective and environmental friendly means to generate electricity from renewable sources. Modern wind turbines are ready to be deployed in large scale as a result of recent developments in wind power technology. Variable speed permanent magnet synchronous generators (PMSG) based wind energy conversion systems (WECS) are becoming more popular. The use of a permanent magnet reduces size, cost and weight of overall WECS. In addition, the absence of field winding and its excitation system avoids heat dissipation in the rotor winding, thereby improving overall efficiency of the WECS. This type of configuration is more appropriate for remote locations, particularly for off-shore wind application, where the geared doubly fed induction generator usually requires regular maintenance due to tearing-wearing in brushes, windings and gear box. This presentation discussed the development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features. A novel adaptive network-based fuzzy inference system was used to estimate the speed and position of variable speed PMSG under fluctuating wind conditions. A novel control strategy was developed for the grid interfacing inverter incorporating power quality improvement features at point of common coupling.

  17. Novel power quality indices based on wavelet packet transform for non-stationary sinusoidal and non-sinusoidal disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Morsi, Walid G. [University of New Brunswick, Fredericton, New Brunswick (Canada); El-Hawary, M.E. [Dalhousie University, Halifax, Nova Scotia (Canada)

    2010-07-15

    High power quality (PQ) level represents one of the main objectives towards smart grid. The currently used PQIs that are a measure of the PQ level are defined under the umbrella of the Fourier foundation that produces unrealistic results in case of non-stationary PQ disturbances. In order to accurately measure those indices, wavelet packet transform (WPT) is used in this paper to reformulate the recommended PQIs and hence benefiting from the WPT capabilities in accurately analyzing non-stationary waveforms and providing a uniform time-frequency sub-bands leading to reduced size of the data to be processed which is a necessity to facilitate the implementation of smart grid. Numerical examples' results considering non-stationary waveforms prove the suitability of the WPT for PQIs measurement; also the results indicate that Daubechies 10 could be the best candidate wavelet basis function that could provide acceptable accuracy while requiring less number of wavelet coefficients and hence reducing the data size. Moreover, a new time-frequency overall and node crest factors are introduced in this paper. The new node crest factor is able to determine the node or the sub-band that is responsible for the largest impact which could not be achieved using traditional approaches. (author)

  18. Assessment of Electric Power Quality in Ships'Modern Systems

    Institute of Scientific and Technical Information of China (English)

    Janusz Mindykowski; XU Xiao-yan

    2004-01-01

    The paper deals with the selected problems of electric power quality in ships'modern systems.In the introduction the fundamentals of electric power quality assessment,such as the relations and consequences among power quality phenomena and indices,secondly as the methods and tools as well as the appropriate instrumentation,have been shortly presented.Afterwards,the basic characteristic of power systems on modern ships has been given.The main focus of the paper is put on the assessment of electric power quality in ships'systems fitted with converter subsystems.The state of the art and actual tendencies in the discussed matter have been shown.Some chosen experimental results,based on the research carried out under supervision of the author,have been presented,too.Finally,some concluding issues have been shortly commented on.

  19. Fault Analysis in a Grid Integrated DFIG Based Wind Energy System with NA CB_P Circuit for Ridethrough Capability and Power Quality Improvement

    Science.gov (United States)

    Swain, Snehaprava; Ray, Pravat Kumar

    2016-12-01

    In this paper a three phase fault analysis is done on a DFIG based grid integrated wind energy system. A Novel Active Crowbar Protection (NACB_P) system is proposed to enhance the Fault-ride through (FRT) capability of DFIG both for symmetrical as well as unsymmetrical grid faults. Hence improves the power quality of the system. The protection scheme proposed here is designed with a capacitor in series with the resistor unlike the conventional Crowbar (CB) having only resistors. The major function of the capacitor in the protection circuit is to eliminate the ripples generated in the rotor current and to protect the converter as well as the DC-link capacitor. It also compensates reactive power required by the DFIG during fault. Due to these advantages the proposed scheme enhances the FRT capability of the DFIG and also improves the power quality of the whole system. Experimentally the fault analysis is done on a 3hp slip ring induction generator and simulation results are carried out on a 1.7 MVA DFIG based WECS under different types of grid faults in MATLAB/Simulation and functionality of the proposed scheme is verified.

  20. European wind turbine testing procedure developments. Task 2: Power quality

    DEFF Research Database (Denmark)

    Sørensen, Poul Ejnar; Friis Pedersen, Troels; Gerdes, G.;

    2001-01-01

    The present report describes the work done in the power quality subtask of the European Wind Turbine Testing Procedure Developments project funded by the EU SMT program. The objective of the power quality subtask has been to make recommendations andprovide background for new standards...... for measurement and testing of wind turbine power quality. The focus in the work has been to support the ongoing standardisation work in IEC with a new standard IEC61400-21 for measurement and assessment of powerquality characteristics of grid connected wind turbines. The work has also been based on the power...... quality measuremnet procedure in the Measnet cooperation of European test stations for wind turbines. The first working item of the project has been toverify the state of the art of the measurement procedures by analyses and comparisons of the measurements and data processing software of the participating...

  1. Power Quality Analysis in Off-Grid Power Platform

    Directory of Open Access Journals (Sweden)

    Stanislav Misak

    2014-01-01

    Full Text Available Research projects in the field of electrical distribution systems are moving to a new philosophy of Smart Grids, where the effort is to use the maximum possible share of power from renewable energy potential. Under this philosophy the emphasis is on energy independence, reliability and safety of operation of energy distribution system. Research in this area leads for example to developing of autonomous local microgrids with the several specific requirements. However, the problem of parameters keeping of quality of electric energy can arise together with increased penetration of distributed generation in microgrids. This problem is caused by decreased short-circuit power of local renewable energy sources, stochastic supply of electric energy from renewable energy sources and operating of active distribution grid in autonomous mode without connection to the external distribution system. General introduction to the power quality evaluation in off-grid power system is introduced in this paper. Initial results from power quality analysis from small off-grids system is presented in this text too.

  2. Power quality and harmonic instrumentation selection

    Energy Technology Data Exchange (ETDEWEB)

    Stebbins, W.L.; Golden, P.

    1996-05-01

    The proliferation of adjustable speed drive (ASD) systems in commercial and industrial settings has prompted a new awareness of the impact of harmonics and other power quality (PQ) concerns. The PQ issues have a direct bearing on the reliability of these systems and the ability to perform the desired tasks in an interruption free manner. Details presented include identifying power quality problems, selecting the proper type of monitoring instruments, and interpretation of data. Included are typical instrument specifications and cost. Additionally the advent of artificial intelligence tools for PQ analysis and the resulting impact on providing solutions is described.

  3. Unified Power Quality Conditioner for voltage and current compensation

    Directory of Open Access Journals (Sweden)

    P.Annapandi

    2012-07-01

    Full Text Available This paper deals with a Unified Power Quality Conditioner (UPQC for load balancing, power factorcorrection, voltage regulation, voltage and current harmonics mitigation, mitigation of voltage sag, swelland voltage dip in a three-phase three-wire distribution system for different combinations of linear and nonlinear loads.The unified power quality conditioner (UPQC is a combination of back to back connected shunt and series active power filters (APFs to a common DC link voltage, which compensates voltage and current based distortions, independently.Using instantaneous active and reactive Power theory ,harmonic detection, reactive power compensation, voltage sag and swell have been simulated and the results are analyzed. The operation and capability of the proposed system was analyzed through simulations with MATLAB / SIMULINK.

  4. Adjustable Speed Drives and Power Quality

    DEFF Research Database (Denmark)

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2016-01-01

    This paper provides an overview and proposes cost-effective and efficient opportunities in improving power quality in Adjustable Speed Drive (ASD) systems. In particular, an Electronic Inductor (EI) technique has been used in single drives to overcome the existing challenges in conventional...

  5. The Power Quality Disturbance Detection and Classification Method Based on EMD%基于EMD的电能质量扰动检测与分类方法

    Institute of Scientific and Technical Information of China (English)

    武荣华; 王天施; 侯宝明

    2013-01-01

    In view of the signal detection and classification of power quality disturbance problem,the power quality disturbances detection and classification methods based on EMD were proposed,and the common several kinds of disturbance signal were simulated.The time of disturbance occurrence and duration,the frequency and amplitude of disturbance can be detected accurately by this method.Such as voltage sags,voltage swells,voltage interruptions and other disturbances raised the signal amplitude and frequency changes can be estimated.The results of MATLAB simulation show that the proposed method is simple and effective.%针对电能质量扰动信号的检测和分类问题,提出了一种基于EMD的电能质量扰动检测与分类方法,并对常见的几种扰动信号进行仿真.应用该方法检测扰动发生时间、持续时间以及扰动的频率与幅值.仿真结果表明,所提算法简洁有效,能够准确分析电能质量扰动信号,可以估计电压凹陷、电压凸起以及电压中断等扰动信号的变化幅度和频率.

  6. Guest Editorial Special Issue on Power Quality in Smart Grids

    DEFF Research Database (Denmark)

    Guerrero, Josep M.

    2017-01-01

    Smart grid (SG) is usually described as a power system utilizing information and communication technology (ICT) and advanced monitoring systems to improve the grid performance and offer a wide range of additional services for the consumers. Some of the main features of such a grid are self......-healing from power disturbances, efficient energy management, automation based on ICT and advanced metering infrastructures (smart metering), integration of distributed power generation, renewable energy resources and storage units as well as high power quality and reliability. In this regard, the concept...

  7. Improvement of power quality using distributed generation

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Munoz, A.; Lopez-Rodriguez, M.A.; Flores-Arias, J.M.; Bellido-Outerino, F.J. [Universidad de Cordoba, Departamento A.C., Electronica y T.E., Escuela Politecnica Superior, Campus de Rabanales, E-14071 Cordoba (Spain); de-la-Rosa, J.J.G. [Universidad de Cadiz, Area de Electronica, Dpto. ISA, TE y Electronica, Escuela Politecnica Superior Avda, Ramon Puyol, S/N, E-11202-Algeciras-Cadiz (Spain); Ruiz-de-Adana, M. [Universidad de Cordoba, Departamento de Quimica Fisica y Termodinamica Aplicada, Campus de Rabanales, E-14071 Cordoba (Spain)

    2010-12-15

    This paper addresses how Distributed Generation (DG), particularly when configured in Combined Heat and Power (CHP) mode, can become a powerful reliability solution in highlight automated factories, especially when integrated with complimentary Power Quality (PQ) measures. The paper presents results from the PQ audit conducted at a highly automated plant over last year. It was found that the main problems for the equipment installed were voltage sags. Among all categories of electrical disturbances, the voltage sag (dip) and momentary interruption are the nemeses of the automated industrial process. The paper analyzes the capabilities of modern electronic power supplies and the convenience of embedded solution. Finally it is addressed the role of the DG/CHP on the reliability of digital factories. (author)

  8. Power quality assessment using an adaptive neural network

    Energy Technology Data Exchange (ETDEWEB)

    Dash, P.K.; Swain, D.P.; Mishra, B.R. [Regional Engineering Coll., Rourkela (India). Dept. of Electrical Engineering; Rahman, S. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)

    1995-12-31

    The paper presents an adaptive neural network approach for the estimation of harmonic components of a power system and the power quality. The neural estimator is based on the use of an adaptive perceptron consisting of a linear adaptive neuron called Adaline. The learning parameters in the proposed algorithm are adjusted to force the error between the actual and desired outputs to satisfy a stable difference error equation. The estimator tracks the Fourier coefficients of the signal data corrupted with noise and decaying dc components very accurately. Adaptive tracking of harmonic components of a power system can easily be done using this algorithm. Several numerical tests have been conducted for the adaptive estimation of harmonic components, total harmonic distortion and power quality of power system signals mixed with noise and decaying dc components.

  9. Design of Interline Unified Power Quality Conditioner for Power Quality Disturbances using Simulink

    Science.gov (United States)

    Kumaraswamy, G.; Reddy, Y. Rajasekhar; Harikrishna, Ch.

    2012-10-01

    Proliferation of electronic equipment in commercial and industrial processes has resulted in increasingly sensitive electrical loads to be fed from power distribution system which introduce contamination to voltage and current waveforms at the point of common coupling of industrial loads. The unified power quality conditioner (UPQC) is connected between two different feeders (lines), hence this method of connection of the UPQC is called as Interline UPQC (IUPQC).This paper proposes a new connection for a UPQC to improve the power quality of two feeders in a distribution system. Interline Unified Power Quality Conditioner (IUPQC), specifically aims at the integration of series VSC and Shunt VSC to provide high quality power supply by means of voltage sag/swell compensation, harmonic elimination and power factor correction in a power distribution network, so that improved power quality can be made available at the point of common coupling. The structure, control and capability of the IUPQC are discussed in this paper. The efficiency of the proposed configuration has been verified through simulation using MATLAB/ SIMULINK.

  10. Mapas tridimensionales de pérdida de la calidad de potencia basados en la teoría tensorial de la potencia Three-dimensional maps of power quality loss based in the power tensor theory

    Directory of Open Access Journals (Sweden)

    Tacca H. E.

    2011-10-01

    Full Text Available Este artículo presenta los resultados de una investigación relacionada con el desarrollo de una herramienta de visualización flexible, para ser usado principalmente por los operadores del sistema eléctrico. La investigación se centró en una técnica para evaluar el deterioro de la calidad de la potencia transmitida en redes eléctricas, basada en la teoría del tensor de potencia. Uno de los objetivos esenciales de la herramienta es de ayudar a los operadores del sistema, proporcionando imágenes con características fácilmente identificables, las cuales, están relacionadas con el deterioro global de la calidad de la energía. El resultado es una interfaz amigable tridimensional. La eficacia de la herramienta se ilustra mediante diferentes escenarios que se recrearon con el sistema de prueba IEEE de 13-barras.This paper presents the results of a project which was aimed at developing a flexible visualisation tool to be used mainly by power system operators. The project concentrated on a technique for assessing the deterioration of power transfer quality in electrical networks based on the power tensor theory. One of the envisioned tool’s essential goals was to aid system operators by providing images of the system with easily identifiable characteristics related to loss or overall deterioration of power quality. The result was a user-friendly, threedimensional graphic interface. The tool’s effectiveness has been illustrated via different scenarios created using the IEEE 13-bus test feeder as an example.

  11. Impacts of fuel quality on power production

    DEFF Research Database (Denmark)

    Harding, S.; Wall, T.; Wigley, F.;

    2007-01-01

    The first ash deposition or slagging and fouling conference, as they are commonly called, was held at the Marchwood Engineering Laboratories in the UK in 1963. Since that time many excellent conferences have occurred to provide interchange, dialogue, experiences and results among those who deal...... with the many opportunities afforded by fuel quality. However, due to the changing sponsorship environment, it has been several years since the last conference which focused on fuel characteristics and their paramount importance in power production. This conference, the 17th in the series, was entitled “Impacts...... of Fuel Quality on Power Production” and was held in Snowbird, UT, from October 29 to November 3, 2006. More than 50 participants from 13 countries throughout the world participated....

  12. Off-grid power quality: Impacts, analysis and solutions

    Science.gov (United States)

    Gautam, Arjun

    Good power quality is a critical factor for the reliable operation of electrical loads in a power system. However, the current drawn by many electronic devices and non-linear loads are non-sinusoidal, which can result in a poor power quality, particularly in off-grid power systems. Poor power quality is characterized by electrical disturbances such as transients, sags, swells, harmonics and even interruptions in the power supply. Off-grid power systems worldwide struggle with system failures and equipment damage due to poor power quality. To better understand off-grid system failures and equipment damage issues, the current and voltage characteristics of a number of electrical devices in two off-grid homes, one using a pure sine wave inverter and the other using a modified sine wave inverter, were recorded with a Fluke 43B power quality analyzer, and the devices' impact on the power quality of the off-grid systems was analyzed. The off-grid power quality data were then compared with data from a grid-connected apartment, to help identify the issues that were specific to off-grid systems. The MATLAB/Simulink software was used to model and analyze power quality for additional configurations of the two off-grid systems mentioned above. Strategies to mitigate the worst power quality issues were selected based upon their function and cost, and a few were tested in an off-grid system. Selection of an inverter was found to be important because not all devices are supported by each type of inverter. For example, the refrigerator in the off-grid home with a modified sine wave inverter produced a significant amount of current and voltage harmonics far above standards. In fact, this type of inverter does not support a number of sensitive devices including motors, refrigerators, microwave ovens, fluorescent lights, battery chargers etc. The major issues for the degradation of power quality in the off-grid system using a pure sine wave inverter were the current harmonics

  13. Fast decision algorithms in low-power embedded processors for quality-of-service based connectivity of mobile sensors in heterogeneous wireless sensor networks.

    Science.gov (United States)

    Jaraíz-Simón, María D; Gómez-Pulido, Juan A; Vega-Rodríguez, Miguel A; Sánchez-Pérez, Juan M

    2012-01-01

    When a mobile wireless sensor is moving along heterogeneous wireless sensor networks, it can be under the coverage of more than one network many times. In these situations, the Vertical Handoff process can happen, where the mobile sensor decides to change its connection from a network to the best network among the available ones according to their quality of service characteristics. A fitness function is used for the handoff decision, being desirable to minimize it. This is an optimization problem which consists of the adjustment of a set of weights for the quality of service. Solving this problem efficiently is relevant to heterogeneous wireless sensor networks in many advanced applications. Numerous works can be found in the literature dealing with the vertical handoff decision, although they all suffer from the same shortfall: a non-comparable efficiency. Therefore, the aim of this work is twofold: first, to develop a fast decision algorithm that explores the entire space of possible combinations of weights, searching that one that minimizes the fitness function; and second, to design and implement a system on chip architecture based on reconfigurable hardware and embedded processors to achieve several goals necessary for competitive mobile terminals: good performance, low power consumption, low economic cost, and small area integration.

  14. Fast Decision Algorithms in Low-Power Embedded Processors for Quality-of-Service Based Connectivity of Mobile Sensors in Heterogeneous Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Juan M. Sánchez-Pérez

    2012-02-01

    Full Text Available When a mobile wireless sensor is moving along heterogeneous wireless sensor networks, it can be under the coverage of more than one network many times. In these situations, the Vertical Handoff process can happen, where the mobile sensor decides to change its connection from a network to the best network among the available ones according to their quality of service characteristics. A fitness function is used for the handoff decision, being desirable to minimize it. This is an optimization problem which consists of the adjustment of a set of weights for the quality of service. Solving this problem efficiently is relevant to heterogeneous wireless sensor networks in many advanced applications. Numerous works can be found in the literature dealing with the vertical handoff decision, although they all suffer from the same shortfall: a non-comparable efficiency. Therefore, the aim of this work is twofold: first, to develop a fast decision algorithm that explores the entire space of possible combinations of weights, searching that one that minimizes the fitness function; and second, to design and implement a system on chip architecture based on reconfigurable hardware and embedded processors to achieve several goals necessary for competitive mobile terminals: good performance, low power consumption, low economic cost, and small area integration.

  15. Lead/acid batteries in systems to improve power quality

    Science.gov (United States)

    Taylor, P.; Butler, P.; Nerbun, W.

    Increasing dependence on computer technology is driving needs for extremely high-quality power to prevent loss of information, material, and workers' time that represent billions of dollars annually. This cost has motivated commercial and Federal research and development of energy storage systems that detect and respond to power-quality failures in milliseconds. Electrochemical batteries are among the storage media under investigation for these systems. Battery energy storage systems that employ either flooded lead/acid or valve-regulated lead/acid battery technologies are becoming commercially available to capture a share of this emerging market. Cooperative research and development between the US Department of Energy and private industry have led to installations of lead/acid-based battery energy storage systems to improve power quality at utility and industrial sites and commercial development of fully integrated, modular battery energy storage system products for power quality. One such system by AC Battery Corporation, called the PQ2000, is installed at a test site at Pacific Gas and Electric Company (San Ramon, CA, USA) and at a customer site at Oglethorpe Power Corporation (Tucker, GA, USA). The PQ2000 employs off-the-shelf power electronics in an integrated methodology to control the factors that affect the performance and service life of production-model, low-maintenance, flooded lead/acid batteries. This system, and other members of this first generation of lead/acid-based energy storage systems, will need to compete vigorously for a share of an expanding, yet very aggressive, power quality market.

  16. Effect of Power Ultrasound on Food Quality

    Science.gov (United States)

    Lee, Hyoungill; Feng, Hao

    Recent food processing technology innovations have been centered around producing foods with fresh-like attributes through minimal processing or nonthermal processing technologies. Instead of using thermal energy to secure food safety that is often accompanied by quality degradation in processed foods, the newly developed processing modalities utilize other types of physical energy such as high pressure, pulsed electric field or magnetic field, ultraviolet light, or acoustic energy to process foods. An improvement in food quality by the new processing methods has been widely reported. In comparison with its low-energy (high-frequency) counterpart which finds applications in food quality inspection, the use of high-intensity ultrasound, also called power ultrasound, in food processing is a relatively new endeavor. To understand the effect of high-intensity ultrasound treatment on food quality, it is important to understand the interactions between acoustic energy and food ingredients, which is covered in Chapter 10. In this chapter, the focus will be on changes in overall food quality attributes that are caused by ultrasound, such as texture, color, flavor, and nutrients.

  17. Power Quality Analysis Using Bilinear Time-Frequency Distributions

    Directory of Open Access Journals (Sweden)

    Sha'ameri AhmadZuri

    2010-01-01

    Full Text Available Abstract Bilinear time-frequency distributions (TFDs are powerful techniques that offer good time and frequency resolution of time-frequency representation (TFR. It is very appropriate to analyze power quality signals which consist of nonstationary and multi-frequency components. However, the TFDs suffer from interference because of cross-terms. Many TFDs have been implemented, and there is no fixed window or kernel that can remove the cross-terms for all types of signals. In this paper, the bilinear TFDs are implemented to analyze power quality signals such as smooth-windowed Wigner-Ville distribution (SWWVD, Choi-Williams distribution (CWD, B-distribution (BD, and modified B-distribution (MBD. The power quality signals focused are swell, sag, interruption, harmonic, interharmonic, and transient based on IEEE Std, 1159-1995. A set of performance measures is defined and used to compare the TFRs. It shows that SWWVD presents the best performance and is selected for power quality signal analysis. Thus, an adaptive optimal kernel SWWVD is designed to determine the separable kernel automatically from the input signal.

  18. Study of Power Quality Monitoring System of Rural Power Grid Based on DSP + ARM%基于DSP+ARM的农村电网电能质量监测系统研究

    Institute of Scientific and Technical Information of China (English)

    杜娟; 张瑾; 刘冰; 许青松

    2011-01-01

    针对农村电网电能质量问题,设计以DSP和ARM为核心的嵌入式系统来检测农村电网的电能质量.在嵌入式Linux操作系统的软件平台上,通过QT/Embedded实现良好的人机交互界面,以TMS320VC5416数据处理器、Samsung公司的S3C2410为硬件核心,以SPI实现DSP与ARM的串口通信,并利用希尔伯特-黄变换(HHT)算法对农村电能质量进行检测,大大提高了对农村电网的用电质量监测能力,同时也为农村电网的重建和改造提供了重要依据.%According to rural power grid power quality problems, the embedded system centered on DSP and ARM is designed to detect rural power grid power quality. In the embedded Linux operating system software platform through the QT/Embedded, the friendly man-machine interface is realized, Taking TMS320VC5416 data processor and Samsung S3C2410 as the hardware core, SPI is used to achieve DSP and ARM serial port communication, and the Hilbert-Huang transform ( HHT) algorithm is used to detect the rural power grid power quality. It has greatly increased the capability of rural power grid power quality monitoring while providing an important basis for the reconstruction of rural power grid.

  19. Modeling and Simulation of Custom Power Devices to Mitigate Power Quality Problems

    Directory of Open Access Journals (Sweden)

    T. Devaraju,

    2010-06-01

    Full Text Available A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure or a misoperation of end use Equipments. Utility distribution networks, sensitive industrial loads, and critical commercial operations all suffer from various types of outages and service interruptions which can cost significant financial 1oss per incident based on process down-time, lost production, idle work forces, and other factors. With the restructuring of Power Systems and with shifting trend towards distributed and dispersed Generation, the issue of Power Quality is going to take newer dimensions. The aim therefore, in this work, is to identify the prominent concerns in the area and thereby to recommend measures that can enhance the quality of the power, keeping in mind their economic viability and technical repercussions. In this paper ectromagnetic transient studies are presented for the following two custom power controllers: the distribution static compensator (D-STATCOM, and the dynamic voltage restorer (DVR. Comprehensive results are presented to assess the performance of each device to mitigate the power quality problems.

  20. High power, high beam quality regenerative amplifier

    Science.gov (United States)

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  1. Anomaly Detection in Power Quality at Data Centers

    Science.gov (United States)

    Grichine, Art; Solano, Wanda M.

    2015-01-01

    The goal during my internship at the National Center for Critical Information Processing and Storage (NCCIPS) is to implement an anomaly detection method through the StruxureWare SCADA Power Monitoring system. The benefit of the anomaly detection mechanism is to provide the capability to detect and anticipate equipment degradation by monitoring power quality prior to equipment failure. First, a study is conducted that examines the existing techniques of power quality management. Based on these findings, and the capabilities of the existing SCADA resources, recommendations are presented for implementing effective anomaly detection. Since voltage, current, and total harmonic distortion demonstrate Gaussian distributions, effective set-points are computed using this model, while maintaining a low false positive count.

  2. Hysteresis Current Controller Based Grid Connected Wind Energy Conversion System for Permanent Magnet Synchronous Generator and Quasi Z-Source Inverter Using Power Quality Improvement

    Directory of Open Access Journals (Sweden)

    E.Rajendran

    2013-10-01

    Full Text Available Wind energy is a leader area of application for variable-speed generators operating on the constant grid frequency. This paper depicts the power quality enhancement in wind power system using permanent magnet synchronous generator (PMSG and Quasi Z-source Inverter. The PMSG is connected to the power network by means of a quasi z-source inverter (qZSI. The PMSG are used by these technologies due to extraordinary characteristics such as a smaller amount weight and volume, superior performance, eradicate the gear box and no need of peripheral power in permanent magnet excitation. The PMSG overcome the induction generator and other generators, because of their splendid performances without take up the grid power. But Induction Generator always needs the grid connectionfor getting power to start. In this paper the quasi Z-source inverter is a present that is a novel topology conjugated from the traditional Z source Inverter. The qZSI inherits all the advantages of the ZSI, that is performs buck-boost, inversion and power control in wind energy conversion system (WECS Moreover, the proposed qZSI the matchless advantages of less component ratings and stable dc current from the source. All over boost control methods are built for the ZSI can be used by the qZSI .This Paper presents hysteresis current control technique for the quasi Z- source inverter.

  3. Detection and Analysis of Power Quality Disturbances Based on LMD and TEO%基于LMD和TEO的电能质量扰动检测分析

    Institute of Scientific and Technical Information of China (English)

    周超; 黄纯

    2016-01-01

    分析了局部均值分解LMD(local mean decomposition)在扰动检测中时间定位不足的原因,提出了基于LMD和Teager能量算子TEO(Tteager energy operator)的电能质量扰动信号检测分析方法。该方法由LMD和Teager能量算子2部分组成。首先利用LMD将电压信号分解成若干个乘积函数PF(product function),再用Teager能量算子解调PF分量得到信号的瞬时幅值包络和瞬时频率。根据时频图频率突变点,可以有效地检测扰动发生的起止时刻。与LMD相比,所提出的方法具有频率、幅值检测准确,定位能力强,端部失真小等优点,能有效检测分析非平稳电能质量扰动信号。%The causes of the deficiencies of local mean decomposition(LMD)in the disturbance detection at the posi⁃tioning time is analyzed. An energy operator demodulating approach based on LMD is applied to the detection and analy⁃sis of power quality disturbance signal. The method consists of LMD and Teager energy operator(TEO). Firstly,voltage signal is decomposed into a number of product functions(PFs)by LMD,then TEO demodulates the PF components to get the instantaneous amplitude envelope and instantaneous frequency of the signal. According to the frequency muta⁃tion point of time-frequency diagram,the starting and ending time points of the disturbance can be effectively located. Compared with the LMD method,the proposed method has accurate detection results for magnitude and frequency of disturbance signal,strong positioning capability and less end distortion,showing that it can effectively detect the non-stationary power quality disturbance signals.

  4. 基于STFT变换和DAGSVMs的电能质量扰动识别%Power quality disturbances detection and identification based on STFT transform and DAGSVMs

    Institute of Scientific and Technical Information of China (English)

    覃思师; 刘前进

    2011-01-01

    The paper proposes a new method for power quality (PQ) disturbances detection and identification based on short time Fourier transform and directed acyclic graph support vector machines (DAGSVMs) . The time-domain maximum amplitude vector can be obtained by Blackman window short time Fourier transform of disturbance signals. Then the method makes it as the eigenvector and sets it to the DAGSVMs to realize the identification of the power quality disturbance type. Besides, the time-domain maximum amplitude vector not only can reflect the character of each disturbance, but also can show the starting and sustainable time of voltage swell, voltage sag, interruption and oscillatory transients. Simulation results show that the method could detect and classify the PQ disturbance effectively, and the classifier has a good performance on correct ratio, training speed and real-time function.%提出了一种基于短时傅里叶变换和DAG(Directed Acyclic Graph)支持向量机的电能质量扰动检测和识别方法.将扰动信号通过Blackman窗短时傅里叶变换,得出时域最大幅值向量,然后把它作为特征向量输入到DAG支持向量机来实现电能质量扰动类型的识别.其中,时域最大幅值向量不仅能反映各种扰动的特征,还能显示电压突升、电压暂降、电压中断和暂态振荡等扰动的发生时刻和持续时间.仿真测试表明,该方法能有效识别各种电能质量扰动,而且识别正确率高,训练时间短,实时性能较好.

  5. Power quality results in energy efficient aluminium smelter operation

    Energy Technology Data Exchange (ETDEWEB)

    Wiestner, Max

    2010-09-15

    New aluminium smelters consume up to 2400MW of electrical energy making the energy efficiency aspect most important. Power quality, optimised power conversion systems and well engineered power plant interfaces are essential for highest energy efficiency. An early optimisation of the power system design will reduce the capital investment cost for the power plant and smelter substation as well as results in most energy efficient aluminium production. This paper describes and intends to discuss the power quality improvement concepts and designs as well as energy cost reduction opportunities which a high power quality system can achieve.

  6. Power quality in high-tech campus: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Munoz, A.; Redel, M.; Gonzalez, M. [Universidad de Cordoba (Spain). Departamento de Electrotecnia y Electronica

    2006-07-01

    This paper presents preliminary results from a power-quality audit conducted at a high-tech campus over the last year. Voltage and current were measured at various R and D buildings; it was found that the main problems for the equipment installed were voltage sags and surges. The paper examines the causes and effects of power disturbances that affect computer or any other microprocessor-based equipment and analyses the auto-protection capabilities of modern power supplies. The convenience of 'enhanced power supply' or 'low-cost customer-side' protection solutions is also discussed. Finally, it addresses the role of the standards on the protection of electronic equipment and the implications for the final customer. (author)

  7. MiSmart - Power quality and monitoring system

    OpenAIRE

    PAHULJE, JAN

    2014-01-01

    In this thesis we describe an application for collecting and analyzing power quality data of electric distribution systems. The thesis is divided into three parts. We begin with a theoretical description of electric distribution networks and define power quality. We then describe the basics of quality monitoring systems and measuring devices, which are used to measure power quality in electric distribution network. The main contribution of this thesis is an implementation of MiSmart, a web pl...

  8. MiSmart - Power quality and monitoring system

    OpenAIRE

    Pahulje, Jan

    2014-01-01

    In this thesis we describe an application for collecting and analyzing power quality data of electric distribution systems. The thesis is divided into three parts. We begin with a theoretical description of electric distribution networks and define power quality. We then describe the basics of quality monitoring systems and measuring devices, which are used to measure power quality in electric distribution network. The main contribution of this thesis is an implementation of MiSmart, a web pl...

  9. A Solution of Power Quality Monitoring System Based on SOA%一种基于SOA架构的电能质量监测系统解决方案

    Institute of Scientific and Technical Information of China (English)

    丁泽俊; 向阳; 夏锐

    2012-01-01

    A pow e r quality monitoring system based on Service -Oriented Architecture (SOA), featuring a set of principles and methodologies for designing and developing software in the form of interoperable services, is presented in this paper. The method as described, using Java Message Service (JMS), not only can be seamlessly integrated with other systems deployed in the power system, such as EMS and MIS, but also can integrate the power quality systems deployed and to be deployed to achieve advanced power quality monitoring. Rather than the power quality data analysis for the single substation, the SOA -based power quality monitoring system can analyze the power quality data in the range of even a province. The experiments validate the effectiveness of the presented solution.%研究一种基于面向服务架构(Service-Oriented Architecture,SOA)的电能质量监测系统解决方案.该方案采用JMS(Java Message Service)技术,以服务提供方式将各模块解耦,既可无缝集成电力系统的调度自动化系统、生产管理等系统,也可集成已部署与将部署的电能质量监测系统.将各系统无缝集成后,综合各系统的功能和数据,还可完成电能质量分析与评估的高级应用.该方案的现场应用效果表明,基于SOA的电能质量监测系统不仅可以完成单个变电站的电能质量高级分析,还能扩展到片区、供电局甚至省(网)级的高级分析应用.

  10. Fast S Transform-Based Classification of Power Quality Disturbance%利用快速S变换的电能质量扰动识别方法

    Institute of Scientific and Technical Information of China (English)

    满蔚仕; 张志禹; 康青; 苗永康; 席晓莉

    2013-01-01

    针对当前基于S变换的电能质量方法计算开销大、不能实时识别电能质量扰动的问题,提出利用快速S变换与最小二乘支持向量机相结合的识别电能质量干扰新方法.该方法从快速S变换得到的一维向量中提取各频率段模系数的标准偏差、最大模系数及额定频率对应的模系数作为特征向量,利用最小二乘支持向量机对电压骤升、电压骤降、电压中断、暂态脉冲、暂态振荡、谐波等几种电能质量干扰进行分类和识别.研究结果表明:与传统的基于S变换的电能质量方法相比,该方法在2个方面节省了时间,一是减少了提取特征量所用的时间,二是由于特征向量数据较少,采用支持向量机样本训练时间减少;特剐是当电压扰动信号持续时间越长时节省效率越高,在同样准确性下,对于长度为1 024点的扰动信号,节省了约99%的时间;除此之外,该方法对信号分类的正确率可达98%,同时还具有较高的抗干扰能力.%Focusing on higher computation cost and lack of real-time detection for all techniques based on traditional S-transform to identify power quality disturbances,a real-time approach combining fast S-transform with least squares support vector machine is proposed.The standard deviation of module coefficients,maximum module coefficient of each frequency band,and module coefficient corresponding to the rated frequency are extracted from the one-dimensional vector of the fast S-transform of the original power quality signals as features,and the least squares support vector machine based on optimized parameters and the minimum output coding is used to classify and identify the voltage swell,voltage sag,voltage interruption,spike,transient oscillation and harmonic waves.Compared with the traditional approach based on S-transform,the proposed approach reduces the tasks in both extracting features and training of the support vector machine classifier due to

  11. A Remote Real-Time Monitoring System for Power Quality

    Institute of Scientific and Technical Information of China (English)

    黄治清; 贺建闽

    2003-01-01

    An introduction is made to the composition, design method and engineering application of a remote real-time monitoring system of power quality in substations based on internet. With virtual instrument and network technique adopted, this system is characterized by good real-time property, high reliability, plentiful functions, and so on. It also can be used to monitor the load of a substation, such as electric locomotives.

  12. Studying and simulating transformer configuration to improve power quality

    Directory of Open Access Journals (Sweden)

    Oscar J. Peña Huaringa

    2011-07-01

    Full Text Available This paper presents a study and simulation of transformer configurations to improve power quality; it provides theoretical support based on the expansion of the Fourier series and analysis of symmetrical components. A test system was set up in the laboratory, taking measurements and checking configuration effectiveness in reducing the system’s harmonic content. The configurations were modelled with PSCAD / EMTDC software, using two 6 pulse rectifiers as test loads and two variable speed drives.

  13. QUALITY EVALUATION OF THE TPP POWER GENERATING UNITS WEAR RECONDITIONING

    Directory of Open Access Journals (Sweden)

    E. M. Farhadzadeh

    2016-01-01

    not merely accounts for the information on alteration in the power generating unit emergency-switching standing time number and duration but also for the data of measurement and computation of technical-and-economic indexes. The technical-and-economic indexes variation analysis refinement allows significant rise in the repair work quality evaluation immediacy and in doing so reduces the costs associated with indistinct performance reliability and economical efficiency ranging of the power units based upon specified requirements.

  14. Evaluation of power quality performance based on rough set and evidence theory%粗糙集与证据理论结合的电网运行优质性综合评价

    Institute of Scientific and Technical Information of China (English)

    蒋亚坤; 李文云; 赵莹; 于峰

    2015-01-01

    电力系统运行的核心目标之一是提供优质电能,电力系统运行的优质性指标主要通过电能质量好坏来体现。为了能够客观、有效地评价电网运行优质性水平,提出一种粗糙集与证据理论结合的电网运行优质性综合评价方法。应用粗糙集理论建立决策强度和决策扩充规则,利用决策表获取证据理论的基本概率赋值,使概率赋值结果更具有客观性。再应用证据理论的融合规则将电压偏差、电压波动、三相不平衡、谐波畸变等优质性指标进行融合,得到各观测点电能质量的优劣状况,实现电网优质性综合评价。算例表明,该方法得到的优质性综合评价结果更客观合理,证明了方法的正确性和优越性。%One of the core objectives of power system operation is to provide high-quality energy, the quality indicators of power system operation are mainly reflected by power quality. In order to assess the power quality objectively and effectively, a comprehensive evaluation method of high-quality network operation based on rough set and evidence theory is proposed. The method applies rough set theory to define the decision-making strength and expansion rules and uses the decision-making table to obtain the basic probability assignment of evidence theory, which make the result of probability assignment more objective. And then by applying the fusion rules of evidence theory to integrate the various indicators of power quality, the pros and cons of ordering from each power quality evaluations can be obtained to achieve a comprehensive evaluation of power quality. The examples show that the results of power quality evaluation are more objective and rational by using this method. So it can prove the correctness and superiority of this method.

  15. RESOLVEMENT OF POWER QUALITY PROBLEMS BY UNIFIED POWER QUALITY CONDITIONER (UPQC)

    OpenAIRE

    Ms. Rohini. R. Dabhade*, Prof. C. Veeresh

    2016-01-01

    In this project presents a Design of a Unified Power Quality conditioner (UPQC) connected to three phase four wire system (3P4W). The neutral of series transformer used in the fourth wire for the 3P4W system. The neutral current that may flow toward transformer neutral point is compensated by using a four-leg voltage source inverter topology for shunt part. The series transformer neutral will be at virtual zero potential during all operating conditions. In this simulation we observe the power...

  16. The Detection and Identification of Transient Power Quality Based on Wavelet Transform%基于小波变换的暂态电能质量的检测与识别

    Institute of Scientific and Technical Information of China (English)

    潘从茂; 李凤婷

    2013-01-01

    The intermittent energy connected to the grid affects the operating characteristics of the power system and power quality, especially the impact of transient power quality should not be overlooked. This paper details Wavelet detection of transient power disturbances basic principle and method based on the wavelet transform which is applied to transient power quality disturbance detection and identification, combined with the example simulation study. Theoretical analysis and simulation results show that this method can achieve a voltage transient power quality disturbances fast, accurate detection, and be able to identify the disturbance type according to the energy function. Research ideas with intermittent energy access system for the detection and recognition of power quality provides an effective and feasible method.%间歇性能源接入电网影响电力系统的运行特性和电能质量,特别是对暂态电能质量的影响不容忽视。本文在详细介绍暂态电能扰动小波检测的基本原理和实现方法的基础上,将小波变换应用于暂态电能质量扰动检测和识别,结合算例进行了仿真研究。理论分析和仿真结果表明该方法能够实现对电压暂态电能质量扰动快速、准确的检测,并能够根据能量函数识别出扰动类型。研究思路可为检测识别含间歇性能源接入系统的电能质量提供一种有效、可行的方法。

  17. Improvement of Power Quality Using a Hybrid Interline UPQC

    Directory of Open Access Journals (Sweden)

    M.K.Elango

    2014-05-01

    Full Text Available This paper proposed the reduced rating star connected transformer based interline unified power quality conditioner. This work comprises of unified power quality conditioner connected between the two feeders, star connected transformer and LC filter. This hybrid approach significantly improves the performance of UPQC under unbalance source voltage condition. The UPQC adopted to compensate current and voltage-quality problems of sensitive loads and suppressing the load current harmonics under distorted supply conditions. The series converter control strategy is based on the fuzzy-logic controller. The extensive simulation results have carried out in MATLAB/Simulink environment power system blockset toolboxes. From the results it has shown that hybrid interline UPQC achieves superior capability of mitigating the effects of voltage sag/swell and suppressing the load current harmonics, phase current harmonics and neutral current under distorted supply conditions. To validate the results produced by the proposed method, it is compared with the conventional UPQC method and better results obtained from the hybrid approach.

  18. Active power line conditioners design, simulation and implementation for improving power quality

    CERN Document Server

    Revuelta, Patricio Salmeron; Litrán, Salvador Pérez

    2015-01-01

    Active Power Line Conditioners: Design, Simulation and Implementation for Improving Power Quality presents a rigorous theoretical and practical approach to active power line conditioners, one of the subjects of most interest in the field of power quality. Its broad approach offers a journey that will allow power engineering professionals, researchers, and graduate students to learn more about the latest landmarks on the different APLC configurations for load active compensation. By introducing the issues and equipment needs that arise when correcting the lack of power quality in power grids

  19. Unified Power Quality Conditioner for voltage and current compensation

    OpenAIRE

    P.Annapandi; Dr.M.Rajaram

    2012-01-01

    This paper deals with a Unified Power Quality Conditioner (UPQC) for load balancing, power factorcorrection, voltage regulation, voltage and current harmonics mitigation, mitigation of voltage sag, swelland voltage dip in a three-phase three-wire distribution system for different combinations of linear and nonlinear loads.The unified power quality conditioner (UPQC) is a combination of back to back connected shunt and series active power filters (APFs) to a common DC link voltage, which compe...

  20. Integrating Photovoltaic Systems in Power System: Power Quality Impacts and Optimal Planning Challenges

    Directory of Open Access Journals (Sweden)

    Aida Fazliana Abdul Kadir

    2014-01-01

    Full Text Available This paper is an overview of some of the main issues in photovoltaic based distributed generation (PVDG. A discussion of the harmonic distortion produced by PVDG units is presented. The maximum permissible penetration level of PVDG in distribution system is also considered. The general procedures of optimal planning for PVDG placement and sizing are also explained in this paper. The result of this review shows that there are different challenges for integrating PVDG in the power systems. One of these challenges is integrated system reliability whereas the amount of power produced by renewable energy source is consistent. Thus, the high penetration of PVDG into grid can decrease the reliability of the power system network. On the other hand, power quality is considered one of the challenges of PVDG whereas the high penetration of PVDGs can lead to more harmonic propagation into the power system network. In addition to that, voltage fluctuation of the integrated PVDG and reverse power flow are two important challenges to this technology. Finally, protection of power system with integrated PVDG is one of the most critical challenges to this technology as the current protection schemes are designed for unidirectional not bidirectional power flow pattern.

  1. 基于FPGA的暂态电能质量的检测方法%Detection method of the FPGA-based transient power quality

    Institute of Scientific and Technical Information of China (English)

    房国志; 王猛; 王康

    2012-01-01

    提出了基于FPGA实现小波变换算法的一种方法.该方法以硬逻辑方式,采用高通分解滤波器和低通分解滤波器来实现小波变换算法,解决了采用小波变换方法进行多分辨分析时由于计算量大限制了在实时监测系统中应用的实时性问题.以在检测信号奇异点上有很好效果的DB5小波为基函数,对在暂态电能质量中电压暂升/暂降、电压中断、电压脉冲、振荡等信号建立模拟扰动信号源并进行了仿真,对比信号奇异点产生时间和仿真结果中奇异点产生时间,结果表明该方法的准确性和可行性.%This paper proposes a method of realizing wavelet transform algorithm, which is based on FPGA. This method realizes wavelet transform algorithm by using hard logic, and adopting high pass decomposition filter and low pass decomposition filter. The enormous computation of multi-resolution analysis limits the real-time of signal processing; the method solves the real-time problems in real-time monitoring system. And because of DB5 wavelet has good effect at detecting signal singularities; it is taken as basis function. Simulations experiment in the transient power quality is done by setting up disturbance signal sources such as voltage swell/sag, voltage interruption, voltage pulse, oscillation signal, etc. The starting time of signal singularities and the starting time of signal singularities in the simulation results are compared. The results of simulation show that the method is accurate and feasible.

  2. Various power quality challenges and solution techniques using FACTS technology for power system

    Science.gov (United States)

    Soni, J. Sandeep; Jangalwa, N. K.; Gupta, R.; Palwalia, D. K.

    2016-03-01

    This paper presents a comprehensive review on the various power quality problems and various solution techniques using FACTS in Power system. The term "Power Quality" is a broad concept and its meaning is taken different by different peoples. It is associated with electrical transmission, distribution and utilization systems those are having experience of any Voltage, current or frequency divergence from normal operation. Due to power quality problems industries have to invest large amount for mitigation of Voltage sags, distortions, harmonics and short term interruptions/disturbances etc. In paper authors tried to cover various possible sources and compensation methods of reactive power in power system.

  3. 基于本体和云模型的电能质量信息状态监测平台%Power quality information status monitoring platform based on ontology and cloud model

    Institute of Scientific and Technical Information of China (English)

    陈国伟; 刘景远; 滕海刚; 刘长树; 吴兰旭

    2015-01-01

    提出了一种适用于智能电网的电能质量信息状态监测平台.将本体技术引入到该平台建设中,建立了电能质量信息状态监测领域的领域本体,借助该领域本体可以实现电能质量信息的快速检索.建立的电能质量信息状态监测检索引擎可以在领域本体的指导下从电能质量数据库中提取出符合条件的数据集合,再将定制处理后的检索结果返回给用户.平台引入了云模型技术,基于云模型完成对电能质量信息的诊断,以实现电能质量信息的状态诊断和实时监测.实例展示介绍了平台的操作界面和具体实现界面,可见该平台具有一定的工程实用价值.%This paper puts forward a power quality information condition monitoring platform suitable for smart grid. It introduces the ontology technology into the construction of the platform and sets up domain ontology in the field of power quality condition monitoring. With the aid of the domain ontology, it can realize fast power quality information retrieval. The power quality information condition monitoring retrieval engine established under the guidance of domain ontology can extract eligible data set from the power quality database, and then return the result to the user. The platform introduces the technology of cloud model to complete the diagnosis of power quality information, in order to realize condition diagnosis and real-time monitoring of power quality information based on cloud model. Examples exhibition introduces the operation interface of the platform and implementation interface, and it can be found the platform has a certain engineering practicability.

  4. 基于改进变权物元可拓模型的电能质量综合评价%Comprehensive Evaluation on Power Quality Based on Improved Matter-Element Extension Model With Variable Weight

    Institute of Scientific and Technical Information of China (English)

    李泓泽; 郭森; 唐辉; 李春杰

    2013-01-01

    对电能质量进行综合评价是电能按质论价和评估点考核奖惩决定的主要依据之一.提出了改进变权物元可拓模型的电能质量综合评价模型,该模型对物元可拓模型的经典域和待评物元以及最大隶属度准则进行了改进,以克服其在电能质量综合评价中的局限性和不足之处;同时,运用变权理论确定了各评级指标的权重,减少了电能质量评价时的主观因素以及体现了评价对象在综合评价中的主动参与.以某110 kV变电站母线实测数据为例,评价结果显示其电能质量等级为合格,但偏向于不合格等级的程度较大.算例结果表明了该模型用于电能质量综合评价的有效性.%As for the pricing by electrical energy quality and the decision of rewards and penalties based on the examination at assessment point,Comprehensive evaluation on power quality is one of the principal foundations.A comprehensive power quality evaluation model based on improved matter-element extension model with variable weight,in which the classical domain of matter-element extension model and the maximum membership criterion are improved to remedy its boundedness and defects in the evaluation of power quality,is proposed.Meanwhile,applying variable weight theory the weights of all rating indices are determined to reduce the influence of subjective factors during the power quality evaluation and incarnate the active participation of evaluated objects during the comprehensive evaluation.Taking measured data form busbar of a certain 1 10kV for example,the evaluation result shows that the grade of power quality is qualified but far from being satisfied.Case study shows that the proposed model is effective for comprehensive evaluation of power quality.

  5. Journal of EEA, Vol. 31, 2014 10 POWER QUALITY ASSESSMENT ...

    African Journals Online (AJOL)

    POWER QUALITY ASSESSMENT AND MITIGATION AT WALYA-STEEL. INDUSTRIES AND ETHIO-PLASTIC SHARE COMPANY. Mengesha Mamo and .... Furthermore, the increase in total current, as the result of harmonics .... Resistance of LF (Ω). 0.03. 0.0262 .... Strategic approach to system Power Quality problem status ...

  6. Power Quality Issues and It’s Mitigation Techniques Tejashree

    Directory of Open Access Journals (Sweden)

    G. More

    2014-07-01

    Full Text Available In this paper the main power quality (PQ problems are presented with there associated causes and consequences. The economic impact associated with PQ are characterized. Also this paper tries to give the solution for reducing the losses produced because of harmonics and increasing the quality of power at consumers’ side.

  7. Power quality analyzer device modeling by real time SIMULINK MATLAB

    Energy Technology Data Exchange (ETDEWEB)

    Martins, C.H.N.; Silva, L.R.M.; Fabri, D.F.; Duque, C.A. [Federal University of Juiz de Fora (UFJF), MG (Brazil)], Emails: chnmartins@yahoo.com.br, leandro.manso@engenharia.ufjf.br, Diego.fabri@engenharia.ufjf.br, Carlos.duque@ufjf.br; Ribeiro, P.F. [Calvin College, Grand Rapids, MI (United States)], E-mail: pfribeiro@ieee.org

    2009-07-01

    The expansion of electronic devices have increased non linear loads. The effect is high levels of electric disturbances and EMC and EMI interferences. The control of power quality parameters are of primordial importance to ensure minimal power quality. This paper deals with the modeling, simulation and development of a device capable of measuring electrical events. (author)

  8. Power quality and integration of wind farms in weak grids in India

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, P.; Hauge Madsen, P. [Risoe National Lab., Roskilde (Denmark). Wind Energy and Atmospheric Physics Dept.; Vikkelsoe, A.; Koelbaek Jensen, K. [Danske Elvaerkers Forening Udredningsafdelingen (DEFU), Lyngby (Denmark); Fathima, K.A.; Unnikrishnan, A.K.

    2000-04-01

    This is the final report of a joint Danish and Indian project' Power Quality and Integration of Wind Farms in Weak Grids'. The power quality issues have been studied and analysed with the Indian conditions as a case. On the basis of meetings with Danish wind turbine industry, Indian electricity boards, nodal agencies, wind turbine industry and authorities, the critical power quality as-pects in India have been identified. Measurements on selected wind farms and wind turbines have quantified the power quality, and analyses of power quality issues, especially reactive power compensation, have been performed. Based on measurements and analyses, preliminary recommendations for grid integration of wind turbines in weak grids have been formulated. (au)

  9. Power quality improvement in switched mode power supplies using ...

    African Journals Online (AJOL)

    user

    A SEPIC stores the energy in an inductor, and transfers that energy to the output storage capacitor. ..... 2011–2017. ... His areas of interest include power electronics, electrical machines and drives, renewable energy systems, active filters, ...

  10. Monitoring and analyzing features of electrical power quality system performance

    Directory of Open Access Journals (Sweden)

    Genci Sharko

    2010-06-01

    Full Text Available Power quality is a set of boundaries that allows electrical systems to function in their intended manner without significant loss of performance or life. The term is used to describe electric power that drives an electrical load and the load's ability to function properly with that electric power. Without the proper quality of the power, an electrical device may malfunction, fail prematurely or not operate at all. There are many reasons why the electric power can be of poor quality and many more causes of such poor quality power. Power quality of power systems, which affects all connected electrical and electronic equipment, is a measure of deviations in voltages, currents, frequency, temperatures, winding forces and torques of particular supply systems and their components. In recent years, a considerable increase in nonlinear loads has been experienced; in particular distributed loads, such as computers, monitors and lighting, and distributed sources. The aim of this paper is to display a way of monitoring and analyzing features of electrical power quality system. As a monitoring example is taken output from power transformer rated at 320 kVA, part of distribution grid of Durres City in Albania.

  11. Non Linear Analysis of MPPT for Power Quality Improvement

    Directory of Open Access Journals (Sweden)

    S. Sankar

    2015-08-01

    Full Text Available In this study the conventional inverter interfacing renewable energy sources with the grid, without any additional hardware cost. Here, the main idea is the maximum utilization of inverter rating which is most of the time underutilized due to intermittent nature of RES. Based on the non-linear characteristics of PV, these thesis designs a VSS controller to realize the maximum power output of PV arrays. The output power from renewable energy sources fluctuates because of weather variations. This study proposes an effective power quality control strategy of renewable energy sources connected to power system using Photovoltaic (PV array. If the main controller used is a PR controller, any dc offset in a control loop will propagate through the system and the inverter terminal voltage will have a nonzero average value. In this strategy both load and inverter current sensing is required to compensate the load current harmonics. The non-linear load current harmonics may result in voltage harmonics and can create a serious PQ problem in the power system network.

  12. Standards for measurements and testing of wind turbine power quality

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, P. [Risoe National Lab., Roskilde (Denmark); Gerdes, G.; Klosse, R.; Santjer, F. [DEWI, Wilhelmshaven (Germany); Robertson, N.; Davy, W. [NEL, Glasgow (United Kingdom); Koulouvari, M.; Morfiadakis, E. [CRES, Pikermi (Greece); Larsson, Aa. [Chalmers Univ. of Technology, Goeteborg (Sweden)

    1999-03-01

    The present paper describes the work done in power quality sub-task of the project `European Wind Turbine Testing Procedure Developments` funded by the EU SMT program. The objective of the power quality sub-task has been to make analyses and new recommendation(s) for the standardisation of measurement and verification of wind turbine power quality. The work has been organised in three major activities. The first activity has been to propose measurement procedures and to verify existing and new measurement procedures. This activity has also involved a comparison of the measurements and data processing of the participating partners. The second activity has been to investigate the influence of terrain, grid properties and wind farm summation on the power quality of wind turbines with constant rotor speed. The third activity has been to investigate the influence of terrain, grid properties and wind farm summation on the power quality of wind turbines with variable rotor speed. (au)

  13. Power quality improvement of unbalanced power system with distributed generation units

    DEFF Research Database (Denmark)

    Hu, Y.; Chen, Zhe; Excell, P.

    2011-01-01

    This paper presents a power electronic system for improving the power quality of the unbalanced distributed generation units in three-phase four-wire system. In the system, small renewable power generation units, such as small PV generator, small wind turbines may be configured as single phase...... generation units. The random nature of renewable power sources may result in significant unbalance in the power network and affect the power quality. An electronic converter system is proposed to correct the system unbalance and harmonics so as to deal with the power quality problems. The operation...... and control of the converter are described. Simulation results have demonstrated that the system can effectively correct the unbalance and enhance the system power quality....

  14. "Power quality system," a new system of quality management for globalization: towards innovation and competitive advantages.

    Science.gov (United States)

    Abdul-Rahman, H; Berawi, M A

    Knowledge Management (KM) addresses the critical issues of organizational adoption, survival and competence in the face of an increasingly changing environment. KM embodies organizational processes that seek a synergistic combination of the data and information processing capabilities of information and communication technologies (ICT), and the creative and innovative capacity of human beings to improve ICT In that role, knowledge management will improve quality management and avoid or minimize losses and weakness that usually come from poor performance as well as increase the competitive level of the company and its ability to survive in the global marketplace. To achieve quality, all parties including the clients, company consultants, contractors, entrepreneurs, suppliers, and the governing bodies (i.e., all involved stake-holders) need to collaborate and commit to achieving quality. The design based organizations in major business and construction companies have to be quality driven to support healthy growth in today's competitive market. In the march towards vision 2020 and globalization (i.e., the one world community) of many companies, their design based organizations need to have superior quality management and knowledge management to anticipate changes. The implementation of a quality system such as the ISO 9000 Standards, Total Quality Management, or Quality Function Deployment (QFD) focuses the company's resources towards achieving faster and better results in the global market with less cost. To anticipate the needs of the marketplace and clients as the world and technology change, a new system, which we call Power Quality System (PQS), has been designed. PQS is a combination of information and communication technologies (ICT) and the creative and innovative capacity of human beings to meet the challenges of the new world business and to develop high quality products.

  15. Cost based reactive power participation for voltage control in multi units based isolated hybrid power system

    Directory of Open Access Journals (Sweden)

    Nitin Kumar Saxena

    2016-12-01

    Full Text Available Multi units of wind and diesel based generators in isolated hybrid power system have technical and operational advantages over single units system. They require dynamic reactive power compensation for fast recovery of voltage under load and input changes. In developing countries like India, investors’ prime concern is to provide continuous electricity at low rate while quality degradation can be permitted within pre defined acceptable range. The use of static compensator along with dynamic compensator may give cost effective reactive power participation for system. This paper presented pricing of reactive power compensation under steady state and transient conditions of system with fixed capacitor and STATCOM. The main contributions of the paper are; (i evaluating reactive power balance equation for generalized multi units of wind and diesel based isolated hybrid power system, (ii reactive power compensation using fixed capacitor and STATCOM in presence of composite load model, (ii fast recovery of voltage response using genetic algorithm based tuning of STATCOM controller, (iii evaluation of reactive power compensation cost for steady and dynamic conditions due to probabilistic change in load and/or input demand and (iv comparison of results with existing reference compensation method.

  16. Radio link quality estimation in low-power wireless networks

    CERN Document Server

    2013-01-01

    This book provides a comprehensive survey on related work for radio link quality estimation, which covers the characteristics of low-power links, the fundamental concepts of link quality estimation in wireless sensor networks, a taxonomy of existing link quality estimators and their performance analysis. It then shows how link quality estimation can be used for designing protocols and mechanisms such as routing and hand-off. The final part is dedicated to radio interference estimation, generation and mitigation.

  17. Standby-battery autonomy versus power quality

    Science.gov (United States)

    Bitterlin, Ian F.

    Batteries are used in a wide variety of applications as an energy store to bridge gaps in the primary source of supplied power for a given period of time. In some cases this bridging time, the battery's "autonomy", is fixed by local legislation but it is also often set by historically common practices. However, even if common practice dictates a long autonomy time, we are entering a new era of "cost and benefit realism" underpinned by environmentally friendly policies and we should challenge these historical practices at every opportunity if it can lead to resource and cost savings. In some cases the application engineer has no choice in the design autonomy; either follow a piece of local legislation (e.g. 4 h autonomy for a "life safety" application), or actually work out what is needed! An example of the latter would be for a remote site, off-grid, using integrated wind/solar power (without emergency generator back-up) where you may have to design-in several days' battery autonomy. This short paper proposes that a battery's autonomy should be related to the time expected for the system to be without the primary power source, balanced by the capital costs and commercial risk of power failure. To discuss this we shall consider the factors in selecting the autonomy time and other related aspects for high voltage battery systems used in facility-wide uninterruptible power supply (UPS) systems.

  18. Wind energy systems solutions for power quality and stabilization

    CERN Document Server

    Ali, Mohd Hasan

    2012-01-01

    Unlike conventional power plants, wind plants emit no air pollutants or greenhouse gases--and wind energy is a free, renewable resource. However, the induction machines commonly used as wind generators have stability problems similar to the transient stability of synchronous machines. To minimize power, frequency, and voltage fluctuations caused by network faults or random wind speed variations, control mechanisms are necessary. Wind Energy Systems: Solutions for Power Quality and Stabilization clearly explains how to solve stability and power quality issues of wind generator systems. Covering

  19. Optimal Design of TCR/FC in Electric Arc Furnaces for Power Quality Improvement in Power Systems

    Directory of Open Access Journals (Sweden)

    Mahdi TORABIAN ESFAHANI

    2009-12-01

    Full Text Available Electric Arc Furnaces (EAFs are unbalanced, nonlinear and time varying loads, which can cause many problems in the power system quality. As the use of arc furnace loads increases in industry, the importance of the power quality problems also increase. So in order to optimize the usages of electric power in EAFs, it is necessary to minimize the effects of arc furnace loads on power quality in power systems as much as possible. Therefore, in this paper, design and simulation of an electric plant supplying an arc furnace is considered. For this purpose, a three phase arc furnace model, which can simulate all the mentioned power quality indices, is developed based on Hyperbolic -Exponential model (V-I model. Then by considering the high changes of reactive power and voltage flicker of nonlinear furnace load, a thyristor controlled reactor compensation with fixed capacitor (TCR/FC are designed and simulated. In this procedure, the reactive power is measured so that maximum speed and accuracy are achieved. Finally, simulation results verify the accuracy of the load modelling and show the effectiveness of the proposed TCR/FC model for reactive compensating of the EAF.

  20. Adaptive power quality signal de-noising based on double-density discrete wavelet transform%双密度小波变换的自适应电能质量信号去噪

    Institute of Scientific and Technical Information of China (English)

    曹世超; 张国勋

    2012-01-01

    为改善电能质量信号的去噪效果,提出一种基于双密度小波变换的自适应电能质量信号去噪算法.双密度小波变换具有近似的平移不变性,能更准确地描述信号的真实特征.而双变量收缩函数充分考虑小波系数的层内层间关系,对小波系数采用结合局部方差估计的双变量收缩函数进行去噪处理,并用收缩后的小波系数重构信号.实验结果表明:该算法在有效滤除噪声的同时,能够更好地保留电能质量信号的特征信息,使去噪信号的视觉信息有较大改善.%In order to improve the quality of the de-noised power quality signal, an efficient adaptive power quality signal de-noising algorithm based on the Double-Density Discrete Wavelet Transform(DD DWT) is proposed. DD DWT has approximately shift invariance and can accurately describe the real characteristics of signals. Meanwhile, the Bivariate Shrinkage Function (BSF) considers the relationship of the inter-level and intra-level coefficients. So, BSF with local variance estimation is adopted to processing wavelet coefficients. Then the signals are synthesized using the wavelet coefficients processed. The experimental results indicate that, the proposed algorithm can remove the noise more efficiently and keep original power quality signal characters, and that the visual quality of the denoised signal is improved.

  1. Power Quality Improvement And Mitigation Of Voltage Sag And Current Swell Using Distributed Power Flow Controller

    Directory of Open Access Journals (Sweden)

    P.NIRMALA

    2014-09-01

    Full Text Available Modern power utilities have to respond to a number of challenges such as growth of electricity demand specially in non-linear loads in power grids, consequently, That higher power quality should be considered. In this paper, DPFC which is similar to unified power flow controller (UPFC in structure, which is used to mitigate the voltage sag and swell as a power quality issue. Unlike UPFC, the common dc-link in DPFC, between the shunt and series converter devices should be eliminated and three-phase series converter is divided to several single-phase series distributed converters through the power transmission line. And also to detect the voltage sags and find out the three single-phase reference voltages of DPFC, the synchronous reference frame method is proposed. Application of DPFC in power quality enhancement is simulated in Mat lab/Simulink environment which show the effectiveness of the proposed structure

  2. Rapid algorithm prototyping and implementation for power quality measurement

    Science.gov (United States)

    Kołek, Krzysztof; Piątek, Krzysztof

    2015-12-01

    This article presents a Model-Based Design (MBD) approach to rapidly implement power quality (PQ) metering algorithms. Power supply quality is a very important aspect of modern power systems and will become even more important in future smart grids. In this case, maintaining the PQ parameters at the desired level will require efficient implementation methods of the metering algorithms. Currently, the development of new, advanced PQ metering algorithms requires new hardware with adequate computational capability and time intensive, cost-ineffective manual implementations. An alternative, considered here, is an MBD approach. The MBD approach focuses on the modelling and validation of the model by simulation, which is well-supported by a Computer-Aided Engineering (CAE) packages. This paper presents two algorithms utilized in modern PQ meters: a phase-locked loop based on an Enhanced Phase Locked Loop (EPLL), and the flicker measurement according to the IEC 61000-4-15 standard. The algorithms were chosen because of their complexity and non-trivial development. They were first modelled in the MATLAB/Simulink package, then tested and validated in a simulation environment. The models, in the form of Simulink diagrams, were next used to automatically generate C code. The code was compiled and executed in real-time on the Zynq Xilinx platform that combines a reconfigurable Field Programmable Gate Array (FPGA) with a dual-core processor. The MBD development of PQ algorithms, automatic code generation, and compilation form a rapid algorithm prototyping and implementation path for PQ measurements. The main advantage of this approach is the ability to focus on the design, validation, and testing stages while skipping over implementation issues. The code generation process renders production-ready code that can be easily used on the target hardware. This is especially important when standards for PQ measurement are in constant development, and the PQ issues in emerging smart

  3. Power Quality Application of Hybrid Drivetrain

    OpenAIRE

    Rassõlkin, Anton; Hõimoja, Hardi

    2012-01-01

    This paper presents a study on the power conditioning features of hybrid powertrain, especially regarding diesel-electric locomotives. Equipped with an embarked energy buffer for diesel generator support and utility grid interface, such a locomotive can be considered as a plug-in series hybrid vehicle. The driveline inductive components, like generator and motor windings, and capacitive components like dc link capacitors can be used to provide STATCOM functions, and the energy buffer can be u...

  4. AC Power Routing System in Home Based on Demand and Supply Utilizing Distributed Power Sources

    Directory of Open Access Journals (Sweden)

    Takashi Hikihara

    2011-04-01

    Full Text Available To help reduce consumption of fossil fuels, renewable, natural and distributed power sources are being adopted. These alternative energy sources inevitably show fluctuations in the amount of output power, frequency, and voltage. The suppression of such fluctuations is a key issue to avoid disturbances in power grids. A similar situation arises as far as the regulation of in-home power flow is concerned. We focus on the quality of supplied and demanded power in particular. In this paper, an in-home power distribution system based on information of power is proposed. The system is developed in order to integrate power dispatch and communication. The experimental results show the feasibility of new flexible and efficient power management approaches.

  5. A power beaming based infrastructure for space power

    Energy Technology Data Exchange (ETDEWEB)

    Bamberger, J.A.

    1991-08-01

    At present all space mission power requirements are met by integral, on-board, self-contained power systems. To provide needed flexibility for space exploration and colonization, an additional approach to on-board, self-contained power systems is needed. Power beaming, an alternative approach to providing power, has the potential to provide increased mission flexibility while reducing total mass launched into space. Laser-power beaming technology provides a viable power and communication infrastructure that can be developed sequentially as it is applied to power satellite constellations in Earth orbit and to orbital transport vehicles transferring satellites and cargos to geosynchronous orbit and beyond. Coupled with nuclear electric propulsion systems for cargo transport, the technology can be used to provide global power to the Lunar surface and to Mars' surface and moons. The technology can be developed sequentially as advances in power system and propulsion system technology occur. This paper presents stepwise development of an infrastructure based on power beaming that can support the space development and exploration goals of the Space Exploration Initiative. Power scenarios based on commonality of power systems hardware with cargo transport vehicles are described. Advantages of this infrastructure are described. 12 refs., 4 figs., 1 tab.

  6. 基于光伏并网的电能质量控制系统%A Power Quality Control System Based on Grid-Connected Photovoltaic Power Generation

    Institute of Scientific and Technical Information of China (English)

    王晓; 罗安; 邓才波; 帅智康; 孙运宾; 肖萍

    2012-01-01

    Considering the features of microgrid with grid-connected photovoltaic (PV) generation, a PV grid-connecting and power quality control system that not only can implement grid-connection of PV generation but also can implement reactive power compensation and filter harmonic currents is proposed. Firstly, the architecture and principle of the proposed system are presented and its mathematical model is built; then a dead-bead compound control strategy suitable to the proposed system is put forward, and theoretical calculation of pulse width modulation under the proposed control strategy is emphatically analyzed and the method to acquire compound instruction is given; finally, the simulation model and experimental platform for the proposed system are constructed and a concrete scheme to implement the proposed system is given. Operational data shows that the architecture and control strategy for the proposed system are effective and reasonable.%结合微网光伏并网系统和电能质量调节器的特点,提出了一种既能够并网发电,又能实现无功补偿和滤除电网谐波电流的光伏并网及电能质量控制系统(micro photovoltaic grid and power quality control system,MPG—PQC)结构。首先介绍了该系统的结构和原理,构建了该系统的数学模型;然后提出了适用于该系统的无差拍复合控制策略,重点分析了该控制策略下调制脉宽的理论计算,给出了复合指令的求取方法;最后,搭建了仿真模型和实验平台,给出了该系统的具体实现方案。运行数据表明了系统结构和控制策略的有效性和合理性。

  7. 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.

  8. Distributed Energy Resources, Power Quality and Reliability - Background

    Energy Technology Data Exchange (ETDEWEB)

    Schienbein, Lawrence A.; DeSteese, John G.

    2002-01-31

    Power quality [PQ] and power reliability [PR] gained importance in the industrialized world as the pace of installation of sensitive appliances and other electrical loads by utility customers accelerated, beginning in the mid 1980s. Utility-grid-connected customers rapidly discovered that this equipment was increasingly sensitive to various abnormalities in the electricity supply.

  9. Modeling of EVCS Power Quality IED Based on IEC61850 Standard%基于IEC61850标准的电动汽车充电站电能质量IED建模

    Institute of Scientific and Technical Information of China (English)

    郭少丰; 吕玉祥; 孙斌; 王金浩

    2014-01-01

    With the development of electric vehicle and the construction and the application of the large-scale Elec-tric Vehicle Charging Station ( EVCS ) , it’s becoming a gradually increasingly significant influence on the power quality of the smart grids for charging station’s heavy loaded charge and discharge. Based on the standard IEC61850,especially facing the methods and features of object-oriented modeling,combined with the technology of power quality monitoring devices of EVCS,this paper analysed the content of the standard IEC61850 applicable to EVCS,proposed new requirements of functional modules of power quality monitoring IED for EVCS,and built a new information model up to the IEC61850 standard. It guaranteed the information transmission of power quality monito-ring IED from EVCS in the smart grid is free,and provided necessary technical support for grasping the influence on the power quality of grids caused by the EVCS.%随着电动汽车的发展和大型电动汽车充电站的建设与应用,充电站大负荷充放电过程对智能电网电能质量的影响日益明显。基于IEC61850标准,特别是面向对象建模的方法与特点,并结合电动汽车充电站电能质量监测装置,分析了IEC61850标准中适用于电动汽车充电站的内容,提出了电动汽车充电站电能质量监测 IED 新的功能要求,建立了符合IEC61850标准的新模型,保证了在智能电网中电动汽车充电站电能质量监测IED信息的自由传输,为掌控电动汽车充电站对电网电能质量的影响提供了必要的技术支持。

  10. Research on Power Quality Monitoring System and Its Data Storage Format Based on LabVIEW%基于LabVIEW的电能质量监测系统及其数据存储格式的研究*

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      利用虚拟仪器技术,通过软硬件结合,设计了基于LabVIEW的电能质量监测系统。阐述了硬件设计方案,并重点讨论了电能质量稳态指标的分析方法,系统实现了对电能质量指标实时测量和分析、数据库存储和格式转换等功能。为了克服监测网中多数据源给电能质量数据统一管理分析带来的不便,系统采用IEEE推荐的PQDIF格式存储数据,详细介绍了LabVIEW软件生成PQDIF文件的方法。实验测试表明系统满足电网监测的需求,同时具备电网监测标准化和智能化的特点。%A power quality monitoring system based on LabVIEW is designed by using the technique of virtual instrument through the combination of hardware and software. This paper mainly discusses the hardware designing proposal and the analytical methods of steady index for power quality. It realizes the functions of real-time measurement and analysis, data storage and convertion and waveform saving. In order to overcome multi-data sources, generated by different monitor equipments of power quality monitor network, to cause inconvenience to unified management and analysis of power quality data, the system adopts the storage data in PQDIF recommended by IEEE. A detailed specification of PQDIF file and its implementing method based on LabVIEW are presented. The experiment results show that the system can satisfy the requirement of power monitoring with the characteristic of standardization and intelligent.

  11. Design of Energy Storage Control Strategy to Improve the PV System Power Quality

    DEFF Research Database (Denmark)

    Lei, Mingyu; Yang, Zilong; Wang, Yibo

    2016-01-01

    Random fluctuation of PV power is becoming a more and more serious problem affecting the power quality and stability of grid as the PV penetration keeps increasing recent years. Aiming at this problem, this paper proposed a control strategy of energy storage system based on Model Predictive Control...

  12. Muscle power is an independent determinant of pain and quality of life in knee osteoarthritis

    Science.gov (United States)

    OBJECTIVE: This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. METHODS: Baseli...

  13. Combined Power Quality Disturbances Recognition Using Wavelet Packet Entropies and S-Transform

    OpenAIRE

    Zhigang Liu; Yan Cui; Wenhui Li

    2015-01-01

    Aiming at the combined power quality +disturbance recognition, an automated recognition method based on wavelet packet entropy (WPE) and modified incomplete S-transform (MIST) is proposed in this paper. By combining wavelet packet Tsallis singular entropy, energy entropy and MIST, a 13-dimension vector of different power quality (PQ) disturbances including single disturbances and combined disturbances is extracted. Then, a ruled decision tree is designed to recognize the combined disturbance...

  14. A METHOD FOR QUALITY POWER PROVIDER TO OPERATE IN DISTORTED SUPPLY CONDITION

    Directory of Open Access Journals (Sweden)

    K.CHANDRASEKARAN

    2011-08-01

    Full Text Available Power Quality is a major concern within power industry and consumers. Poor quality of supply will affect the performance of customer equipment such as computers, microprocessors, adjustable speed drives, power electronic controllers, life saving equipment in hospitals, etc. and result in heavy financial losses to customers due to loss of production or breakdown in industries or loss of life in a hospital. The two major power quality disturbances are voltage sag and harmonic distortion. In this paper, a Quality Power Provider (QPP based on voltage source inverter is modeled by simulation to compensate the power quality disturbances such as voltage sag and voltage harmonics in the distorted supply condition. The phase locked loop (PLL is an important control unit of the QPP control scheme. To obtain accurate phase information and frequency of the input supply, the dqPLL method has been proposed. Simulation results based on MATLAB and PSCAD software are presented to verify the performance of the proposed QPP. QPP has improved the quality of power supply at the sensitive load end.

  15. Ontology-based intelligent retrieval model for power quality monitoring information%基于本体的电能质量监测信息智能检索模型

    Institute of Scientific and Technical Information of China (English)

    谢康; 杨洪耕; 黄静; 张逸

    2013-01-01

    针对目前国内外电能质量监测系统普遍采用基于目录查询的传统检索方式,难以满足用户快速、高效、个性化的从海量监测数据中检索有用信息来从不同侧面评估电能质量,检索结果也难以反映电能质量各指标间相互影响的问题,提出了一种基于本体的电能质量监测信息智能检索模型的设计思路;探讨了该智能检索模型的本体关系及构建方法、体系结构和检索流程,并以模糊综合评估方法为例,说明了本智能检索模型的实现过程与关键步骤.该文所提出的智能检索模型设计思路对实际电能质量监测信息智能检索系统的实现具有一定的指导意义和工程实用价值.%At present, most of PQMSs use directory-query-based retrieval methods, and it is unable to meet user's requirements to retrieve information efficiently from the massive monitoring data which is used to evaluate power quality ( PQ ) by different sides. Moreover, the retrieval results also fail to reflect the mutual influence between PQ indexes. To solve these problems effectively, a model named Intelligent Retrieval Model for Power Quality Monitoring Information (IRMPQMI) is proposed; and the concept of designing of the model, ontology relation model and construction method, architecture and retrieval process of IRMPQMI are discussed. This method can help to retrieve the potential information of power quality monitoring data and give the evaluation results, which provides the basis for decision making of power supply bureau. Numerical results with fuzzy comprehensive evaluation show the implementation procedures and committed steps of IRMPQMI. The idea of IRMPQMI is a guide and has high practical value to the real Intelligent Retrieval System for Power Quality Monitoring Information.

  16. A Method of Locating Transient Disturbance of Power Quality Based on Morphological Edge Detection%基于形态边缘检测的电能质量暂态扰动定位方法

    Institute of Scientific and Technical Information of China (English)

    欧阳森; 黄润鸿

    2012-01-01

    A morphological edge detection based method to locate transient disturbance of power quality is proposed. To solve the problem of power signals detection inaccuracy caused by background gradient due to periodic variation of power signals and existing interferences during sampling process, a quantitative assessment method based on soft threshold is induced in to improve detection accuracy. Firstly, a standard to assess the filtering effect is put forward to choose the size of structuring elements adaptively to perform morphological filtering of original signals; then the Top-Hat transform is applied to morphological gradient by flat structuring elements to suppress background gradient to achieve location result preliminarily; finally combining with the processing of soft threshold, the location of transient disturbance of power quality is implemented. A series of simulation results of power quality transient disturbances show that the proposed location method can accurately locate the disturbances and possesses strong ability of anti-interference.%提出了一种基于形态边缘检测的电能质量暂态扰动定位方法,在解决电力信号因周期性变化和采样过程中存在的各种干扰而引起的背景梯度影响扰动检测准确度问题的同时,引入软阈值的定量评价方法来提高其准确性。首先,提出滤波效果的评价方法,自适应选取结构元素大小对原始信号进行滤波处理;然后用扁平结构元素对形态梯度进行Top.Hat变换以抑制背景梯度,初步得到定位结果;最后结合软阈值的处理方法,实现对电能质量暂态扰动的定位。一系列的电能质量暂态扰动的仿真分析表明,该算法定位准确,抗干扰能力强,具有较好的普遍适用性。

  17. Review of power quality applications of energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Swaminathan, S.; Sen, R.K. [Sentech, Inc., Bethesda, MD (United States)

    1997-05-01

    Under the sponsorship of the US Department of Energy (DOE) Office of Utility Technologies, the Energy Storage Systems Analysis and Development Department at Sandia National Laboratories contracted Sentech, Inc., to assess the impact of power quality problems on the electricity supply system. This report contains the results of several studies that have identified the cost of power quality events for electricity users and providers. The large annual cost of poor power quality represents a national inefficiency and is reflected in the cost of goods sold, reducing US competitiveness. The Energy Storage Systems (ESS) Program takes the position that mitigation merits the attention of not only the DOE but affected industries as well as businesses capable of assisting in developing solutions to these problems. This study represents the preliminary stages of an overall strategy by the ESS Program to understand the magnitude of these problems so as to begin the process of engaging industry partners in developing solutions.

  18. Results from power quality measurements in Germany - An overview

    Energy Technology Data Exchange (ETDEWEB)

    Gerdes, G.J.; Santjer, F. [German Wind Energy Inst, Wilhelmshaven (Germany)

    1996-12-31

    Grid interferences caused by wind turbines (WT) are getting a severe problem in Germany with the fast increasing number of installed turbines. The wind energy capacity was doubled annually in the past three years. The actual situation and the plannings for the next years will lead to a situation, where high wind energy penetration will exercise a big influence on the power and voltage quality of local utility networks. Measurements performed in Germany according to a national guideline show a big variety in power quality performance of WT`s, which does affect the requirements for grid connection and thus the economical situation of wind energy projects to a large extent. The results from more than 25 power quality measurements will be discussed in this paper. 5 refs., 5 figs., 1 tab.

  19. Quality Assurance Framework Implementation Guide for Isolated Community Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Esterly, Sean R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Baring-Gould, Edward I. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burman, Kari A. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-08-15

    This implementation guide is a companion document to the 'Quality Assurance Framework for Mini-Grids' technical report. This document is intended to be used by one of the many stakeholder groups that take part in the implementation of isolated power systems. Although the QAF could be applied to a single system, it was designed primarily to be used within the context of a larger national or regional rural electrification program in which many individual systems are being installed. This guide includes a detailed overview of the Quality Assurance Framework and provides guidance focused on the implementation of the Framework from the perspective of the different stakeholders that are commonly involved in expanding energy development within specific communities or regions. For the successful long-term implementation of a specific rural electrification program using mini-grid systems, six key stakeholders have been identified that are typically engaged, each with a different set of priorities 1. Regulatory agency 2. Governmental ministry 3. System developers 4. Mini-utility 5. Investors 6. Customers/consumers. This document is broken into two distinct sections. The first focuses on the administrative processes in the development and operation of community-based mini-grid programs, while the second focuses on the process around the installation of the mini-grid project itself.

  20. Tracking of Power Quality Indicators during Wind Farm Islanding Experiment

    DEFF Research Database (Denmark)

    Terzija, V.; Crossley, P.A.; Stanojevic, V.

    2007-01-01

    The application of the two-stage Newton Type Algorithm for the tracking of the power quality indicators (in accordance with IEEE Standard 1459-2000) is presented in the paper. To estimate their spectra and fundamental frequency, the current and voltage signals are first processed and then the power...... quality indicators calculated. The algorithm considers frequency as an unknown parameter and estimates it whilst determining the input signal spectrum; this ensures the algorithm is insensitive to frequency changes. The proposed algorithm was evaluated using signals acquired during a wind farm islanding...

  1. Multiple power quality disturbances recognition using S-transform and rule based classification technique%基于S变换和规则基的复合电能质量扰动识别

    Institute of Scientific and Technical Information of China (English)

    陈华丰; 杨志刚; 曾涛

    2015-01-01

    提出了一种复合电能质量扰动识别方法。为避免复合电能质量扰动类型中单一扰动相互影响而造成的特征混叠或失效问题,采用FFT变换结合动态测度法提取6个特征和S变换提取5个特征,从基频、中频、高频、基频标准差、频谱极值点对称等各个方面刻画扰动信号的特征;然后构建基于规则基“IF—THEN”形式的分类器,提取的特征输入分类器后能自动识别电能质量扰动类型。仿真结果表明,在一定噪声条件下,所提出的分类方法能准确识别26种扰动类型,其中包含8种单一扰动类型以及18种双重扰动类型。%A new approach to recognize multiple power quality disturbances is proposed.In order to avoid characteris-tics aliasing or failures because of interferences between the single disturbances, six features in power quality disturb-ance signals are extracted using Fast Fourier Transform ( FFT) combined with dynamic measure method and five kinds of features in power quality disturbance signals are extracted based on S-transform.Disturbance signals are character-ized by these features from the baseband, intermediate frequency, high-frequency, standard deviation of the funda-mental frequency and extreme point symmetry.Then a classifier is designed with eight rules in the form of “IF-THEN”, finally the extracted features were input into the classifier for disturbances recognition.Simulation results show that this method can effectively recognize 26 kinds of power quality disturbances under certain signal to noise ra-tio including eight single disturbances and eighteen double disturbances.

  2. Optimal Power Control in Wireless Powered Sensor Networks: A Dynamic Game-Based Approach

    Science.gov (United States)

    Xu, Haitao; Guo, Chao; Zhang, Long

    2017-01-01

    In wireless powered sensor networks (WPSN), it is essential to research uplink transmit power control in order to achieve throughput performance balancing and energy scheduling. Each sensor should have an optimal transmit power level for revenue maximization. In this paper, we discuss a dynamic game-based algorithm for optimal power control in WPSN. The main idea is to use the non-cooperative differential game to control the uplink transmit power of wireless sensors in WPSN, to extend their working hours and to meet QoS (Quality of Services) requirements. Subsequently, the Nash equilibrium solutions are obtained through Bellman dynamic programming. At the same time, an uplink power control algorithm is proposed in a distributed manner. Through numerical simulations, we demonstrate that our algorithm can obtain optimal power control and reach convergence for an infinite horizon. PMID:28282945

  3. Synthetic Evaluation of Power Quality Based on Dynamic Time Warping Spatial Distance Measurement%基于动态时间弯曲空间距离度量的电能质量综合评估

    Institute of Scientific and Technical Information of China (English)

    林德清; 顾伟; 王元凯; 袁晓冬; 李群; 王锐

    2013-01-01

    将电能质量进行综合评估得出的量化结果,是衡量电能质量优劣的依据之一,有利于实现电能按质定价的市场机制.采用集成层次分析法和熵值法确定电能质量各项指标的综合权重值;同时,将空间距离度量的思想应用于电能质量综合评估,将电能质量指标问题转化为空间上的模式距离问题,采用动态时间弯曲算法进行序列模式识别,计算经加权化的标准电能质量指标序列、待评估电能质量指标序列与理想电能质量指标序列的匹配系数,进而确定电能质量等级,实现电能质量的综合评估与分级评估.实例计算结果表明,所提出的综合评估方法具有一定的有效性和可行性.%The quantized result from synthetic evaluation of power quality is one of the foundations to assess power quality and is favorable to implement the market mechanism of pricing electric energy according to power quality. Integrating analytic hierarchy process (AHP) with entropy weight, the synthetical weights of power quality indices are determined; meanwhile, the thinking of spatial distance measurement is applied to synthetical evaluation of power quality to turn the power quality indices into pattern distance in space. The dynamic time wrapping (DTW) algorithm is adopted for sequence pattern identification to calculate matching coefficients among weighted standard power quality index sequence, power quality index sequence to be evaluated and ideal power quality index sequence, and then the grade of power quality is determined to implement the synthetical evaluation and level assessment of power quality. Calculation results of case study show that the proposed synthetical evaluation method is effective and feasible.

  4. Power Quality Evaluation of 480-V, 2-MVA UPS Systems

    Energy Technology Data Exchange (ETDEWEB)

    CAMM,E.H.; COREY,GARTH P.; ROBERTS,B.

    2000-06-21

    A mobile 480-V, 2-MVA UPS System utilizing battery energy storage was installed at S and C Electric Company's Polymer Products Fabrication Building in Chicago, Illinois in May 1999 to provide uninterrupted power to the building for up to 15 seconds in the event of a voltage sag or momentary interruption in the local utility supply. Similar units can be applied at medium voltage through the application of a step-up transformer to provide momentary power disturbance ride through of up to 30 seconds for loads up to 15 MVA at system voltages ranging from 4.16 kV to 34.5 kV. A power quality evaluation of the installation was performed over a six-month period from July 1999 to early January 2000. This paper describes the details and results of this power quality evaluation, which involved two phases. Phase I involved the collection and review of power disturbance data and the effects on process equipment, while Phase II involved power quality monitoring of utility source and building load voltages and currents over a period of six months. Review of power disturbance data and equipment power-disturbance ride-through characteristics during Phase I of the project indicated that the polymer fabrication process in the building is affected by the tripping of motors driving hydraulic pumps for the thermal set molding machines. The tripping of these motors may have resulted in direct production losses in 1998 of approximately $468,000. The monitoring conducted during Phase II of the project showed that the PureWave UPS operated as intended during 12 utility voltage sag events to protect the building's load against momentary power disturbances. In addition, the unit operated successfully during many staged interruptions involving opening of a source-side circuit breaker.

  5. Potential impact of superconductivity on power quality enhancment

    Science.gov (United States)

    McConnell, B. W.

    1992-02-01

    Electric power quality problems are estimated to cost U.S. industry 26 billion dollars per year in lost production. This paper provides a summary of the problem's magnitude, an overview of the underlying causes, discusses the present methods used by industry to reduce the problem's impact and the associated cost, and examines the potential for superconducting technology to effect alternative solutions. The present market for uninterruptible power supplies (UPS) and power conditioners is also discussed and the benefits of applying high temperature superconductors (HTS) are summarized.

  6. Power Customer Classification Service Mode Based on the Customer Value and Perceived Service Quality%基于客户价值和感知服务质量的电力客户分级服务模式

    Institute of Scientific and Technical Information of China (English)

    陈金木; 黄尚渊; 徐栋; 陆贤峰

    2014-01-01

    The traditional electric power customer classification emphasizes the social value but neglects its economic value, so it is not conducive to the improvement of customer satisfaction and social and economic benefit of power supply enterprise. This article proposes the electric power customer classification method based on customer value, taking customers' contribution of electricity utilization, customers' standard electricity utilization and customer cooperation as classification criteria, to comprehensively measure the customer value. Aiming at the deficiency of the existing electric power customer service and referring to customer service quality perception theory, the power customer service strategy combination is built from the reliability, responsiveness, assurance, empathy and tangibility, and puts forward some strategies for different service of different levels of customers.%传统的电力客户分类偏重于客户的社会价值,忽视了其经济价值,不利于客户满意度和供电企业社会及经济效益的提升。本文提出基于客户价值的电力客户分类方法,将客户用电贡献、客户用电规范性、客户合作等三个维度作为分类标准,以此全面衡量客户价值。针对现有电力客户服务中的不足,借鉴顾客服务感知质量理论,从可靠性、响应性、保证性、移情性和有形性等五个方面构建了电力客户服务策略组合,并提出了针对不同级别客户的差异化服务策略。

  7. Particle Swarm Optimization Based Reactive Power Optimization

    CERN Document Server

    Sujin, P R; Linda, M Mary

    2010-01-01

    Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several constraints. The objective of the proposed PSO is to minimize the total support cost from generators and reactive compensators. It is achieved by maintaining the whole system power loss as minimum...

  8. Quality electricity lines of external power systems electric traction DC

    Directory of Open Access Journals (Sweden)

    A.V. Petrov

    2012-08-01

    Full Text Available The results of studies that compare and analyze the numerical values of some key indicators quality electricity in the lines of the external power supply system the electric traction DC. As a supplement are additional and fundamental values of energy losses in them.

  9. Social Power: Effect on Spouses' Quality of Personal Life.

    Science.gov (United States)

    Thomas, Cher Carrie

    It is the dimension of power or control, either in the workplace or in the family, that determines the degree to which social relations are alienating. The consequences of social inequality for the quality of personal life were examined in 314 married couples, of whom 70 were dual-earning non-parents, 123 were dual-earning parents, and 41 were…

  10. Monolithic fuel cell based power source for burst power generation

    Science.gov (United States)

    Fee, D. C.; Blackburn, P. E.; Busch, D. E.; Dees, D. W.; Dusek, J.; Easler, T. E.; Ellingson, W. A.; Flandermeyer, B. K.; Fousek, R. J.; Heiberger, J. J.

    A unique fuel cell coupled with a low power nuclear reactor presents an attractive approach for SDI burst power requirements. The monolithic fuel cell looks attractive for space applications and represents a quantum jump in fuel cell technology. Such a breakthrough in design is the enabling technology for lightweight, low volume power sources for space based pulse power systems. The monolith is unique among fuel cells in being an all solid state device. The capability for miniaturization, inherent in solid state devices, gives the low volume required for space missions. In addition, the solid oxide fuel cell technology employed in the monolith has high temperature reject heat and can be operated in either closed or open cycles. Both these features are attractive for integration into a burst power system.

  11. High-power CSI-fed induction motor drive with optimal power distribution based control

    Science.gov (United States)

    Kwak, S.-S.

    2011-11-01

    In this article, a current source inverter (CSI) fed induction motor drive with an optimal power distribution control is proposed for high-power applications. The CSI-fed drive is configured with a six-step CSI along with a pulsewidth modulated voltage source inverter (PWM-VSI) and capacitors. Due to the PWM-VSI and the capacitor, sinusoidal motor currents and voltages with high quality as well as natural commutation of the six-step CSI can be obtained. Since this CSI-fed drive can deliver required output power through both the six-step CSI and PWM-VSI, this article shows that the kVA ratings of both the inverters can be reduced by proper real power distribution. The optimal power distribution under load requirements, based on power flow modelling of the CSI-fed drive, is proposed to not only minimise the PWM-VSI rating but also reduce the six-step CSI rating. The dc-link current control of the six-step CSI is developed to realise the optimal power distribution. Furthermore, a vector controlled drive for high-power induction motors is proposed based on the optimal power distribution. Experimental results verify the high-power CSI-fed drive with the optimal power distribution control.

  12. An Implementation of Exploratory Start for Power Quality Disturbance Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Turgay Yalcin

    2016-10-01

    Full Text Available Identification of system disturbances and detection of them guarantees smart grids power quality system reliability and long lasting life of the power system. The key goal of this study is to generate non - time consuming features for CPU, for recognizing different types of non-stationary and non-linear smart grid faults based on signal processing techniques. This paper proposes a new solution for real time power system monitoring against power quality faults focusing on voltage sag and noise. EEMD is used for noise reduction with first intrinsic mode function (imf1. Hilbert Huang Transform (HHT is used for generating instantaneous amplitude (IA and instantaneous frequency (IF feature of real time voltage sag power signal. The proposed power system monitoring system is able to detect power system voltage sag disturbances and capable of recognize and remove EMI (Electromagnetic Interference-Noise.  In this study based on experimental studies, Hilbert Huang based pattern recognition technique was used to investigate power signal to diagnose voltage sag in power grid. SVM and Decision Tree (C4.5 were operated and their achievements were matched for calculation error and CPU time. According to the analysis, decision tree algorithm without dimensionality reduction produces the best solution.

  13. Single-stage unity power factor based electronic ballast

    Indian Academy of Sciences (India)

    ASHISH SHRIVASTAVA; BHIM SINGH

    2016-10-01

    This paper deals with the design, modeling, analysis and implementation of unity power factor (UPF) based electronic ballast for a fluorescent lamp (FL). The proposed electronic ballast uses a boost AC–DC converter as a power factor corrector (PFC) to improve the power quality at the input ac mains. In this singlestage UPF based electronic ballast, boost PFC converter and a half bridge series resonant inverter (HBSRI) share a common power switch. Thus one power switch is reduced as compared to the conventional two-stage approach. The design, modeling, analysis and implementation of this topology were carried out in MATLAB-Simulink environment for a T8 36 W, 220 V, 50 Hz fluorescent lamp. The switching frequency was kept morethan the resonant frequency of the inverter, to ensure the zero voltage switching (ZVS) operation of both power switches. This resulted in reduction of high frequency switching losses. The power quality parameters such as displacement power factor (DPF), distortion factor (DF), power factor (PF), crest factor (CF) and total harmonicdistortion of ac mains current (THDi) were evaluated to analyze the performance of proposed electronic ballast. Test results on a developed prototype of PFC electronic ballast were included to validate the design and simulated results.

  14. PROVIDING QUALITY OF ELECTRIC POWER IN ELECTRIC POWER SYSTEM IN PARALLEL OPERATION WITH WIND TURBINE

    Directory of Open Access Journals (Sweden)

    Yu. A. Rolik

    2016-01-01

    Full Text Available The problem of providing electric power quality in the electric power systems (EPS that are equipped with sufficiently long air or cable transmission lines is under consideration. This problem proved to be of particular relevance to the EPS in which a source of electrical energy is the generator of wind turbines since the wind itself is an instable primary energy source. Determination of the degree of automation of voltage regulation in the EPS is reduced to the choice of methods and means of regulation of power quality parameters. The concept of a voltage loss and the causes of the latter are explained by the simplest power system that is presented by a single-line diagram. It is suggested to regulate voltage by means of changing parameters of the network with the use of the method of reducing loss of line voltage by reducing its reactance. The latter is achieved by longitudinal capacitive compensation of the inductive reactance of the line. The effect is illustrated by vector diagrams of currents and voltages in the equivalent circuits of transmission lines with and without the use of longitudinal capacitive compensation. The analysis of adduced formulas demonstrated that the use of this method of regulation is useful only in the systems of power supply with a relatively low power factor (cosφ < 0.7 to 0.9. This power factor is typical for the situation of inclusion the wind turbine with asynchronous generator in the network since the speed of wind is instable. The voltage regulation fulfilled with the aid of the proposed method will make it possible to provide the required quality of the consumers’ busbars voltage in this situation. In is turn, it will make possible to create the necessary conditions for the economical transmission of electric power with the lowest outlay of reactive power and the lowest outlay of active power losses.

  15. Application of Wavelet-based Active Power Filter in Accelerator Magnet Power Supply

    CERN Document Server

    Xiaoling, Guo

    2013-01-01

    As modern accelerators demand excellent stability to magnet power supply (PS), it is necessary to decrease harmonic currents passing magnets. Aim at depressing rappel current from PS in Beijing electron-positron collider II, a wavelet-based active power filter (APF) is proposed in this paper. APF is an effective device to improve the quality of currents. As a countermeasure to these harmonic currents, the APF circuit generates a harmonic current, countervailing harmonic current from PS. An active power filter based on wavelet transform is proposed in this paper. Discrete wavelet transform is used to analyze the harmonic components in supply current, and active power filter circuit works according to the analysis results. At end of this paper, the simulation and experiment results are given to prove the effect of the mentioned Active power filter.

  16. Power Quality Analysis in 6 MW Wind Turbine Using Static Synchronous Compensator

    Directory of Open Access Journals (Sweden)

    R. Valarmathi

    2012-01-01

    Full Text Available Problem statement: An inherent problem with wind turbine power generation systems is the low power quality due to intermittent power generation in these systems. This not only affects the power generation but also the grid it is connected to. Approach: In this study a configuration consisting of a 6MW Wind Farm based on conventional Fixed Speed Induction Generator is analyzed. To improve the transient stability in the wind turbine generator a STATCOM is introduced in the system as an active voltage/var supporter. The impact of the introduced STATCOM and subsequent performance improvement in the power quality is studied. Results and Conclusion: The improved short-term voltage obtained when a STATCOM is introduced under various wind speed conditions is quantified. It is proved that STATCOM has a direct impact on reliability, however SVC needsto be studied due to their lower cost.

  17. Mitigation of Power Quality problems by UPQC for Renewable Energy Resources using Fuzzy Logic Technique

    Directory of Open Access Journals (Sweden)

    Phaneendra Venkat Gatta

    2014-05-01

    Full Text Available The wind energy conversion system Wind Farms (WF are employ squirrel cage induction generator (SCIG. The injection of wind power into an electric grid causes the power quality problems such as variation of voltage, flicker, harmonics etc, and these are measured according to national/international guidelines. To solve these problems Custom Power Devices (CUPS are used. This paper has proposed a compensation strategy based on a particular cups device for Unified Power Quality Compensator (UPQC with an application of PI and Fuzzy Logic Controllers. The proposed strategy controls both active and reactive power in the converters of UPQC. This paper presents the comparison between without UPQC, UPQC with PI controller and UPQC with Fuzzy Logic Controller. By using MATLAB/SIMULINK software the control strategies are designed. The simulation results are shown for comparison of different control strategies and by performing FFT analysis Total Harmonic Distortions (THD are calculated.

  18. A Design of Wireless Sensor Networks for a Power Quality Monitoring System

    Directory of Open Access Journals (Sweden)

    Sanggil Kang

    2010-11-01

    Full Text Available Power grids deal with the business of generation, transmission, and distribution of electric power. Recently, interest in power quality in electrical distribution systems has increased rapidly. In Korea, the communication network to deliver voltage, current, and temperature measurements gathered from pole transformers to remote monitoring centers employs cellular mobile technology. Due to high cost of the cellular mobile technology, power quality monitoring measurements are limited and data gathering intervals are large. This causes difficulties in providing the power quality monitoring service. To alleviate the problems, in this paper we present a communication infrastructure to provide low cost, reliable data delivery. The communication infrastructure consists of wired connections between substations and monitoring centers, and wireless connections between pole transformers and substations. For the wireless connection, we employ a wireless sensor network and design its corresponding data forwarding protocol to improve the quality of data delivery. For the design, we adopt a tree-based data forwarding protocol in order to customize the distribution pattern of the power quality information. We verify the performance of the proposed data forwarding protocol quantitatively using the NS-2 network simulator.

  19. 基于自适应提升格式的暂态电能质量扰动检测及定位%Detection and Location of Transient Power Quality Disturbances Based on Adaptive Lifting Scheme

    Institute of Scientific and Technical Information of China (English)

    杨汉生

    2011-01-01

    In order to further improve the accuracy of detecting and locating the transient power quality, this paper analyses the correlation of the transient power quality disturbances and determines the prediction and updated parameters of lifting scheme.The transient power quality problems such as voltage swell, voltage sag, voltage interruption, impulsive transient and oscillatory transient are simulated using MATLAB.The simulation results show that the method can accurately detect the above-mentioned five kinds of transient power quality disturbances.The results can give theoretical support to the design of power quality analyzer.%为了进一步提高暂态电能质量扰动检测及定位的准确率,该文分析了暂态电能质量扰动的相关性,选择预测和更新算子,实现对扰动信号的自适应检测;利用MATLAB对电压骤升、电压骤降、电压瞬时中断、脉冲暂态和振荡暂态等暂态电能质量问题进行仿真研究,仿真结果表明:该方法能快速检测出上述5种暂态电能质量扰动.研究结果为电能质量分析仪器设计提供了理论支持.

  20. An extensible database architecture for nationwide power quality monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Kuecuek, Dilek; Inan, Tolga; Salor, Oezguel; Demirci, Turan; Buhan, Serkan; Boyrazoglu, Burak [TUBITAK Uzay, Power Electronics Group, TR 06531 Ankara (Turkey); Akkaya, Yener; Uensar, Oezguer; Altintas, Erinc; Haliloglu, Burhan [Turkish Electricity Transmission Co. Inc., TR 06490 Ankara (Turkey); Cadirci, Isik [TUBITAK Uzay, Power Electronics Group, TR 06531 Ankara (Turkey); Hacettepe University, Electrical and Electronics Eng. Dept., TR 06532 Ankara (Turkey); Ermis, Muammer [METU, Electrical and Electronics Eng. Dept., TR 06531 Ankara (Turkey)

    2010-07-15

    Electrical power quality (PQ) data is one of the prevalent types of engineering data. Its measurement at relevant sampling rates leads to large volumes of PQ data to be managed and analyzed. In this paper, an extensible database architecture is presented based on a novel generic data model for PQ data. The proposed architecture is operated on the nationwide PQ data of the Turkish Electricity Transmission System measured in the field by mobile PQ monitoring systems. The architecture is extensible in the sense that it can be used to store and manage PQ data collected by any means with little or no customization. The architecture has three modules: a PQ database corresponding to the implementation of the generic data model, a visual user query interface to enable its users to specify queries to the PQ database and a query processor acting as a bridge between the query interface and the database. The operation of the architecture is illustrated on the field PQ data with several query examples through the visual query interface. The execution of the architecture on this data of considerable volume supports its applicability and convenience for PQ data. (author)

  1. METHODOLOGY OF DETERMINATION OF QUALITY INDEX OF MAINTENANCE SERVICE SYSTEM OF POWER EQUIPMENT OF TRACTION SUBSTATIONS

    Directory of Open Access Journals (Sweden)

    O.O. Matusevych

    2016-03-01

    Full Text Available Purpose. The purpose of this paper is development of methodology for definition of a quality system of maintenance and repair (M and P power equipment of traction substations (TS of electrified railways operating under conditions of uncertainty based on expert information. Methodology. The basic tenets of the theory of fuzzy sets and marks, linguistic and interval estimates of experts were applied to solve this problem. Results. Analysis of the existing diversity of approaches to development of modern methods of improvement of M and P allows us to conclude that the improvement in the quality of the system is achieved by solving individual problems increase the operational reliability of power equipment of traction substations in the following main interrelated areas. There are technical, economic and organizational. The basis of the quality evaluation system is initial data and expertise developed version of the document formalized quality evaluation of electrical equipment of traction substations by experts. The choice of determining the level of Quality service system based on the marks, linguistic and interval estimates of experts, which are reflected in quantitative and / or qualitative form was done. The possible options for expert data presentation and their corresponding quantitative methods of calculating the integral index of quality improvement system maintenance and P of traction substations were described. The methodology and the method of assessing the quality of system maintenance and P of TS allows quickly respond to changing operating conditions of power equipment of traction substations, and to determine the most effective strategies for maintenance of electrical and P TS under conditions of uncertainty functioning distance electricity. Originality. The method of a systematic approach to improve the quality of the system maintenance and P of power equipment of traction substation under conditions of uncertainty based on expert

  2. 基于PSO-MP算法和RBF神经网络的电能质量扰动识别%The identification of power quality disturbance based on PSO-MP algorithm and RBF neural network

    Institute of Scientific and Technical Information of China (English)

    王云静; 李燕; 曲正伟; 刘圣楠

    2016-01-01

    It is of great significance to accurately identify the type of disturbance signal to analyze and control the pow-er quality problem.In this paper, a new method of power quality disturbance identification based on matching pursuit optimized by particle swarm optimization ( PSO-MP) and RBF neural network is proposed.Firstly, in order to let the residue signal to better reflect the different disturbance signal difference, the fundamental atomic library is constructed to extract the fundamental frequency signals;Then, the MP algorithm is optimized by PSO to reduce the calculation a-mount, which combines with discrete Gabor atom libraries to accurately extract atomic parameters of residual disturb-ance signal by sparse decomposition, Finally, the RBF neural network is used to identify disturbance signals by fea-tures, which is the mean and standard deviation of the atomic parameter and projection of residual signal on the atom. Simulation examples show that the proposed method can effectively identify several common power quality disturbances with a small amount of computation and good anti-noise performance.%准确识别扰动信号类型对分析和治理电能质量问题具有重要意义。文中提出一种基于粒子群优化匹配追踪算法( PSO-MP)和RBF神经网络的电能质量扰动识别方法。首先,构建工频原子库将工频信号提取出来,得到的残余信号能更好地体现扰动信号差异性;再利用PSO优化匹配追踪算法以减小计算量,并结合离散Gabor原子库对残余扰动信号进行稀疏分解,准确提取其原子参数;最后将原子参数以及残余信号在原子上的投影的均值和标准偏差作为特征量,利用RBF神经网络对扰动信号进行识别。仿真算例表明,该方法能够有效地识别几种常见的电能质量扰动,且具有抗噪性能强、计算量小等优点。

  3. High-quality Wind Power Scenario Forecasts for Decision-making Under Uncertainty in Power Systems

    DEFF Research Database (Denmark)

    Delikaraoglou, Stefanos; Pinson, Pierre

    2014-01-01

    The large scale integration of wind generation in existing power systems requires novel operational strategies and market clearing mechanisms to account for the variable nature of this energy source. An efficient method to cope with this uncertainty is stochastic optimization which however requires...... high-quality forecasts in the form of scenarios. The main goal of this work is to release a public dataset of wind power forecasts to be used as a reference for future research. To that extent, we provide a complete framework to describe wind power uncertainty in terms of single...

  4. Power Quality and Harmonic Analysis of End User Devices

    Directory of Open Access Journals (Sweden)

    Sonia Leva

    2012-12-01

    Full Text Available Among the non-linear loads used in household, Compact Fluorescent Lamps (CFLs and LED lamps are becoming more widespread, while incandescent lamps are intended to be replaced by these types of lighting devices. LEDs and CFLs are significantly more efficient and economical than incandescent lamps, and are expected to be used in 100% of residential lighting in the future. As nonlinear loads, LEDs and CFLs produce highly distorted currents. A large number of customers using LEDs or CFLs for domestic, commercial and industrial lighting could determine important Power Quality problems. The paper reports experimental measurement results regarding Power Quality in indoor lighting systems. The harmonic absorptions of several types of luminaries are analyzed, highlighting the impact behavior of different lamps function of used luminaries’ technologies. The recorded harmonic absorption allows characterizing the harmonic spectrum variability of the investigated lamps.

  5. MEMS-Based Power Generation Techniques for Implantable Biosensing Applications

    Directory of Open Access Journals (Sweden)

    Jonathan Lueke

    2011-01-01

    Full Text Available Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient.

  6. Electric Power Quality and Distributed Generation in Cuba

    Directory of Open Access Journals (Sweden)

    Miguel Castro Fernández

    2010-10-01

    Full Text Available Diesel engine generator (RM is one of the most used technologies on distributed generation (DG. The presence of RM, no manner its operation form need an analysis about differents problems: one of them is related with power quality (PQ. First results obained inside one study directed to obtain answers about differents perturbations for the RM presence like shortcircuit and voltage variation on RM termianls and rejected charge are presented in this paper.

  7. Power Quality. Implications at the Point of Connection

    Energy Technology Data Exchange (ETDEWEB)

    Cobben, J.F.G.

    2007-06-12

    The main developments in the field of power quality and mentioned before were an important trigger in arriving at the research objectives. Condensing all information three main research objectives can be described as: (a) Classification of power quality phenomena to arrive at an analysis tool for grid operators, which makes it possible to handle an enormous amount of data and to give customers and the regulator clearer information about the quality of supply voltage; (b) The influence of dispersed generation due to a large amount of renewable energy sources on power quality, especially on the voltage level and slow voltage variations. Also the possible contribution to the harmonic distortion is analysed; (c) Power quality interaction between 'supply' voltage and 'exchanged' current at the point of common coupling (point of connection or POC to the grid). Especially the relation between current capacity of a POC, the grid impedance and the current at the POC is analysed for harmonics and flicker. In chapter 1 power quality in general is described, the problems are stated and the research topics discussed. Further understanding of the different power quality phenomena, is the topic of chapter 2 and the need to use the indices is described. Also the need to develop methods for compressing power quality data and to make this data fit for use is described. The classification explained in this chapter is an example of practical solution, which has been implemented in a system for substation automation. In chapter 3, the voltage magnitude variation as power quality phenomena is analysed. The influence of dispersed generation in relation to this phenomenon is studied. Also the limits of implementing dispersed generation in existing low voltage grids are calculated. The limited possibilities of voltage level regulation with reactive power in the low voltage grid are described, including the influences on the losses in the grid. Chapter 4 is the chapter

  8. Power Quality. Implications at the Point of Connection

    Energy Technology Data Exchange (ETDEWEB)

    Cobben, J.F.G.

    2007-06-12

    The main developments in the field of power quality and mentioned before were an important trigger in arriving at the research objectives. Condensing all information three main research objectives can be described as: (a) Classification of power quality phenomena to arrive at an analysis tool for grid operators, which makes it possible to handle an enormous amount of data and to give customers and the regulator clearer information about the quality of supply voltage; (b) The influence of dispersed generation due to a large amount of renewable energy sources on power quality, especially on the voltage level and slow voltage variations. Also the possible contribution to the harmonic distortion is analysed; (c) Power quality interaction between 'supply' voltage and 'exchanged' current at the point of common coupling (point of connection or POC to the grid). Especially the relation between current capacity of a POC, the grid impedance and the current at the POC is analysed for harmonics and flicker. In chapter 1 power quality in general is described, the problems are stated and the research topics discussed. Further understanding of the different power quality phenomena, is the topic of chapter 2 and the need to use the indices is described. Also the need to develop methods for compressing power quality data and to make this data fit for use is described. The classification explained in this chapter is an example of practical solution, which has been implemented in a system for substation automation. In chapter 3, the voltage magnitude variation as power quality phenomena is analysed. The influence of dispersed generation in relation to this phenomenon is studied. Also the limits of implementing dispersed generation in existing low voltage grids are calculated. The limited possibilities of voltage level regulation with reactive power in the low voltage grid are described, including the influences on the losses in the grid. Chapter 4 is the chapter

  9. Power Quality Improvement Using Hybrid Power Flow Controller in Power System

    Directory of Open Access Journals (Sweden)

    Manidhar Thula ,

    2014-01-01

    Full Text Available This paper discusses the applicability of Hybrid Power Flow Controller (HPFC as an alternative to Unified Power Flow Controller (UPFC for improvement of power system performance. UPFC is a flexible AC transmission system (FACTS device containing two switching converters, one in series and one in shunt. To configure the HPFC, one of the switching converters of the UPFC is replaced by thyristor controlled variable impedances, thus reducing the cost. In this paper, the HPFC has been configured by multilevel Voltage Source Converter (VSC used for the shunt compensation branches and a thyristor controlled variable impedance used for series compensation. It is shown that with suitable control the HPFC can inject a voltage of required magnitude in series with the line at any desired angle, just like UPFC. This helps in providing compensation equivalent to UPFC and improving the steady state stability limits of the power system.

  10. Hybrid Power Management-Based Vehicle Architecture

    Science.gov (United States)

    Eichenberg, Dennis J.

    2011-01-01

    Hybrid Power Management (HPM) is the integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications (s ee figure). The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The basic vehicle architecture consists of a primary power source, and possibly other power sources, that provides all power to a common energy storage system that is used to power the drive motors and vehicle accessory systems. This architecture also provides power as an emergency power system. Each component is independent, permitting it to be optimized for its intended purpose. The key element of HPM is the energy storage system. All generated power is sent to the energy storage system, and all loads derive their power from that system. This can significantly reduce the power requirement of the primary power source, while increasing the vehicle reliability. Ultracapacitors are ideal for an HPM-based energy storage system due to their exceptionally long cycle life, high reliability, high efficiency, high power density, and excellent low-temperature performance. Multiple power sources and multiple loads are easily incorporated into an HPM-based vehicle. A gas turbine is a good primary power source because of its high efficiency, high power density, long life, high reliability, and ability to operate on a wide range of fuels. An HPM controller maintains optimal control over each vehicle component. This flexible operating system can be applied to all vehicles to considerably improve vehicle efficiency, reliability, safety, security, and performance. The HPM-based vehicle architecture has many advantages over conventional vehicle architectures. Ultracapacitors have a much longer cycle life than batteries, which greatly improves system reliability, reduces life-of-system costs, and reduces environmental impact as ultracapacitors will probably never need to be

  11. Power Quality Issues In Indian Power Distribution Utilities And Feasible Solutions

    Directory of Open Access Journals (Sweden)

    Narasimha Pandit

    2015-08-01

    Full Text Available One important contributing factor to Indias slow pace of development in general and relatively poor industrial growth in particular is the poor quality and reliability of the electrical power. Earlier the consumers of electrical energy were mere acceptors. Interruptions and other voltage disturbances were part of the deal. But today electric power is viewed as a product with certain characteristics which can be measured predicted guaranteed improved etc. which has become an integral part of our life. This paper gives insights on different Power Quality PQ problems experienced by the Indian electricity consumers and the reasons for those problems. This paper proposes feasible solutions to assist in employing or implementing appropriate mitigation techniques with an optimism of an improvement in the field scenario as more and more investments are proposed in Generation Transmission and Distribution Sectors and stringent codes and standards are being imposed for those who do not maintain minimum PQ level in the field.

  12. Future Photovoltaic Power Generation for Space-Based Power Utilities

    Science.gov (United States)

    Bailey, S.; Landis, G.; Raffaelle, R.; Hepp, A.

    2002-01-01

    A recent NASA program, Space Solar Power Exploratory Research and Technology (SERT), investigated the technologies needed to provide cost-competitive ground baseload electrical power from space based solar energy conversion. This goal mandated low cost, light weight gigawatt (GW) power generation. Investment in solar power generation technologies would also benefit high power military, commercial and science missions. These missions are generally those involving solar electric propulsion, surface power systems to sustain an outpost or a permanent colony on the surface of the moon or mars, space based lasers or radar, or as large earth orbiting power stations which can serve as central utilities for other orbiting spacecraft, or as in the SERT program, potentially beaming power to the earth itself. This paper will discuss requirements for the two latter options, the current state of the art of space solar cells, and a variety of both evolving thin film cells as well as new technologies which may impact the future choice of space solar cells for a high power mission application. The space world has primarily transitioned to commercially available III-V (GaInP/GaAs/Ge) cells with 24-26% air mass zero (AMO) efficiencies. Research in the III-V multi-junction solar cells has focused on fabricating either lattice-mismatched materials with optimum stacking bandgaps or new lattice matched materials with optimum bandgaps. In the near term this will yield a 30% commercially available space cell and in the far term possibly a 40% cell. Cost reduction would be achieved if these cells could be grown on a silicon rather than a germanium substrate since the substrate is ~65% of the cell cost or, better yet, on a polyimide or possibly a ceramic substrate. An overview of multi-junction cell characteristics will be presented here. Thin film cells require substantially less material and have promised the advantage of large area, low cost manufacturing. However, space cell requirements

  13. Healthcare quality maturity assessment model based on quality drivers.

    Science.gov (United States)

    Ramadan, Nadia; Arafeh, Mazen

    2016-04-18

    Purpose - Healthcare providers differ in their readiness and maturity levels regarding quality and quality management systems applications. The purpose of this paper is to serve as a useful quantitative quality maturity-level assessment tool for healthcare organizations. Design/methodology/approach - The model proposes five quality maturity levels (chaotic, primitive, structured, mature and proficient) based on six quality drivers: top management, people, operations, culture, quality focus and accreditation. Findings - Healthcare managers can apply the model to identify the status quo, quality shortcomings and evaluating ongoing progress. Practical implications - The model has been incorporated in an interactive Excel worksheet that visually displays the quality maturity-level risk meter. The tool has been applied successfully to local hospitals. Originality/value - The proposed six quality driver scales appear to measure healthcare provider maturity levels on a single quality meter.

  14. Application of Extended Kalman Filter to the Modeling of Electric Arc Furnace for Power Quality Issues

    Institute of Scientific and Technical Information of China (English)

    JIN Zhi-jian; WANG Feng-hua; ZHU Zi-shu

    2007-01-01

    Electric arc furnaces (EAFs) represent one of the most disturbing loads in the subtransmission or transmission electric power systems. Therefore, it is necessary to build a practical model to descript the behavior of EAF in the simulation of power system for power quality issues. This paper deals with the modeling of EAF based on the combination of extended Kalman filter to identify the parameter of arc current and the power balance equation to obtain the dynamic, multi-valued u-i characteristics of EAF load. The whole EAF systems are simulated by means of power system blockset in Matlab to validate the proposed EAF model. This model can also be used to assess the impact of the new plant or highly varying nonlinear loads that exhibit chaos in power systems.

  15. SEVEN LEVEL CONTROL OF SHUNT ACTIVE POWER FILTER FOR POWER QUALITY ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    G. JAYAKRISHNA

    2011-09-01

    Full Text Available Shunt Active Power Filter (SAPF is one of the controllers to enhance power quality (PQ. This paper presents Hybrid Cascaded Seven-Level Inverter (HCSLI used in SAPF to compensate reactive power, improve the power factor and to suppress the total harmonic distortion (THD in supply current due to linear load and Non- Linear Diode Rectifier Loads (NLDRLs.In this paper d-q reference frame theory for reference current computation, Constant Switching Frequency Multicarrier Sub-Harmonic Pulse Width Modulation (CSFMSHPWM technique for controlling the switches of HCSLI, Fuzzy logic controller (FLC for regulating dc side capacitor voltage are proposed. The results are validated through simulation using Mat Lab/simulink with and without SAPF for linear and nonlinear loads.

  16. POWER QUALITY CONTROL IN A WIND POWER GENERATING SYSTEM USING SVPWM CONTROLLED UNIFIED POWER QUALITY CONDITIONER WITH GENETIC ALGORITHM

    Directory of Open Access Journals (Sweden)

    P.SARAVANAN

    2013-06-01

    Full Text Available Renewable energy resources (RES are being increasingly connected in distribution systems utilizing power electronic converters.This paper proposes a novel control design for achieving maximum benefits from the grid-interfacing inverters when installed in 3-phase 3-wire distribution systems. The main aim of the proposed system is to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current. Modulation technique used is Space Vector Pulse Width Modulation (SVPWM. Simulation and experimental studies on a three phase 3 wire distribution system is used to verify the performance and real time implementation of the control design.

  17. Power quality considerations for nuclear spectroscopy applications: Grounding

    Energy Technology Data Exchange (ETDEWEB)

    García-Hernández, J.M., E-mail: josemanuel.garcia@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, ININ, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac, 52750 Estado de México, México (Mexico); Instituto Tecnológico de Toluca, Departamento de Estudios de Posgrado e Investigación, Av. Tecnológico S/N, ExRancho La Virgen, 52140 Metepec, México (Mexico); Ramírez-Jiménez, F.J., E-mail: fjr@ieee.org [Instituto Nacional de Investigaciones Nucleares, ININ, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac, 52750 Estado de México, México (Mexico); Instituto Tecnológico de Toluca, Departamento de Estudios de Posgrado e Investigación, Av. Tecnológico S/N, ExRancho La Virgen, 52140 Metepec, México (Mexico); Mondragón-Contreras, L.; López-Callejas, R. [Instituto Nacional de Investigaciones Nucleares, ININ, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac, 52750 Estado de México, México (Mexico); Instituto Tecnológico de Toluca, Departamento de Estudios de Posgrado e Investigación, Av. Tecnológico S/N, ExRancho La Virgen, 52140 Metepec, México (Mexico); Torres-Bribiesca, M.A. [Instituto Nacional de Investigaciones Nucleares, ININ, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac, 52750 Estado de México, México (Mexico); and others

    2013-11-21

    Traditionally the electrical installations are designed for supplying power and to assure the personnel safety. In nuclear analysis laboratories, additional issues about grounding also must be considered for proper operation of high resolution nuclear spectroscopy systems. This paper shows the traditional ways of grounding nuclear spectroscopy systems and through different scenarios, it shows the effects on the more sensitive parameter of these systems: the energy resolution, it also proposes the constant monitoring of a power quality parameter as a way to preserve or to improve the resolution of the systems, avoiding the influence of excessive extrinsic noise. -- Highlights: •We analyze the performance of nuclear spectroscopy systems with different configurations of the grounding system. •The neutral to ground voltage is an indicator of the ground conditions, a high value may contribute to the increase of the FWHM in nuclear spectroscopy systems. •The use of an isolated ground system is the best option to preserve the best FWHM value. •The application of power quality concepts can help to guaranty the best configuration of the grounding system.

  18. Using technique vibration diagnostics for assessing the quality of power transmission line supports repairs

    Directory of Open Access Journals (Sweden)

    Cherpakov Aleksander

    2017-01-01

    Full Text Available The considered method for assessing the quality of the repair work to restore the rack supports of transmission lines is based on the method of vibration diagnostics. Power transmission line supports with a symmetrical destruction of the protective layer of concrete in the ground in violation of the construction section were chosen as an object. Finite element modelling package Ansys was used in assessing the quality of repair work. The example of evaluating the quality of repair using the relative adhesion defective area design criteria in the analysis of natural vibration frequencies is given.

  19. Investigation of Energy Storage Devices Impact on Improvement of Power Quality Aspects

    Directory of Open Access Journals (Sweden)

    S. Torabzad

    2012-03-01

    Full Text Available Energy production and storage are in the midst of some major changes. During the past decade, energy production and storage have become a high priority for business and government because of concerns relating to the environment and sustainability of energy sources. The power quality problems that have occurred on the existing, aging system will continue to worsen as intermittent, renewable energy systems are added. Fastacting energy storage is required to help combat this problem. Among the many FACTS devices which can improve the power system operation and power quality problems, Static Compensator (STATCOM and Unified Power Flow Controller (UPFC are of the most promising new FACTS technologies. Both of these devices utilize capacitors as the dc bus. Since capacitors are passive elements with very limited energy storage, they cannot provide controllable real power for extended period. This paper investigates the impact of integrating a Battery Energy Storage System (BESS and/or a Superconducting Magnetic Energy Storage (SMES across the dc bus of STATCOM. This will allow fast control of both real and reactive power to improve power system transient stability and to provide extra damping against power system oscillation in a multi-area system linked by weak inter-connection. Comparative dynamic performances of these devices are presented in this study. A control strategy is proposed to integrate these devices to improve the active power management within the constraints of the power system to which the device is connected. The proposed controller based on hysterisis control ensures unity power factor and sinusoidal supply current irrespective of the variation in the load demand waveform and magnitude. Results from simulation studies using realistic model of the power electronic devices on the dynamic performance of these schemes will be presented.

  20. International water and steam quality standards on thermal power plants at all-volatile treatment

    Science.gov (United States)

    Petrova, T. I.; Orlov, K. A.; Dooley, R. B.

    2016-12-01

    One of the methods for the improvement of reliability and efficiency of the equipment at heat power plants is the decrease in the rate of corrosion of structural materials and sedimentation in water/steam circuit. These processes can be reduced to minimum by using the water with low impurity content and coolant treatment. For many years, water and steam quality standards were developed in various countries (United States, Germany, Japan, etc.) for specific types of equipment. The International Association for the Properties of Water and Steam (IAPWS), which brings together specialists from 21 countries, developed the water and steam quality standards for various types of power equipment based on theoretical studies and long-term operating experience of power equipment. Recently, various water-chemistry conditions are applied on heatpower equipment including conventional boilers and HRSGs with combined cycle power plants (Combined Cycle Power Plants (CCPP)). In paper, the maintenance conditions of water chemistry with ammonia or volatile amine dosing are described: reducing AVT(R), oxidizing AVT(O), and oxygen OT. Each of them is provided by the water and steam quality standards and recommendations are given on their maintenance under various operation conditions. It is noted that the quality control of heat carrier must be carried out with a particular care on the HPPs with combined cycle gas turbine units, where frequent starts and halts are performed.

  1. A Novel Multiobjective Control of DVR to Enhance Power Quality of Sensitive Load

    Science.gov (United States)

    Pandu, Sathish Babu; Nagappan, Kamaraj

    2015-01-01

    The Dynamic Voltage Restorer (DVR) is one of the fast, flexible, and cost effective solutions available in compensating the voltage-related power quality problems in power distribution systems. In this paper is discussed how power quality enhancement of sensitive load is achieved by applying three versions of Autonomous Group Particle Swarm Optimization like AGPSO1, AGPSO2, and AGPSO3 for tuning the Proportional-Integral DVR controller under balanced and nonlinear load conditions. A novel multiobjective function is formulated to express the control performance of the system, which is quantified using three power quality indices such as Total Harmonic Distortion (THD), voltage sag index, and RMS voltage variation. The obtained results are compared with the Proportional-Integral (PI) controller tuned by Ziegler-Nichols (ZN) method and also by Simple Particle Swarm Optimization based PI controlled DVR. The proposed methodology has improved the performance in terms of the considered power quality indices and the simulation has been carried out in MATLAB/Simulink environment. PMID:26613100

  2. Power Quality Improvement Wind Energy System Using Cascaded Multilevel Inverter

    Directory of Open Access Journals (Sweden)

    J.S. Sathiyanarayanan

    2013-02-01

    Full Text Available In this paper, a wind energy conversion system based on a cascaded H-bridgemultilevel inverter (CHBMLI topology has been proposed to be used for the grid interface of largesplit winding alternators (SWAs. A new method has been suggested for the generation of referencecurrents for the voltage source inverter (VSI depending upon the available wind power. TheCHBMLI has been used as a VSI and operated in a current control mode order to achieve theobjectives of real power injection and load compensation (power factor correction, load balancing,and harmonic compensation based on the proposed reference generation scheme. In the fieldexcitation control of SWA provides a single means vary the dc link voltages of all the CHBssimultaneously and proportionately.

  3. Causes, Effects and Solutions of Poor Quality Problems in the Power Systems

    OpenAIRE

    Vikash Anand; Srivastava, S. K.

    2014-01-01

    The term electric power quality broadly refers to maintaining a nearly sinusoidal power distribution bus voltage at rated magnitude and frequency. In addition, the energy supplied to a consumer must be uninterrupted from reliability point of view. Though power quality is mainly a distribution system problem, power transmission system may also have impact on quality of power. With the ever-increasing use of sophisticated controls and equipment in industrial, commercial, institu...

  4. 基于小波分解的电网动态电能质量扰动检测%Grid Dynamic Power Quality Disturbance Detection Based on Wavelet Decomposition

    Institute of Scientific and Technical Information of China (English)

    秦立军; 杨万涛

    2015-01-01

    动态电能质量问题包括短时电压变化及各种暂态现象,这是近期暴露出来有待解决的新问题。利用小波分解进行动态电能质量的扰动分析与检测。以db4为小波基函数,进行6层多分辨率分析。观察仿真波形,发现信号的非零点发生电压骤降、骤升、中断、暂态脉冲和暂态振荡等动态扰动时,小波分解第1、2层的高频部分(cd1、cd2)有明显的模极大值点,可根据检测模极大值点来判断扰动发生和结束的时刻。而当过零点发生在电压骤降、骤升、中断时,若用此作为判据,会有一定误差。%Dynamic power quality problems include short duration voltage variations and various transient phenomena, which are new problems exposed in recent years and need to be resolved. Wavelet decomposition is used to make disturbance analysis and detection of dynamic power quality. With db4 as wavelet basis function, 6-layer multiresolution analysis is made. Simulation waveform analysis show that when dynamic disturbances of the signal such as voltage sags, voltage swells, voltage interruptions, transient pulse and transient oscillation occur on a non-zero point, the high-frequency part (cd1, cd2) on the first and second layers of the wavelet decomposition has obvious modulus maxima, and the modulus maxima can be detected to determine the time the disturbances occur and the termination of the disturbances. When voltage sags, voltage swells and voltage interruptions happen on the zero-crossing point, it will produce errors if the criterion is still based on modulus maxima.

  5. U.S. Forward Operating Base Applications of Nuclear Power

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, George W. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-01-01

    This paper provides a high level overview of current nuclear power technology and the potential use of nuclear power at military bases. The size, power ranges, and applicability of nuclear power units for military base power are reviewed. Previous and current reactor projects are described to further define the potential for nuclear power for military power.

  6. Modal-Power-Based Haptic Motion Recognition

    Science.gov (United States)

    Kasahara, Yusuke; Shimono, Tomoyuki; Kuwahara, Hiroaki; Sato, Masataka; Ohnishi, Kouhei

    Motion recognition based on sensory information is important for providing assistance to human using robots. Several studies have been carried out on motion recognition based on image information. However, in the motion of humans contact with an object can not be evaluated precisely by image-based recognition. This is because the considering force information is very important for describing contact motion. In this paper, a modal-power-based haptic motion recognition is proposed; modal power is considered to reveal information on both position and force. Modal power is considered to be one of the defining features of human motion. A motion recognition algorithm based on linear discriminant analysis is proposed to distinguish between similar motions. Haptic information is extracted using a bilateral master-slave system. Then, the observed motion is decomposed in terms of primitive functions in a modal space. The experimental results show the effectiveness of the proposed method.

  7. 基于小波理论的微电网电能质量检测方法应用%Micro Grid Electric Power Quality Inspection Method Application Based on Wavelet Theory

    Institute of Scientific and Technical Information of China (English)

    刘中书; 张磊; 武粉桃; 李育敏; 李力

    2015-01-01

    Micro gird is a new type power grid structure with distributed power generation as main body, which is hot issue of smart grid development and research. Due to micro grid electric power quality is liable to be comprehensively influenced by new energy features, inverters features and load transient behavior, it has characteristics of sudden change, easily disturbed and fierce volatility, which requests fast speed and high accuracy of micro grid electric power quality inspection. Focused on characteristics of micro grid electric power quality, the author uses wavelet theory to inspect micro grid electric power quality. Through wavelet transform theory to de-noising sampled signal, wavelet phase method to perturbation localization and wavelet energy threshold method to identify micro grid electric power quality mutation category. It finally verifies inspection method by building model simulation according to actual micro grid.%微电网作为以分布式发电为主体的新型电网结构,已成为智能电网发展和研究的热点问题。由于微电网电能质量受到新能源特性、逆变器特性和负荷的暂态特性共同影响,具有了变化突然、易受扰动影响、波动剧烈等特点,这就要求对微电网电能质量检测提出了速度快,精度高的要求。针对微电网电能质量特性,利用小波理论对微电网电能质量进行检测。通过小波变换理论进行采样信号的消噪、利用小波相子法进行扰动定位,再利用小波能量阈值法对微电网电能质量突变类别进行识别,最终通过对实际微电网进行建模仿真进行了该检测方法的验证。

  8. Low power adder based auditory filter architecture.

    Science.gov (United States)

    Rahiman, P F Khaleelur; Jayanthi, V S

    2014-01-01

    Cochlea devices are powered up with the help of batteries and they should possess long working life to avoid replacing of devices at regular interval of years. Hence the devices with low power consumptions are required. In cochlea devices there are numerous filters, each responsible for frequency variant signals, which helps in identifying speech signals of different audible range. In this paper, multiplierless lookup table (LUT) based auditory filter is implemented. Power aware adder architectures are utilized to add the output samples of the LUT, available at every clock cycle. The design is developed and modeled using Verilog HDL, simulated using Mentor Graphics Model-Sim Simulator, and synthesized using Synopsys Design Compiler tool. The design was mapped to TSMC 65 nm technological node. The standard ASIC design methodology has been adapted to carry out the power analysis. The proposed FIR filter architecture has reduced the leakage power by 15% and increased its performance by 2.76%.

  9. Power Line Communication Based Home Security System

    Directory of Open Access Journals (Sweden)

    Sankalp N. Gujar

    2013-11-01

    Full Text Available The aim of this paper is to demonstrate the use of Power line (A.C mains based security system i.e. developing the hardware for a microcontroller module that is to be interfaced to sensors which will detect breaches in security and developing a power line communication modem for sending/receiving data from the microcontroller modules over the power line. As soon as any one of the sensors in an establishment is triggered, the microcontroller will send data to the power line communication modem over UART. The modem will then convert the incoming data into a packet, modulate it using ASK and transmit it over the power line through the coupling circuit. The modem at the security cabin will demodulate this packet and send it to the microcontroller over UART. The microcontroller then activates the alarm and displays the location and nature of the breach on the display

  10. Power Consumption Based Android Malware Detection

    Directory of Open Access Journals (Sweden)

    Hongyu Yang

    2016-01-01

    Full Text Available In order to solve the problem that Android platform’s sand-box mechanism prevents security protection software from accessing effective information to detect malware, this paper proposes a malicious software detection method based on power consumption. Firstly, the mobile battery consumption status information was obtained, and the Gaussian mixture model (GMM was built by using Mel frequency cepstral coefficients (MFCC. Then, the GMM was used to analyze power consumption; malicious software can be classified and detected through classification processing. Experiment results demonstrate that the function of an application and its power consumption have a close relationship, and our method can detect some typical malicious application software accurately.

  11. A Novel Control Method for Unified Power Quality Conditioner Using Nine-Switch Power Conditioner

    Directory of Open Access Journals (Sweden)

    B.Narendra,

    2015-05-01

    Full Text Available A nine-switch power converter having two sets of out-put terminals was recently proposed in place of the traditional back-to-back power converter that uses 12 switches in total. The nine-switch converter has already been proven to have certain advantages, in addition to its component saving topological feature. Despite these advantages, the nine-switch converter has so far found limited applications due to its many perceived performance tradeoffs like requiring an oversized dc-link capacitor, limited amplitude sharing, and constrained phase shift between its two sets of output terminals. Instead of accepting these tradeoffs as limitations, a nineswitch power conditioner is proposed here that virtually “converts” most of these topological short comings into interesting performance advantages. Aiming further to reduce its switching losses, an appropriate discontinuous modulation scheme is proposed and studied here in detail to doubly ensure that maxi-mal reduction of commutations is achieved. With an appropriately designed control scheme then incorporated, the nine-switch converter is shown to favorably raise the overall power quality in experiment, hence justifying its role as a power conditioner at a reduced semiconductor cost.

  12. Design and Implementation of a High Quality Power Supply Scheme for Distributed Generation in a Micro-Grid

    OpenAIRE

    2013-01-01

    A low carbon, high efficiency and high quality power supply scheme for Distributed Generation (DG) in a micro-grid is presented. A three-phase, four-leg DG grid-interfacing converter based on the improved structure of a Unified Power Quality Conditioner (UPQC, including a series converter and a parallel converter) is adopted, and improved indirect and direct control strategies are proposed. It can be observed that these strategies effectively compensate for voltage sags, voltage swells and vo...

  13. Research on the evaluation method with power quality of wind power based on probability theory and evidence theory%基于概率论与证据理论的风电场电能质量评估方法研究

    Institute of Scientific and Technical Information of China (English)

    王勇; 刘金宁; 曹曼; 王文婷

    2012-01-01

    An appraisal method based on probability theory and evidence theory was proposed to evaluate the power quality for wind plant. This method modified the probability theory by fuzzy assessment to estimate every index sample, and introduced the D-S evidence theory to calculate the index weight, which abated the force of experts' subjective factors and made the result more objectively and exactly.%针对风电场电能质量提出一种基于概率论和证据理论的评估方法.该方法综合模糊评判法和概率统计法评价电能质量各指标样本,引入D-S证据理论计算指标权重,减少了主观因素对评估结果的影响,使评估结果更客观、准确.

  14. 基于小波变换的暂态电能质量扰动检测与定位研究%Detection and Location for the Transient Power Quality Based on Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    王安; 粟时平; 邓奇峰; 向莎莎

    2012-01-01

    The paper provides insight study of transient power quality disturbance detection and location of the wavelet transform. First, analyzed the basic principles of wavelet multi-resolution and fast calculation method, and then studied the wavelet transform and sudden-changed signals, noise correlation. On this basis, detailing the process of the application of wavelet transform for transient power quality disturbance detection and location of the principle. And finally, using Matlab software to simulate the process, it gave the simulation results of a variety of power quality disturbance detection and location of detection and location. Theoretical analysis and simulation results show that application of wavelet transform of transient power quality disturbance detection and location has accurate, real-time, easy to implement, etc., it is an ideal of transient power quality disturbance detection and localization.%本文深入探讨了暂态电能质量扰动检测与定位的小波变换方法。首先,分析了小波变换的基本原理及其快速计算的多分辨率方法,然后研究了小波变换极值与信号突变、噪声的相关性,在此基础上,详细阐述了应用小波变换进行暂态电能质量扰动检测与定位的原理过程,最后,运用Matlab软件进行了计算机仿真,给出了各种态电能质量扰动检测与定位检测与定位的仿真结果。理论分析和仿真结果显示应用小波变化对暂态电能质量扰动进行检测和定位,具有精确、实时、易实现等优点,是一种较理想的暂态电能质量扰动检测与定位方法。

  15. An active damper for stabilizing power electronics-based AC systems

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Liserre, Marco

    2013-01-01

    The mutual interactions between the parallel grid-connected converters coupled through the grid impedance tend to result in a number of stability and power quality challenges. To address them, this paper proposes an active damper concept based on a low-power, high-bandwidth power converter. The b...

  16. Effects of a Meditation Program on Nurses' Power and Quality of Life.

    Science.gov (United States)

    Chang, Sun Ju; Kwak, Eun Young; Hahm, Bong-Jin; Seo, Se Hee; Lee, Da Woon; Jang, Sun Joo

    2016-07-01

    This study evaluated the effects of meditation programs on nurses' power and quality of life. In this study, Barrett's power theory derived from Rogers' unitary human being science was used as a theoretical framework. A randomized controlled design with 50 recruited and randomly allocated participants was used. The results demonstrated that the eight-week meditation program significantly improved nurses' power and quality of life. These results suggest that meditation has positive effects on power and quality of life.

  17. Using employer purchasing power to improve the quality of perinatal care.

    Science.gov (United States)

    Castles, A G; Milstein, A; Damberg, C L

    1999-01-01

    Large employers have become increasingly involved in helping to set the agenda for quality measurement and improvement. Moreover, they are beginning to hold health care organizations accountable for their performance through marketplace incentives, including the public reporting of comparative quality data and the linkage of reimbursement to performance on quality measures. The Pacific Business Group on Health (PBGH) is an employer coalition that has been prominent in establishing models for collaborative quality measurement and improvement in the California marketplace. PBGH's involvement in quality stems from an environment in which purchasers were faced with high health care costs, yet virtually no information with which to assess the value their employees received from that care. Research indicating widespread variation in performance across health care organizations and seemingly limited oversight for quality of care within the industry has further motivated purchasers' efforts to better understand the quality of care being delivered to their em-ployees. Using the purchasing power of employers representing 2.5-million covered lives, PBGH endeavors to encourage the transition of the health care marketplace from one that competes solely on price to one that competes on price and quality. This entails collaborating with the health care industry to develop and publicly report valid performance data for use by both large employers and consumers of health care services. It also includes communicating to the marketplace purchasers' commitment to making purchasing decisions based on quality as well as cost. PBGH efforts to measure, report, and improve quality have been demonstrated by several undertakings in the perinatal care arena, including research to assess cesarean section rates and newborn readmission rates across California hospitals.employer coalition, purchaser, quality measurement, quality improvement, report cards, perinatal quality of care.

  18. Quality-based fingerprint segmentation

    CSIR Research Space (South Africa)

    Mngenge, NA

    2012-06-01

    Full Text Available is block-wise, it utilizes the auto-correlation matrix of gradients and its eigenvalue to compute the score quality measure of each block. The score quality measures both local contrast and orientation in each block. The threshold is computed by taking...

  19. Influence of wind gusts in power quality on wind farms

    Directory of Open Access Journals (Sweden)

    Gonzalo Guerrón

    2014-09-01

    Full Text Available (Received: 2014/04/30 - Accepted: 2014/09/22World energy matrix is changing due to the increase of energy consumption in the last years. Installation of unconventional renewable energy plants in many countries has become a solution to this event. Integration of this type of energy to the electric network causes interest in the study of phenomena that affects energy production. This document is a review of concepts and events occurring on energy quality and how they interact in a wind farm. The efficiency of wind turbines is affected by many factors, the most outstanding are: substations activities and weather issues such as wind gusts, which causes variations in the power curve. Constant monitoring on electric systems and data processing offers a high potential in improving the process of production and distribution of energy.

  20. Application of a power quality analyser to the monitoring of sand preparation processes in foundry plants

    Directory of Open Access Journals (Sweden)

    K. Smyksy

    2011-10-01

    Full Text Available Process control plays a major role in supervision and identification of states, for example in monitoring of electric circuits power- supplying the foundry machines and devices, such as sand preparation processes, moulding technologies, melting, cleaning and finishing of castings. The monitoring and control equipment includes the power quality analysers. Testing is done using a Japanese analyser KEW 6319 (Kyoritsu applied to monitoring of the sand preparation process in a foundry plant with low level of mechanization, equipped with the sand preparation unit based on a roller mixer.

  1. 基于 FFT 与小波变换结合的嵌入式电能质量检测系统%The Embedded System for Power Quality Detection Based on FFT and Wavelet Theory

    Institute of Scientific and Technical Information of China (English)

    沈海滨; 郑寿森; 祁新梅

    2014-01-01

    The advantages of FFT application in frequency domain and wavelet theory in time domain were studied , and an Embedded System for Power Quality Detection ( ESPQD ) based on radix-4 FFT and Wavelet Transform is developed .The ESPQD uses the wavelet theory to monitor the transient power qualityincluding voltage dip , voltage swell and so on .FFT is applied to analysis harmonics of electrical signals in steady-state.Three different states including steady-state, voltage dip and transient interference were tested with both the ESPQD hardware system and Matlab simulation for verification .The results show that the amplitude error of fundamental wave is within 0.3%, meeting the A level standard of the u-tility grid standards GB/T 14549-93 about harmonic measuring instruments .The system can also pre-cisely and quickly detect the abrupt changes of the electrical signals during voltage dip and transient in -terference .The time difference between ESPQD and simulation is within 1.6 ms and the system can be used in real time measurement .%该文研究应用FFT在频域与小波变换在时域的优势,设计搭建了基_4 FFT与Daub4小波变换结合的嵌入式电能质量检测系统。该系统利用小波变换检测电压骤升、骤降等暂态问题,使用FFT分析稳态下电信号谐波。为验证系统的实际检测能力,分别对稳态、电压骤降、电压暂态干扰三种状况进行了实时监测测试和Matlab软件分析,结果表明:该嵌入式电能质量检测系统在稳态时,检测基波幅值的误差为0.3%,满足公用电网GB/T 14549-93对谐波测量仪器的A级标准;同时,在电压骤降、电压暂态干扰状态下也能准确检测到电信号的突变时间,实际系统检测和软件仿真结果误差在1.6 ms内,满足实时性要求。

  2. Compensation for Power Quality Improvement in Electric Arc Furnace with Considering Economic Index

    OpenAIRE

    2012-01-01

    In recent years, on the one hand with increasing application of nonlinear loads in power systems and no sinusoidal currents that extracted from system, and on the other hand increasing loads sensitive to power quality and destructive effects of nonlinear loads on power quality of power systems, compensation these loads has been converted to one of the main issues in power systems. The use of flexible AC transmission system (FACTS) devices is one of the most progressive methods which are used ...

  3. A Single-Phase Voltage-Controlled Grid-Connected Photovoltaic System With Power Quality Conditioner Functionality

    DEFF Research Database (Denmark)

    Kerekes, Tamas; Liserre, Marco; Mastromauro, R. A.

    2009-01-01

    Future ancillary services provided by photovoltaic (PV) systems could facilitate their penetration in power systems. Also low power PV systems can be designed to improve the power quality. This paper presents a single-phase photovoltaic system that provides grid voltage support and compensation...... of harmonic distortion at the point of common coupling (PCC) thanks to a repetitive controller. The power provided by the PV panels is controlled by a Maximum Power Point Tracking (MPPT) algorithm based on the incremental conductance method specifically modified to control the phase of the PV inverter voltage...

  4. A novel electric power quality monitoring system for transient analysis

    OpenAIRE

    2014-01-01

    Electricity is vital for our daily life in modern cites. In order to ensure its reliability and supply, an electric power monitoring system is indispensable in an electric power system. Currently, most electric power monitoring systems are designed for steady-state monitoring only. They may not be able to monitor instantaneous power disturbances, such as voltage surge, happened in electric power systems. In fact, instantaneous power disturbances are frequently found in electric power systems,...

  5. 基于db4提升小波的暂态电能质量的检测%Detection of Transient Power Quality Based on db4 Lifting Wavelet

    Institute of Scientific and Technical Information of China (English)

    孙影; 柴玉华; 桑松

    2012-01-01

    Transient disturbances are one of the most important factors it influence power quality in power system, and do harm to the power system and power users. According to non-stationary and burst capability of the transient disturbing signals, this paper analyzes the characteristics of db4 lifting wavelet transient, proposes a structure, containing update—predict—update—predict—update, choses the appropriate sampling frequency and decomposition level, to detect and locate trie transient power quality disturbances. In the MATLAB environment, the db4 lifting wavelet transient is used for detection and location on the voltage sags, voltage swells, voltage interruption, transient pulse, transient oscillation and other transient power quality disturbing signals. Simulation results indicates that the method has a millisecond level accuracy and can be implemented precisely positioning on starting and ending time of the disturbance signals, and with high calculation speed.%暂态扰动是影响电能质量的重要因素之一,对电力用户和电力系统都会产生危害.针对暂态扰动信号具有非平稳性、突变性的特点,分析了db4提升小波变换的特性,提出了更新-预测-更新预测-更新的结构,选择了合适的采样频率和分解层数,对暂态电能质量扰动信号进行检测与定位.在MATLAB仿真环境下,利用db4提升小波变换对电压暂降、暂升、中断以及暂态脉冲、振荡等几种暂态电能质量扰动信号进行检测与定位,仿真结果表明,该方法可以实现对扰动信号起止时刻更为准确的检测与定位,且计算速度快.

  6. A Market-Based Virtual Power Plant

    DEFF Research Database (Denmark)

    You, Shi; Træholt, Chresten; Poulsen, Bjarne

    2009-01-01

    The fast growing penetration of Distributed Energy Resources (DER) and the continuing trend towards a more liberalized electricity market requires more efficient energy management strategies to handle both emerging technical and economic issues. In this paper, a market-based Virtual Power Plant...

  7. Power quality and integration of wind farms in weak grids in India

    DEFF Research Database (Denmark)

    Sørensen, Poul Ejnar; Madsen, Peter Hauge; Vikkelsø, A.;

    2000-01-01

    This is the final report of a joint Danish and Indian project "Power Quality and Integration of Wind Farms in Weak Grids". The power quality issues have been studied and analysed with the Indian conditions as a case. On the basis of meetings with Danishwind turbine industry, Indian electricity...... boards, nodal agencies, wind turbine industry and authorities, the critical power quality as-pects in India have been identified. Measurements on selected wind farms and wind turbines have quantified the powerquality, and analyses of power quality issues, especially reactive power compensation, have been...

  8. Silver based batteries for high power applications

    Science.gov (United States)

    Karpinski, A. P.; Russell, S. J.; Serenyi, J. R.; Murphy, J. P.

    The present status of silver oxide-zinc technology and applications has been described by Karpinski et al. [A.P. Karpinski, B. Makovetski, S.J. Russell, J.R. Serenyi, D.C. Williams, Silver-Zinc: status of technology and applications, Journal of Power Sources, 80 (1999) 53-60], where the silver-zinc couple is still the preferred choice where high specific energy/energy density, coupled with high specific power/power density are important for high-rate, weight or size/configuration sensitive applications. Perhaps the silver oxide cathode can be considered one of the most versatile electrode materials. When coupled with other anodes and corresponding electrolyte management system, the silver electrode provides for a wide array of electrochemical systems that can be tailored to meet the most demanding, high power requirements. Besides zinc, the most notable include cadmium, iron, metal hydride, and hydrogen electrode for secondary systems, while primary systems include lithium and aluminum. Alloys including silver are also available, such as silver chloride, which when coupled with magnesium or aluminum are primarily used in many seawater applications. The selection and use of these couples is normally the result of a trade-off of many factors. These include performance, safety, risk, reliability, and cost. When high power is required, silver oxide-zinc, silver oxide-aluminum, and silver oxide-lithium are the most energetic. For moderate performance (i.e., lower power), silver oxide-zinc or silver-cadmium would be the system of choice. This paper summarizes the suitability of the silver-based couples, with an emphasis on the silver-zinc system, as primary or rechargeable power sources for high energy/power applications.

  9. Adaline and its application in power quality disturbances detection and frequency tracking

    Energy Technology Data Exchange (ETDEWEB)

    Ai, Qian; Zhou, Yuguang; Xu, Weihua [Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030 (China)

    2007-04-15

    For power quality detection, several techniques have been proposed in the literature. In the paper, some shortcomings of the conventional methods that are usually used to analyze the power quality issues are firstly pointed out. A kind of artificial neural network, adaline, and its new algorithm for analysis of power quality are presented. The new algorithm has the advantages of being simply calculated and easily implemented through hardware. The simulating results of voltage quality disturbances detection and especially frequency tracking demonstrate that the new adaline and its algorithm can be applied to the precise analysis for power quality. (author)

  10. CLASSIFICATION OF POWER QUALITY CONSIDERING VOLTAGE SAGS IN DISTRIBUTION SYSTEMS USING KDD PROCESS

    Directory of Open Access Journals (Sweden)

    Anderson Roges Teixeira Góes

    2015-08-01

    Full Text Available In this paper, we propose a methodology to classify Power Quality (PQ in distribution systems based on voltage sags. The methodology uses the KDD process (Knowledge Discovery in Databases in order to establish a quality level to be printed in labels. The methodology was applied to feeders on a substation located in Curitiba, Paraná, Brazil, considering attributes such as sag length (remnant voltage, duration and frequency (number of occurrences on a given period of time. On the Data Mining Stage (the main stage on KDD Process, three different techniques were used, in a comparative way, for pattern recognition, in order to achieve the quality classification for the feeders: Artificial Neural Networks (ANN; Support Vector Machines (SVM and Genetic Algorithms (GA. By printing a label with quality level information, utilities companies (power concessionaires can get better organized for mitigation procedures by establishing clear targets. Moreover, the same way costumers already receive information regarding PQ based on interruptions, they will also be able to receive information based on voltage sags.

  11. Quality Assurance in Nuclear Power Plants; La garantia de calidad en la Centrales Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Zamarron Casinello, J. M. (CC.AA. Almaraz-Trillo); Gasca Pinilla, R. (Asociacion Nuclear Asco-Vandellos II); Sala Candela, A. (IBERDROLA); Valle Pena (NUCLENOR); Ruiz Rodriguez, C. (UNION FENOSA)

    2000-07-01

    In 1970, 10CFR50 Appendix B. Quality Assurance Criteria for Nuclear Power Plants & Fuel Reprocessing Plants, was approved in USA. This is based on 18 criteria and requires American nuclear power plants to establish as quickly as possible a Quality Assurance Program (QAP) specifying how to comply with the criteria contained in this Appendix. The Ministry of Industry required that this standard be observed in Spanish plants. In The first-generation plants (Jose Cabrera, Santa Maria de Garona and Vandellos 1), which were built before this new standard was developed, the concept of Quality Assurance has only been applied to the operating phase, whereas in second-generation plants (Almaraz, Asco3 and Cofrentes) and third-generation plants (Vandellos 2 and Trillo), the concept was applied from the very beginning of the project: design phases, construction and finally plant operation. In 1979, the IAEA publihed practical code 50-C-QA as an international reference document. It contains 13 criteria that coincide with and complement those established in Appendex B of 10CFR50. As a result, the nuclear power plants in all neighboring countries will be enforcing similar Quality Assurance criteria. (Author)

  12. Power quality analysis of hybrid renewable energy system

    Directory of Open Access Journals (Sweden)

    Rinchin W. Mosobi

    2015-12-01

    Full Text Available An hybrid renewable energy sources consisting of solar photovoltaic, wind energy system, and a microhydro system is proposed in this paper. This system is suitable for supplying electricity to isolated locations or remote villages far from the grid supply. The solar photovoltaic system is modeled with two power converters, the first one being a DC-DC converter along with an maximum power point tracking to achieve a regulated DC output voltage and the second one being a DC-AC converter to obtain AC output. The wind energy system is modeled with a wind-turbine prime mover with varying wind speed and fixed pitch angle to drive an self excited induction generator (SEIG. Owing to inherent drooping characteristics of the SEIG, a closed loop turbine input system is incorporated. The microhydro system is modeled with a constant input power to drive an SEIG. The three different sources are integrated through an AC bus and the proposed hybrid system is supplied to R, R-L, and induction motor loads. A static compensator is proposed to improve the load voltage and current profiles; it also mitigates the harmonic contents of the voltage and current. The static synchronous compensator is realized by means of a three-phase IGBT-based current-controlled voltage source inverter with a self-supporting DC bus. The complete system is modeled and simulated using Matlab/Simulink. The simulation results obtained illustrate the feasibility of the proposed system and are found to be satisfactory.

  13. Process-Based Quality (PBQ) Tools Development

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, J.L.

    2001-12-03

    The objective of this effort is to benchmark the development of process-based quality tools for application in CAD (computer-aided design) model-based applications. The processes of interest are design, manufacturing, and quality process applications. A study was commissioned addressing the impact, current technologies, and known problem areas in application of 3D MCAD (3-dimensional mechanical computer-aided design) models and model integrity on downstream manufacturing and quality processes. The downstream manufacturing and product quality processes are profoundly influenced and dependent on model quality and modeling process integrity. The goal is to illustrate and expedite the modeling and downstream model-based technologies for available or conceptual methods and tools to achieve maximum economic advantage and advance process-based quality concepts.

  14. Localization and identification of transient power quality disturbances based on generalized S-transform%基于广义S变换的暂态电能质量扰动定位与识别

    Institute of Scientific and Technical Information of China (English)

    刘奇; 周雒维; 卢伟国

    2012-01-01

    S-transform has fixed time-frequency resolution, leading to poor results of localizing transient power quality disturbances. A new method to localize the disturbances is proposed based on generalized S-transform. The method detects mutation peak in the high frequency time-amplitude curve, in order to increase localization accuracy. At first, modulus time-frequency matrix is calculated by generalized S-transform, then the disturbances' start-stop time is localized using the high frequency time-amplitude curve, and four identification features are extracted according to maximum frequency spectrum curve, fundamental frequency amplitude curve and the localization results. At last, automatic classification of disturbance signals is performed by use of a rule-based decision tree. Simulation results show that the proposed localization method is simple and intuitive, with high accuracy. The number of identification features is small and they are effective with good classification results.This work is supported by National Natural Science Foundation of China (No. 51077137).%S变换由于时频分辨率固定,从而导致定位暂态电能质量扰动的效果差.提出一种基于广义S变换的扰动定位新方法,利用高频处时间幅值曲线的突变点峰值进行定位检测,以提高扰动的定位精度.首先通过广义S变换得到扰动信号的模时频矩阵,然后利用高频处时间幅值曲线定位扰动的起止时刻,再根据最大频谱曲线、基频幅值曲线与定位结果提取四个识别特征量,最后基于分类规则树方法实现扰动信号的自动分类.仿真结果表明,所提出的定位方法简单直观,精度较高;提取的识别特征量少而有效,分类效果良好.

  15. Lunar Base Thermoelectric Power Station Study

    Science.gov (United States)

    Determan, William; Frye, Patrick; Mondt, Jack; Fleurial, Jean-Pierre; Johnson, Ken; Stapfer, Gerhard; Brooks, Michael; Heshmatpour, Ben

    2006-01-01

    Under NASA's Project Prometheus, the Nuclear Space Power Systems Program, the Jet Propulsion Laboratory, Pratt & Whitney Rocketdyne, and Teledyne Energy Systems have teamed with a number of universities, under the Segmented Thermoelectric Multicouple Converter (STMC) Task, to develop the next generation of advanced thermoelectric converters for space reactor power systems. Work on the STMC converter assembly has progressed to the point where the lower temperature stage of the segmented multicouple converter assembly is ready for laboratory testing, and promising candidates for the upper stage materials have been identified and their properties are being characterized. One aspect of the program involves mission application studies to help define the potential benefits from the use of these STMC technologies for designated NASA missions such as a lunar base power station where kilowatts of power would be required to maintain a permanent manned presence on the surface of the moon. A modular 50 kWe thermoelectric power station concept was developed to address a specific set of requirements developed for this particular mission concept. Previous lunar lander concepts had proposed the use of lunar regolith as in-situ radiation shielding material for a reactor power station with a one kilometer exclusion zone radius to minimize astronaut radiation dose rate levels. In the present concept, we will examine the benefits and requirements for a hermetically-sealed reactor thermoelectric power station module suspended within a man-made lunar surface cavity. The concept appears to maximize the shielding capabilities of the lunar regolith while minimizing its handling requirements. Both thermal and nuclear radiation levels from operation of the station, at its 100-m exclusion zone radius, were evaluated and found to be acceptable. Site preparation activities are reviewed as well as transport issues for this concept. The goal of the study was to review the entire life cycle of the

  16. On power quality measures for wind-diesel systems. A conceptual framework and a case study

    Energy Technology Data Exchange (ETDEWEB)

    Bindner, H.W. [Risoe National Lab., Test Station for Wind Turbines, Roskilde (Denmark); Lundager, P. [Darup Associates Inc., CAT Science and Technology Park, Roskilde (Denmark)

    1995-01-01

    By their definition wind diesel systems are electrical power supply systems with variations of both voltage and frequency of the grid. In order to evaluate prospective systems designs in terms of power quality and compare with alternatives in a rational way it is necessary to work within an agreed framework of definitions of the measures to be applied. This paper contributes to the development by presenting a conceptual framework for power quality in terms of both grid frequency and voltage in a time scale, where system dynamics in the usual sense is included, but switching and harmonics are not considered. Concerning voltage variations the proposed framework rests on previous work (e.g. CENELEC) and current work (DEFU/Risoe and Mayer/Joule II), and the main contribution of this paper concerns frequency variations. The framework consists of definitions of power quality measures, a set of criteria for the power quality and a technique for modelling the system. In addition to this, when possible, measurements are made to calibrate the model or verify the predicted behaviour of the system. The definitions are based on statistical measures for the frequency of occurrence of instantaneous and mean values. The paper will outline criteria in a qualitative way. The modelling technique referred to in the paper is the one used in the JODYMOD Dynamic Wind Diesel Simulation Package, developed by European team with support from the JOULE I programme. The paper includes a case study, in which the fram work is applied on the simple and robust experimental wind diesel system at Risoe National Laboratory. (au)

  17. Combined Power Quality Disturbances Recognition Using Wavelet Packet Entropies and S-Transform

    Directory of Open Access Journals (Sweden)

    Zhigang Liu

    2015-08-01

    Full Text Available Aiming at the combined power quality +disturbance recognition, an automated recognition method based on wavelet packet entropy (WPE and modified incomplete S-transform (MIST is proposed in this paper. By combining wavelet packet Tsallis singular entropy, energy entropy and MIST, a 13-dimension vector of different power quality (PQ disturbances including single disturbances and combined disturbances is extracted. Then, a ruled decision tree is designed to recognize the combined disturbances. The proposed method is tested and evaluated using a large number of simulated PQ disturbances and some real-life signals, which include voltage sag, swell, interruption, oscillation transient, impulsive transient, harmonics, voltage fluctuation and their combinations. In addition, the comparison of the proposed recognition approach with some existing techniques is made. The experimental results show that the proposed method can effectively recognize the single and combined PQ disturbances.

  18. Assessment of Power Quality Disturbances in the Distribution System Using Kalman Filter and Fuzzy Expert System

    Directory of Open Access Journals (Sweden)

    P. Kalyana Sundaram

    2016-11-01

    Full Text Available The paper presents a novel method for the assessment of the power quality disturbances in the distribution system using the Kalman filter and fuzzy expert system. In this method the various classes of disturbance signals are developed through the Matlab Simulink on the test system model. The characteristic features of the disturbance signals are extracted based on the Kalman filter technique. The obtained features such as amplitude and slope are given as the two inputs to the fuzzy expert system. It applied some rules on these inputs to assess the various PQ disturbances. Fuzzy classifier has been carried out and tested for various power quality disturbances. The results clearly demonstrate that the proposed method in the distribution system has the ability to detect and classify PQ events.

  19. Environmental Quality and the U.S. Power Sector: Air Quality, Land Use and Environmental Justice

    Energy Technology Data Exchange (ETDEWEB)

    Massetti, Emanuele [Georgia Inst. of Technology, Atlanta, GA (United States); Brown, Marilyn Ann [Georgia Inst. of Technology, Atlanta, GA (United States); Lapsa, Melissa Voss [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sharma, Isha [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bradbury, James [U.S. Dept. of Energy, Washington, DC (United States); Cunliff, Colin [American Association for the Advancement of Science, Washington, DC (United States); Li, Yufei [Georgia Inst. of Technology, Atlanta, GA (United States)

    2017-01-04

    This baseline report summarizes key environmental quality issues associated with electricity generation, transmission, distribution, and end use in the United States. Its scope includes non-greenhouse gas air pollution (i.e., sulfur dioxide, nitrogen oxides, particulate matter and hazardous air pollutants), land use, water pollution, ecological impacts, human health, and environmental justice. The discussion characterizes both current impacts and recent trends, as well as assessments of key drivers of change. For example, the air emissions section includes a quantitative decomposition analysis of the drivers of change in sulfur dioxide emissions reductions from coal-fired power plants. The report is divided into four topical sections: air emissions, land use and ecology, water quality, and environmental justice.

  20. Causes, Effects and Solutions of Poor Quality Problems in the Power Systems

    Directory of Open Access Journals (Sweden)

    Vikash Anand

    2014-05-01

    Full Text Available The term electric power quality broadly refers to maintaining a nearly sinusoidal power distribution bus voltage at rated magnitude and frequency. In addition, the energy supplied to a consumer must be uninterrupted from reliability point of view. Though power quality is mainly a distribution system problem, power transmission system may also have impact on quality of power. With the ever-increasing use of sophisticated controls and equipment in industrial, commercial, institutional, and governmental facilities, the continuity, reliability, and quality of electrical service has become extremely crucial to many power users. Electrical systems are subject to a wide variety of power quality problems which can interrupt production processes, affect sensitive equipment, and cause downtime, scrap, and capacity losses. Momentary voltage fluctuations can disastrously impact production. . . extended outages have a greater impact.

  1. The Level of Power Quality Measurement and Evaluation in A Stone Crusher Plant

    Directory of Open Access Journals (Sweden)

    Mustafa ŞEKKELİ

    2009-03-01

    Full Text Available Both electric utilities and end users of electric power are becoming increasingly concerned about the quality of electric power. Quality of electrical energy in the electrical system that is requested continuous power (uninterrupted power, constant frequency and with constant amplitude can be explained by sinusoidal voltage. Deformation of voltage in the form of sinusoidal waveform is explained as a harmonic. Harmonics are most important factors in decreasing quality of energy in the electrical system. In industrial plants, existence of harmocins and voltage drop, causes serious problems both in plant and network. This problem affects the cost. In this study, a power quality measurements are carried out in stone crusher plant. Harmonics and voltage drop has been measured and evaluated with the power analyzer. In the power quality measurements, harmonic level of the plant is not so bad. However, it is recommended that compensation system with harmonic elimination can be established in plant.

  2. FC/PV Fed SAF with Fuzzy Logic Control for Power Quality Enhancement

    Directory of Open Access Journals (Sweden)

    R. Balamurugan

    2015-02-01

    Full Text Available In this paper, a Fuel cell (FC / Photovoltaic cell (PV/ Battery operated three phase Shunt Active power Filter (SAF is proposed for improving the power quality at the utility side. Fuzzy based instantaneous p-q theory control is proposed for SAF. This SAF consists of Voltage Source PWM Converter (VSC and a DC link capacitor supplied by a FC/PV/Battery. The filter provides harmonic mitigation with reactive power compensation and neutral compensation for loads at the Point of Common Coupling (PCC. A Single switch boost DC-DC converter connects the FC/PV/Battery with the VSC to maintain the load. The performance of the proposed SAF is tested in MATLAB / SIMULINK environment with Fuzzy logic controller (FLC. The controller maintains the DC link voltage based on the current reference generated by the p-q theory. The Hysteresis PWM current controller is employed to generate the gating pulses to the switches in VSC. The simulation results of the proposed SAF validate the effectiveness of FLC in power quality enhancement.

  3. Low power adder based digital filter for QRS detector.

    Science.gov (United States)

    Murali, L; Chitra, D; Manigandan, T

    2014-01-01

    Most of the Biomedical applications use dedicated processors for the implementation of complex signal processing. Among them, sensor network is also a type, which has the constraint of low power consumption. Since the processing elements are the most copiously used operations in the signal processors, the power consumption of this has the major impact on the system level application. In this paper, we introduce low power concept of transistor stacking to reduce leakage power; and new architectures based on stacking to implement the full adder and its significance at the digital filter level for QRS detector are implemented. The proposed concept has lesser leakage power at the adder as well as filter level with trade-off in other quality metrics of the design. This enabled the design to be dealt with as the low-power corner and can be made adaptable to any level of hierarchical abstractions as per the requirement of the application. The proposed architectures are designed, modeled at RTL level using the Verilog-HDL, and synthesized in Synopsys Design Compiler by mapping the design to 65 nm technology library standard cells.

  4. Compensation for Power Quality Improvement in Electric Arc Furnace with Considering Economic Index

    Directory of Open Access Journals (Sweden)

    Ghazanfar Shahgholian

    2012-03-01

    Full Text Available In recent years, on the one hand with increasing application of nonlinear loads in power systems and no sinusoidal currents that extracted from system, and on the other hand increasing loads sensitive to power quality and destructive effects of nonlinear loads on power quality of power systems, compensation these loads has been converted to one of the main issues in power systems. The use of flexible AC transmission system (FACTS devices is one of the most progressive methods which are used for improving power quality. In this paper, series and parallel compensators of static synchronous compensator (STATCOM and dynamic voltage restorer (DVR are introduced and the comparison of these two in compensating of power quality phenomena from electric arc furnace is provided. STATCOM is a shunt active filter and DVR is a series active filter. Method which has been selected for control of every one of these devices is an optimal control way that it minimizes power losses.

  5. The climate and air-quality benefits of wind and solar power in the United States

    Science.gov (United States)

    Millstein, Dev; Wiser, Ryan; Bolinger, Mark; Barbose, Galen

    2017-09-01

    Wind and solar energy reduce combustion-based electricity generation and provide air-quality and greenhouse gas emission benefits. These benefits vary dramatically by region and over time. From 2007 to 2015, solar and wind power deployment increased rapidly while regulatory changes and fossil fuel price changes led to steep cuts in overall power-sector emissions. Here we evaluate how wind and solar climate and air-quality benefits evolved during this time period. We find cumulative wind and solar air-quality benefits of 2015 US$29.7-112.8 billion mostly from 3,000 to 12,700 avoided premature mortalities, and cumulative climate benefits of 2015 US$5.3-106.8 billion. The ranges span results across a suite of air-quality and health impact models and social cost of carbon estimates. We find that binding cap-and-trade pollutant markets may reduce these cumulative benefits by up to 16%. In 2015, based on central estimates, combined marginal benefits equal 7.3 ¢ kWh‑1 (wind) and 4.0 ¢ kWh‑1 (solar).

  6. Understanding coal quality and its relationship to power plant performance and costs

    Energy Technology Data Exchange (ETDEWEB)

    Jennison, K.D.; Stallard, G.S. [Black & Veatch International, Overland Park, KS (United States)

    1995-12-01

    The availability of reliable, reasonably priced energy is a necessary cornerstone for established and emerging economies. In addition to addressing coal quality issues strictly at a plant level, it is now prudent to consider long-term performance and economics of particular fuel sources to be selected in the light of system economics and reliability. In order to evaluate coal quality issues in a more comprehensive manner, it is important to develop both an approach and a set of tools which can support the various phases of the planning/analysis processes. The processes must consider the following: (1) Cost/availability of other potential coal supplies, including {open_quotes}raw{close_quotes} domestic sources, {open_quotes}cleaned {close_quotes} domestic sources, and other internationally marketed coals. (2) Power plant performance issues as function of plant design and fuel properties. (3) System expansion plans, candidate technologies, and associated capital and operating costs. (4) Projected load demand, for system and for individual units within the system. (5) Legislative issues such as environmental pressures, power purchase agreements, etc. which could alter the solution. (6) Economics of potential plans/strategies based on overall cost-effectiveness of the utility system, not just individual units. (7) Anticipated unit configuration, including addition of environmental control equipment or other repowering options. The Coal Quality Impact Model (CQIM{trademark}) is a PC-based computer program capable of predicting coal-related cost and performance impacts at electric power generating sites. The CQIM was developed for EPRI by Black & Veatch and represents over a decade of effort geared toward developing an extensible state-of-the-art coal quality assessment tool. This paper will introduce CQIM, its capabilities, and its application to Eastern European coal quality assessment needs.

  7. Power quality disturbance analysis based on wavelettransform and improved Prony method%基于小波变换和改进Prony方法的电能质量扰动分析

    Institute of Scientific and Technical Information of China (English)

    任子晖; 刘昊岳; 徐进霞

    2016-01-01

    传统的电能质量分析方法通常只针对某一类特定的电能质量扰动问题进行分析,为了实现对常见电能扰动信号进行有效的区分与辨识,提出小波分析与 Prony 方法相结合的分析算法。首先引入小波多分辨分析(multi-resolution analysis),选取合适的小波函数对扰动信号进行分解,判断分解信号是否存在模极大值点,从而区分出稳态与暂态电能质量扰动问题。对于暂态扰动问题,优化了Mallat重构层数,提取出暂态扰动波形,以实现对扰动类型的判断。对于稳态扰动问题,改进Prony方法对于系统阶数估计的过程,提高了参数辨识精度。最后对混合扰动信号进行分析,并使用Matlab进行了仿真和实验验证。仿真和实验结果表明,该算法能准确地识别出各种类型的电能质量扰动信号。%The traditional analysis method for power quality only analyzes one kind of specific problems. In order to effectively distinguish and identify common power disturbance signal, an algorithm combining wavelet analysis with Prony method is proposed. Firstly,the wavelet multi-resolution analysis is introduced, the appropriate wavelet function is proposed to decompose the disturbance signal and whether the decomposed signal modulus maxima exist is judged.Thus the steady state and transient state power quality disturbance problems are distinguished. For the transientdisturbance problem, Mallat refactoring layer is optimized, the transient disturbance waveform are extracted andthe type of disturbance is distinguished. For the steady disturbance problem, the process of estimating system order by Prony method and the accuracy of parameter identification are improved.Finally,mixed disturbance signals are analyzedandthe simulation and experimental verification are performed by Matlab. Results of simulation and experiments show that the proposed method algorithm can accurately identify the various types

  8. Power Quality Disturbance ldentification Based on LMD Energy Entropy and GK Fuzzy Clustering%基于LMD能量熵和GK模糊聚类的电能质量扰动识别

    Institute of Scientific and Technical Information of China (English)

    张淑清; 李盼; 冯璐; 李男; 张航飞; 乔永静; 徐剑涛

    2016-01-01

    提出一种基于局部均值分解方法( LMD)能量熵和GK模糊聚类相结合的电能质量扰动识别的新方法。LMD能量熵具有局域化的特性并且能够表征扰动信号复杂度,可以量化扰动特征。GK模糊聚类可处理分布不规则数据,因此可对各种扰动信号进行识别。非平稳的扰动信号首先由LMD分解,得到若干个有物理意义的乘积函数( PF),通过Shannon熵的特征筛选方法对PF分量进行筛选,求取其能量熵组成特征向量。进而通过GK聚类对特征向量进行识别分类。实验表明,该方法能够有效准确地识别电能扰动信号,并具有良好的抗噪性。%A new approach for power quality disturbance identification based on local mean decomposition( LMD ) energy entropy and GK fuzzy clustering is introduced. LMD energy entropy has localized features and can represent the complexity of disturbance signals,quantizing disturbance characteristic. GK fuzzy clustering can process data with irregular distribution,so as to identify various disturbance signals. Non-stationary disturbance signals are decomposed by LMD, obtaining a number of product function( PF)components with physical meaning,which is screened out by Shannon entropy feature selection methods to obtain the energy entropies and construct the eigenvectors. The constructed eigenvectors are further put into GK classifier to recognize different identification types. The experiment demonstrated that the method is able to identify disturbance signals accurately,with better anti-noise performance.

  9. Fuzzy Logic Based Power System Contingency Ranking

    Directory of Open Access Journals (Sweden)

    A. Y. Abdelaziz

    2013-02-01

    Full Text Available Voltage stability is a major concern in planning and operations of power systems. It is well known that voltage instability and collapse have led to major system failures. Modern transmission networks are more heavily loaded than ever before to meet the growing demand. One of the major consequences resulted from such a stressed system is voltage collapse or instability. This paper presents maximum loadability identification of a load bus in a power transmission network. In this study, Fast Voltage Stability Index (FVSI is utilized as the indicator of the maximum loadability termed as Qmax. In this technique, reactive power loading will be increased gradually at particular load bus until the FVSI reaches close to unity. Therefore, a critical value of FVSI was set as the maximum loadability point. This value ensures the system from entering voltage-collapse region. The main purpose in the maximum loadability assessment is to plan for the maximum allowable load value to avoid voltage collapse; which is important in power system planning risk assessment.The most important task in security analysis is the problem of identifying the critical contingencies from a large list of credible contingencies and ranks them according to their severity. The condition of voltage stability in a power system can be characterized by the use of voltage stability indices. This paper presents fuzzy approach for ranking the contingencies using composite-index based on parallel operated fuzzy inference engine. The Line Flow index (L.F and bus Voltage Magnitude (VM of the load buses are expressed in fuzzy set notation. Further, they are evaluated using Fuzzy rules to obtain overall Criticality Index. Contingencies are ranked based on decreasing order of Criticality Index and then provides the comparison of ranking obtained with FVSI method.

  10. Ultracapacitor-Based Uninterrupted Power Supply System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2011-01-01

    The ultracapacitor-based uninterrupted power supply (UPS) system enhances system reliability; reduces life-of-system, maintenance, and downtime costs; and greatly reduces environmental impact when compared to conventional UPS energy storage systems. This design provides power when required and absorbs power when required to smooth the system load and also has excellent low-temperature performance. The UPS used during hardware tests at Glenn is an efficient, compact, maintenance-free, rack-mount, pure sine-wave inverter unit. The UPS provides a continuous output power up to 1,700 W with a surge rating of 1,870 W for up to one minute at a nominal output voltage of 115 VAC. The ultracapacitor energy storage system tested in conjunction with the UPS is rated at 5.8 F. This is a bank of ten symmetric ultracapacitor modules. Each module is actively balanced using a linear voltage balancing technique in which the cell-to-cell leakage is dependent upon the imbalance of the individual cells. The ultracapacitors are charged by a DC power supply, which can provide up to 300 VDC at 4 A. A constant-voltage, constant-current power supply was selected for this application. The long life of ultracapacitors greatly enhances system reliability, which is significant in critical applications such as medical power systems and space power systems. The energy storage system can usually last longer than the application, given its 20-year life span. This means that the ultracapacitors will probably never need to be replaced and disposed of, whereas batteries require frequent replacement and disposal. The charge-discharge efficiency of rechargeable batteries is approximately 50 percent, and after some hundreds of charges and discharges, they must be replaced. The charge-discharge efficiency of ultracapacitors exceeds 90 percent, and can accept more than a million charges and discharges. Thus, there is a significant energy savings through the efficiency improvement, and there is far less

  11. Improved Power Quality Monitoring through Phasor Measurement Unit Data Interpretation

    DEFF Research Database (Denmark)

    Pertl, Michael; Marinelli, Mattia; Bindner, Henrik W.

    2015-01-01

    the correct actions for operating the system. In future power systems more measuring sensors including phasor measurement units will be available distributed all over the power system. They can and should be utilized to increase the observability of the power system. In this paper the impact of photovoltaic....... The voltage unbalance factor (VUF) could be a ‘new’ observable for a particular power system condition. Information about the actual injected wind power for a certain grid area could be derived without knowing/measuring the real wind power injection....

  12. Failure analysis on China power grid based on power law

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng WENG; Yiguang HONG; Ancheng XUE; Shengwei MEI

    2006-01-01

    This paper is concerned with the mechanism of blackouts in China power system from the viewpoint of self-organized criticality. By using two estimation algorithms of scaled window variance (SWV) and rescaled rangestatistics (R/S), this paper studies the blackout data in China power system during 1988-1997. The result of analysis shows that the blackout data of 1994-1997 coincides well with the autocorrelation. Furthermore, it is found that the function of blackout probability vs. blackout size exhibits power law distribution.

  13. Net analyte signal based statistical quality control

    NARCIS (Netherlands)

    Skibsted, E.T.S.; Boelens, H.F.M.; Westerhuis, J.A.; Smilde, A.K.; Broad, N.W.; Rees, D.R.; Witte, D.T.

    2005-01-01

    Net analyte signal statistical quality control (NAS-SQC) is a new methodology to perform multivariate product quality monitoring based on the net analyte signal approach. The main advantage of NAS-SQC is that the systematic variation in the product due to the analyte (or property) of interest is sep

  14. Evaluating the quality of scenarios of short-term wind power generation

    DEFF Research Database (Denmark)

    Pinson, Pierre; Girard, R.

    2012-01-01

    Scenarios of short-term wind power generation are becoming increasingly popular as input to multi-stage decision-making problems e.g. multivariate stochastic optimization and stochastic programming. The quality of these scenarios is intuitively expected to substantially impact the benets from...... their use in decision-making. So far however, their verication is almost always focused on their marginal distributions for each individual lead time only, thus overlooking their temporal interdependence structure. The shortcomings of such an approach are discussed. Multivariate verication tools, as well...... as diagnostic approaches based on event-based verication are then presented. Their application to the evaluation of various sets of scenarios of short-term wind power generation demonstrates them as valuable discrimination tools....

  15. Power Quality Control and Design of Power Converter for Variable-Speed Wind Energy Conversion System with Permanent-Magnet Synchronous Generator

    Directory of Open Access Journals (Sweden)

    Yüksel Oğuz

    2013-01-01

    Full Text Available The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.

  16. Power quality control and design of power converter for variable-speed wind energy conversion system with permanent-magnet synchronous generator.

    Science.gov (United States)

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.

  17. Power Quality Control and Design of Power Converter for Variable-Speed Wind Energy Conversion System with Permanent-Magnet Synchronous Generator

    Science.gov (United States)

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%. PMID:24453905

  18. Opportunities for Wind Power In Low- and Mid-Quality Resource Regions

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, Eric; Mai, Trieu; Heimiller, Donna; Ho, Jonathan; Stehly, Tyler

    2016-05-25

    In this presentation for American Wind Energy Association (AWEA) WINDPOWER 2016 conference, the authors discuss wind power today in low and mid-quality resource regions, the anticipated role of wind power in the future electric sector, market potential in low and mid-quality resource regions, and anticipated innovations to capture that market potential.

  19. Electric Power quality Analysis in research reactor: Impacts on nuclear safety assessment and electrical distribution reliability

    Energy Technology Data Exchange (ETDEWEB)

    Touati, Said; Chennai, Salim; Souli, Aissa [Nuclear Research Centre of Birine, Ain Oussera, Djelfa Province (Algeria)

    2015-07-01

    The increased requirements on supervision, control, and performance in modern power systems make power quality monitoring a common practise for utilities. Large databases are created and automatic processing of the data is required for fast and effective use of the available information. Aim of the work presented in this paper is the development of tools for analysis of monitoring power quality data and in particular measurements of voltage and currents in various level of electrical power distribution. The study is extended to evaluate the reliability of the electrical system in nuclear plant. Power Quality is a measure of how well a system supports reliable operation of its loads. A power disturbance or event can involve voltage, current, or frequency. Power disturbances can originate in consumer power systems, consumer loads, or the utility. The effect of power quality problems is the loss power supply leading to severe damage to equipments. So, we try to track and improve system reliability. The assessment can be focused on the study of impact of short circuits on the system, harmonics distortion, power factor improvement and effects of transient disturbances on the Electrical System during motor starting and power system fault conditions. We focus also on the review of the Electrical System design against the Nuclear Directorate Safety Assessment principles, including those extended during the last Fukushima nuclear accident. The simplified configuration of the required system can be extended from this simple scheme. To achieve these studies, we have used a demo ETAP power station software for several simulations. (authors)

  20. A Space Based Solar Power Satellite System

    Science.gov (United States)

    Engel, J. M.; Polling, D.; Ustamujic, F.; Yaldiz, R.; et al.

    2002-01-01

    (SPoTS) supplying other satellites with energy. SPoTS is due to be commercially viable and operative in 2020. of Technology designed the SPoTS during a full-time design period of six weeks as a third year final project. The team, organized according to the principles of systems engineering, first conducted a literature study on space wireless energy transfer to select the most suitable candidates for use on the SPoTS. After that, several different system concepts have been generated and evaluated, the most promising concept being worked out in greater detail. km altitude. Each SPoTS satellite has a 50m diameter inflatable solar collector that focuses all received sunlight. Then, the received sunlight is further redirected by means of four pointing mirrors toward four individual customer satellites. A market-analysis study showed, that providing power to geo-stationary communication satellites during their eclipse would be most beneficial. At arrival at geo-stationary orbit, the focused beam has expended to such an extent that its density equals one solar flux. This means that customer satellites can continue to use their regular solar arrays during their eclipse for power generation, resulting in a satellite battery mass reduction. the customer satellites in geo-stationary orbit, the transmitted energy beams needs to be pointed with very high accuracy. Computations showed that for this degree of accuracy, sensors are needed, which are not mainstream nowadays. Therefore further research must be conducted in this area in order to make these high-accuracy-pointing systems commercially attractive for use on the SPoTS satellites around 2020. Total 20-year system lifetime cost for 18 SPoT satellites are estimated at approximately USD 6 billion [FY2001]. In order to compete with traditional battery-based satellite power systems or possible ground based wireless power transfer systems the price per kWh for the customer must be significantly lower than the present one

  1. Power and the Association with Relationship Quality in South African Couples: Implications for HIV/AIDS Interventions

    Science.gov (United States)

    Conroy, Amy A.; McGrath, Nuala; van Rooyen, Heidi; Hosegood, Victoria; Johnson, Mallory O.; Fritz, Katherine; Marr, Alexander; Ngubane, Thulani; Darbes, Lynae A.

    2016-01-01

    Introduction Power imbalances within sexual relationships have significant implications for HIV prevention in sub-Saharan Africa. Little is known about how power influences the quality of a relationship, which could be an important pathway leading to healthy behavior around HIV/AIDS. Methods This paper uses data from 448 heterosexual couples (896 individuals) in rural KwaZulu-Natal, South Africa who completed baseline surveys from 2012–2014 as part of a couples-based HIV intervention trial. Using an actor-partner interdependence perspective, we assessed: (1) how both partners’ perceptions of power influences their own (i.e., actor effect) and their partner’s reports of relationship quality (i.e., partner effect); and (2) whether these associations differed by gender. We examined three constructs related to power (female power, male equitable gender norms, and shared power) and four domains of relationship quality (intimacy, trust, mutually constructive communication, and conflict). Results For actor effects, shared power was strongly and consistently associated with higher relationship quality across all four domains. The effect of shared power on trust, mutually constructive communication, and conflict were stronger for men than women. The findings for female power and male equitable gender norms were more mixed. Female power was positively associated with women’s reports of trust and mutually constructive communication, but negatively associated with intimacy. Male equitable gender norms were positively associated with men’s reports of mutually constructive communication. For partner effects, male equitable gender norms were positively associated with women’s reports of intimacy and negatively associated with women’s reports of conflict. Conclusions Research and health interventions aiming to improving HIV-related behaviors should consider sources of shared power within couples and potential leverage points for empowerment at the couple level

  2. ONTOLOGY BASED QUALITY EVALUATION FOR SPATIAL DATA

    Directory of Open Access Journals (Sweden)

    C. Yılmaz

    2015-08-01

    Full Text Available Many institutions will be providing data to the National Spatial Data Infrastructure (NSDI. Current technical background of the NSDI is based on syntactic web services. It is expected that this will be replaced by semantic web services. The quality of the data provided is important in terms of the decision-making process and the accuracy of transactions. Therefore, the data quality needs to be tested. This topic has been neglected in Turkey. Data quality control for NSDI may be done by private or public “data accreditation” institutions. A methodology is required for data quality evaluation. There are studies for data quality including ISO standards, academic studies and software to evaluate spatial data quality. ISO 19157 standard defines the data quality elements. Proprietary software such as, 1Spatial’s 1Validate and ESRI’s Data Reviewer offers quality evaluation based on their own classification of rules. Commonly, rule based approaches are used for geospatial data quality check. In this study, we look for the technical components to devise and implement a rule based approach with ontologies using free and open source software in semantic web context. Semantic web uses ontologies to deliver well-defined web resources and make them accessible to end-users and processes. We have created an ontology conforming to the geospatial data and defined some sample rules to show how to test data with respect to data quality elements including; attribute, topo-semantic and geometrical consistency using free and open source software. To test data against rules, sample GeoSPARQL queries are created, associated with specifications.

  3. Optimal Power Procurement and Demand Response with Quality-of-Usage Guarantees

    CERN Document Server

    Huang, Longbo; Ramchandran, Kannan

    2011-01-01

    In this paper, we propose a general operating scheme which allows the utility company to jointly perform power procurement and demand response so as to maximize the social welfare. Our model takes into consideration the effect of the renewable energy and the multi-stage feature of the power procurement process. It also enables the utility company to provide quality-of-usage (QoU) guarantee to the power consumers, which ensures that the average power usage level meets the target value for each user. To maximize the social welfare, we develop a low-complexity algorithm called the \\emph{welfare maximization algorithm} (WMA), which performs joint power procurement and dynamic pricing. WMA is constructed based on a two-timescale Lyapunov optimization technique. We prove that WMA achieves a close-to-optimal utility and ensures that the QoU requirement is met with bounded deficit. WMA can be implemented in a distributed manner and is robust with respect to system dynamics uncertainty.

  4. Proportional derivative based stabilizing control of paralleled grid converters with cables in renewable power plants

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    Resonant interactions of grid-connected converters with each other and with cable capacitance are challenging the stability and power quality of renewable energy sources based power plants. This paper addresses the instability of current control of converters with the multiple resonance frequenci...

  5. An active damper for stabilizing power-electronics-based AC systems

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Liserre, Marco

    2014-01-01

    The interactions among the parallel grid-connected converters coupled through the grid impedance tend to result in stability and power quality problems. To address them, this paper proposes an active damper based on a high bandwidth power electronics converter. The general idea behind this propos...

  6. Biological indices for classification of water quality around Mae Moh power plant, Thailand

    Directory of Open Access Journals (Sweden)

    Pongsarun Junshum and Siripen Traichaiyaporn

    2007-12-01

    Full Text Available The algal communities and water quality were monitored at eight sampling sites around Mae Moh power plant during January-December 2003. Three biological indices, viz. algal genus pollution index, saprobic index, and Shannon-Weaver index, were adopted to classify the water quality around the power plant in comparison with the measured physico-chemical water quality. The result shows that the Shannon-Weaver diversity index appears to be much more applicable and interpretable for the classification of water quality around the Mae Moh power plant than the algal genus pollution index and the saprobic index.

  7. Generation of high energy and good beam quality pulses with a master oscillator power amplifier

    Institute of Scientific and Technical Information of China (English)

    Zhigang Li(李志刚); Z.Xiong; Nicholas Moore; Chen Tao; G.C.Lim; Weiling Huang(黄维玲); Dexiu Huang(黄德修)

    2004-01-01

    A high efficiency and high peak power laser system with short-pulse and good beam quality has been demonstrated by using a master oscillator power amplifier with two-pass amplification configuration. The master oscillator, end-pumped with a fiber-coupled laser diode array, provides low power but excellent beam quality pulses, and the amplifier boosts the pulse energy by orders without significant beam quality degradation. Short pulses of 8.5 ns with energy up to 130 mJ and approximately diffraction limited beam quality have been demonstrated.

  8. MPPT CONTROLLER BASED SOLAR POWER GENERATION USING A MULTILEVEL INVERTER

    Directory of Open Access Journals (Sweden)

    Kelam Bhargav

    2016-02-01

    Full Text Available Solar energy is a renewable energy that is found abundantly in nature. It is green energy that can be utilized throughout day, therefore maximum energy has to captured from the panel. MPPT algorithm is incorporated to capture maximum energy. A multilevel inverter is a power electronic converter that synthesizes a desired output voltage from several levels of dc voltages of dc voltages as inputs. With an increasing number of dc voltage source, the sinusoidal waveform is obtained by the output voltage, while using a fundamental frequency-switching scheme. The advantage of multilevel inverter is very small output voltage, results in higher output quality and lower switching losses. This paper proposes a MPPT controller based solar power generation system, which consist of dc/dc converter and a new nine-level inverter.

  9. A New Power Quality Disturbance Detection Method Based on the Improved LMD%基于改进LMD的电能质量扰动检测新方法

    Institute of Scientific and Technical Information of China (English)

    宋海军; 黄传金; 刘宏超; 陈铁军; 李景丽; 罗勇

    2014-01-01

    介绍了一种新的非线性、非平稳信号分析方法--局部均值分解(local mean decomposition,LMD),分析了LMD用于扰动信号检测时的优缺点及原因。在此基础上,提出一种改进的局部均值分解(improved local mean decomposition,ILMD)电能质量扰动检测及时频分析新方法,该方法由LMD和希尔伯特变换(Hilbert Transform,HT)2部分组成。先用 LMD 提取信号的乘积函数(product function,PF),由PF分量的调幅函数可得信号瞬时幅值;再对PF分量进行HT求取瞬时频率。ILMD方法可有效定位发生扰动的起止时刻,克服LMD在定位能力上的不足。与采用希尔伯特黄变换(Hilbert Huang transform,HHT)方法相比,ILMD具有瞬时幅值函数端部失真小、瞬时幅频曲线波动小和幅值与频率检测精度高等优点。仿真信号和500 kV变电站电容器组投切时的电压信号分析结果证明所提方法的可行性和有效性。%A new signal analysis method of non-linear, non-stationary-local mean decomposition (LMD) was introduced. The advantages and disadvantages of the application of LMD in the disturbance signal detection were analyzed. On this basis, the paper presented an improved local mean decomposition (ILMD) power quality disturbance detection and time-frequency analysis method. The method was composed of two parts:LMD and Hilbert transform. Firstly, to extract the product function (PF) of the signal based on LMD, and to obtain the instantaneous amplitude of the signal from the PF components of the amplitude modulation function. Then, to apply the Hilbert transform to obtain the instantaneous frequency of PF. The improved LMD method could effectively locate the beginning and ending time of the disturbances occurred and overcome the deficiencies of the LMD positioning capability. By using the method, the curves of the instantaneous amplitude had less distortion in wave head and that of the instantaneous frequency had

  10. Using Smart Meters Data for Energy Management Operations and Power Quality Monitoring in a Microgrid

    DEFF Research Database (Denmark)

    Palacios-Garcia, Emilio J.; Diaz, Enrique Rodriguez; Anvari-Moghaddam, Amjad

    2017-01-01

    Smart metering devices have become an essential part in the development of the current electrical network toward the paradigm of Smart Grid. These meters present in most of the cases, functionalities whose analysis capabilities go further beyond the basic automated meter readings for billing...... of a commercial advanced metering infrastructure (AMI) in the context of a smart building with an energy management system (EMS). Furthermore, power quality monitoring based on this AMI is explained. All the details regarding the implementation in a laboratory scale application, as well as the obtained results...

  11. Design and Analysis of Multi Level D-STATCOM to Improve the Power Quality

    Directory of Open Access Journals (Sweden)

    Dinesh. Badavath,

    2014-01-01

    Full Text Available In the last decade, the electrical power quality issue has been the main concern of the power companies. Power quality is defined as the index which both the delivery and consumption of electric power affect on the performance of electrical apparatus. From a customer point of view, a power quality problem can be defined as any problem is manifested on voltage, current, or frequency deviation that results in power failure. The power electronics progressive, especially in flexible alternating-current transmission system (FACTS and custom power devices, affects power quality improvement. This paper presents an investigation of seven-Level Cascaded H - bridge (CHB Inverter as Distribution Static Compensator (DSTATCOM in Power System (PS for compensation of reactive power and harmonics. The advantages of CHB inverter are low harmonic distortion, reduced number of switches and suppression of switching losses. The DSTATCOM helps to improve the power factor and eliminate the Total Harmonics Distortion (THD drawn from a Non-Liner Diode Rectifier Load (NLDRL. The D-Q reference frame theory is used to generate the reference compensating currents for DSTATCOM while Proportional and Integral (PI control is used for capacitor dc voltage regulation. A CHB Inverter is considered for shunt compensation of a 11 Kv distribution system. Finally a level shifted PWM (LSPWM and phase shifted PWM (PSPWM techniques are adopted to investigate the performance of CHB Inverter. The results are obtained through Matlab/Simulink software package.

  12. Adaptive preheating duration control for low-power ambient air quality sensor networks.

    Science.gov (United States)

    Baek, Yoonchul; Atiq, Mahin K; Kim, Hyung Seok

    2014-03-20

    Ceramic gas sensors used for measuring ambient air quality have features suitable for practical applications such as healthcare and air quality management, but have a major drawback-large power consumption to preheat the sensor for accurate measurements. In this paper; the adaptive preheating duration control (APC) method is proposed to reduce the power consumption of ambient air quality sensor networks. APC reduces the duration of unnecessary preheating, thereby alleviating power consumption. Furthermore, the APC can allow systems to meet user requirements such as accuracy and periodicity factor when detecting the concentration of a target gas. A performance evaluation of the power consumption of gas sensors is conducted with various user requirements and factors that affect the preheating duration of the gas sensor. This shows that the power consumption of the APC is lower than that of continuous power supply methods and constant power supply/cutoff methods.

  13. Adaptive Preheating Duration Control for Low-Power Ambient Air Quality Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yoonchul Baek

    2014-03-01

    Full Text Available Ceramic gas sensors used for measuring ambient air quality have features suitable for practical applications such as healthcare and air quality management, but have a major drawback—large power consumption to preheat the sensor for accurate measurements. In this paper; the adaptive preheating duration control (APC method is proposed to reduce the power consumption of ambient air quality sensor networks. APC reduces the duration of unnecessary preheating, thereby alleviating power consumption. Furthermore, the APC can allow systems to meet user requirements such as accuracy and periodicity factor when detecting the concentration of a target gas. A performance evaluation of the power consumption of gas sensors is conducted with various user requirements and factors that affect the preheating duration of the gas sensor. This shows that the power consumption of the APC is lower than that of continuous power supply methods and constant power supply/cutoff methods.

  14. Model-Based Power Plant Master Control

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Katarina; Thomas, Jean; Funkquist, Jonas

    2010-08-15

    The main goal of the project has been to evaluate the potential of a coordinated master control for a solid fuel power plant in terms of tracking capability, stability and robustness. The control strategy has been model-based predictive control (MPC) and the plant used in the case study has been the Vattenfall power plant Idbaecken in Nykoeping. A dynamic plant model based on nonlinear physical models was used to imitate the true plant in MATLAB/SIMULINK simulations. The basis for this model was already developed in previous Vattenfall internal projects, along with a simulation model of the existing control implementation with traditional PID controllers. The existing PID control is used as a reference performance, and it has been thoroughly studied and tuned in these previous Vattenfall internal projects. A turbine model was developed with characteristics based on the results of steady-state simulations of the plant using the software EBSILON. Using the derived model as a representative for the actual process, an MPC control strategy was developed using linearization and gain-scheduling. The control signal constraints (rate of change) and constraints on outputs were implemented to comply with plant constraints. After tuning the MPC control parameters, a number of simulation scenarios were performed to compare the MPC strategy with the existing PID control structure. The simulation scenarios also included cases highlighting the robustness properties of the MPC strategy. From the study, the main conclusions are: - The proposed Master MPC controller shows excellent set-point tracking performance even though the plant has strong interactions and non-linearity, and the controls and their rate of change are bounded. - The proposed Master MPC controller is robust, stable in the presence of disturbances and parameter variations. Even though the current study only considered a very small number of the possible disturbances and modelling errors, the considered cases are

  15. The Cross Flow Turbine Behavior towards the Turbine Rotation Quality, Efficiency, and Generated Power

    OpenAIRE

    Haurissa, Jusuf; Wahyudi, Slamet; Irawan, Yudy Surya; Soenoko, Rudy

    2012-01-01

    page number: 448-453; International audience; The focus of this research is the turbine flow behavior toward the turbine rotation quality, the turbine efficiency and the turbine power generated. The turbine rotation quality is really needed for the high quality electricity power generated. The method used in this research is the experimental method. The fluid flow behavior was observed by using a Casio 1000 handy camera and a Canon 550D camera. The data obtained from this observation is in a ...

  16. The Cross Flow Turbine Behavior towards the Turbine Rotation Quality, Efficiency, and Generated Power

    OpenAIRE

    Haurissa, Jusuf; Wahyudi, Slamet; Irawan,Yudy Surya; Soenoko, Rudy

    2012-01-01

    page number: 448-453; International audience; The focus of this research is the turbine flow behavior toward the turbine rotation quality, the turbine efficiency and the turbine power generated. The turbine rotation quality is really needed for the high quality electricity power generated. The method used in this research is the experimental method. The fluid flow behavior was observed by using a Casio 1000 handy camera and a Canon 550D camera. The data obtained from this observation is in a ...

  17. Space-Based Solar Power System Architecture

    Science.gov (United States)

    2012-12-01

    Panel 100,000,000 kg Power Storage 176,000 kg Diode- pumped Laser Transmitter 5,000,000 kg TOTAL SYSTEM WEIGHT 105,181,400 kg 73 deployed...64 a. Power Storage Requirements .................................................65 b. Energy Transfer...alternatives to fossil fuels: nuclear fission reactors, hydroelectric power, wind turbines and solar power to name just a few. Each has advantages

  18. Modeling and analysis of harmonic resonance in a power electronics based AC power system

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Chen, Zhe

    2013-01-01

    The dynamic interactions among the interconnected power converters may bring in harmonic resonance in a power electronics based power system. This paper addresses this issue in a power system dominated by multiple current- and voltage-controlled inverters with LCL- and LC-filters. The impedance-b...

  19. Power-Quality Improvement in PFC Bridgeless SEPIC-Fed BLDC Motor Drive

    Science.gov (United States)

    Singh, Bhim; Bist, Vashist

    2013-06-01

    This article presents a design of a power factor correction (PFC)-based brushless DC (BLDC) motor drive. The speed control of BLDC motor is achieved by controlling the DC link voltage of the voltage source inverter (VSI) feeding BLDC motor using a single voltage sensor. A front-end bridgeless single-ended primary inductance converter (SEPIC) is used for DC link voltage control and PFC operation. A bridgeless SEPIC is designed to operate in discontinuous inductor current mode (DICM) thus utilizing a simple control scheme of voltage follower. An electronic commutation of BLDC motor is used for VSI to operate in a low-frequency operation for reduced switching losses in the VSI. Moreover, a bridgeless topology offers less conduction losses due to absence of diode bridge rectifier for further increasing the efficiency. The proposed BLDC motor drive is designed to operate over a wide range of speed control with an improved power-quality at the AC mains under the recommended international power-quality standards such as IEC 61000-3-2.

  20. Applying FBD-power theory to analysing effective lighting devices’ impact on power quality and electric grid efficiency

    Directory of Open Access Journals (Sweden)

    Andrés Pavas

    2011-07-01

    Full Text Available Currently the impact of high efficient lighting devices such as compact fluorescent lamps (CFL and light emitting diodes (LED is an important concern for the electrotechnical community. This paper makes a contribution towards determining the impact of these devices on electric grid power quality and efficiency, proposed by means of applying FBD-power theory to the currents absorbed by CFLs and LEDs. An analysis of the waveform distortion regarding IEEE standard 519 and efficiency detriment quantification are presented.

  1. Competing Air Quality and Water Conservation Co-benefits from Power Sector Decarbonization

    Science.gov (United States)

    Peng, W.; Wagner, F.; Mauzerall, D. L.; Ramana, M. V.; Zhai, H.; Small, M.; Zhang, X.; Dalin, C.

    2016-12-01

    Decarbonizing the power sector can reduce fossil-based generation and associated air pollution and water use. However, power sector configurations that prioritize air quality benefits can be different from those that maximize water conservation benefits. Despite extensive work to optimize the generation mix under an air pollution or water constraint, little research has examined electricity transmission networks and the choice of which fossil fuel units to displace in order to achieve both environmental objectives simultaneously. When air pollution and water stress occur in different regions, the optimal transmission and displacement decisions still depend on priorities placed on air quality and water conservation benefits even if low-carbon generation planning is fixed. Here we use China as a test case, and develop a new optimization framework to study transmission and displacement decisions and the resulting air quality and water use impacts for six power sector decarbonization scenarios in 2030 ( 50% of national generation is low carbon). We fix low-carbon generation in each scenario (e.g. type, location, quantity) and vary technology choices and deployment patterns across scenarios. The objective is to minimize the total physical costs (transmission costs and coal power generation costs) and the estimated environmental costs. Environmental costs are estimated by multiplying effective air pollutant emissions (EMeff, emissions weighted by population density) and effective water use (Weff, water use weighted by a local water stress index) by their unit economic values, Vem and Vw. We are hence able to examine the effect of varying policy priorities by imposing different combinations of Vem and Vw. In all six scenarios, we find that increasing the priority on air quality co-benefits (higher Vem) reduces air pollution impacts (lower EMeff) at the expense of lower water conservation (higher Weff); and vice versa. Such results can largely be explained by differences

  2. Developing a PQ monitoring system for assessing power quality and critical areas detection

    Directory of Open Access Journals (Sweden)

    Miguel Romero

    2011-10-01

    Full Text Available This paper outlines the development of a power quality monitoring system. The system is aimed at assessing power quality and detecting critical areas throughout at distribution system. Such system integrates a hardware system and a software processing tool developed in four main stages. Power quality disturbances are registered by PQ meters and the data is transmitted through a 3G wireless network. This data is processed and filtered in an open source database. Some interesting statistical indices related to voltage sags, swells, flicker and voltage unbalance are obtained. The last stage displays the indices geo-referenced on power quality maps, allowing the identification of critical areas according to different criteria. The results can be analyzed using clustering tools to identify differentiated quality groups in a city. The proposed system is an open source tool useful to electricity utilities to analyze and manage large amount of data.

  3. TEDS Base Station Power Amplifier using Low-Noise Envelope Tracking Power Supply

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael A. E.

    2009-01-01

    This paper demonstrates a highly linear and efficient TETRA enhanced data service (TEDS) base-station RF power amplifier (RFPA). Based on the well-known combination of an envelope tracking (ET) power supply and a linear class-A/B RFPA, adequate adjacent channel power ratio (ACPR) and wideband noise...

  4. High Quality Factor Resonators for Inductive Power Transfer Systems

    Science.gov (United States)

    Etemadrezaei, Mohammad

    In this dissertation, the Inductive Power Transfer (IPT) systems for multi-MHz frequency of operation are investigated, and new ideas for magnetic link inductive coils are presented. (Abstract shortened by ProQuest.).

  5. Power Electronic Transformer based Three-Phase PWM AC Drives

    Science.gov (United States)

    Basu, Kaushik

    A Transformer is used to provide galvanic isolation and to connect systems at different voltage levels. It is one of the largest and most expensive component in most of the high voltage and high power systems. Its size is inversely proportional to the operating frequency. The central idea behind a power electronic transformer (PET) also known as solid state transformer is to reduce the size of the transformer by increasing the frequency. Power electronic converters are used to change the frequency of operation. Steady reduction in the cost of the semiconductor switches and the advent of advanced magnetic materials with very low loss density and high saturation flux density implies economic viability and feasibility of a design with high power density. Application of PET is in generation of power from renewable energy sources, especially wind and solar. Other important application include grid tied inverters, UPS e.t.c. In this thesis non-resonant, single stage, bi-directional PET is considered. The main objective of this converter is to generate adjustable speed and magnitude pulse width modulated (PWM) ac waveforms from an ac or dc grid with a high frequency ac link. The windings of a high frequency transformer contains leakage inductance. Any switching transition of the power electronic converter connecting the inductive load and the transformer requires commutation of leakage energy. Commutation by passive means results in power loss, decrease in the frequency of operation, distortion in the output voltage waveform, reduction in reliability and power density. In this work a source based partially loss-less commutation of leakage energy has been proposed. This technique also results in partial soft-switching. A series of converters with novel PWM strategies have been proposed to minimize the frequency of leakage inductance commutation. These PETs achieve most of the important features of modern PWM ac drives including 1) Input power factor correction, 2) Common

  6. The Energy Processing by Power Electronics and its Impact on Power Quality

    Directory of Open Access Journals (Sweden)

    J.E. Rocha

    2012-11-01

    Full Text Available This paper discusses the electrical architectures adopted in wind turbines and its impact on the harmonic flux at the connected electric network. The integration of wind electric generators with the power grid needs energy processing by power electronics. It shows that different types of wind turbine generator systems use different types of electronic converters. This work provides a discussion on harmonic distortion taking place on the generator side, as well as in the power grid side. Keywords: grid connection, harmonic distortion, power electronics and converters, wind energy conversion systems, wind power, wind technology, wind turbines

  7. Design considerations for lunar base photovoltaic power systems

    Science.gov (United States)

    Hickman, J. Mark; Curtis, Henry B.; Landis, Geoffrey A.

    1990-01-01

    A survey was made of factors that may affect the design of photovoltaic arrays for a lunar base. These factors, which include the lunar environment and system design criteria, are examined. A photovoltaic power system design with a triangular array geometry is discussed and compared to a nuclear reactor power systems and a power system utilizing both nuclear and solar power sources.

  8. Estimation of Power Quality Indicators During a Real Wind Farm Islanding Experiment

    DEFF Research Database (Denmark)

    Terzija, Vladimir; Stanojević, V.; Štrbac, G.

    2008-01-01

    of voltages and currents are estimated. Frequency and its rate of change are directly estimated from voltage input signals. In the second algorithm stage the power quality indicators are calculated. The algorithm considers frequency as an unknown model parameter simultaneously estimated with the voltage......The two-stage Newton Type Algorithm for the tracking of the power quality indicators, frequency and rate of frequency changes is presented in the paper. By this definitions for power quality indicators according to the IEEE Standard 1459-2000 were used. In the first algorithm stage the spectra...

  9. Management of Power Quality Issues in Low Voltage Networks using Electric Vehicles: Experimental Validation

    DEFF Research Database (Denmark)

    Martinenas, Sergejus; Knezovic, Katarina; Marinelli, Mattia

    2016-01-01

    As Electric Vehicles (EVs) are becoming more wide spread, their high power consumption presents challenges for the residential low voltage networks, especially when connected to long feeders with unevenly distributed loads. However, if intelligently integrated, EVs can also partially solve...... the existing and future power quality problems. One of the main aspects of the power quality relates to voltage quality. The aim of this work is to experimentally analyse whether series-produced EVs, adhering to contemporary standard and without relying on any V2G capability, can mitigate line voltage drops...

  10. A power flow based model for the analysis of vulnerability in power networks

    Science.gov (United States)

    Wang, Zhuoyang; Chen, Guo; Hill, David J.; Dong, Zhao Yang

    2016-10-01

    An innovative model which considers power flow, one of the most important characteristics in a power system, is proposed for the analysis of power grid vulnerability. Moreover, based on the complex network theory and the Max-Flow theorem, a new vulnerability index is presented to identify the vulnerable lines in a power grid. In addition, comparative simulations between the power flow based model and existing models are investigated on the IEEE 118-bus system. The simulation results demonstrate that the proposed model and the index are more effective in power grid vulnerability analysis.

  11. Software-Based Wireless Power Transfer Platform for Various Power Control Experiments

    OpenAIRE

    Sun-Han Hwang; Chung G. Kang; Yong-Ho Son; Byung-Jun Jang

    2015-01-01

    In this paper, we present the design and evaluation of a software-based wireless power transfer platform that enables the development of a prototype involving various open- and closed-loop power control functions. Our platform is based on a loosely coupled planar wireless power transfer circuit that uses a class-E power amplifier. In conjunction with this circuit, we implement flexible control functions using a National Instruments Data Acquisition (NI DAQ) board and algorithms in the MATLAB/...

  12. A Series-LC-Filtered Active Damper for AC Power Electronics Based Power Systems

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    This paper proposes an active damper with a series LC-filter for suppressing resonances in an ac power electronics based power system. The added filter capacitor helps to lower the voltage stress of the converter to be used for implementing the damper. Unlike active filters for the compensation...... is built, where the damper is integrated into a grid-connected converter. The results obtained from the experiments demonstrate the stability enhancement of ac power electronics based power systems by the active damper....

  13. A Novel Detection and Classification Algorithm for Power Quality Disturbances using Wavelets

    Directory of Open Access Journals (Sweden)

    C. Sharmeela

    2006-01-01

    Full Text Available This study presents a novel method to detect and classify power quality disturbances using wavelets. The proposed algorithm uses different wavelets each for a particular class of disturbance. The method uses wavelet filter banks in an effective way and does multiple filtering to detect the disturbances. A qualitative comparison of results shows the advantages and drawbacks of each wavelet when applied to the detection of the disturbances. This method is tested for a large class of test conditions simulated in MATLAB. Power quality monitoring together with the ability of the proposed algorithm to classify the disturbances will be a powerful tool for the power system engineers.

  14. Network-based production quality control

    Science.gov (United States)

    Kwon, Yongjin; Tseng, Bill; Chiou, Richard

    2007-09-01

    This study investigates the feasibility of remote quality control using a host of advanced automation equipment with Internet accessibility. Recent emphasis on product quality and reduction of waste stems from the dynamic, globalized and customer-driven market, which brings opportunities and threats to companies, depending on the response speed and production strategies. The current trends in industry also include a wide spread of distributed manufacturing systems, where design, production, and management facilities are geographically dispersed. This situation mandates not only the accessibility to remotely located production equipment for monitoring and control, but efficient means of responding to changing environment to counter process variations and diverse customer demands. To compete under such an environment, companies are striving to achieve 100%, sensor-based, automated inspection for zero-defect manufacturing. In this study, the Internet-based quality control scheme is referred to as "E-Quality for Manufacturing" or "EQM" for short. By its definition, EQM refers to a holistic approach to design and to embed efficient quality control functions in the context of network integrated manufacturing systems. Such system let designers located far away from the production facility to monitor, control and adjust the quality inspection processes as production design evolves.

  15. A Three-Part Electricity Price Mechanism for Photovoltaic-Battery Energy Storage Power Plants Considering the Power Quality and Ancillary Service

    Directory of Open Access Journals (Sweden)

    Yajing Gao

    2017-08-01

    Full Text Available To solve the problem of solar abandoning, which is accompanied by the rapid development of photovoltaic (PV power generation, a demonstration of a photovoltaic-battery energy storage system (PV-BESS power plant has been constructed in Qinghai province in China. However, it is difficult for the PV-BESS power plant to survive and develop with the current electricity price mechanism and subsidy policy. In this paper, a three-part electricity price mechanism is proposed based on a deep analysis of the construction and operation costs and economic income. The on-grid electricity price is divided into three parts: the capacity price, graded electricity price, and ancillary service price. First, to ensure that the investment of the PV-BESS power plant would achieve the industry benchmark income, the capacity price and benchmark electricity price are calculated using the discounted cash flow method. Then, the graded electricity price is calculated according to the grade of the quality of grid-connected power. Finally, the ancillary service price is calculated based on the graded electricity price and ancillary service compensation. The case studies verify the validity of the three-part electricity price mechanism. The verification shows that the three-part electricity price mechanism can help PV-BESS power plants to obtain good economic returns, which can promote the development of PV-BESS power plants.

  16. Agent-based power sharing scheme for active hybrid power sources

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Zhenhua [Department of Electrical and Computer Engineering, University of Miami, Coral Gables, FL 33146 (United States)

    2008-02-15

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles. (author)

  17. Agent-based power sharing scheme for active hybrid power sources

    Science.gov (United States)

    Jiang, Zhenhua

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

  18. Mitochondrial Quality Control: Decommissioning Power Plants in Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Rukmini Mukherjee

    2013-01-01

    Full Text Available The cell has an intricate quality control system to protect its mitochondria from oxidative stress. This surveillance system is multi-tiered and comprises molecules that are present inside the mitochondria, in the cytosol, and in other organelles like the nucleus and endoplasmic reticulum. These molecules cross talk with each other and protect the mitochondria from oxidative stress. Oxidative stress is a fundamental part of early disease pathogenesis of neurodegenerative diseases. These disorders also damage the cellular quality control machinery that protects the cell against oxidative stress. This exacerbates the oxidative damage and causes extensive neuronal cell death that is characteristic of neurodegeneration.

  19. Efficient chaotic based satellite power supply subsystem

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Turci, Luiz Felipe [Technological Institute of Aeronautics (ITA), Sao Jose dos Campos, SP (Brazil)], E-mail: felipeturci@yahoo.com.br; Macau, Elbert E.N. [National Institute of Space Research (Inpe), Sao Jose dos Campos, SP (Brazil)], E-mail: elbert@lac.inpe.br; Yoneyama, Takashi [Technological Institute of Aeronautics (ITA), Sao Jose dos Campos, SP (Brazil)], E-mail: takashi@ita.br

    2009-10-15

    In this work, we investigate the use of the Dynamical System Theory to increase the efficiency of the satellite power supply subsystems. The core of a satellite power subsystem relies on its DC/DC converter. This is a very nonlinear system that presents a multitude of phenomena ranging from bifurcations, quasi-periodicity, chaos, coexistence of attractors, among others. The traditional power subsystem design techniques try to avoid these nonlinear phenomena so that it is possible to use linear system theory in small regions about the equilibrium points. Here, we show that more efficiency can be drawn from a power supply subsystem if the DC/DC converter operates in regions of high nonlinearity. In special, if it operates in a chaotic regime, is has an intrinsic sensitivity that can be exploited to efficiently drive the power subsystem over high ranges of power requests by using control of chaos techniques.

  20. Power Gating Based Ground Bounce Noise Reduction

    Directory of Open Access Journals (Sweden)

    M. Uma Maheswari

    2014-08-01

    Full Text Available As low power circuits are most popular the decrease in supply voltage leads to increase in leakage power with respect to the technology scaling. So for removing this kind of leakages and to provide a better power efficiency many power gating techniques are used. But the leakage due to ground connection to the active part of the circuit is very high rather than all other leakages. As it is mainly due to the back EMF of the ground connection it was called it as ground bounce noise. To reduce this noise different methodologies are designed. In this paper the design of such an efficient technique related to ground bounce noise reduction using power gating circuits and comparing the results using DSCH and Microwind low power tools. In this paper the analysis of adders such as full adders using different types of power gated circuits using low power VLSI design techniques and to present the comparison results between different power gating methods.

  1. Measuring laser power as a force: a new paradigm to accurately monitor optical power during laser-based machining operations

    Science.gov (United States)

    Williams, Paul; Simonds, Brian; Sowards, Jeffrey; Hadler, Joshua

    2016-03-01

    In laser manufacturing operations, accurate measurement of laser power is important for product quality, operational repeatability, and process validation. Accurate real-time measurement of high-power lasers, however, is difficult. Typical thermal power meters must absorb all the laser power in order to measure it. This constrains power meters to be large, slow and exclusive (that is, the laser cannot be used for its intended purpose during the measurement). To address these limitations, we have developed a different paradigm in laser power measurement where the power is not measured according to its thermal equivalent but rather by measuring the laser beam's momentum (radiation pressure). Very simply, light reflecting from a mirror imparts a small force perpendicular to the mirror which is proportional to the optical power. By mounting a high-reflectivity mirror on a high-sensitivity force transducer (scale), we are able to measure laser power in the range of tens of watts up to ~ 100 kW. The critical parameters for such a device are mirror reflectivity, angle of incidence, and scale sensitivity and accuracy. We will describe our experimental characterization of a radiation-pressure-based optical power meter. We have tested it for modulated and CW laser powers up to 92 kW in the laboratory and up to 20 kW in an experimental laser welding booth. We will describe present accuracy, temporal response, sources of measurement uncertainty, and hurdles which must be overcome to have an accurate power meter capable of routine operation as a turning mirror within a laser delivery head.

  2. Modeling and Analysis of Harmonic Stability in an AC Power-Electronics-Based Power System

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Wu, Weimin

    2014-01-01

    This paper addresses the harmonic stability caused by the interactions among the wideband control of power converters and passive components in an AC power-electronicsbased power system. The impedance-based analytical approach is employed and expanded to a meshed and balanced threephase network...

  3. Optimizing efficiency on conventional transformer based low power AC/DC standby power supplies

    DEFF Research Database (Denmark)

    Nielsen, Nils

    2004-01-01

    This article describes the research results for simple and cheap methods to reduce the idle- and load-losses in very low power conventional transformer based power supplies intended for standby usage. In this case "very low power" means 50 Hz/230 V-AC to 5 V-DC@1 W. The efficiency is measured...... on two common power supply topologies designed for this power level. The two described topologies uses either a series (or linear) or a buck regulation approach. Common to the test power supplies is they either are using a standard cheap off-the-shelf transformer, or one, which are loss optimized by very...

  4. A Review of Distributed Control Techniques for Power Quality Improvement in Micro-grids

    Science.gov (United States)

    Zeeshan, Hafiz Muhammad Ali; Nisar, Fatima; Hassan, Ahmad

    2017-05-01

    Micro-grid is typically visualized as a small scale local power supply network dependent on distributed energy resources (DERs) that can operate simultaneously with grid as well as in standalone manner. The distributed generator of a micro-grid system is usually a converter-inverter type topology acting as a non-linear load, and injecting harmonics into the distribution feeder. Hence, the negative effects on power quality by the usage of distributed generation sources and components are clearly witnessed. In this paper, a review of distributed control approaches for power quality improvement is presented which encompasses harmonic compensation, loss mitigation and optimum power sharing in multi-source-load distributed power network. The decentralized subsystems for harmonic compensation and active-reactive power sharing accuracy have been analysed in detail. Results have been validated to be consistent with IEEE standards.

  5. High power microwave system based on power combining and pulse compression of conventional klystrons

    CERN Document Server

    Xiong, Zheng-Feng; Cheng, Cheng; Ning, Hui; Tang, Chuan-Xiang

    2015-01-01

    A high power microwave system based on power combining and pulse compression of conventional klystrons is introduced in this paper. This system mainly consists of pulse modulator, power combiner, driving source of klystrons and pulse compressor. A solid state induction modulator and pulse transformer were used to drive two 50 MW S-band klystrons with pulse widths 4 {\\mu}s in parallel, after power combining and pulse compression, the tested peak power had reached about 210 MW with pulse widths nearly 400 ns at 25 Hz, while the experimental maximum output power was just limited by the power capacity of loads. This type of high power microwave system has widely application prospect in RF system of large scale particle accelerators, high power radar transmitters and high level electromagnetic environment generators.

  6. 76 FR 45741 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Diesel-Powered Motor...

    Science.gov (United States)

    2011-08-01

    ... Commonwealth of Pennsylvania for the purpose of incorporating the Commonwealth's Diesel-Powered Motor Vehicle... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Diesel-Powered Motor Vehicle Idling Act AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed...

  7. A control strategy for multi-functional converter to improve grid power quality

    DEFF Research Database (Denmark)

    Li, Fei; Wang, Xiongfei; Chen, Zhe

    2011-01-01

    The extensive use of converter-interfacing distributed energy resources (DER), combined with a large amount of nonlinear and unbalanced loads connected to the distribution power system, has led to power quality problem. This paper proposes a control strategy for a three-phase four-leg multi-funct...

  8. Auctioning Wind Power Sites when Environmental Quality Matters

    OpenAIRE

    2008-01-01

    In this work we frame within auction theory an index that allows to order different projects for the construction of onshore wind energy plants and that explicitly takes into account their environmental quality. Wind farm projects are defined as vectors of attributes, encompassed in four categories: the technical properties of each project; its social impact; its environmental impact and the share of earnings that proponents offer to the collectivity in compensation for the negative externali...

  9. Electronic noses: Powerful tools in meat quality assessment.

    Science.gov (United States)

    Wojnowski, Wojciech; Majchrzak, Tomasz; Dymerski, Tomasz; Gębicki, Jacek; Namieśnik, Jacek

    2017-09-01

    Main factors that are considered by consumers when choosing meat products are colour and aroma, of which the latter is a more reliable indicator of quality. However, a simple sensory evaluation of hedonistic qualities is often not sufficient to determine whether protein is past its shelf life, and consumption of spoiled meat can lead to serious health hazards. Some volatile compounds can be used as spoilage indicators, and so a device equipped with a sensor sensitive to particular odorants would prove useful. Unfortunately, no such single compound has yet been identified, as the changes taking place in a sample of meat during storage are contingent on numerous factors. On the other hand, a combination of volatile compounds may form a unique 'fingerprint' which can be analysed pattern recognition algorithms with an electronic nose. It can supplement established techniques of meat quality assessment by providing results that correlate well with hedonic perception in a short time and at a low cost. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Improving Quality of Service and Reducing Power Consumption with WAN accelerator in Cloud Computing Environments

    Directory of Open Access Journals (Sweden)

    Shin-ichi Kuribayashi

    2013-02-01

    Full Text Available The widespread use of cloud computing services is expected to deteriorate a Quality of Service andtoincrease the power consumption of ICT devices, since the distance to a server becomes longer thanbefore. Migration of virtual machines over a wide area can solve many problems such as load balancingand power saving in cloud computing environments.This paper proposes to dynamically apply WAN accelerator within the network when a virtual machine ismoved to a distant center, in order to prevent the degradation in performance after live migration ofvirtual machines over a wide area. mSCTP-based data transfer using different TCP connections beforeand after migration is proposed in order to use a currently available WAN accelerator. This paper doesnot consider the performance degradation of live migration itself. Then, this paper proposes to reduce thepower consumption of ICT devices, which consists of installing WAN accelerators as part of cloudresources actively and increasing the packet transfer rate of communication link temporarily. It isdemonstrated that the power consumption with WAN accelerator could be reduced to one-tenth of thatwithout WAN accelerator.

  11. Knowledge, Power and Meanings Shaping Quality Assurance in Higher Education: A Systemic Critique

    Science.gov (United States)

    Houston, Don; Paewai, Shelley

    2013-01-01

    Internationally, quality assurance schemes persist despite long-standing dissatisfaction and critique of their impact and outcomes. Adopting a critical systems perspective, the article explores the relationships between the knowledge, power and meanings that stakeholder groups bring to the design and implementation of quality assurance systems.…

  12. Power conversion and quality of the Santa Clara 2 MW direct carbonate fuel cell demonstration plant

    Energy Technology Data Exchange (ETDEWEB)

    Skok, A.J. [Fuel Cell Engineering Corp., Danbury, CT (United States); Abueg, R.Z. [Basic Measuring Instruments, Santa Clara, CA (United States); Schwartz, P. [Fluor Daniel, Inc., Irvine, CA (United States)] [and others

    1996-12-31

    The Santa Clara Demonstration Project (SCDP) is the first application of a commercial-scale carbonate fuel cell power plant on a US electric utility system. It is also the largest fuel cell power plant ever operated in the United States. The 2MW plant, located in Santa Clara, California, utilizes carbonate fuel cell technology developed by Energy Research Corporation (ERC) of Danbury, Connecticut. The ultimate goal of a fuel cell power plant is to deliver usable power into an electrical distribution system. The power conversion sub-system does this for the Santa Clara Demonstration Plant. A description of this sub-system and its capabilities follows. The sub-system has demonstrated the capability to deliver real power, reactive power and to absorb reactive power on a utility grid. The sub-system can be operated in the same manner as a conventional rotating generator except with enhanced capabilities for reactive power. Measurements demonstrated the power quality from the plant in various operating modes was high quality utility grade power.

  13. Model based monitoring of stormwater runoff quality

    DEFF Research Database (Denmark)

    Birch, Heidi; Vezzaro, Luca; Mikkelsen, Peter Steen

    2012-01-01

    the information obtained about MPs discharged from the monitored system. A dynamic stormwater quality model was calibrated using MP data collected by volume-proportional and passive sampling in a storm drainage system in the outskirts of Copenhagen (Denmark) and a 10-year rain series was used to find annual......) for calibration of the model resulted in the same predicted level but narrower model prediction bounds than calibrations based on volume-proportional samples, allowing a better exploitation of the resources allocated for stormwater quality management.......Monitoring of micropollutants (MP) in stormwater is essential to evaluate the impacts of stormwater on the receiving aquatic environment. The aim of this study was to investigate how different strategies for monitoring of stormwater quality (combination of model with field sampling) affect...

  14. The development of a standard for a power plant analytical chemistry quality management system

    Energy Technology Data Exchange (ETDEWEB)

    Meils, D.E. [Scientech, LLC, Dunedin, FL (United States); Mastroianni, J.A. [Scientech Information Services, Oshawa, ON (Canada)

    2008-04-15

    This paper reports on the changes that have taken place since 2004 in the development of a Standard that defines those objectives that must be met in order for a power plant laboratory to demonstrate it operates a technically competent quality management system and is capable of producing technically competent results. The Standard for a Power Plant Analytical Chemistry Quality Management System was produced by the Power Plant Chemistry QA/QC Advisory Group and includes those practices required to meet the stated objectives. (orig.)

  15. Power Supplies for Space Systems Quality Assurance by Sandia Laboratories

    Science.gov (United States)

    Hannigan, R. L.; Harnar, R. R.

    1976-07-01

    The Sandia Laboratories` participation in Quality Assurance programs for Radioisotopic Thermoelectric Generators which have been used in space systems over the past 10 years is summarized. Basic elements of this QA program are briefly described and recognition of assistance from other Sandia organizations is included. Descriptions of the various systems for which Sandia has had the QA responsibility are presented, including SNAP 19 (Nimbus, Pioneer, Viking), SNAP 27 (Apollo), Transit, Multi Hundred Watt (LES 8/9 and MJS), and a new program, High Performance Generator Mod 3. The outlook for Sandia participation in RTG programs for the next several years is noted.

  16. Impact of wind turbine based on double feed induction generator and FACTS devices on power systems

    Directory of Open Access Journals (Sweden)

    Labiba ADJOUDJ

    2015-05-01

    Full Text Available Integration of wind turbines may have significant impacts on power system operation and generation of electricity from wind power has received considerable attention. This paper analyses the impact of integrating wind generation based on double feed induction generators (DFIG and Flexible AC Transmission System (FACTS on the voltage collapse and active losses of network IEEE 30 bus test. Therefore, we must choose among FACTS devices, those with specific applications such as maintaining the voltage at the desired value and the control of power flow, SVC is the most effective in the compensation of reactive as well as maintaining the voltage, and TCSC is the best choice for a proper control of power flow and consequently the reduction of active losses. The simulation results show clearly the effect of wind power plants and FACTS on the grid, voltage stability and power quality of electric power system.

  17. Optical remote sensing and correlation of office equipment functional state and stress levels via power quality disturbances inefficiencies

    Science.gov (United States)

    Sternberg, Oren; Bednarski, Valerie R.; Perez, Israel; Wheeland, Sara; Rockway, John D.

    2016-09-01

    Non-invasive optical techniques pertaining to the remote sensing of power quality disturbances (PQD) are part of an emerging technology field typically dominated by radio frequency (RF) and invasive-based techniques. Algorithms and methods to analyze and address PQD such as probabilistic neural networks and fully informed particle swarms have been explored in industry and academia. Such methods are tuned to work with RF equipment and electronics in existing power grids. As both commercial and defense assets are heavily power-dependent, understanding electrical transients and failure events using non-invasive detection techniques is crucial. In this paper we correlate power quality empirical models to the observed optical response. We also empirically demonstrate a first-order approach to map household, office and commercial equipment PQD to user functions and stress levels. We employ a physics-based image and signal processing approach, which demonstrates measured non-invasive (remote sensing) techniques to detect and map the base frequency associated with the power source to the various PQD on a calibrated source.

  18. Power analysis and trend detection for water quality monitoring data. An application for the Greater Yellowstone Inventory and Monitoring Network

    Science.gov (United States)

    Irvine, Kathryn M.; Manlove, Kezia; Hollimon, Cynthia

    2012-01-01

    An important consideration for long term monitoring programs is determining the required sampling effort to detect trends in specific ecological indicators of interest. To enhance the Greater Yellowstone Inventory and Monitoring Network’s water resources protocol(s) (O’Ney 2006 and O’Ney et al. 2009 [under review]), we developed a set of tools to: (1) determine the statistical power for detecting trends of varying magnitude in a specified water quality parameter over different lengths of sampling (years) and different within-year collection frequencies (monthly or seasonal sampling) at particular locations using historical data, and (2) perform periodic trend analyses for water quality parameters while addressing seasonality and flow weighting. A power analysis for trend detection is a statistical procedure used to estimate the probability of rejecting the hypothesis of no trend when in fact there is a trend, within a specific modeling framework. In this report, we base our power estimates on using the seasonal Kendall test (Helsel and Hirsch 2002) for detecting trend in water quality parameters measured at fixed locations over multiple years. We also present procedures (R-scripts) for conducting a periodic trend analysis using the seasonal Kendall test with and without flow adjustment. This report provides the R-scripts developed for power and trend analysis, tutorials, and the associated tables and graphs. The purpose of this report is to provide practical information for monitoring network staff on how to use these statistical tools for water quality monitoring data sets.

  19. Distributed generation system with PEM fuel cell for electrical power quality improvement

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, D.; Beites, L.F.; Blazquez, F. [Department of Electrical Engineering, ETSII, Escuela de Ingenieros Industriales, Universidad Politecnica de Madrid, C/ Jose Gutierrez Abascal 2, 28006 Madrid (Spain); Ballesteros, J.C. [Endesa Generacion, S.A. c/ Ribera de Loira 60, 28042 Madrid (Spain)

    2008-08-15

    In this paper, a physical model for a distributed generation (DG) system with power quality improvement capability is presented. The generating system consists of a 5 kW PEM fuel cell, a natural gas reformer, hydrogen storage bottles and a bank of ultra-capacitors. Additional power quality functions are implemented with a vector-controlled electronic converter for regulating the injected power. The capabilities of the system were experimentally tested on a scaled electrical network. It is composed of different lines, built with linear inductances and resistances, and taking into account both linear and non-linear loads. The ability to improve power quality was tested by means of different voltage and frequency perturbations produced on the physical model electrical network. (author)

  20. User Context Aware Base Station Power Flow Model

    OpenAIRE

    Walsh, Barbara; Farrell, Ronan

    2005-01-01

    At present the testing of power amplifiers within base station transmitters is limited to testing at component level as opposed to testing at the system level. While the detection of catastrophic failure is possible, that of performance degradation is not. This paper proposes a base station model with respect to transmitter output power with the aim of introducing system level monitoring of the power amplifier behaviour within the base station. Our model reflects the expe...

  1. A capacitive RF power sensor based on MEMS technology

    NARCIS (Netherlands)

    Fernandez, Luis Jose

    2005-01-01

    Existing power sensors for RF signals are based on thermistors, diodes and thermocouples. These power sensors are used as terminating devices and therefore they dissipate the complete incoming signal. Furthermore, new telecommunication systems require low weight, volume and power consumption and a h

  2. A capacitive rf power sensor based on mems technology

    NARCIS (Netherlands)

    Fernandez, L.J.

    2005-01-01

    Existing power sensors for RF signals are based on thermistors, diodes and thermocouples. These power sensors are used as terminating devices and therefore they dissipate the complete incoming signal. Furthermore, new telecommunication systems require low weight, volume and power consumption and a

  3. Model based active power control of a wind turbine

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Soltani, Mohsen; Poulsen, Niels Kjølstad;

    2014-01-01

    in the electricity market that selling the reserve power is more profitable than producing with the full capacity. Therefore wind turbines can be down-regulated and sell the differential capacity as the reserve power. In this paper we suggest a model based approach to control wind turbines for active power reference...

  4. Lower Power Design for UHF RF CMOS Circuits Based on the Power Consumption Acuity

    Directory of Open Access Journals (Sweden)

    Niu Xiang-jie

    2014-01-01

    Full Text Available Excessive energy consumption of UHF tag is the bottleneck of energy saving in its wide range of applications. To address this issue, a lower power design for UHF RF CMOS circuits based on power consumption acuity is proposed in this paper. Through in-depth analysis of the static and dynamic power generation principle of UHF RF circuits in the work, the power consumption acuity can be calculated by using the correlation of circuit power and input vector. Subsequently, under the guide of this acuity, the UHF RF CMOS circuits with better energy saving can be designed. Furthermore, according to the performance indicators of EPC CIG2 UHF RFID in UHF identification, the corresponding circuit is designed and implemented. The test results show that the design of UHF RF circuit based on the acuity of power consumption can reduce 35%–40% power consumption.

  5. Site selection of active damper for stabilizing power electronics based power distribution system

    DEFF Research Database (Denmark)

    Yoon, Changwoo; Wang, Xiongfei; Bak, Claus Leth

    2015-01-01

    Stability in the nowadays distribution power system is endangered by interaction problems that may arise from newly added power-electronics based power devices. Recently, a new concept to deal with this higher frequency instability, the active damper, has been proposed. The active damper is a power...... electronics based power device, which provides an adjustable damping capability to the power system where the voltage harmonic instability is measured. It can stabilize by adjusting the equivalent node impedance with its plug and play feature. This feature gives many degrees of freedom of its installation...... point when the system has many nodes. Therefore, this paper addresses the proper placement of an active damper in an unstable small-scale power distribution system. A time-domain model of the Cigre benchmark low-vltage network is used as a test field. The result shows the active damper location...

  6. FPGA Based Low Power ROM Design Using Capacitance Scaling

    DEFF Research Database (Denmark)

    Bansal, Meenakshi; Bansal, Neha; Saini, Rishita

    2015-01-01

    An ideal capacitor will not dissipate any power, but a real capacitor wil l have some power dissipation. In this work, we are going to design capacitance scaling based low power ROM design. In order to test the compatibility of this ROM design with latest i7 Processor, we are operating this ROM w...... in I/O Power, saving of 0.2% occur in Leakage Power, there will be a saving of 11.54% occur in Total Power. This design is implemented on Virtex-5 FPGA using Xilinx ISE and Verilog....

  7. Optimized Envelope Tracking Power Supply for Tetra2 Base Station RF Power Amplifier

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

    2008-01-01

    An ultra-fast tracking power supply (UFTPS) for envelope tracking in a 50kHz 64-QAM Tetra2 base station power amplification system is demonstrated. A simple method for optimizing the step response of the PID+PD sliding-mode control system is presented and demonstrated, along with a PLL-based scheme...

  8. Power Management during Scan Based Sequential Circuit Testing

    CERN Document Server

    p, Reshma

    2011-01-01

    This paper shows that not every scan cell contributes equally to the power consumption during scan based test. The transitions at some scan cells cause more toggles at the internal signal lines of a circuit than the transitions at other scan cells. Hence the transitions at these scan cells have a larger impact on the power consumption during test application. These scan cells are called power sensitive scan cells.A verilog based approach is proposed to identify a set of power sensitive scan cells. Additional hardware is added to freeze the outputs of power sensitive scan cells during scan shifting in order to reduce the shift power consumption.when multiple scan chain is incorporated along with freezing the power sensitive scan cell,over all power during testing can be reduced to a larger extend.

  9. Research on battery array based on solar power

    Science.gov (United States)

    Li, Junhong

    2017-03-01

    Almost all of the energy of solar power supply system comes from solar energy, which is a kind of pollution-free green energy, using independent photovoltaic system as base station power supply. In this paper, taking the solar power system as the research object, we made MATLAB simulation analysis of the independent solar photovoltaic system battery array. The simulation results showed that the output voltage and the output current of the solar array based on solar power system are affected by the illumination intensity and temperature change. In addition, it also showed that at any temperature and illumination intensity, there will a largest output power.

  10. EMC and power quality standards for 20-kHz power distribution

    Science.gov (United States)

    Hansen, Irving G.

    1987-01-01

    The Space Station Power Distribution System has been baselined as a sinusoidal single phase, 440 VRMS system. This system has certain unique characteristics directly affecting its application. In particular, existing systematic description and control documents were modified to reflect the high operating frequency. This paper will discuss amendments made on Mil STD 704 (Electrical Power Characteristics), and Mil STD 461-B (Electromagnetic Emission and Susceptibility Requirements for the Control of Electromagnetic Interference). In some cases these amendments reflect changes of several orders of magnitude. Implications and impacts of these changes are discussed.

  11. The Quality of Accounting Earnings and Change in Political Power Map: Evidence from Indonesia

    Directory of Open Access Journals (Sweden)

    Harymawan Iman

    2017-01-01

    Full Text Available This study investigates the earnings quality of politically connected firms listed in Indonesian Stock Exchange during 2006-2010. This study compare two definition (Soeharto Dependency Index (SDI and Politically Exposed Person (PEP of political connections to capture the effect of the changes of political power map on the earnings quality of politically connected firms in Indonesia. The finding shows that the quality of accounting earnings of politically connected firms which were formerly closely related to President Soeharto in 1998 are not significantly different to other firms. Furthermore, when this study employ politically exposed person as a proxy of political connections, the findings shows that connected firms have significantly lower quality accounting earnings. Consistent with prior findings, this study shows that change in political power map in Indonesia affect the level of earnings quality of politically connected firms.

  12. Low Power Complex Multiplier based FFT Processor

    Directory of Open Access Journals (Sweden)

    V.Sarada

    2015-08-01

    Full Text Available High speed processing of signals has led to the requirement of very high speed conversion of signals from time domain to frequency domain. Recent years there has been increasing demand for low power designs in the field of Digital signal processing. Power consumption is the most important aspect while considering the system performance. In order to design high performance Fast Fourier Transform (FFT and realization, efficient internal structure is required. In this paper we present FFT Single Path Delay feedback (SDF pipeline architecture using radix -24 algorithm .The complex multiplier is realized by using Digit Slicing Concept multiplier less architecture. To reduce computation complexity radix 24 algorithms is used. The proposed design has been coded in Verilog HDL and synthesizes by Cadence tool. The result demonstrates that the power is reduced compared with complex multiplication used CSD (Canonic Signed Digit multiplier.

  13. Knowledge-based systems for power management

    Science.gov (United States)

    Lollar, L. F.

    1992-01-01

    NASA-Marshall's Electrical Power Branch has undertaken the development of expert systems in support of further advancements in electrical power system automation. Attention is given to the features (1) of the Fault Recovery and Management Expert System, (2) a resource scheduler or Master of Automated Expert Scheduling Through Resource Orchestration, and (3) an adaptive load-priority manager, or Load Priority List Management System. The characteristics of an advisory battery manager for the Hubble Space Telescope, designated the 'nickel-hydrogen expert system', are also noted.

  14. The air quality and regional climate effects of widespread solar power generation under a changing regulatory environment

    Science.gov (United States)

    Millstein, D.; Zhai, P.; Menon, S.

    2011-12-01

    Over the past decade significant reductions of NOx and SOx emissions from coal burning power plants in the U.S. have been achieved due to regulatory action and substitution of new generation towards natural gas and wind power. Low natural gas prices, ever decreasing solar generation costs, and proposed regulatory changes, such as to the Cross State Air Pollution Rule, promise further long-run coal power plant emission reductions. Reduced power plant emissions have the potential to affect ozone and particulate air quality and influence regional climate through aerosol cloud interactions and visibility effects. Here we investigate, on a national scale, the effects on future (~2030) air quality and regional climate of power plant emission regulations in contrast to and combination with policies designed to aggressively promote solar electricity generation. A sophisticated, economic and engineering based, hourly power generation dispatch model is developed to explore the integration of significant solar generation resources (>10% on an energy basis) at various regions across the county, providing detailed estimates of substitution of solar generation for fossil fuel generation resources. Future air pollutant emissions from all sectors of the economy are scaled based on the U.S. Environmental Protection Agency's National Emission Inventory to account for activity changes based on population and economic projections derived from county level U.S. Census data and the Energy Information Administration's Annual Energy Outlook. Further adjustments are made for technological and regulatory changes applicable within various sectors, for example, emission intensity adjustments to on-road diesel trucking due to exhaust treatment and improved engine design. The future year 2030 is selected for the emissions scenarios to allow for the development of significant solar generation resources. A regional climate and air quality model (Weather Research and Forecasting, WRF model) is

  15. Estimation of Power Quality Indicators During a Real Wind Farm Islanding Experiment

    DEFF Research Database (Denmark)

    Terzija, Vladimir; Stanojević, V.; Štrbac, G.

    2008-01-01

    The two-stage Newton Type Algorithm for the tracking of the power quality indicators, frequency and rate of frequency changes is presented in the paper. By this definitions for power quality indicators according to the IEEE Standard 1459-2000 were used. In the first algorithm stage the spectra of...... spectrum. The proposed algorithm is implemented for the analysis of transient processes during a real islanding experiment on the Rejsby Hede wind farm in Denmark.......The two-stage Newton Type Algorithm for the tracking of the power quality indicators, frequency and rate of frequency changes is presented in the paper. By this definitions for power quality indicators according to the IEEE Standard 1459-2000 were used. In the first algorithm stage the spectra...... of voltages and currents are estimated. Frequency and its rate of change are directly estimated from voltage input signals. In the second algorithm stage the power quality indicators are calculated. The algorithm considers frequency as an unknown model parameter simultaneously estimated with the voltage...

  16. POWER QUALITY ANALYSIS AND ITS DEVELOPMENT%电能质量问题剖析

    Institute of Scientific and Technical Information of China (English)

    肖湘宁; 徐永海

    2001-01-01

    The power quality problems being paid attention to in recent years are summarized in this paper. From the development process of power quality research, to the reason of paying attention to power quality and then to the standardization of the definition, classification, range and term for power quality which is so far discussed and explored, the achievements of research by IEC and IEEE and related sections are presented. It is pointed out also that studying the various power system electromagnetic disturbances as a whole on the basis of well understanding power quality problems, and gradually establishing the overall power quality management system are the important tasks in China.%概述了近年来国际上越来越关注的电能质量问题,分析了电能质量问题的产生及日益引起关注的原因,以及在讨论和探索有关电能质量的定义、分类、范围和术语的标准化等方面,介绍了国际电工委员会(IEC)和电气与电子工程师协会(IEEE)和相关部门所做的研究成果。如何认识和理解电能质量问题,把诸多电力系统电磁现象视为一个整体加以研究,逐渐构成中国的全面电能质量管理体系是摆在中国电力科技工作者面前的一项重要工作。

  17. Grid simulator for power quality assessment of micro-grids

    DEFF Research Database (Denmark)

    Carrasco, Joaquin Eloy Garcia; Vasquez, Juan Carlos; Guerrero, Josep M.

    2013-01-01

    In this study, a grid simulator based on a back-to-back inverter topology with resonant controllers is presented. The simulator is able to generate three-phase voltages for a range of amplitudes and frequencies with different types of perturbations, such as voltage sags, steady-state unbalanced v...

  18. Gait Variability Related to Muscle Quality and Muscle Power Output in Frail Nonagenarian Older Adults.

    Science.gov (United States)

    Martinikorena, Ion; Martínez-Ramírez, Alicia; Gómez, Marisol; Lecumberri, Pablo; Casas-Herrero, Alvaro; Cadore, Eduardo L; Millor, Nora; Zambom-Ferraresi, Fabricio; Idoate, Fernando; Izquierdo, Mikel

    2016-02-01

    Frailty has become the center of attention of basic, clinical, and demographic research because of its incidence level and the gravity of adverse outcomes with age. Moreover, with advanced age, motor variability increases, particularly in gait. Muscle quality and muscle power seem to be closely associated with performance on functional tests in frail populations. Insight into the relationships among muscle power, muscle quality, and functional capacity could improve the quality of life in this population. In this study, the relationship between the quality of the muscle mass and muscle strength with gait performance in a frail population was examined. Twenty-two institutionalized frail elderly individuals (93.1 ± 3.6) participated in this study. Muscle quality was measured by segmenting areas of high- and low-density fibers as observed in computed tomography images. The assessed functional outcomes were leg strength and power, velocity of gait, and kinematic gait parameters obtained from a tri-axial inertial sensor. Our results showed that a greater number of high-density fibers, specifically those of the quadriceps femoris muscle, were associated with better gait performance in terms of step time variability, regularity, and symmetry. Additionally, gait variability was associated with muscle power. In contrast, no significant relationship was observed between gait velocity and either muscle quality or muscle power. Gait pattern disorders could be explained by a deterioration of the lower limb muscles. It is known that an impaired gait is an important predictor of falls in older populations; thus, the loss of muscle quality and power could underlie the impairments in motor control and balance that lead to falls and adverse outcomes. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  19. Power system stabilizers based on modern control techniques

    Energy Technology Data Exchange (ETDEWEB)

    Malik, O.P.; Chen, G.P.; Zhang, Y.; El-Metwally, K. [Calgary Univ., AB (Canada). Dept. of Electrical and Computer Engineering

    1994-12-31

    Developments in digital technology have made it feasible to develop and implement improved controllers based on sophisticated control techniques. Power system stabilizers based on adaptive control, fuzzy logic and artificial networks are being developed. Each of these control techniques possesses unique features and strengths. In this paper, the relative performance of power systems stabilizers based on adaptive control, fuzzy logic and neural network, both in simulation studies and real time tests on a physical model of a power system, is presented and compared to that of a fixed parameter conventional power system stabilizer. (author) 16 refs., 45 figs., 3 tabs.

  20. Power-based control of physical systems

    NARCIS (Netherlands)

    Garcia-Canseco, Eloisa; Jeltsema, Dimitri; Ortega, Romeo; Scherpen, Jacquelien M. A.

    2010-01-01

    It is well known that energy-balancing control is stymied by the presence of pervasive dissipation. To overcome this problem in electrical circuits, the alternative paradigm of power shaping was introduced in Ortega, Jeltsema, and Scherpen (2003)-where, as suggested by its name, stabilization is ach

  1. A Review of Power Electronics Based Microgrids

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Guerrero, Josep M.; Blaabjerg, Frede

    2012-01-01

    of microgrid configurations is given. Then, possible structure options and control methods of DER units are presented, which is followed by the descriptions of system controls and power management strategies for AC microgrids. Finally, future trends of microgrids are discussed pointing out how this concept can...

  2. Quality engineering tools focused on high power LED driver design using boost power stages in switch mode

    Science.gov (United States)

    Ileana, Ioan; Risteiu, Mircea; Marc, Gheorghe

    2016-12-01

    This paper is a part of our research dedicated to high power LED lamps designing. The boost-up selected technology wants to meet driver producers' tendency in the frame of efficiency and disturbances constrains. In our work we used modeling and simulation tools for implementing scenarios of the driver work when some controlling functions are executed (output voltage/ current versus input voltage and fixed switching frequency, input and output electric power transfer versus switching frequency, transient inductor voltage analysis, and transient out capacitor analysis). Some electrical and thermal stress conditions are also analyzed. Based on these aspects, a high reliable power LED driver has been designed.

  3. Improvement of Power Quality using Fuzzy Logic Controller In Grid Connected Photovoltaic Cell Using UPQC

    Directory of Open Access Journals (Sweden)

    K.Ramalingeswara Rao

    2014-07-01

    Full Text Available In this paper, the design of combined operation of UPQC and PV-ARRAY is designed. The proposed system is composed of series and shunt inverters connected back to back by a dc-link to which pv-array is connected. This system is able to compensate voltage and current related problems both in inter-connected mode and islanding mode by injecting active power to grid. The fundamental aspect is that the power electronic devices (PE and sensitive equipments (SE are normally designed to work in non-polluted power system, so they would suffer from malfunctions when supply voltage is not pure sinusoidal. Thus this proposed operating strategy with flexible operation mode improves the power quality of the grid system combining photovoltaic array with a control of unified power quality conditioner. Pulse Width Modulation (PWM is used in both three phase four leg inverters. A Proportional Integral (PI and Fuzzy Logic Controllers are used for power quality improvement by reducing the distortions in the output power. The simulated results were compared among the two controller’s strategies With pi controller and fuzzy logic controller

  4. Power plant fuel switching and air quality in a tropical, forested environment

    Science.gov (United States)

    Medeiros, Adan S. S.; Calderaro, Gisele; Guimarães, Patricia C.; Magalhaes, Mateus R.; Morais, Marcos V. B.; Rafee, Sameh A. A.; Ribeiro, Igor O.; Andreoli, Rita V.; Martins, Jorge A.; Martins, Leila D.; Martin, Scot T.; Souza, Rodrigo A. F.

    2017-07-01

    How a changing energy matrix for electricity production affects air quality is considered for an urban region in a tropical, forested environment. Manaus, the largest city in the central Amazon Basin of Brazil, is in the process of changing its energy matrix for electricity production from fuel oil and diesel to natural gas over an approximately 10-year period, with a minor contribution by hydropower. Three scenarios of urban air quality, specifically afternoon ozone concentrations, were simulated using the Weather Research and Forecasting (WRF-Chem) model. The first scenario used fuel oil and diesel for electricity production, which was the reality in 2008. The second scenario was based on the fuel mix from 2014, the most current year for which data were available. The third scenario considered nearly complete use of natural gas for electricity production, which is the anticipated future, possibly for 2018. For each case, inventories of anthropogenic emissions were based on electricity generation, refinery operations, and transportation. Transportation and refinery operations were held constant across the three scenarios to focus on effects of power plant fuel switching in a tropical context. The simulated NOx and CO emissions for the urban region decrease by 89 and 55 %, respectively, after the complete change in the energy matrix. The results of the simulations indicate that a change to natural gas significantly decreases maximum afternoon ozone concentrations over the population center, reducing ozone by > 70 % for the most polluted days. The sensitivity of ozone concentrations to the fuel switchover is consistent with a NOx-limited regime, as expected for a tropical forest having high emissions of biogenic volatile organic compounds, high water vapor concentrations, and abundant solar radiation. There are key differences in a shifting energy matrix in a tropical, forested environment compared to other world environments. Policies favoring the burning of

  5. Bionic Vision-Based Intelligent Power Line Inspection System.

    Science.gov (United States)

    Li, Qingwu; Ma, Yunpeng; He, Feijia; Xi, Shuya; Xu, Jinxin

    2017-01-01

    Detecting the threats of the external obstacles to the power lines can ensure the stability of the power system. Inspired by the attention mechanism and binocular vision of human visual system, an intelligent power line inspection system is presented in this paper. Human visual attention mechanism in this intelligent inspection system is used to detect and track power lines in image sequences according to the shape information of power lines, and the binocular visual model is used to calculate the 3D coordinate information of obstacles and power lines. In order to improve the real time and accuracy of the system, we propose a new matching strategy based on the traditional SURF algorithm. The experimental results show that the system is able to accurately locate the position of the obstacles around power lines automatically, and the designed power line inspection system is effective in complex backgrounds, and there are no missing detection instances under different conditions.

  6. Effects of Nonverbal Behavior on Perceptions of Power Bases.

    Science.gov (United States)

    Aguinis, Herman; Simonsen, Melissa M.; Pierce, Charles A.

    1998-01-01

    Manipulates three types of nonverbal behaviors and examines their effects on perceptions of power bases. Reports that a relaxed facial expression increased the ratings for five of the selected power bases; furthermore, direct eye contact yielded higher credibility ratings. Provides evidence that various nonverbal behaviors have only additive…

  7. Effects of Nonverbal Behavior on Perceptions of Power Bases.

    Science.gov (United States)

    Aguinis, Herman; Simonsen, Melissa M.; Pierce, Charles A.

    1998-01-01

    Manipulates three types of nonverbal behaviors and examines their effects on perceptions of power bases. Reports that a relaxed facial expression increased the ratings for five of the selected power bases; furthermore, direct eye contact yielded higher credibility ratings. Provides evidence that various nonverbal behaviors have only additive…

  8. Mn based olivine electrode material with high power and energy.

    Science.gov (United States)

    Kim, Jongsoon; Seo, Dong-Hwa; Kim, Sung-Wook; Park, Young-Uk; Kang, Kisuk

    2010-02-28

    We report the Mn based olivine electrode material with high power and energy. Easier and more frequent nucleation by Fe and Co in Mn-based olivines significantly enhanced the rate capability as evidenced by the electrochemical results.

  9. Antimisting kerosene: Base fuel effects, blending and quality control techniques

    Science.gov (United States)

    Yavrouian, A. H.; Ernest, J.; Sarohia, V.

    1984-01-01

    The problems associated with blending of the AMK additive with Jet A, and the base fuel effects on AMK properties are addressed. The results from the evaluation of some of the quality control techniques for AMK are presented. The principal conclusions of this investigation are: significant compositional differences for base fuel (Jet A) within the ASTM specification DI655; higher aromatic content of the base fuel was found to be beneficial for the polymer dissolution at ambient (20 C) temperature; using static mixer technology, the antimisting additive (FM-9) is in-line blended with Jet A, producing AMK which has adequate fire-protection properties 15 to 20 minutes after blending; degradability of freshly blended and equilibrated AMK indicated that maximum degradability is reached after adequate fire protection is obtained; the results of AMK degradability as measured by filter ratio, confirmed previous RAE data that power requirements to decade freshly blended AMK are significantly higher than equilibrated AMK; blending of the additive by using FM-9 concentrate in Jet A produces equilibrated AMK almost instantly; nephelometry offers a simple continuous monitoring capability and is used as a real time quality control device for AMK; and trajectory (jet thurst) and pressure drop tests are useful laboratory techniques for evaluating AMK quality.

  10. Extensive Taguchi's Quality Loss Function Based On Asymmetric tolerances

    Institute of Scientific and Technical Information of China (English)

    ZHU Wei; LI Yuan-sheng; LIU Feng

    2004-01-01

    If specification interval is asymmetric, basic specification is the target value of quality characteristics. In this paper Taguchi's quality loss function is applied to describe quality loss based on asymmetric tolerances. The measurement of quality loss which is caused by the deviation of quality characteristics from basic specification is further presented.

  11. A novel symmetrical microwave power sensor based on MEMS technology

    Institute of Scientific and Technical Information of China (English)

    Wang Debo; Liao Xiaoping

    2009-01-01

    A novel symmetrical microwave power sensor based on MEMS technology is presented. In this power sensor, the left section inputs the microwave power, while the right section inputs the DC power. Because of its symmetrical structure, this power sensor provides more accurate microwave power measurement capability without mismatch uncertainty and temperature drift. The loss caused by the microwave signal is simulated in this power sensor. This power sensor is designed and fabricated using GaAs MMIC technology. And it is measured in the frequency range up to 20 GHz with an input power in the 0-80 mW range. Over the 80 mW dynamic range, the sensitivity can achieve about 0.2 mV/mW. The difference between the input power in the two sections is below 0.1% for an equal output voltage. In short, the key aspect of this power sensor is that the microwave power measurement is replaced with a DC power measurement.

  12. Computer-integrated quality management system for power stations. Computer-integriertes Qualitaetsmanagementsystem fuer Kraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Durst, K.H.; Scheurer, K.; Meinhardt, H. (Siemens AG, Offenbach (Germany). Abt. Qualitaetssicherung)

    1993-03-01

    Conventional CAQ systems, which were developed for monitoring mass production, are not very suitable for quality assurance in the construction and operation of plant and power stations. Long life products have to be monitored in plant and power station construction, which were manufactured in small batches for individually. So that the quality of these products can be monitored and can be assured economically and reliably by preventive maintenance measures, it is necessary to combine the plant documentation, repeated tests and repair or replacement measures in a 'computer-integrated quality management system'. For large complex plants, such as power stations, an operation guidance system was developed which includes all important plant information and makes it available in a user-friendly way to the concern's management. The article introduces this system. (orig.).

  13. Quality and performance of laser cutting with a high power SM fiber laser

    DEFF Research Database (Denmark)

    Kristiansen, Morten; Selchau, Jacob; Olsen, F. O.

    2013-01-01

    The introduction of high power single mode fiber lasers allows for a beam of high power and a good beam quality factor (M2 ” 1.2), compared to the multimode fiber lasers often utilised in macro laser metal cutting. This paper describes fundamental studies of macro laser metal cutting with a single...... mode fiber laser to study the performance of such lasers in terms of cut quality and process performance. Linear cut experiments have been performed applying a 3kW single mode fiber laser and varying the following parameters: laser power, cutting speed, focal length, focus position, cutting gas...... influence the cut quality and the maximum cutting speed in the investigated parameter space. Furthermore the achieved cutting performance is benchmarked to laser cutting with other types of lasers, CO2-lasers, disc-lasers as well as multimode fiber lasers....

  14. Classification of Underlying Causes of Power Quality Disturbances: Deterministic versus Statistical Methods

    Directory of Open Access Journals (Sweden)

    Emmanouil Styvaktakis

    2007-01-01

    Full Text Available This paper presents the two main types of classification methods for power quality disturbances based on underlying causes: deterministic classification, giving an expert system as an example, and statistical classification, with support vector machines (a novel method as an example. An expert system is suitable when one has limited amount of data and sufficient power system expert knowledge; however, its application requires a set of threshold values. Statistical methods are suitable when large amount of data is available for training. Two important issues to guarantee the effectiveness of a classifier, data segmentation, and feature extraction are discussed. Segmentation of a sequence of data recording is preprocessing to partition the data into segments each representing a duration containing either an event or a transition between two events. Extraction of features is applied to each segment individually. Some useful features and their effectiveness are then discussed. Some experimental results are included for demonstrating the effectiveness of both systems. Finally, conclusions are given together with the discussion of some future research directions.

  15. Analysis of Power Quality Signals Using an Adaptive Time-Frequency Distribution

    Directory of Open Access Journals (Sweden)

    Nabeel A. Khan

    2016-11-01

    Full Text Available Spikes frequently occur in power quality (PQ disturbance signals due to various causes such as switching of the inductive loads and the energization of the capacitor bank. Such signals are difficult to analyze using existing time-frequency (TF methods as these signals have two orthogonal directions in a TF plane. To address this issue, this paper proposes an adaptive TF distribution (TFD for the analysis of PQ signals. In the proposed adaptive method, the smoothing kernel’s direction is locally adapted based on the direction of energy in the joint TF domain, and hence an improved TF resolution can be obtained. Furthermore, the performance of the proposed adaptive technique in analyzing electrical PQ is thoroughly studied for both synthetic and real world electrical power signals with the help of extensive simulations. The simulation results (specially for empirical data indicate that the adaptive TFD method achieves high energy concentration in the TF domain for signals composed of tones and spikes. Moreover, the local adaptation of the smoothing kernel in the adaptive TFD enables the extraction of TF signature of spikes from TF images, which further helps in measuring the energy of spikes in a given signal. This new measure can be used to both detect the spikes as well as to quantify the extent of distortion caused by the spikes in a given signal.

  16. Systems definition space based power conversion systems: Executive summary

    Science.gov (United States)

    1977-01-01

    Potential space-located systems for the generation of electrical power for use on earth were investigated. These systems were of three basic types: (1) systems producing electrical power from solar energy; (2) systems producing electrical power from nuclear reactors; (3) systems for augmenting ground-based solar power plants by orbital sunlight reflectors. Configurations implementing these concepts were developed through an optimization process intended to yield the lowest cost for each. A complete program was developed for each concept, identifying required production rates, quantities of launches, required facilities, etc. Each program was costed in order to provide the electric power cost appropriate to each concept.

  17. Software-Based Wireless Power Transfer Platform for Various Power Control Experiments

    Directory of Open Access Journals (Sweden)

    Sun-Han Hwang

    2015-07-01

    Full Text Available In this paper, we present the design and evaluation of a software-based wireless power transfer platform that enables the development of a prototype involving various open- and closed-loop power control functions. Our platform is based on a loosely coupled planar wireless power transfer circuit that uses a class-E power amplifier. In conjunction with this circuit, we implement flexible control functions using a National Instruments Data Acquisition (NI DAQ board and algorithms in the MATLAB/Simulink. To verify the effectiveness of our platform, we conduct two types of power-control experiments: a no-load or metal detection using open-loop power control, and an output voltage regulation for different receiver positions using closed-loop power control. The use of the MATLAB/Simulink software as a part of the planar wireless power transfer platform for power control experiments is shown to serve as a useful and inexpensive alternative to conventional hardware-based platforms.

  18. Market Based Analysis of Power System Interconnections

    Science.gov (United States)

    Obushevs, Artjoms; Turcik, Mario; Oleinikova, Irina; Junghans, Gatis

    2011-01-01

    Analysis in this Article is focused on usage of transmission grid under liberalized market with implicit transmission capacity allocation method, e.g. Nordic market. Attention is paid on fundamental changes in transmission utilization and its economical effective operation. For interconnection and power flow analysis and losses calculation model of Nordic grid was developed and transmission losses calculation method was created. Given approach will improve economical efficiency of system operation in electricity market conditions.

  19. Security region based real and reactive power pricing of power system

    Institute of Scientific and Technical Information of China (English)

    YU YiXin; WANG YanJun

    2008-01-01

    This paper develops a novel model and an algorithm of security region based real and reactive power pricing of power systems. In the proposed model, the reactive power production cost is represented as the opportunity cost. The static voltage stability region in the cut set power space (CVSR) and the practical dynamic secu-rity region (PDSR) in the injection power space are used to represent the con-straints of voltage stability and transient stability, so that the consideration of this kind of constraints in the optimization becomes very easy. In the proposed algo-rithm, a decoupled optimization and iteration method of active power production cost and reactive power production cost is suggested. According to the K-T opti-mality conditions, the prices of active power and reactive power, and the different components corresponding to the concerned security constraints are derived. The components of spot prices can reflect the influence of different node power injec-tions on each kind of security constraints, so that through the node price all of the participants in power market can be stimulated to take an active part in maintaining the system security. An illustrative example on the New England 10-generator 39-bus System is used to demonstrate the proposed method.

  20. Security region based real and reactive power pricing of power system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper develops a novel model and an algorithm of security region based real and reactive power pricing of power systems.In the proposed model,the reactive power production cost is represented as the opportunity cost.The static voltage stability region in the cut set power space(CVSR) and the practical dynamic security region(PDSR) in the injection power space are used to represent the constraints of voltage stability and transient stability,so that the consideration of this kind of constraints in the optimization becomes very easy.In the proposed algorithm,a decoupled optimization and iteration method of active power production cost and reactive power production cost is suggested.According to the K-T optimality conditions,the prices of active power and reactive power,and the different components corresponding to the concerned security constraints are derived.The components of spot prices can reflect the influence of different node power injections on each kind of security constraints,so that through the node price all of the participants in power market can be stimulated to take an active part in maintaining the system security.An illustrative example on the New England 10-genetator 39-bus System is used to demonstrate the proposed method.

  1. Design and Implementation of a High Quality Power Supply Scheme for Distributed Generation in a Micro-Grid

    Directory of Open Access Journals (Sweden)

    Mingchao Xia

    2013-09-01

    Full Text Available A low carbon, high efficiency and high quality power supply scheme for Distributed Generation (DG in a micro-grid is presented. A three-phase, four-leg DG grid-interfacing converter based on the improved structure of a Unified Power Quality Conditioner (UPQC, including a series converter and a parallel converter is adopted, and improved indirect and direct control strategies are proposed. It can be observed that these strategies effectively compensate for voltage sags, voltage swells and voltage distortion, as well as voltage power quality problems resulting from the nonlinear and unbalanced loads in a micro-grid. While solving the coupling interference from series–parallel, the grid-interfacing converter can achieve proper load power sharing in a micro-grid. In particular, an improved minimum-energy compensation method is proposed that can overcome the conventional compensation algorithm defects, ensure the load voltage’s phase angle stability, improve the voltage compensating ability and range, reduce the capacity and cost of converters, and reduce the shock of micro-grid switching between grid-connected mode and islanded mode. Moreover, the advantages/disadvantages and application situation of the two improved control strategies are analyzed. Finally, the performance of the proposed control strategies has been verified through a MATLAB/Simulink simulation under various operating conditions.

  2. Modeling, control, and dispatch of photovoltaic-based power distribution systems

    Science.gov (United States)

    Carrasco, Miguel

    Small-scale generators, also called distributed generators (DGs), are primed to play a central role in future distribution systems. If properly integrated, DGs present two main advantages: (i) they help decongest existing transmission grids; and (ii) CO2 emissions are reduced since most DGs are based on renewables like wind and solar. Their integration into distribution systems is one of the main challenges the power industry will be facing in the coming years. Photovoltaic (PV) power generation represents a key technology for realizing the DG concept. In this dissertation, technical solutions are developed that enable an increased penetration of PV systems, while improving the efficiency, reliability, and power quality of power distribution grids. The presented research spans from PV array modeling, parameter identification and estimation methods, through advanced control strategies for the power electronic interfaces, to system--level optimal dispatch strategies. Simulation-based and experimental validation results show the performance of the proposed techniques.

  3. Nonlinear disturbance attenuation control for four-leg active power filter based on voltage source inverter

    Institute of Scientific and Technical Information of China (English)

    Juming CHEN; Feng LIU; Shengwei MEI

    2006-01-01

    Active power filter (APF) based on voltage source inverter (VSI) is one of the important measures for handling the power quality problem. Mathematically, the APF model in a power grid is a typical nonlinear one. The idea of passivity is a powerful tool to study the stabilization of such a nonlinear system. In this paper, a state-space model of the four-leg APF is derived, based on which a new H-infinity controller for current tracking is proposed from the passivity point of view. It can achieve not only asymptotic tracking, but also disturbance attenuation in the sense of L2-gain. Subsequently,a sufficient condition to guarantee the boundedness and desired mean of the DC voltage is also given. This straightforward condition is consistent with the power-balancing law of electrical circuits. Simulations performed on PSCAD platform verify the validity of the new approach.

  4. A Price-Based Approach for Voltage Regulation and Power Loss Minimization in Power Distribution Networks

    NARCIS (Netherlands)

    Jafarian, Matin; Scherpen, Jacquelien M.A.; Aiello, Marco

    2016-01-01

    We present a price-based approach to deal with the challenges of the electrical power distribution systems with renewable generations. In specific, we address the power loss minimization and voltage regulation taking into account the actual grid capacity. Analogously, the cost function is reformulat

  5. Muscle Power Is an Independent Determinant of Pain and Quality of Life in Knee Osteoarthritis.

    Science.gov (United States)

    Reid, Kieran F; Price, Lori Lyn; Harvey, William F; Driban, Jeffrey B; Hau, Cynthia; Fielding, Roger A; Wang, Chenchen

    2015-12-01

    This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. Baseline data on 190 subjects with knee OA (mean ± SD age 60.2 ± 10.4 years, body mass index 32.7 ± 7.2 kg/m(2) ) were obtained from a randomized controlled trial. Knee pain was measured using the Western Ontario and McMaster Universities Osteoarthritis Index, and health-related quality of life was assessed using the Short Form 36 (SF-36). One-repetition maximum (1RM) strength was assessed using the bilateral leg press, and peak muscle power was measured during 5 maximum voluntary velocity repetitions at 40% and 70% of 1RM. In univariate analysis, greater muscle power was significantly associated with pain (r = -0.17, P muscle power was a significant independent predictor of pain (P ≤ 0.05) and PCS scores (P ≤ 0.04). However, muscle strength was not an independent determinant of pain or quality of life (P ≥ 0.06). Muscle power is an independent determinant of pain and quality of life in knee OA. Compared to strength, muscle power may be a more clinically important measure of muscle function within this population. New trials to systematically examine the impact of muscle power training interventions on disease severity in knee OA are particularly warranted. © 2015, American College of Rheumatology.

  6. Power quality assessment of grid-connected wind farms considering regulations in turkey

    Energy Technology Data Exchange (ETDEWEB)

    Kocatepe, Celal; Inan, Aslan; Arikan, Oktay; Yumurtaci, Recep; Kekezoglu, Bedri; Baysal, Mustafa; Bozkurt, Altug [Yildiz Technical University, Department of Electrical Engineering, 34349 istanbul (Turkey); Akkaya, Yener [Turkish Electricity Transmission Company, R and D Manager, inoenue Bulvari, 06490 Ankara (Turkey)

    2009-12-15

    This paper presents measurement system and detailed analysis of power quality at the substation of two different wind farm sites which are of low and high power rate. Measurement system has been designed using a data acquisition board (DAQ), Labview software, Matlab programming and a portable PC. The system has been installed at medium voltage level at substation of both wind farms. The real measurement results at substations are compared to current regulations in Turkey. (author)

  7. Modeling and Simulation of Series Compensator to Mitigate Power Quality Problems

    Directory of Open Access Journals (Sweden)

    S.Sadaiappan,

    2010-12-01

    Full Text Available Power Electronics and Advanced Control technologies have made it possible to mitigate power quality problems and maintain the operation of sensitive loads. Among power system disturbances, voltage sags, swells and harmonics are some of the severe problems to the sensitive loads. The series compensation method is best suited to protect such loads against those disturbances. The use of a series compensator (SC to improve power quality is an isolated power system is investigated. The role of the compensator is not only to mitigate the effects of voltage sag, but also to reduce the harmonic distortion due to the presence of non linear loads in the network. In this paper, a series compensator is proposed and a method of harmonic compensation is described and a method to mitigate voltage sag is investigated. The proposed series compensator consists of Energy Storage System (ESS and Voltage Source Inverter (VSI, Injection Transformer. The ESS can be a capacitor of suitable capacity. ESS would act as a buffer and generally provides the energy needed for load ride-through during voltage sag. Injection Transformer is used to inject the voltage in transmission line in appropriate level.In this way the terminal voltage of the protected sensitive load can be regulated to maintain a constant level. The modeling and imulation of the proposed series compensator was implemented in Matlab Simulink work space. Simulation results showed that the proposed series compensator was efficient in mitigating voltage sags and harmonics and thus improve the power quality of the isolated power system. This approach is different from conventional methods and provides effective solution. If this method is enhanced in future it could provide much more improved power quality.

  8. Power Quality Improvement and LVRT Capability Enhancement of Wind Farms by Means of an Inductive Filtering Method

    Directory of Open Access Journals (Sweden)

    Yanjian Peng

    2016-04-01

    Full Text Available Unlike the traditional method for power quality improvement and low-voltage ride through (LVRT capability enhancement of wind farms, this paper proposes a new wind power integrated system by means of an inductive filtering method, especially if it contains a grid-connected transformer, a static synchronous compensator (STATCOM and fully-tuned (FT branches. First, the main circuit topology of the new wind power integrated system is presented. Then, the mathematical model is established to reveal the mechanism of harmonic suppression and the reactive compensation of the proposed wind power integrated system, and then the realization conditions of the inductive filtering method is obtained. Further, the control strategy of STATCOM is introduced. Based on the measured data for a real wind farm, the simulation studies are carried out to illustrate the performance of the proposed new wind power integrated system. The results indicate that the new system can not only enhance the LVRT capability of wind farms, but also prevent harmonic components flowing into the primary (grid winding of the grid-connected transformer. Moreover, since the new method can compensate for reactive power in a wind farm, the power factor at the grid side can be improved effectively.

  9. Review of Ship Microgrids: System Architectures, Storage Technologies and Power Quality Aspects

    Directory of Open Access Journals (Sweden)

    Shantha Gamini Jayasinghe

    2017-02-01

    Full Text Available Ship microgrids have recently received increased attention, mainly due to the extensive use of power electronically interfaced loads and sources. Characteristics of these microgrids are similar to islanded terrestrial microgrids, except the presence of highly dynamic large loads, such as propulsion loads. The presence of such loads and sources with power-electronic converter interfaces lead to severe power quality issues in ship microgrids. Generally, these issues can be classified as voltage variations, frequency variations and waveform distortions which are commonly referred to as harmonic distortions. Amongst the solutions identified, energy storage is considered to be the most promising technology for mitigating voltage and/or frequency deviations. Passive filtering is the commonly used technology for reducing harmonic distortions, which requires bulky capacitors and inductors. Active filtering is emerging as an alternative, which could be realised even within the same interfacing converter of the energy storage system. The aim of this paper is to investigate recent developments in these areas and provide readers with a critical review on power quality issues, energy storage technologies and strategies that could be used to improve the power quality in ship microgrids. Moreover, a brief introduction to ship power system architectures is also presented in the paper.

  10. Modeling,Analysis and Simulation ofThree Phase Hybrid Power Filter forPower Quality Improvement

    Directory of Open Access Journals (Sweden)

    Prashanta Kumar Das

    2012-05-01

    Full Text Available A three-phase hybrid series power filter is constituted by a series active filter and a passive filter connected in parallel with the load. The control strategy is based on the “dual formulation of the electric power vectorial theory”. The proposed algorithm eliminates the current harmonics of supply. It also improves the power factor and harmonic compensation features of the associated passive filter even if there is a change in system parameters.A shunt hybrid power filter is constituted by a shunt active filter and a passive filter connected in parallel with the load, is proposed with same control strategy. Simulations have been carried out on the MATLAB-SIMULINK platform with different loads and with variation in the source impedance.

  11. Effects of Village Power Quality on Fuel Consumption and Operating Expenses

    Energy Technology Data Exchange (ETDEWEB)

    Richard Wies; Ron Johnson

    2008-12-31

    Alaska's rural village electric utilities are isolated from the Alaska railbelt electrical grid intertie and from each other. Different strategies have been developed for providing power to meet demand in each of these rural communities. Many of these communities rely on diesel electric generators (DEGs) for power. Some villages have also installed renewable power sources and automated generation systems for controlling the DEGs and other sources of power. For example, Lime Village has installed a diesel battery photovoltaic hybrid system, Kotzebue and Wales have wind-diesel hybrid systems, and McGrath has installed a highly automated system for controlling diesel generators. Poor power quality and diesel engine efficiency in village power systems increases the cost of meeting the load. Power quality problems may consist of poor power factor (PF) or waveform disturbances, while diesel engine efficiency depends primarily on loading, the fuel type, the engine temperature, and the use of waste heat for nearby buildings. These costs take the form of increased fuel use, increased generator maintenance, and decreased reliability. With the cost of bulk fuel in some villages approaching $1.32/liter ($5.00/gallon) a modest 5% decrease in fuel use can result in substantial savings with short payback periods depending on the village's load profile and the cost of corrective measures. This project over its five year history has investigated approaches to improving power quality and implementing fuel savings measures through the use of performance assessment software tools developed in MATLAB{reg_sign} Simulink{reg_sign} and the implementation of remote monitoring, automated generation control, and the addition of renewable energy sources in select villages. The results have shown how many of these communities would benefit from the use of automated generation control by implementing a simple economic dispatch scheme and the integration of renewable energy sources

  12. On-Chip Power-Combining for High-Power Schottky Diode-Based Frequency Multipliers

    Science.gov (United States)

    Chattopadhyay, Goutam; Mehdi, Imran; Schlecht, Erich T.; Lee, Choonsup; Siles, Jose V.; Maestrini, Alain E.; Thomas, Bertrand; Jung, Cecile D.

    2013-01-01

    A 1.6-THz power-combined Schottky frequency tripler was designed to handle approximately 30 mW input power. The design of Schottky-based triplers at this frequency range is mainly constrained by the shrinkage of the waveguide dimensions with frequency and the minimum diode mesa sizes, which limits the maximum number of diodes that can be placed on the chip to no more than two. Hence, multiple-chip power-combined schemes become necessary to increase the power-handling capabilities of high-frequency multipliers. The design presented here overcomes difficulties by performing the power-combining directly on-chip. Four E-probes are located at a single input waveguide in order to equally pump four multiplying structures (featuring two diodes each). The produced output power is then recombined at the output using the same concept.

  13. Continuation Power Flow Method based Assessment of Static Voltage Stability considering the Power System Contingencies

    Directory of Open Access Journals (Sweden)

    Khan Aafreen

    2014-11-01

    Full Text Available Power system security is recognized as one of the major problems in many power systems throughout the world. Power system insecurity such as transmission lines being overloaded causes transmission elements cascade outages, which may lead to complete blackout. In accordance with these reasons, the prediction and recognition of voltage instability in power system has particular importance and it makes the network security stronger. This work, by considering the power system contingencies based on the effects of them on Mega Watt Margin (MWM and maximum loading point (MLP is focused to analyse the voltage stability using continuation power flow method. The study has been carried out on IEEE 30-Bus Test System using MATLAB and PSAT softwares and results are presented.

  14. Multifunctional Voltage Source Inverter for Renewable Energy Integration and Power Quality Conditioning

    OpenAIRE

    2014-01-01

    In order to utilize the energy from the renewable energy sources, power conversion system is necessary, in which the voltage source inverter (VSI) is usually the last stage for injecting power to the grid. It is an economical solution to add the function of power quality conditioning to the grid-connected VSI in the low-voltage distribution system. Two multifunctional VSIs are studied in this paper, that is, inductive-coupling VSI and capacitive-coupling VSI, which are named after the fundame...

  15. Kilowatt isotope power system. Phase II plan. Volume V. Safety, quality assurance and reliability

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-15

    The development of a Kilowatt Isotope Power System (KIPS) was begun in 1975 for the purpose of satisfying the power requirements of satellites in the 1980's. The KIPS is a /sup 238/PuO/sub 2/-fueled organic Rankine cycle turbine power system to provide a design output of 500 to 2000 W. Included in this volume are: launch and flight safety considerations; quality assurance techniques and procedures to be followed through system fabrication, assembly and inspection; and the reliability program made up of reliability prediction analysis, failure mode analysis and criticality analysis. (LCL)

  16. Relationship between nurses' leadership styles and power bases.

    Science.gov (United States)

    García García, Inmaculada; Santa-Bárbara, Emilio Sánchez

    2009-01-01

    This quantitative study aimed to empirically evidence the relationship between the power bases of the leader and the leadership styles of nurses. The random sample consisted of 204 nursing professionals from a public hospital. The following measurement instruments were used: the SBDQ (Supervisory Behavior Description Questionnaire) to identify leadership styles and the Power Perception Profile to determine the types of power used by leaders. Descriptive, bivariate and multivariate analyses were used. Based on the results, two relationships proposed by the SLT (Situational Leadership Theory) were verified: between coercive power and S1 leadership style (telling), and between referent power and S3 leadership style (participating). In other cases, results have been opposite to expectations: the use of power proposed by the model decreases the probability of performing the prescribed leadership style.

  17. Nitrogen-Based Fuels: A Power-to-Fuel-to-Power Analysis.

    Science.gov (United States)

    Grinberg Dana, Alon; Elishav, Oren; Bardow, André; Shter, Gennady E; Grader, Gideon S

    2016-07-25

    What are the fuels of the future? Seven representative carbon- and nitrogen-based fuels are evaluated on an energy basis in a power-to-fuel-to-power analysis as possible future chemical hydrogen-storage media. It is intriguing to consider that a nitrogen economy, where hydrogen obtained from water splitting is chemically stored on abundant nitrogen in the form of a nontoxic and safe nitrogen-based alternative fuel, is energetically feasible.

  18. On the Dual-Decomposition-Based Resource and Power Allocation with Sleeping Strategy for Heterogeneous Networks

    KAUST Repository

    Alsharoa, Ahmad M.

    2015-05-01

    In this paper, the problem of radio and power resource management in long term evolution heterogeneous networks (LTE HetNets) is investigated. The goal is to minimize the total power consumption of the network while satisfying the user quality of service determined by each target data rate. We study the model where one macrocell base station is placed in the cell center, and multiple small cell base stations and femtocell access points are distributed around it. The dual decomposition technique is adopted to jointly optimize the power and carrier allocation in the downlink direction in addition to the selection of turned off small cell base stations. Our numerical results investigate the performance of the proposed scheme versus different system parameters and show an important saving in terms of total power consumption. © 2015 IEEE.

  19. Reinforcement learning based backstepping control of power system oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Karimi, Ali; Eftekharnejad, Sara; Feliachi, Ali [Advanced Power and Electric Research Center (APERC), West Virginia University, Morgantown, WV 26506-6109 (United States)

    2009-11-15

    This paper proposes a reinforcement learning based backstepping control technique for damping oscillations in electric power systems using the generators excitation systems. Decentralized controllers are first designed using the backstepping technique. Then, reinforcement learning is used to tune the gains of these controllers to adapt to various operating conditions. Simulation results for a two area power system show that the proposed control technique provides better damping than (i) conventional power system stabilizers and (ii) backstepping fixed gain controllers. (author)

  20. Magnetic Field Emission Comparison at Different Quality Factors with Series-Parallel Compensation Network for Wireless Power Transfer to Vehicles

    DEFF Research Database (Denmark)

    Batra, Tushar; Schaltz, Erik

    2014-01-01

    Input current of wireless power transfer system is limited by current rating of power converter on the primary side. Power rating of wireless power transfer system increases linearly with the quality factor for series-parallel topology of the system at a given primary current. Magnetic emissions...

  1. Piezoelectric-based hybrid reserve power sources for munitions

    Science.gov (United States)

    Rastegar, J.; Kwok, P.

    2017-04-01

    Reserve power sources are used extensively in munitions and other devices, such as emergency devices or remote sensors that need to be powered only once and for a relatively short duration. Current chemical reserve power sources, including thermal batteries and liquid reserve batteries sometimes require more than 100 msec to become fully activated. In many applications, however, electrical energy is required in a few msec following the launch event. In such applications, other power sources are needed to provide power until the reserve battery is fully activated. The amount of electrical energy that is required by most munitions before chemical reserve batteries are fully activated is generally small and can be provided by properly designed piezoelectric-based energy harvesting devices. In this paper, the development of a hybrid reserve power source that is constructed by integration of a piezoelectric-based energy harvesting device with a reserve battery to provide power almost instantaneously upon munitions firing or other similar events is being reported. A review of the state of the art in piezoelectric-based electrical energy harvesting methods and devices and their charge collection electronics for use in the developed hybrid power sources is provided together with the results of testing of the piezoelectric component of the power source and its electronic safety and charge collection electronics.

  2. Piezoelectric-based hybrid reserve power sources for munitions

    Science.gov (United States)

    Rastegar, Jahangir; Pereira, Carlos M.; Feng, Dake

    2016-05-01

    Reserve power sources are used extensively in munitions and other devices such as emergency devices or remote sensors that have to be powered only once and for a relatively short duration. Current chemical reserve power sources, including thermal batteries and liquid reserve batteries require sometimes in excess of 100 msec to become fully activated. In many applications, however, electrical energy is required in a few msec following the launch event. In such applications, other power sources have to be provided to provide power until the reserve battery is fully activated. The amount of electrical energy that is required by most munitions before chemical reserve batteries are fully activated is generally small and can be provided by properly designed piezoelectric-based energy harvesting devices. In this paper the development of a hybrid reserve power source obtained by the integration of a piezoelectric-based energy harvesting device with a reserve battery that can provide power almost instantaneously upon munitions firing or other similar events is being reported. A review of the state of the art in piezoelectric-based electrical energy harvesting methods and devices and their charge collection electronics for use in the developed hybrid power sources is also provided together with the results of testing of the piezoelectric component of the power source and its electronic safety and charge collection electronics.

  3. Power Base of Unmanned Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    A. A. Laptsevich

    2011-01-01

    Full Text Available A molecular-kinetic approach to an analysis of thermal energy converters has been developed in the paper. The approach allows to carry out a computer simulation under various conditions of converter application. The paper considers possibilities to improve heat engines and electro-dynamic motors. It has been revealed that an increase of the UAV flight time can be achieved not only through an efficient usage of energy generated during fuel combustion but also through arrangement of open power systems that implement a heat pump principle. A prospect concerning energy development of transport facilities is to create interconnected systems of open-type with application of heat pumps. 

  4. MCU-Based Solar Powered Chicken Feeder

    Directory of Open Access Journals (Sweden)

    Elenor M. Reyes

    2015-12-01

    Full Text Available Poultry is a great potential industry particularly in Batangas Province. The method of feeding chicken needs to be considered as chicken must be fed regularly to be more productive. The conventional method of feeding chicken is the need to continuously provide the food, be alert and conscious on the food remaining in cages and to feed the chickens in a correct period of time to avoid the decline of the production. Growers also find it difficult to manage their businesses effectively because they need to be around the cages every now and then to monitor the poultry. Timing and exactness are the key to provide a uniform time in feeding the chickens. This will benefit the owner of the business in terms of time and effort. Another advantage of this project is in terms of savings to the owner of the poultry business. This technology was designed to automatically feed chickens at a given period of time and to give alarm when the feeds are running out of supply. The power to be supplied to this prototype will be drawn from the sun by means of solar panels and will be stored in typical car battery. The feeds will be stored in a container and evenly distributed by using a conveyor to the feeding basin of the poultry. It will be more efficient than manual conventional way of feeding because less effort will be needed in feeding the chickens and less feeds will be wasted. In addition to that, the stored power can also be used for lighting purposes for the growers to save energy and energy bills.

  5. Competency-Based Education: A Framework for Measuring Quality Courses

    Science.gov (United States)

    Krause, Jackie; Dias, Laura Portolese; Schedler, Chris

    2015-01-01

    The growth of competency-based education in an online environment requires the development and measurement of quality competency-based courses. While quality measures for online courses have been developed and standardized, they do not directly align with emerging best practices and principles in the design of quality competency-based online…

  6. Competency-Based Education: A Framework for Measuring Quality Courses

    Science.gov (United States)

    Krause, Jackie; Dias, Laura Portolese; Schedler, Chris

    2015-01-01

    The growth of competency-based education in an online environment requires the development and measurement of quality competency-based courses. While quality measures for online courses have been developed and standardized, they do not directly align with emerging best practices and principles in the design of quality competency-based online…

  7. Tertiary Control of Voltage Unbalance Compensation for Optimal Power Quality in Islanded Microgrids

    DEFF Research Database (Denmark)

    Meng, Lexuan; Tang, Fen; Savaghebi, Mehdi;

    2014-01-01

    the voltage unbalance limits in local buses and DG terminals. This method realizes multi-power-quality-level control in a multi-bus islanded system by optimally utilizing DGs as distributed compensators and saves the investment for additional compensation equipment. Hardware-in-the-loop results demonstrate...

  8. Tertiary control of voltage unbalance compensation for optimal power quality in islanded microgrids

    DEFF Research Database (Denmark)

    Meng, Lexuan; Tang, Fen; Savaghebi, Mehdi

    2016-01-01

    DG considering the voltage unbalance limits in local buses and DG terminals. This method realizes multi-power-quality-level control in a multi-bus islanded system by optimally utilizing DGs as distributed compensators and saves the investment for additional compensation equipment. Hardware-in...

  9. Evaluation of conventional electric power generating industry quality assurance and reliability practices

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.T.; Lauffenburger, H.A.

    1981-03-01

    The techniques and practices utilized in an allied industry (electric power generation) that might serve as a baseline for formulating Quality Assurance and Reliability (QA and R) procedures for photovoltaic solar energy systems were studied. The study results provide direct near-term input for establishing validation methods as part of the SERI performance criteria and test standards development task.

  10. Evaluating perceived quality of CELPE service. A Brazilian power company case study

    Energy Technology Data Exchange (ETDEWEB)

    De Barros Filho, Joao Paes; Da Silva, Cleriston Fritsch Damasio; Do Nascimento Melo, Maria Auxiliadora; De Medeiros, Denise Dumke [Federal University of Pernambuco (UFPE), Center of Technology and Geosciences, 5th floor, Academico Helio Ramos av., Cidade Universitaria, Recife, PE 50.670-901 (Brazil)

    2009-04-15

    This paper presents an application of a methodology for the diagnosis and analysis of the service quality perceived by a Particular Group of CELPE Corporate Customers, a Brazilian power company at Pernambuco State. Concepts, on the power sector, of Quality in Services, Performance Objectives and Critical Factors of Success have been used to develop the analysis. Next, the Critical Factors for a power company were determined and classified in accordance with the performance objectives: Quality, Dependability, Speed and Flexibility. From the factors established, a questionnaire was created to collect data. The case studied involves quantitative research on CELPE's private corporate principal customers using statistical tests to measure internal consistency reliability of the questionnaire scales and to identify underlying concepts, in the four groups analyzed, through which the private corporate customers perceive quality in the given services. Among the goals of this study are to improve the relationship with principal Private Corporate Clients, to create customer loyalty, and to maximize efforts in providing the power supply service, all of them with a view to improving and determining the Global Satisfaction Index. (author)

  11. Evaluating perceived quality of CELPE service: A Brazilian power company case study

    Energy Technology Data Exchange (ETDEWEB)

    Paes de Barros Filho, Joao [Federal University of Pernambuco (UFPE), Center of Technology and Geosciences, 5th floor, Academico Helio Ramos av., Cidade Universitaria, Recife, PE 50.670-901 (Brazil)], E-mail: joaopaes@celpe.com.br; Fritsch Damasio da Silva, Cleriston [Federal University of Pernambuco (UFPE), Center of Technology and Geosciences, 5th floor, Academico Helio Ramos av., Cidade Universitaria, Recife, PE 50.670-901 (Brazil)], E-mail: cleriston_silva@yahoo.com.br; Nascimento Melo, Maria Auxiliadora do [Federal University of Pernambuco (UFPE), Center of Technology and Geosciences, 5th floor, Academico Helio Ramos av., Cidade Universitaria, Recife, PE 50.670-901 (Brazil)], E-mail: manmelo@ufpe.br; Dumke de Medeiros, Denise [Federal University of Pernambuco (UFPE), Center of Technology and Geosciences, 5th floor, Academico Helio Ramos av., Cidade Universitaria, Recife, PE 50.670-901 (Brazil)], E-mail: ddm@ufpe.br

    2009-04-15

    This paper presents an application of a methodology for the diagnosis and analysis of the service quality perceived by a Particular Group of CELPE Corporate Customers, a Brazilian power company at Pernambuco State. Concepts, on the power sector, of Quality in Services, Performance Objectives and Critical Factors of Success have been used to develop the analysis. Next, the Critical Factors for a power company were determined and classified in accordance with the performance objectives: Quality, Dependability, Speed and Flexibility. From the factors established, a questionnaire was created to collect data. The case studied involves quantitative research on CELPE's private corporate principal customers using statistical tests to measure internal consistency reliability of the questionnaire scales and to identify underlying concepts, in the four groups analyzed, through which the private corporate customers perceive quality in the given services. Among the goals of this study are to improve the relationship with principal Private Corporate Clients, to create customer loyalty, and to maximize efforts in providing the power supply service, all of them with a view to improving and determining the Global Satisfaction Index.

  12. Power-Quality-Oriented Optimization in Multiple Three-Phase Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Yang, Yongheng; Davari, Pooya; Blaabjerg, Frede;

    2016-01-01

    , low cost, and high reliability during operation. Yet, DRs and SCRs bring harmonic distortions in the mains and thus lowering the overall efficiency. Power quality standards/rules are thus released. For multiple ASD systems, certain harmonics of the total grid current can be mitigated by phase...

  13. Power quality issues into a Danish low-voltage grid with electric vehicles

    DEFF Research Database (Denmark)

    Marra, Francesco; Jensen, Morten M.; Garcia-Valle, Rodrigo

    2011-01-01

    An increased interest on electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) is dealing with their introduction into low voltage (LV) distribution grids. Lately, analysis on power quality issues has received attention when considering EVs as additional load. The charging of EVs...

  14. Hegemonic Power Process in Team-based Work

    NARCIS (Netherlands)

    Doorewaard, J.A.C.M.; Brouns, B.B.G.

    2003-01-01

    The purpose of this paper is to portray how implicit “hegemonic power processes” channel the way in which self-managing teams deal with organisational dilemmas. Hegemonic power processes in team-based work are, to a great extent concealed, processes of meaning and identity formation. These processes

  15. Hydrogen-based power generation from bioethanol steam reforming

    Science.gov (United States)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-12-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  16. Hydrogen-based power generation from bioethanol steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Tasnadi-Asztalos, Zs., E-mail: tazsolt@chem.ubbcluj.ro; Cormos, C. C., E-mail: cormos@chem.ubbcluj.ro; Agachi, P. S. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos, Postal code: 400028, Cluj-Napoca (Romania)

    2015-12-23

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO{sub 2} emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  17. Photovoltaic power system considerations for future lunar bases

    Science.gov (United States)

    Flood, Dennis J.; Appelbaum, Joseph

    1989-01-01

    The cost of transportation to the lunar surface places a premium on developing ultralightweight power system technology to support the eventual establishment of a lunar base. The photovoltaic technology issues to be addressed by the Surface Power program element of NASA's Project Pathfinder are described.

  18. Faraday isolator based on TSAG crystal for high power lasers.

    Science.gov (United States)

    Mironov, E A; Palashov, O V

    2014-09-22

    A Faraday isolator based on a new magneto-optical medium, TSAG (terbium scandium aluminum garnet) crystal, has been constructed and investigated experimentally. The device provides an isolation ratio of more than 30 dB at 500 W laser power. It is shown that this medium can be used in Faraday isolators for kilowatt-level laser powers.

  19. Neural Network Model Based Cluster Head Selection for Power Control

    Directory of Open Access Journals (Sweden)

    Krishan Kumar

    2011-01-01

    Full Text Available Mobile ad-hoc network has challenge of the limited power to prolong the lifetime of the network, because power is a valuable resource in mobile ad-hoc network. The status of power consumption should be continuously monitored after network deployment. In this paper, we propose coverage aware neural network based power control routing with the objective of maximizing the network lifetime. Cluster head selection is proposed using adaptive learning in neural networks followed by coverage. The simulation results show that the proposed scheme can be used in wide area of applications in mobile ad-hoc network.

  20. Location Refinement and Power Coverage Analysis Based on Distributed Antenna

    Institute of Scientific and Technical Information of China (English)

    赵晓楠; 侯春萍; 汪清; 陈华; 浦亮洲

    2016-01-01

    To establish wireless channel suitable for the cabin environment, the power coverage was investigated with distributed antenna system and centralized antenna system based on the actual measurement of channel im-pulse response. The results indicated that the distributed antenna system has more uniform power coverage than the centralized antenna system. The average relative errors of receiving power of both antennas were calculated. The optimal position of the centralized antenna was obtained by Gaussian function refinement, making the system achieve a better transmission power with the same coverage effect, and providing a reference for antenna location in the future real communication in the cabin.

  1. A Robust Synchronization to Enhance the Power Quality of Renewable Energy Systems

    DEFF Research Database (Denmark)

    Hadjidemetriou, Lenos; Kyriakides, Elias; Blaabjerg, Frede

    2015-01-01

    The increasing penetration of renewable energy sources (RESs) in the power grid requires high-quality power injection under various grid conditions. The synchronization method, usually a phase-locked loop (PLL) algorithm, is directly affecting the response of the grid-side converter of the RES....... This paper proposes a new PLL algorithm that uses an advanced decoupling network implemented in the stationary reference frame with limited requirements for processing time to enable a fast and accurate synchronization even under harmonic distorted voltage and low-voltage grid faults. The robust response...... of the proposed PLL is validated, and the effect of the proposed synchronization on the performance of the grid-connected renewable energy system is investigated. This investigation proves that the robust, accurate, and dynamic response of the new PLL can enhance the quality of the injected power from the RES...

  2. A Wind Power and Load Prediction Based Frequency Control Approach for Wind-Diesel-Battery Hybrid Power System

    OpenAIRE

    Chao Peng; Zhenzhen Zhang; Jia Wu

    2015-01-01

    A frequency control approach based on wind power and load power prediction information is proposed for wind-diesel-battery hybrid power system (WDBHPS). To maintain the frequency stability by wind power and diesel generation as much as possible, a fuzzy control theory based wind and diesel power control module is designed according to wind power and load prediction information. To compensate frequency fluctuation in real time and enhance system disturbance rejection ability, a battery energy ...

  3. Power quality affects teacher wellbeing and student behavior in three Minnesota Schools

    Energy Technology Data Exchange (ETDEWEB)

    Havas, Magda [Environmental and Resource Studies, Trent University, Peterborough, ON, K9J 7B8 (Canada)], E-mail: mhavas@trentu.ca; Olstad, Angela [Melrose-Mindoro Elementary School, N181 State Road 108, Melrose WI, USA 54642 (United States)], E-mail: olstad@mel-min.k12.wi.us

    2008-09-01

    Background: Poor power quality (dirty electricity) is ubiquitous especially in schools with fluorescent lights and computers. Previous studies have shown a relationship between power quality and student behavior/teacher health. Objectives: The purpose of this study is to determine the ability of power line filters to reduce dirty electricity in a school environment and to document changes in health and behavior among teachers and students. Method: We installed Graham Stetzer filters and dummy filters and measured power quality in three Minnesota Schools. Teachers completed a daily questionnaire regarding their health and the behavior of their students for an 8-week period. Teachers were unaware of which filters were installed at any one time (single blind study). Results: Dirty electricity was reduced by more than 90% in the three schools and during this period teacher health improved as did student behavior in the middle/elementary schools. Headaches, general weakness, dry eyes/mouth, facial flushing, asthma, skin irritations, overall mood including depression and anxiety improved significantly among staff. Of the 44 teachers who participated 64% were better, 30% were worse, and 6% did not change. Behavior of high school students did not improve but elementary/middle school students were more active in class; more responsive, more focused; had fewer health complaints; and had a better overall learning experience. Conclusions: Dirty electricity in schools may be adversely affecting wellbeing of teachers and behavior of their students, especially younger students in middle and elementary school. Power line filters improve power quality and may also protect those who are sensitive to this energy. Work on electric and magnetic field metrics with and without Stetzer filters urgently needs to be carried out to determine just what characteristics of the dirty electricity may be interacting with the people.

  4. 6 5KVA POWER INVERTER DESIGN AND SIMULATION BASED ...

    African Journals Online (AJOL)

    DR. AMINU

    Five (5) kVA power inverter was designed and simulated base on two topologies; Boost ... stages were plotted and the results show a significant increase in the voltage and duty cycle. ... also provides the industries with effective methods to.

  5. Probabilistic Model-Based Diagnosis for Electrical Power Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — We present in this article a case study of the probabilistic approach to model-based diagnosis. Here, the diagnosed system is a real-world electrical power system,...

  6. Striction-based Power Monitoring in Space Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The program delivers a completely new technology solution to isolation and sensing of power flow (current and voltage). Based on striction materials technology,...

  7. Parental Perceptions of Child Care Quality in Centre-Based and Home-Based Settings: Associations with External Quality Ratings

    Science.gov (United States)

    Lehrer, Joanne S.; Lemay, Lise; Bigras, Nathalie

    2015-01-01

    The current study examined how parental perceptions of child care quality were related to external quality ratings and considered how parental perceptions of quality varied according to child care context (home-based or centre-based settings). Parents of 179 4-year-old children who attended child care centres (n = 141) and home-based settings…

  8. 160 W high-power, high-efficiency, near-diffraction-limited beam quality all-fiber picosecond pulse laser

    Science.gov (United States)

    Sun, Chang; Ge, Tingwu; An, Na; Cao, Kang; Wang, Zhiyong

    2016-10-01

    We experimentally demonstrate a high-power, high-efficiency, near-diffraction-limited beam quality all-fiber picosecond pulse laser, which consists of a passively mode-locked seed laser and three-stage master power amplifiers. A repetition frequency multiplier and a high Yb-doped gain fiber with shorter length are utilized in the laser system to suppress the nonlinear effects and reduce the pulse broadening caused by dispersion. Moreover, the homemade light mode controllers based on a coiling and tapering fiber technique and the active fiber of the amplifier with a relatively small mode area are adopted to improve the beam quality. In addition, by experimentally adjusting the active fiber length, the optical conversion efficiency of the overall laser system can be optimized. Eventually, a 160 W high-power, high-efficiency, near-diffraction-limited picosecond pulse fiber laser is obtained, with the beam quality factor M2 at 1.12 and an optical conversion efficiency of the system of 75%.

  9. Analysis of VSC based FACTS stabilizers in damping power system oscillations : multi-machine power systems

    Energy Technology Data Exchange (ETDEWEB)

    Du, W. [Southeast Univ., Nanjing (China)]|[Bath Univ., Bath (United Kingdom); Wang, H.F. [Queen' s Univ. of Belfast, Belfast (United Kingdom); Dunn, R. [Bath Univ., Bath (United Kingdom)

    2008-07-01

    The Voltage Source Converter (VSC) for Flexible AC Transmission Systems (FACTS) devices can be equipped with a supplementary damping function to improve power system oscillation stability. This paper presented a general analytical method to study this type of VSC based FACTS stabilizers in damping power system oscillations. These converters include electronic devices such as the Static Synchronous Compensator (STATCOM), the Series Static Synchronous Compensator, (SSSC) and the Unified Power Flow Controller (UPFC). A proposed analysis was provided for the simple case of single-machine infinite-bus power systems. This paper also presented the extension of the proposed method to the more general case of multi-machine power systems. 10 refs., 5 figs.

  10. Systems definition space-based power conversion systems. [for satellite power transmission to earth

    Science.gov (United States)

    1976-01-01

    Potential space-located systems for the generation of electrical power for use on Earth are discussed and include: (1) systems producing electrical power from solar energy; (2) systems producing electrical power from nuclear reactors; and (3) systems for augmenting ground-based solar power plants by orbital sunlight reflectors. Systems (1) and (2) would utilize a microwave beam system to transmit their output to Earth. Configurations implementing these concepts were developed through an optimization process intended to yield the lowest cost for each. A complete program was developed for each concept, identifying required production rates, quantities of launches, required facilities, etc. Each program was costed in order to provide the electric power cost appropriate to each concept.

  11. Enhancement of Power Quality in Transmission Line Using Flexible Ac Transmission System Device U.P.F.C (Unified Power Flow Controller

    Directory of Open Access Journals (Sweden)

    B. Divya Lakshmi

    2014-04-01

    Full Text Available Present scenario states that power demand has been increased in a rapid and random manner. Hence power generated is unable to meet the power demand so power scarcity exists. There is an approximate loss of (20 - 40 % of power generated during its transmission. Hence there is a need for enhancing the power quality in transmission lines. In order to improve the power quality our paper make use of FACTS DEVICES. FACTS devices can be added to power transmission and distribution systems at appropriate locations to improve system performance. The real and reactive powers can be easily controlled in a power system with FACTS devices. Flexible AC Transmission System creates a tremendous quality impact on power system stability. This paper describes the basic principle of operation of UPFC, its advantages and to compare its performance with the various FACTS equipment available. The objective of this paper is to keep the power system to remain in voltage stable condition when it experiences a load change and contingency, also deals with the simulation of various FACTS controllers using simulation program with MATLAB/SIMULINK

  12. Magnetic Field Emission Comparison at Different Quality Factors with Series-Parallel Compensation Network for Wireless Power Transfer to Vehicles

    DEFF Research Database (Denmark)

    Batra, Tushar; Schaltz, Erik

    2014-01-01

    Input current of wireless power transfer system is limited by current rating of power converter on the primary side. Power rating of wireless power transfer system increases linearly with the quality factor for series-parallel topology of the system at a given primary current. Magnetic emissions...... increase in the power rating with the quality factor. This paper signifies that at fixed primary current, operation of wireless power transfer system at higher quality factor is favorable with respect to the magnetic emissions....... to the surroundings also increase with increase in the quality factor. In this paper, first analytical expressions are developed for comparing magnetic emissions at different quality factors. Theoretical and simulation (Comsol) results show comparatively lower increase for the magnetic field emissions to the linear...

  13. Power, Democracy and Problem-Based Learning

    DEFF Research Database (Denmark)

    Du, Xiangyun; Stentoft, Diana; Dahms, Mona-Lisa

    2007-01-01

      Problem Based Learning (PBL) as an educational approach has been increasingly applied in educational settings around the world. Given that PBL - as well as any other educational approach - is rooted in a given cultural context and thus carries the ‘fingerprint' of the specific context, an inter...

  14. Behavior-Based Power Management in Autonomous Mobile Robots

    Science.gov (United States)

    2008-03-27

    Behavior-Based Power Management In Autonomous Mobile Robots THESIS Charles A. Fetzek, First Lieutenant, USAF AFIT/GCE/ENG/08-05 DEPARTMENT OF THE AIR...of Defense, or the United States Government. AFIT/GCE/ENG/08-05 Behavior-Based Power Management In Autonomous Mobile Robots THESIS Presented to the...Management In Autonomous Mobile Robots Charles A. Fetzek, B.S.C.E. First Lieutenant, USAF Approved: /signed/ 4 Mar 2008 Dr. Gilbert L. Peterson (Chairman

  15. POWER OPTIMIZATION ALGORITHM BASED ON XNOR/OR LOGIC

    Institute of Scientific and Technical Information of China (English)

    Wang Pengjun; Lu Jingang; Xu Jian; Dai Jing

    2009-01-01

    Based on the investigation of the XNOR/OR logical expression and the propagation algorithm of signal probability, a low power synthesis algorithm based on the XNOR/OR logic is proposed in this paper. The proposed algorithm has been implemented with C language. Fourteen Microelectronics Center North Carolina (MCNC) benchmarks are tested, and the results show that the proposed algorithm not only significantly reduces the average power consumption up to 27% without area and delay compensations, but also makes the runtime shorter.

  16. Study of Emergency Power Based on Solar Battery Charging

    OpenAIRE

    Wang Lei; Zhu Mengfu; Chen Ping; Deng Cheng; Liu Zhimeng; Wang Yanan

    2016-01-01

    To study an emergency power based on solar battery charging. Based on the electric-generation principle of solar panel, solar energy is changed into electrical energy. Through voltage conversion circuit and filter circuit, electrical energy is stored in the energy storage battery. The emergency power realizes the conversion from solar energy to electrical energy. The battery control unit has the function of PWM (Pulse-Width Modulation) charging, overcharging protection, over-discharging prote...

  17. Gallium Nitride -based Microwave Power Varactors for Wireless Base Station Applications

    Science.gov (United States)

    Lu, Wei

    With the development of wireless communication systems, the demand for providing tunability in the wireless communication circuits becomes more and more intense. Among the technologies, semiconductor varactor is the critical component that is capable of implementing tunable and adaptive characteristics, particularly for the frond-end components of the wireless communication systems. For base station applications, high voltage handling capability, typically of 100 V or greater, high quality factor (Q), typically of above 100 at operation frequency, and high linearity, OIP3 > 65 dBm, are required. This work will mainly discuss in detail the design, fabrication and characterization to achieve the high-voltage high-Q and high-linearity microwave power varactors for wireless base station applications. Some preliminary varactor applications in the test tunable circuits will be demonstrated too. In this dissertation, we first introduce the physics of the semiconductor varactors and the motivation for choosing GaN as the candidate material for this microwave power varactor. Then we elucidate the critical design considerations for achieving high breakdown voltage, high quality factor and high linearity. The novel Schottky barrier engineered design using a thin InGaN surface layer on top of GaN to enhance the breakdown voltage of GaN-based Schottky diodes is therefore introduced. We then show the theoretical and experimental studies on the suppression mechanisms for electron tunneling in the InGaN/GaN Schottky barriers. The detailed material characterization for the InGaN/GaN material system and its application for the enhancement-mode HEMTs are also presented. Next, we discuss the initial device fabrication procedure and the improving methods based on the initial DC and RF measurement results. Thereafter, we report the detailed characterizations of the fabricated devices including the high-voltage I-V and C-V, S-parameters for 1-port and 2-port devices, linearity and

  18. A PSO based unified power flow controller for damping of power system oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Shayeghi, H. [Technical Engineering Dept., Univ. of Mohaghegh Ardabili, Daneshgah Street, P.O. Box 179, Ardabil (Iran); Shayanfar, H.A. [Center of Excellence for Power Automation and Operation, Electrical Engineering Dept., Iran Univ. of Science and Technology, Tehran (Iran); Jalilzadeh, S.; Safari, A. [Technical Engineering Dept., Zanjan Univ., Zanjan (Iran)

    2009-10-15

    On the basis of the linearized Phillips-Herffron model of a single-machine power system, we approach the problem of select the best input control signal of the unified power flow controller (UPFC) and design optimal UPFC based damping controller in order to enhance the damping of the power system low frequency oscillations. The potential of the UPFC supplementary controllers to enhance the dynamic stability is evaluated. This controller is tuned to simultaneously shift the undamped electromechanical modes to a prescribed zone in the s-plane. The problem of robustly UPFC based damping controller is formulated as an optimization problem according to the eigenvalue-based multiobjective function comprising the damping factor, and the damping ratio of the undamped electromechanical modes to be solved using particle swarm optimization technique (PSO) that has a strong ability to find the most optimistic results. To ensure the robustness of the proposed damping controller, the design process takes into account a wide range of operating conditions and system configurations. The effectiveness of the proposed controller is demonstrated through eigenvalue analysis, nonlinear time-domain simulation and some performance indices studies. The results analysis reveals that the tuned PSO based UPFC controller using the proposed multiobjective function has an excellent capability in damping power system low frequency oscillations and enhance greatly the dynamic stability of the power systems. Moreover, the system performance analysis under different operating conditions show that the {delta}{sub E} based controller is superior to the m{sub B} based controller. (author)

  19. Effect of Laser Power on the Quality of Drilled Micro Hole Using Cu50Zr50 Amorphous Alloys Foils

    Directory of Open Access Journals (Sweden)

    Chuan-Jie Wang

    2014-11-01

    Full Text Available The rapid growth of the micro-electro-mechanical systems (MEMS is being driven by the rapid development of the micro manufacturing processes. Laser beam machining is one of the micro manufacturing processes which can shape almost all ranges of engineering materials. In this study, the effect of laser power on the quality of drilled micro holes using Cu50Zr50 amorphous alloys foils is experimentally investigated. It indicates that both entrance and exit circularities diameters increase with laser power. The circularities of the holes at the entry and the exit are in the range of 0.893 to 0.997. The taper of drilled holes increases quickly to a stable value with the increase of laser power from 60 to 110 W, then decreases quickly when the laser power becomes larger than 170 W. The micro holes with a diameter of 400 to 1200 μm are manufactured successfully by laser drilling processes. The formation mechanism of the quality of the laser drilled hole is analyzed based on the laser beam and the properties of amorphous alloys foils.

  20. Adaptive-Fuzzy Controller Based Shunt Active Filter for Power Line Conditioners

    Directory of Open Access Journals (Sweden)

    KamalaKanta Mahapatra

    2011-08-01

    Full Text Available This paper presents a novel Fuzzy Logic Controller (FLC in conjunction with Phase Locked Loop (PLL based shunt active filter for Power Line Conditioners (PLCs to improve the power quality in the distribution system. The active filter is implemented with current controlled Voltage Source Inverter (VSI for compensating current harmonics and reactive power at the point of common coupling. The VSI gate control switching pulses are derived from proposed Adaptive-Fuzzy-Hysteresis Current Controller (HCC and this method calculates the hysteresis bandwidth effectively using fuzzy logic. The bandwidth can be adjusted based on compensation current variation, which is used to optimize the required switching frequency and improves active filter substantially. These shunt active power filter system is investigated and verified under steady and transient-state with non-linear load conditions. This shunt active filter is in compliance with IEEE 519 and IEC 61000-3 recommended harmonic standards.

  1. A New SIR-Based Sigmoid Power Control Game in Cognitive Radio Networks

    Science.gov (United States)

    Al-Gumaei, Yousef Ali; Noordin, Kamarul Ariffin; Reza, Ahmed Wasif; Dimyati, Kaharudin

    2014-01-01

    Interference resulting from Cognitive Radios (CRs) is the most important aspect of cognitive radio networks that leads to degradation in Quality of Service (QoS) in both primary and CR systems. Power control is one of the efficient techniques that can be used to reduce interference and satisfy the Signal-to-Interference Ratio (SIR) constraint among CRs. This paper proposes a new distributed power control algorithm based on game theory approach in cognitive radio networks. The proposal focuses on the channel status of cognitive radio users to improve system performance. A new cost function for SIR-based power control via a sigmoid weighting factor is introduced. The existence of Nash Equilibrium and convergence of the algorithm are also proved. The advantage of the proposed algorithm is the possibility to utilize and implement it in a distributed manner. Simulation results show considerable savings on Nash Equilibrium power compared to relevant algorithms while reduction in achieved SIR is insignificant. PMID:25286044

  2. Opposition-Based Improved PSO for Optimal Reactive Power Dispatch and Voltage Control

    Directory of Open Access Journals (Sweden)

    Shengrang Cao

    2015-01-01

    Full Text Available An opposition-based improved particle swarm optimization algorithm (OIPSO is presented for solving multiobjective reactive power optimization problem. OIPSO uses the opposition learning to improve search efficiency, adopts inertia weight factors to balance global and local exploration, and takes crossover and mutation and neighborhood model strategy to enhance population diversity. Then, a new multiobjective model is built, which includes system network loss, voltage dissatisfaction, and switching operation. Based on the market cost prices, objective functions are converted to least-cost model. In modeling process, switching operation cost is described according to the life cycle cost of transformer, and voltage dissatisfaction penalty is developed considering different voltage quality requirements of customers. The experiment is done on the new mathematical model. Through the simulation of IEEE 30-, 118-bus power systems, the results prove that OIPSO is more efficient to solve reactive power optimization problems and the model is more accurate to reflect the real power system operation.

  3. Low Power Systolic Array Based Digital Filter for DSP Applications

    Directory of Open Access Journals (Sweden)

    S. Karthick

    2015-01-01

    Full Text Available Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures.

  4. Low Power Systolic Array Based Digital Filter for DSP Applications.

    Science.gov (United States)

    Karthick, S; Valarmathy, S; Prabhu, E

    2015-01-01

    Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP) based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures.

  5. The Environment Friendly Power Source for Power Supply of Mobile Communication Base Stations

    Science.gov (United States)

    Rudenko, N. V.; Ershov, V. V.; Evstafiev, V. V.

    2017-05-01

    The article describes the technical proposals to improve environmental and resource characteristics of the autonomous power supply systems of mobile communication base stations based on renewable energy sources, while ensuring the required reliability and security of power supply. These include: the replacement of diesel-generator with clean energy source - an electrochemical generator based on hydrogen fuel cells; the use of wind turbines with a vertical axis; use of specialized batteries. Based on the analysis of the know technical solutions, the structural circuit diagram of the hybrid solar-wind-hydrogen power plant and the basic principles of the algorithm of its work were proposed. The implementation of these proposals will improve the environmental and resource characteristics.

  6. Improving the Power Quality of Six Parallel Operated Onshore Wind Turbines using UPFC

    Directory of Open Access Journals (Sweden)

    N. Archana

    2015-08-01

    Full Text Available This study is aimed at improving the power quality of an onshore wind turbine connected to the grid, using a Unified Power Factor Controller. A six parallel operated onshore wind turbine is used as a model to demonstrate the effectiveness of the proposed system. The wind generating system consists of doubly fed induction generator connected to the wind turbine. An average model of the doubly fed induction generator is used and the control signals are generated using closed loop control. The unified power factor controller is modeled using grid and rotor side converters and controlled using closed loop pulse width modulated signals. The proposed system reduces the reactive power of the system, which is proved by simulating the system using MATLAB SIMULINK environment.

  7. Critical Quality Source Diagnosis for Dam Concrete Construction Based on Quality Gain-loss Function

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2014-06-01

    Full Text Available In dam concrete construction process, it not only has quality loss arising from quality fluctuation, but also gains quality compensation effect due to the mutual cooperation and adaptation coupling between working procedures (WPs. The calculation and transmission complexity of the quality loss and quality compensation affect the quality management of dam concrete construction. As the quality compensation effect existing in the production practice cannot be described by Taguchi quality loss function, the concept of quality gain-loss function was presented in this paper, which was based on endowing the constant term in the expansion of Taylor series with physical meaning—quality compensation. Based on quality gain-loss function theory, a new quality gain-loss transmission model of dam concrete construction based on GERT network was constructed and its effective algorithm was designed. WP quality gain-loss and its impact on the final product were reasonably measured, and the critical quality routes and critical quality WPs were detected and diagnosed in dam concrete construction network. Summer temperature-controlled concrete construction in the third phase of Three Gorges Project (TGP was taken as an example to carry out the study, and the calculation results showed the validity and practicability of the presented model and algorithm.

  8. A Power Prediction Method for Photovoltaic Power Plant Based on Wavelet Decomposition and Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Honglu Zhu

    2015-12-01

    Full Text Available The power prediction for photovoltaic (PV power plants has significant importance for their grid connection. Due to PV power’s periodicity and non-stationary characteristics, traditional power prediction methods based on linear or time series models are no longer applicable. This paper presents a method combining the advantages of the wavelet decomposition (WD and artificial neural network (ANN to solve this problem. With the ability of ANN to address nonlinear relationships, theoretical solar irradiance and meteorological variables are chosen as the input of the hybrid model based on WD and ANN. The output power of the PV plant is decomposed using WD to separated useful information from disturbances. The ANNs are used to build the models of the decomposed PV output power. Finally, the outputs of the ANN models are reconstructed into the forecasted PV plant power. The presented method is compared with the traditional forecasting method based on ANN. The results shows that the method described in this paper needs less calculation time and has better forecasting precision.

  9. Implementation and performance results of neural network for power quality event detection

    Science.gov (United States)

    Huang, Weijian; Tian, Wenzhi

    2008-10-01

    A novel method to detect power quality event in distributed power system combing wavelet network with the improved back-propagation algorithm is presented. The paper tries to explain to design complex supported orthogonal wavelets by compactly supported orthogonal real wavelets, and then explore the extraction of disturbance signal to obtain the feature information, and finally propose several novel wavelet combined information to analyze the disturbance signal, superior to real wavelet analysis result. The feature obtained from WT coefficients are inputted into wavelet network for power quality disturbance pattern recognition. The power quality disturbance recognition model is established and the improved back-propagation algorithm is used to fulfill the network parameter initialization. By means of choosing enough samples to train the recognition model, the type of disturbance can be obtained when signal representing fault is inputted to the trained network. The results of simulation analysis show that the complex wavelet transform combined with wavelet network are more sensitive to signal singularity, and found to be significant improvement over current methods in real-time detection.

  10. Power Quality Experimental Analysis on Rural Home Grid-Connected PV Systems

    Directory of Open Access Journals (Sweden)

    Rita Jorge Cerqueira Pinto

    2015-01-01

    Full Text Available Microgeneration is the small-scale generation of heat or electric power or both, by individuals or buildings to meet their own needs. Recently, microgeneration is being regarded as a means to decentralize the power production of renewable energies, reducing the impacts on the grid caused by unexpected energy demands. Given the increase in microgeneration facilities, determining the quantity of energy produced and the power quality assumes growing importance in low, medium, or high voltage facilities. This paper presents a power quality analysis of two different facilities with photovoltaic generation localized in a rural area of Portugal, describing the voltage and frequency behaviour, the harmonic contents, and the total harmonic distortion. Statistical data are presented regarding the number of voltage events and occurrence of dips and swells in both facilities as a percentage of rated voltage. We conclude that some PV systems can severely affect voltage quality, forcing the grid to work at and even above the maximum voltage standard limit.

  11. Comparison of wind turbines based on power curve analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    In the study measured power curves for 46 wind turbines were analyzed with the purpose to establish the basis for a consistent comparison of the efficiency of the wind turbines. Emphasis is on wind turbines above 500 kW rated power, with power curves measured after 1994 according to international recommendations. The available power curves fulfilling these requirements were smoothened according to a procedure developed for the purpose in such a way that the smoothened power curves are equally representative as the measured curves. The resulting smoothened power curves are presented in a standardized format for the subsequent processing. Using wind turbine data from the power curve documentation the analysis results in curves for specific energy production (kWh/M{sup 2}/yr) versus specific rotor load (kW/M{sup 2}) for a range of mean wind speeds. On this basis generalized curves for specific annual energy production versus specific rotor load are established for a number of generalized wind turbine concepts. The 46 smoothened standardized power curves presented in the report, the procedure developed to establish them, and the results of the analysis based on them aim at providers of measured power curves as well as users of them including manufacturers, advisors and decision makers. (au)

  12. a strategy to improve the quality of the electric power produced by a ...

    African Journals Online (AJOL)

    Menga F. D, Djongyang N, Danwé R, Tchinda R and Zaatri A

    2016-05-01

    May 1, 2016 ... The results obtained after implementation and simulation under Matlab/Simulink ... During its transformation processes, it releases ... The mechanical torque of the turbine based on the extracted power is given by [9]: m v. C. P.

  13. Air quality measurements versus model predictions: a case study for the Sugozu power plant

    Energy Technology Data Exchange (ETDEWEB)

    A. Korur; C. Derinoz; C. Yurteri [ENVY Energy and Environmental Investments Inc., Ankara (Turkey)

    2003-07-01

    Air quality modeling is one of the tools used in Environmental Impact Assessment (EIA) studies in order to predict the potential impacts of atmospheric emissions. The main advantage of air quality modeling is the simulation of the ground-level concentrations under different conditions (i.e., meteorological variations and other pollutant sources in the vicinity). The accuracy of model predictions, on the other hand, depends mainly on the quality of the input data reflecting meteorological and topographical conditions as well as emission sources. In this regard, the model predictions should be supported with monitoring data. In the paper, the predictions of Gaussian air dispersion model (Industrial Source Complex - ISC) for SO{sub 2} and NO{sub 2} carried out in the vicinity of the Sugozu Power Plant on the coast of Turkey are compared with the air quality monitoring results of the same region. 2 refs., 3 figs., 2 tabs.

  14. Combustion Quality Estimation in Power Station Boilers using Median Threshold Clustering Algorithms

    Directory of Open Access Journals (Sweden)

    K.Sujatha

    2010-07-01

    Full Text Available The estimation of combustion quality in power station boilers is of great importance in the present scenario as it plays an important role in controlling the air pollution. The harmful gases like NOx and CO from the chimney causes air pollution. The amount of NOx and CO concentration in flue gas can be maintained within admissible limits by analyzing the flame colour. The colour of the flame is affected by combustion quality. When complete combustion takes place the amount these gases at the exit are within tolerance. Hence if the quality of combustion was estimated from the flame using image processing technique, it is possible to minimize the air pollution. This new strategy developed uses median threshold for feature reduction and various clustering algorithms to estimate the quality of combustion.

  15. 分布式光伏电站接入电网电能质量评估计算%Power Quality Evaluation for Distributed Grid-Connected Photovoltaic Power Station

    Institute of Scientific and Technical Information of China (English)

    姜桂秀; 黄磊; 舒杰; 吴志锋

    2013-01-01

    When the photovoltaic power station is connected to the utility grid, the adverse impact was made on many aspects due to the inherent characteristics and the change of grid structure and power flow, such as power quality, planning operation and relay protection. For better use of solar energy and less effect on power energy quality of the system, making power quality testing and evaluation are needed in the design period before the photovoltaic substation connected into power system. In this paper, the power quality requirements of a practical distributed PV power station are summarized. The numerical model of grid-connected photovoltaic power station is built based on the Matlab/Simulink platform, and the power quality testing and evaluation of the photovoltaic substation connecting into power system are made. The results show that the power quality demands of the connecting points of the photovoltaic substation are satisfied, and the photovoltaic power station is allowed to connect into the power system.%光伏电站接入配电网后,在改变电网原有拓扑结构和潮流方向的同时,其电能输出特性直接影响到电网的电能质量。为保障现有电网的安全稳定,更好利用太阳能,在光伏电站接入系统前的设计阶段需对光伏収电接入系统迚行电能质量评估。结合实际工程案例,以某MW级分布式光伏电站为研究对象,根据分布式光伏电站接入电网时的电能质量要求,基于Matlab/Simulink仿真平台迚行建模,对幵网电能质量迚行评估计算,幵迚行相应的分析。计算结果表明:该分布式光伏电站接入点符合电能质量要求,允许接入系统。

  16. A Control Strategy for Single-phase Grid-Connected Inverter with Power Quality Regulatory Function

    Directory of Open Access Journals (Sweden)

    Luo Ling

    2013-07-01

    Full Text Available A single-phase grid-connected inverter system based on LCL filter is established,which combines the features of inverter and active power filter. A composite control strategy for grid-connected inverter with the function of implementing reactive power compensation and harmonic compensation in the grid-connected power generation is proposed. Firstly, grid-connected inverter system structure and model is analyzed. A quasi-Proportional Resonant control method to gain the control of grid-connected fundamental wave current containing reactive power compensation current as well as the control of harmonic compensation currents is put forward; then the calculation methods of  composite control command current based on both second order generalized integrator-quadrature signal generator (SOGI-QSG and instantaneous reactive power theory are given. Finally, the effectiveness of the control strategy proposed in this paper is verified by simulation.

  17. Measurement of mechanical quality factors of polymers in flexural vibration for high-power ultrasonic application.

    Science.gov (United States)

    Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2016-07-01

    A method for measuring the mechanical quality factor (Q factor) of materials in large-amplitude flexural vibrations was devised on the basis of the original definition of the Q factor. The Q factor, the ratio of the reactive energy to the dissipated energy, was calculated from the vibration velocity distribution. The bar thickness was selected considering the effect of the thickness on the estimation error. In the experimental setup, a 1-mm-thick polymer-based bar was used as a sample and fixed on the top of a longitudinal transducer. Using transducers of different lengths, flexural waves in the frequency range of 20-90kHz were generated on the bar. The vibration strain in the experiment reached 0.06%. According to the Bernoulli-Euler model, the reactive energy and dissipated energy were estimated from the vertical velocity distribution on the bar, and the Q factors were measured as the driving frequency and strain were varied. The experimental results showed that the Q factors decrease as the driving frequencies and strains increase. At a frequency of 28.30kHz, the Q factor of poly(phenylene sulfide) (PPS) reached approximately 460 when the strain was smaller than 0.005%. PPS exhibited a much higher Q factor than the other tested polymers, which implies that it is a potentially applicable material as the elastomer for high-power ultrasonic devices.

  18. Multifunctional Voltage Source Inverter for Renewable Energy Integration and Power Quality Conditioning

    Directory of Open Access Journals (Sweden)

    NingYi Dai

    2014-01-01

    Full Text Available In order to utilize the energy from the renewable energy sources, power conversion system is necessary, in which the voltage source inverter (VSI is usually the last stage for injecting power to the grid. It is an economical solution to add the function of power quality conditioning to the grid-connected VSI in the low-voltage distribution system. Two multifunctional VSIs are studied in this paper, that is, inductive-coupling VSI and capacitive-coupling VSI, which are named after the fundamental frequency impedance of their coupling branch. The operation voltages of the two VSIs are compared when they are used for renewable energy integration and power quality conditioning simultaneously. The operation voltage of the capacitive-coupling VSI can be set much lower than that of the inductive-coupling VSI when reactive power is for compensating inductive loads. Since a large portion of the loads in the distribution system are inductive, the capacitive-coupling VSI is further studied. The design and control method of the multifunctional capacitive-coupling VSI are proposed in this paper. Simulation and experimental results are provided to show its validity.

  19. Multifunctional voltage source inverter for renewable energy integration and power quality conditioning.

    Science.gov (United States)

    Dai, NingYi; Lam, Chi-Seng; Zhang, WenChen

    2014-01-01

    In order to utilize the energy from the renewable energy sources, power conversion system is necessary, in which the voltage source inverter (VSI) is usually the last stage for injecting power to the grid. It is an economical solution to add the function of power quality conditioning to the grid-connected VSI in the low-voltage distribution system. Two multifunctional VSIs are studied in this paper, that is, inductive-coupling VSI and capacitive-coupling VSI, which are named after the fundamental frequency impedance of their coupling branch. The operation voltages of the two VSIs are compared when they are used for renewable energy integration and power quality conditioning simultaneously. The operation voltage of the capacitive-coupling VSI can be set much lower than that of the inductive-coupling VSI when reactive power is for compensating inductive loads. Since a large portion of the loads in the distribution system are inductive, the capacitive-coupling VSI is further studied. The design and control method of the multifunctional capacitive-coupling VSI are proposed in this paper. Simulation and experimental results are provided to show its validity.

  20. Improvement of quality service based on common benchmarks and indicators

    Directory of Open Access Journals (Sweden)

    Pohaydak, Olha Bohdanivna

    2011-11-01

    Full Text Available Consider ways to improve the quality management system based on common criteria and indicators for evaluating the quality of products, works and services in housing and domestic service.

  1. Water quality assessment using SVD-based principal component ...

    African Journals Online (AJOL)

    Water quality assessment using SVD-based principal component analysis of hydrological data. ... value decomposition (SVD) of hydrological data was tested for water quality assessment. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  2. Application of Devices and Systems Designed for Power Quality Monitoring and Assessment

    Directory of Open Access Journals (Sweden)

    Wiesław Gil

    2014-03-01

    Full Text Available The paper presents the problems associated with increasing demands on the equipment and systems for power quality assessment (PQ, installed at power substations. Difficulties are signaled due to current lack of standards defining the test methodology of measuring devices. The necessary device properties and the structure of a large system operated in real time and designed to assess the PQ are discussed. The usefulness of multi-channel analyzers featuring the identification and registration of transients is pointed out. The desirability of synchrophasor assessment implementation and device integration by standard PN-EN 61850 with other SAS devices is also justified.

  3. A Lyapunov theory based UPFC controller for power flow control

    Energy Technology Data Exchange (ETDEWEB)

    Zangeneh, Ali; Kazemi, Ahad; Hajatipour, Majid; Jadid, Shahram [Center of Excellence for Power Systems Automation and Operation, Iran University of Science and Technology, Tehran (Iran)

    2009-09-15

    Unified power flow controller (UPFC) is the most comprehensive multivariable device among the FACTS controllers. Capability of power flow control is the most important responsibility of UPFC. According to high importance of power flow control in transmission lines, the proper controller should be robust against uncertainty and disturbance and also have suitable settling time. For this purpose, a new controller is designed based on the Lyapunov theory and its stability is also evaluated. The Main goal of this paper is to design a controller which enables a power system to track reference signals precisely and to be robust in the presence of uncertainty of system parameters and disturbances. The performance of the proposed controller is simulated on a two bus test system and compared with a conventional PI controller. The simulation results show the power and accuracy of the proposed controller. (author)

  4. Enhanced GSA-Based Optimization for Minimization of Power Losses in Power System

    Directory of Open Access Journals (Sweden)

    Gonggui Chen

    2015-01-01

    Full Text Available Gravitational Search Algorithm (GSA is a heuristic method based on Newton’s law of gravitational attraction and law of motion. In this paper, to further improve the optimization performance of GSA, the memory characteristic of Particle Swarm Optimization (PSO is employed in GSAPSO for searching a better solution. Besides, to testify the prominent strength of GSAPSO, GSA, PSO, and GSAPSO are applied for the solution of optimal reactive power dispatch (ORPD of power system. Conventionally, ORPD is defined as a problem of minimizing the total active power transmission losses by setting control variables while satisfying numerous constraints. Therefore ORPD is a complicated mixed integer nonlinear optimization problem including many constraints. IEEE14-bus, IEEE30-bus, and IEEE57-bus test power systems are used to implement this study, respectively. The obtained results of simulation experiments using GSAPSO method, especially the power loss reduction rates, are compared to those yielded by the other modern artificial intelligence-based techniques including the conventional GSA and PSO methods. The results presented in this paper reveal the potential and effectiveness of the proposed method for solving ORPD problem of power system.

  5. SELF-POWERED WIRELESS SENSOR NODE POWER MODELING BASED ON IEEE 802.11 COMMUNICATION PROTOCOL

    Energy Technology Data Exchange (ETDEWEB)

    Vivek Agarwal; Raymond A. DeCarlo; Lefteri H. Tsoukalas

    2016-04-01

    Design and technical advancements in sensing, processing, and wireless communication capabilities of small, portable devices known as wireless sensor nodes (WSNs) have drawn extensive research attention and are vastly applied in science and engineering applications. The WSNs are typically powered by a chemical battery source that has a load dependent finite lifetime. Most applications, including the nuclear industry applications, require WSNs to operate for an extended period of time beginning with their deployment. To ensure longevity, it is important to develop self-powered WSNs. The benefit of self-powered WSNs goes far beyond the cost savings of removing the need for cable installation and maintenance. Self-powered WSNs will potentially offer significant expansion in remote monitoring of nuclear facilities, and provide important data on plant equipment and component status during normal operation, as well as in case of abnormal operation, station blackouts or post-accident evaluation. Advancements in power harvesting technologies enable electric energy generation from many sources, including kinetic, thermal, and radiated energy. For the ongoing research at Idaho National Laboratory, a solid-state thermoelectric-based technology, the thermoelectric generator (TEG), is used to convert thermal energy to power a WSN. The design and development of TEGs to power WSNs that would remain active for a long period of time requires comprehensive understanding of WSN operational. This motivates the research in modeling the lifetime, i.e., power consumption, of a WSN by taking into consideration various node and network level activities. A WSN must perform three essential tasks: sense events, perform quick local information processing of sensed events, and wirelessly exchange locally processed data with the base station or with other WSNs in the network. Each task has a power cost per unit tine and an additional cost when switching between tasks. There are number of other

  6. DC-DC switching converter based power distribution vs serial power distribution EMC strategies

    CERN Document Server

    Arteche, F; Iglesias, M; Rivetta, C; Arcega, F G; Vila, I

    2009-01-01

    This paper presents a detailed and comparative analysis from the electromagnetic compatibility point of view of the proposed power distributions for the SLHC tracker up-grade. The main idea is to identify and quantify the noise sources, noise distribution at the system level and the sensitive areas in the front-end electronics corresponding to both proposed topologies: The DC-DC converter based power distribution and the serial power distribution. These studies will be used to define critical points on both systems to be studied and prototyped to ensure the correct integration of the system taking critically into account the electromagnetic compatibility. This analysis at the system level is crucial to ensure the final performance of the detector using non conventional power distributions, avoiding interference problems and excessive losses that can lead to catastrophic failures or expensive and un-practical solutions.

  7. Study of Emergency Power Based on Solar Battery Charging

    Directory of Open Access Journals (Sweden)

    Wang Lei

    2016-01-01

    Full Text Available To study an emergency power based on solar battery charging. Based on the electric-generation principle of solar panel, solar energy is changed into electrical energy. Through voltage conversion circuit and filter circuit, electrical energy is stored in the energy storage battery. The emergency power realizes the conversion from solar energy to electrical energy. The battery control unit has the function of PWM (Pulse-Width Modulation charging, overcharging protection, over-discharging protection and over-current protection. It also realizes the fast and safe charging of energy storage battery. The emergency power could provide both 12V AC power for emergency equipment such as miniature PSA oxygen concentrator and 5V USB for electronic equipment (mobile phone, GPS device, rechargeable light, etc..

  8. 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.

  9. Advanced photovoltaic power system technology for lunar base applications

    Science.gov (United States)

    Brinker, David J.; Flood, Dennis J.

    1992-01-01

    The development of an advanced photovoltaic power system that would have application for a manned lunar base is currently planned under the Surface Power element of Pathfinder. Significant mass savings over state-of-the-art photovoltaic/battery systems are possible with the use of advanced lightweight solar arrays coupled with regenerative fuel cell storage. The solar blanket, using either ultrathin GaAs or amorphous silicon solar cells, would be integrated with a reduced-g structure. Regenerative fuel cells with high-pressure gas storage in filament-wound tanks are planned for energy storage. An advanced PV/RFC power system is a leading candidate for a manned lunar base as it offers a tremendous weight advantage over state-of-the-art photovoltaic/battery systems and is comparable in mass to other advanced power generation technologies.

  10. BEST WEIGHT PATTERN EVALUATION BASED SECURITY CONSTRAINED POWER DISPATCH ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents a methodology which determines the allocation of power demand among the committed generating units while minimizes number of objectives as well as meets physical and technological system constraints. The procedure considers two decoupled problems based upon the dependency of their goals on either active power or reactive power generation. Both the problems have been solved sequentially to achieve optimal allocation of active and reactive power generation while minimizes operating cost, gaseous pollutants emission objectives and active power transmission loss with consideration of system operating constraints along with generators prohibited operating zones and transmission line flow limits. The active and reactive power line flows are obtained with the help of generalized generation shift distribution factors (GGDF) and generalized Z-bus distribution factors (GZBDF), respectively. First problem is solved in multi-objective framework in which the best weights assigned to objectives are determined while employing weighting method and in second problem,active power loss of the system is minimized subject to system constraints. The validity of the proposed method is demonstrated on 30-bus IEEE power system.

  11. On the Statistics of Noisy Space Vector in Power Quality Analysis

    Directory of Open Access Journals (Sweden)

    Diego Bellan

    2016-10-01

    Full Text Available This work deals with the analysis of the impact of additive noise on the geometrical features of the space vector shape on the complex plane. The space vector shape is of great importance in the power quality analysis of modern three-phase power systems since its geometrical features are closely related to the voltage supply quality. In case of voltage sag or swell the space vector shape changes accordingly. In case of additive noise the geometrical parameters of the space vector shape can be treated as random variables. In the paper, the mean values and the variances of such parameters are derived in closed form as functions of the noise level and of the sampling conditions. Analytical results are validated through numerical simulation of the whole measurement process.

  12. Permanent magnetic ferrite based power-tunable metamaterials

    Science.gov (United States)

    Zhang, Guanqiao; Lan, Chuwen; Gao, Rui; Zhou, Ji

    2017-08-01

    Power-tunable metamaterials based on barium permanent magnetic ferrite have been proposed and fabricated in this research. Scattering parameter measurements confirm a shift in resonant frequency in correlation to changes in incident electromagnetic power within microwave frequency band. The tunable phenomenon represented by a blue-shift in transmission spectra in the metamaterials array can be attributed to a decrease in saturation magnetization resulting from FMR-induced temperature elevation upon resonant conditions. This power-dependent behavior offers a simple and practical route towards dynamically fine-tunable ferrite metamaterials.

  13. Base drive circuit for a four-terminal power Darlington

    Science.gov (United States)

    Lee, Fred C.; Carter, Roy A.

    1983-01-01

    A high power switching circuit which utilizes a four-terminal Darlington transistor block to improve switching speed, particularly in rapid turn-off. Two independent reverse drive currents are utilized during turn off in order to expel the minority carriers of the Darlington pair at their own charge sweep-out rate. The reverse drive current may be provided by a current transformer, the secondary of which is tapped to the base terminal of the power stage of the Darlington block. In one application, the switching circuit is used in each power switching element in a chopper-inverter drive of an electric vehicle propulsion system.

  14. Wireless power transfer based on dielectric resonators with colossal permittivity

    Science.gov (United States)

    Song, Mingzhao; Belov, Pavel; Kapitanova, Polina

    2016-11-01

    Magnetic resonant wireless power transfer system based on dielectric disk resonators made of colossal permittivity (ɛ = 1000) and low loss (tan δ = 2.5 × 10-4) microwave ceramic is experimentally investigated. The system operates at the magnetic dipole mode excited in the resonators providing maximal power transfer efficiency of 90% at the frequency 232 MHz. By applying an impedance matching technique, the efficiency of 50% is achieved within the separation between the resonators d = 16 cm (3.8 radii of the resonator). The separation, misalignment and rotation dependencies of wireless power transfer efficiency are experimentally studied.

  15. Changes in the quality of life in severely disabled people following provision of powered indoor/outdoor chairs

    OpenAIRE

    Davies, A; De Souza, LH; Frank, AO

    2003-01-01

    Purpose:To determine the benefits for patients who received an Electric Powered Indoor/outdoor Chair (EPIOC) and to quantify their perceived changes to their quality of life. Method: Community-based cohort study of all patients provided with an EPIOC over 4 months; and followed up about 3 months later in a community served by a regional wheelchair service in North West London (population about 3.1 million) using the EuroQol EQ-5D with visual analogue scales for each of the 5 dimensions o...

  16. Solution of optimal power flow using evolutionary-based algorithms

    African Journals Online (AJOL)

    This paper applies two reliable and efficient evolutionary-based methods named Shuffled Frog Leaping Algorithm ... Grey Wolf Optimizer (GWO) to solve Optimal Power Flow (OPF) problem. OPF is ..... The wolves search for the prey based on the alpha, beta, and delta positions. ..... Energy Conversion and Management, Vol.

  17. Power Provision Based on Self-Sacrificing Craft

    Science.gov (United States)

    Hinchey, Michael G. (Inventor); Vassev, Emil I. (Inventor); Hinchey, Bridget (Inventor); Sterrit, Roy (Inventor)

    2015-01-01

    A biologically-inspired system and method is provided for self-adapting behavior of swarm-based exploration missions, whereby individual components, for example, spacecraft, in the system can sacrifice themselves for the greater good of the entire system. The self-sacrifice can involve donating resources or assets, such as power provisions, to a different component of an autonomous system. A receiving component of the system can benefit from receiving the donated resource or power provision.

  18. Beam-shaping technique for improving the beam quality of a high-power laser-diode stack.

    Science.gov (United States)

    Gao, Xin; Ohashi, Hiroyuki; Okamoto, Hiroshi; Takasaka, Masaomi; Shinoda, Kazunori

    2006-06-01

    We report a beam-shaping technique that reconfigures the beams to improve the beam quality and enhance the power density for a ten-array high-power laser-diode stack by using two optical rectangular cubes and two stripe-mirror plates. The reshaped beam has threefold improvement in beam quality, and its power density is effectively enhanced. On the basis of this technique, we focus the beam of the high-power laser-diode stack to effectively end pump a high-power fiber laser.

  19. Standardized quality in MOOC based learning

    Directory of Open Access Journals (Sweden)

    Maiorescu Irina

    2015-04-01

    Full Text Available Quality in the field of e-learning and, particularly, in the field of MOOC( Massive Open Online Courses, is a topic of growing importance in both academic institutions and in the private sector as it has generally been proved that quality management can contribute to improving the performance of organizations, regardless of their object of activity. Despite the fact that there are standards relating to quality management in a general manner, professionals, academic staff, specialists and bodies felt the need for having a standardized approach of the quality in the sector of e-learning. Therefore, in the last years, in different countries quality guidelines have been developed and used for e-Learning or distance education (for example the ASTD criteria for e- Learning, the BLA Quality Mark, Quality Platform Learning by D-ELAN etc.. The current paper aims to give insights to this new form of online education provided by MOOC platforms using the specific quality standard approach.

  20. Power Adaptation Based on Truncated Channel Inversion for Hybrid FSO/RF Transmission With Adaptive Combining

    KAUST Repository

    Rakia, Tamer

    2015-07-23

    Hybrid free-space optical (FSO)/radio-frequency (RF) systems have emerged as a promising solution for high-data-rate wireless communications. In this paper, we consider power adaptation strategies based on truncated channel inversion for the hybrid FSO/RF system employing adaptive combining. Specifically, we adaptively set the RF link transmission power when FSO link quality is unacceptable to ensure constant combined signal-to-noise ratio (SNR) at the receiver. Two adaptation strategies are proposed. One strategy depends on the received RF SNR, whereas the other one depends on the combined SNR of both links. Analytical expressions for the outage probability of the hybrid system with and without power adaptation are obtained. Numerical examples show that the hybrid FSO/RF system with power adaptation achieves a considerable outage performance improvement over the conventional system.

  1. RSSI/LQI-based transmission power control for body area networks in healthcare environment.

    Science.gov (United States)

    Kim, Seungku; Kim, Seokhwan; Eom, Doo-Seop

    2013-05-01

    This paper presents a novel transmission power control protocol for body area networks. Conventional transmission power control protocols adjust the transmission power on the basis of the received signal strength indication (RSSI). However, in case of the presence of interference, the RSSI is not a correct indicator to determine the link state. We first present the empirical evidence for this and then propose a practical protocol to discriminate between the signal attenuation and interference using the RSSI and link quality indication (LQI). This protocol controls the transmission power and avoids interference based on the link state. Finally, we discuss the implementation of the proposed protocol on Tmote Sky and evaluate the performance in the presence and absence of interference. The experimental results showed that the proposed protocol has high energy-efficiency and reliability, even in the presence of interference.

  2. Power-Rate Allocation in DS/CDMA Based on Discretized Verhulst Equilibrium

    CERN Document Server

    Sampaio, Lucas Dias H; Proença, Mario Lemes; Abrão, Taufik

    2010-01-01

    This paper proposes to extend the discrete Verhulst power equilibrium approach, previously suggested in [1], to the power-rate optimal allocation problem. Multirate users associated to different types of traffic are aggregated to distinct user' classes, with the assurance of minimum rate allocation per user and QoS. Herein, Verhulst power allocation algorithm was adapted to the single-input-single-output DS/CDMA jointly power-rate control problem. The analysis was carried out taking into account the convergence time, quality of solution, in terms of the normalized squared error (NSE), when compared with the analytical solution based on interference matrix inverse, and computational complexity. Numerical results demonstrate the validity of the proposed resource allocation methodology.

  3. Logistics case study based research: Towards higher quality

    DEFF Research Database (Denmark)

    Pedrosa, Alex; Näslund, Dag; Jasmand, Claudia

    2012-01-01

    Purpose – This paper assesses the quality of the case study based research approach as documented in articles published during the past 13 years, based on a synthesis of indicators for the quality criteria truth-value, transferability, and traceability. Design/methodology/approach – Content...... analysis of 134 case study based articles published in six leading logistics and supply chain management (SCM) journals between 1998 and 2010 is used to assess and evaluate the quality of the case study based research approach as documented in these publications. Findings – This research provides...... an overview of the quality of the case study based research approach. Results show that the quality is generally low, supporting the ongoing, but empirically unsupported criticism on the quality of case study based research. The results also highlight which specific aspects authors and reviewers need...

  4. Mitigation of Power Quality Problems in Grid-Interactive Distributed Generation System

    Science.gov (United States)

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

    2016-04-01

    Having an inter-tie between low/medium voltage grid and distributed generation (DG), both exposes to power quality (PQ) problems created by each other. This paper addresses various PQ problems arise due to integration of DG with grid. The major PQ problems are due to unbalanced and non-linear load connected at DG, unbalanced voltage variations on transmission line and unbalanced grid voltages which severely affect the performance of the system. To mitigate the above mentioned PQ problems, a novel integrated control of distribution static shunt compensator (DSTATCOM) is presented in this paper. DSTATCOM control helps in reducing the unbalance factor of PCC voltage. It also eliminates harmonics from line currents and makes them balanced. Moreover, DSTATCOM supplies the reactive power required by the load locally and hence, grid need not to supply the reactive power. To show the efficacy of the proposed controller, several operating conditions are considered and verified through simulation using MATLAB/SIMULINK.

  5. A Study on Power Quality Improvement in PWM Controlled AC Voltage Controller

    Directory of Open Access Journals (Sweden)

    Ahmet ALTINTAŞ

    2009-04-01

    Full Text Available A lot of topologies of pulse-width modulated (PWM-AC controllers for single-phase and three-phase systems are proposed up to date. PWM-AC controllers have important advantages compared with the phase-controlled AC controllers using thyristors and triacs. The PWM-AC controller has sinusoidal current waveforms, smaller THD values, better power factor, faster dynamics, and smaller input/output filter. This article presents a novel control technique for application to PWM-AC controllers with ability of generating fewer harmonics. In the proposed control method, both the traditional AC voltage controllers and the PWM-AC controllers are combined; and smaller THD values are obtained. Thus, the harmonic pollution in the power system will be reduced; and consequently, the power quality will be increased. For this purpose, computer simulations are performed in order to investigate the proposed controller performance. The obtained results are compared with the conventional PWM-AC controller.

  6. Power system distributed oscilation detection based on Synchrophasor data

    Science.gov (United States)

    Ning, Jiawei

    Along with increasing demand for electricity, integration of renewable energy and deregulation of power market, power industry is facing unprecedented challenges nowadays. Within the last couple of decades, several serious blackouts have been taking place in United States. As an effective approach to prevent that, power system small signal stability monitoring has been drawing more interests and attentions from researchers. With wide-spread implementation of Synchrophasors around the world in the last decade, power systems real-time online monitoring becomes much more feasible. Comparing with planning study analysis, real-time online monitoring would benefit control room operators immediately and directly. Among all online monitoring methods, Oscillation Modal Analysis (OMA), a modal identification method based on routine measurement data where the input is unmeasured ambient excitation, is a great tool to evaluate and monitor power system small signal stability. Indeed, high sampling Synchrophasor data around power system is fitted perfectly as inputs to OMA. Existing methods in OMA for power systems are all based on centralized algorithms applying at control centers only; however, with rapid growing number of online Synchrophasors the computation burden at control centers is and will be continually exponentially expanded. The increasing computation time at control center compromises the real-time feature of online monitoring. The communication efforts between substation and control center will also be out of reach. Meanwhile, it is difficult or even impossible for centralized algorithms to detect some poorly damped local modes. In order to avert previous shortcomings of centralized OMA methods and embrace the new changes in the power systems, two new distributed oscillation detection methods with two new decentralized structures are presented in this dissertation. Since the new schemes brought substations into the big oscillation detection picture, the proposed

  7. Simulation and Study of Power Quality Issues in a Fixed Speed Wind Farm Substation

    Directory of Open Access Journals (Sweden)

    T. Magesh

    2015-01-01

    Full Text Available Power quality issues associated with the fixed speed wind farm substation located at Coimbatore district are investigated as the wind generators are tripping frequently. The investigations are carried out using two power quality analyzers, Fluke 435 and Dranetz PX5.8, with one of them connected at group control breaker of the 110 kV feeder and the other at the selected 0.69 kV generator busbar during the period of maximum power generation. From the analysis of the recorded data it is found that sag, swell, and transients are the major events which are responsible for the tripping of the generators. In the present study, simulation models for wind, turbine, shaft, pitch mechanism, induction generator, and grid are developed using DIgSILENT. Using the turbine characteristics, a two-dimensional lookup table is designed to generate a reference pitch angle necessary to simulate the power curve of the passive stall controlled wind turbine. Various scenarios and their effects on the performance of the wind farm are studied and validated with the recorded data and waveforms. The simulation model will be useful for the designers for planning and development of the wind farm before implementation.

  8. Simulation and study of power quality issues in a fixed speed wind farm substation.

    Science.gov (United States)

    Magesh, T; Chellamuthu, C

    2015-01-01

    Power quality issues associated with the fixed speed wind farm substation located at Coimbatore district are investigated as the wind generators are tripping frequently. The investigations are carried out using two power quality analyzers, Fluke 435 and Dranetz PX5.8, with one of them connected at group control breaker of the 110 kV feeder and the other at the selected 0.69 kV generator busbar during the period of maximum power generation. From the analysis of the recorded data it is found that sag, swell, and transients are the major events which are responsible for the tripping of the generators. In the present study, simulation models for wind, turbine, shaft, pitch mechanism, induction generator, and grid are developed using DIgSILENT. Using the turbine characteristics, a two-dimensional lookup table is designed to generate a reference pitch angle necessary to simulate the power curve of the passive stall controlled wind turbine. Various scenarios and their effects on the performance of the wind farm are studied and validated with the recorded data and waveforms. The simulation model will be useful for the designers for planning and development of the wind farm before implementation.

  9. 基于XML的电能质量标准数据共享模型及跨平台数据交换%XML-based power quality data sharing model and cross-platform data exchange

    Institute of Scientific and Technical Information of China (English)

    张竞; 肖先勇

    2007-01-01

    IEEE提出的标准二进制电能质量数据格式(PQDIF)采用了通道定义和数据序列分离的数据结构,不仅降低了数据查询效率,而且读取、修改和结合应用程序实现复杂.在现有PQDIF数据模型的基础上,提出了一种用XML实现的电能质量数据模型:模型将测量类型、相位、序列值等以子对象方式嵌套于3种记录类型,通道定义和数据序列以索引相连,提高了数据查询效率;同时在XML模式定义中采用base64binary二进制储存PQ数据,有效地减少数据占用空间;最后,提出了基于模式转换的映射数据交换方法,任何2个XML文档解析出来的树结构元素都可以根据距离根节点的深度和数据字典进行语义自动匹配,精确度更高,处理速度也更快.基于以上数据交换模型和模式转换方法成功地实现了异构电能质量数据的交换,实践证明所提出的数据模型及实现方式具有良好的鲁棒性和可行性,能较好地实现电能质量数据的跨平台交换与共享.

  10. POWER CONTROL BASED COOPERATIVE OPPORTUNISTIC ROUTING IN WIRELESS SENSOR NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Hu Haifeng; Zhu Qi

    2009-01-01

    This paper proposes an approach called PC-CORP (Power Control based Cooperative Opportunistic Routing Protocol) for WSN (Wireless Sensor Networks), providing robustness to the random variations in network connectivity while ensuring better data forwarding efficiency in an energy efficient manner. Based on the realistic radio model, we combine the region-based routing, rendezvous scheme, sleep discipline and cooperative communication together to model data forwarding by cross layer design in WSN. At the same time, a lightweight transmission power control algorithm called PC-AIMD (Power Control Additive Increase Multiplicative Decrease) is introduced to utilize the cooperation of relay nodes to improve the forwarding efficiency performance and increase the robustness of the routing protocol. In the simulation, the performance of PC-COPR is investigated in terms of the adaptation of variations in network connectivity and satisfying the QoS requirements of application.

  11. Crowdsourcing based subjective quality assessment of adaptive video streaming

    DEFF Research Database (Denmark)

    Shahid, M.; Søgaard, Jacob; Pokhrel, J.

    2014-01-01

    humans are considered to be the most valid method of the as- sessment of QoE. Besides lab-based subjective experiments, crowdsourcing based subjective assessment of video quality is gaining popularity as an alternative method. This paper presents insights into a study that investigates perceptual pref......- erences of various adaptive video streaming scenarios through crowdsourcing based subjective quality assessment.......In order to cater for user’s quality of experience (QoE) re- quirements, HTTP adaptive streaming (HAS) based solutions of video services have become popular recently. User QoE feedback can be instrumental in improving the capabilities of such services. Perceptual quality experiments that involve...

  12. Audiovisual Quality Fusion based on Relative Multimodal Complexity

    DEFF Research Database (Denmark)

    You, Junyong; Korhonen, Jari; Reiter, Ulrich

    2011-01-01

    In multimodal presentations the perceived audiovisual quality assessment is significantly influenced by the content of both the audio and visual tracks. Based on our earlier subjective quality test for finding the optimal trade-off between audio and video quality, this paper proposes a novel meth...

  13. Fuzzy Based Evaluation of Software Quality Using Quality Models and Goal Models

    Directory of Open Access Journals (Sweden)

    Arfan Mansoor

    2015-09-01

    Full Text Available Software quality requirements are essential part for the success of software development. Defined and guaranteed quality in software development requires identifying, refining, and predicting quality properties by appropriate means. Goal models of goal oriented requirements engineering (GORE and quality models are useful for modelling of functional goals as well as for quality goals. Once the goal models are obtained representing the functional requirements and integrated quality goals, there is need to evaluate each functional requirement arising from functional goals and quality requirement arising from quality goals. The process consist of two main parts. In first part, the goal models are used to evaluate functional goals. The leaf level goals are used to establish the evaluation criteria. Stakeholders are also involved to contribute their opinions about the importance of each goal (functional and/or quality goal. Stakeholder opinions are then converted into quantifiable numbers using triangle fuzzy numbers (TFN. After applying the defuzzification process on TFN, the scores (weights are obtained for each goal. In second part specific quality goals are identified, refined/tailored based on existing quality models and their evaluation is performed similarly using TFN and by applying defuzzification process. The two step process helps to evaluate each goal based on stakeholder opinions and to evaluate the impact of quality requirements. It also helps to evaluate the relationships among functional goals and quality goals. The process is described and applied on ’cyclecomputer’ case study.

  14. Power active filter control based on a resonant disturbance observer

    OpenAIRE

    Ramos Fuentes, German A.; Cortés Romero, John Alexander; Zou, Zhixiang; Costa Castelló, Ramon; Zhou, Keliang

    2015-01-01

    Active filters are power electronics devices used to eliminate harmonics from the distribution network. This article presents an active disturbance rejection control scheme for active filters. The controller is based on a linear disturbance observer combined with a disturbance rejection scheme. The parameter tuning is based on a combined pole placement and an optimal estimation based on Kalman-Bucy filter. Proposed scheme is validated through simulation and experimental work in an active filter.

  15. Small reactor power systems for manned planetary surface bases

    Science.gov (United States)

    Bloomfield, Harvey S.

    1987-01-01

    A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options.

  16. Survey on Power Optimization for Disk Based Systems

    Directory of Open Access Journals (Sweden)

    G. Ravikumar

    2011-09-01

    Full Text Available Energy optimization has become a growing concern in the present world. Energy optimization can influence the overall system design and reliability. Power can greatly influence the performance of the disk, as power dissipation generates heat that affects stability and reliability of the component, particularly for large server systems. Hence, developers concentrate on the configuration of disk arrays which can deliver extremely high performance. Though, there are several significant techniques for tackling disk power for laptops and workstations, using them in a server environment are a considerable challenge, especially under stringent performance needs. Excessive power consumption is a major barrier to the market acceptance of hard disks in mobile electronic devices. Studying and reducing power consumption, however, often comprises running time intensive disk traces on real hardware with specialized power-monitoring equipment. Most of the conventional energy optimization techniques are based on architectural level techniques and is found to be effective only in certain scenarios. This paper proposes a survey on the disk energy optimization techniques. This paper analyses the functionalities, advantages and the disadvantages of the various techniques for the disk power consumption.

  17. Development of Android based Smart Power Saving System

    Science.gov (United States)

    Gupta, Ashutosh; Kumar, Pradeep; Ghosh, Tathagata; Bhawna, Shruthi. S.

    2017-08-01

    An android based smart power saving system has been presented in this paper. For this purpose, an application is developed for controlling the intensity of an AC supply using a dimmer circuit in android platform and to monitor the current flow on different intensity level a current sensor is used in the circuit. Dimmer circuit provides a 16-different intensity level to control the flow of current and help in power saving. The system is very simple and robust as it is based on android platform.

  18. Wind power prediction based on genetic neural network

    Science.gov (United States)

    Zhang, Suhan

    2017-04-01

    The scale of grid connected wind farms keeps increasing. To ensure the stability of power system operation, make a reasonable scheduling scheme and improve the competitiveness of wind farm in the electricity generation market, it's important to accurately forecast the short-term wind power. To reduce the influence of the nonlinear relationship between the disturbance factor and the wind power, the improved prediction model based on genetic algorithm and neural network method is established. To overcome the shortcomings of long training time of BP neural network and easy to fall into local minimum and improve the accuracy of the neural network, genetic algorithm is adopted to optimize the parameters and topology of neural network. The historical data is used as input to predict short-term wind power. The effectiveness and feasibility of the method is verified by the actual data of a certain wind farm as an example.

  19. High power density reactors based on direct cooled particle beds

    Science.gov (United States)

    Powell, J. R.; Horn, F. L.

    Reactors based on direct cooled High Temperature Gas Cooled Reactor (HTGR) type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out along the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBRs) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed.

  20. Air Quality Monitoring: Risk-Based Choices

    Science.gov (United States)

    James, John T.

    2009-01-01

    Air monitoring is secondary to rigid control of risks to air quality. Air quality monitoring requires us to target the credible residual risks. Constraints on monitoring devices are severe. Must transition from archival to real-time, on-board monitoring. Must provide data to crew in a way that they can interpret findings. Dust management and monitoring may be a major concern for exploration class missions.