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Sample records for active power filters

  1. Power System Harmonic Compensation Using Shunt Active Power Filter.

    Directory of Open Access Journals (Sweden)

    Shiuly Mukherjee

    2014-07-01

    Full Text Available This paper shows the method of improving the power quality using shunt active power filter. The proposedtopic comprises of PI controller, filter hysteresis current control loop, dc link capacitor. The switching signal generation for filter is fromhysteresis current controller techniques. With the all these element shunt active power filter reduce the total harmonic distortion. Thispaper represents the simulation and analysis of the using three phase three wire system active filter to compensate harmonics .Theproposed shunt active filter model uses balanced non-linear load. This paper successfully lowers the THD within IEEE norms and satisfactorily works to compensatecurrent harmonics.

  2. Adaptive Compensation of Reactive Power With Shunt Active Power Filters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Hansen, Steffan;

    2008-01-01

    This paper describes an adaptive method for compensating the reactive power with an active power filter (APF), which is initially rated for mitigation of only the harmonic currents given by a nonlinear industrial load. It is proven that, if the harmonic currents do not load the APF at the rated...

  3. Prediction control of active power filters

    Institute of Scientific and Technical Information of China (English)

    王莉娜; 罗安

    2003-01-01

    A prediction method to obtain harmonic reference for active power filter is presented. It is a new use ofthe adaptive predictive filter based on FIR. The delay inherent in digital controller is successfully compensated by u-sing the proposed method, and the computing load is not very large compared with the conventional method. Moreo-ver, no additional hardware is needed. Its DSP-based realization is also presented, which is characterized by time-va-riant rate sampling, quasi synchronous sampling, and synchronous operation among the line frequency, PWM gener-ating and sampling in A/D unit. Synchronous operation releases the limitation on PWM modulation ratio and guar-antees that the electrical noises resulting from the switching operation of IGBTs do not interfere with the sampledcurrent. The simulation and experimental results verify the satisfactory performance of the proposed method.

  4. Harmonics Mitigation Using Active Power Filter

    Directory of Open Access Journals (Sweden)

    Sourabh Gupta

    2013-06-01

    Full Text Available This paper is proposed to reconsider the development of active power filter (APF technologies that are routinely utilized to mitigate harmonics in utility power lines. This reconsider can furthermore be considered as a “tutorial-type paper” as it provides a holistic coverage of the APF technologies by omitting the tedious details, but without losing the major essence of the subject matter. It is wanted that by this approach, it would be likely to lure more power engineering readers to be involved in this important and growing area. The discussion starts with a short overview of harmonic distortion difficulties and their impacts on electric power and powered value. The operation of common APF topologies, namely the shunt, sequence and hybrid APFs are recounted in minutia. This is followed by a reconsider on different types of reference pointer estimation extraction methods. In specific, the application of the p-q and elongation p-q theorems to extract the quotation pointers are elaborated, as they are the most commonly discovered in practical APF systems eventually, an overview of the APF command schemes is provided. A short consideration on the APF-solar photovoltaic scheme is furthermore granted. At the end of the paper, important references are cited to aid readers who are interested to discover the subject in larger detail.

  5. 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.

  6. 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.

  7. Design and control of LCL-filter with active damping for Active Power Filter

    DEFF Research Database (Denmark)

    Zeng, Guohong; Rasmussen, Tonny Wederberg; Ma, L

    2010-01-01

    In the application of shunt Active Power Filter (APF) to compensate nonlinear load's harmonic, reactive and negative sequence current, it is more effective to use a LCL-filter than an L-filter as an interface between the Voltage Source Converter (VSC) and grid. In this paper, a designing procedure...... of LCL-filter for APF is introduced, which is aimed for simplified the implementation. To suppress the resonance that may be excited in the system, which brings in stability problems, an active damping control strategy using the current feed-back of the filter capacitor is adopted. By selecting two equal...

  8. Hybrid simulation: an active power filter case study

    Directory of Open Access Journals (Sweden)

    Y. A. Garcés

    2011-10-01

    Full Text Available The hybrid simulation concept consisting of a combination of computer simulation and laboratory tests. This approach is a cost effective alternative to physically testing the whole system and allows better understanding of complex coupled systems.This paper describes implementing an active power filter (APF hybrid prototype where the source system and load are implemented as a real-time simulation and the system of static power converter acting as an active power filter is implemented in physical hardware. It also confirmed the hybrid simulation results by implementing the simulation in MATLAB-Simulink regarding the same system implemented during the active power filter analysis and design stage.

  9. Neuro-fuzzy based Controller for Solving Active Power Filter

    Directory of Open Access Journals (Sweden)

    Homayoun Ebrahimian

    2016-03-01

    Full Text Available In this paper, two soft computing techniques by fuzzy logic, neural network are used to design alternative control schemes for switching the APF active power filter (APF. The control of a shunt active power filter designed for harmonic and reactive current mitigation. Application of the mentioned model has been combined by an intelligent algorithm for improving the efficiency of proposed controller. Effectiveness of the proposed method has been applied over test case and shows the validity of proposed model.

  10. DESIGN CONSIDERATIONS FOR SERIES HYBRID ACTIVE POWER FILTER

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Some important factors for designing a series hybrid active power filter (SHAPF) are presented in this paper for the case when the load is varied in a wide range and/or the source voltage is seriously distorted. Special design of passive filters, adaptive control of parameter and multi variant control are discussed in detail. The filter is stable, has good performance, and causes small capacitive reactive current. The simulation and experimental results accorded with the theoretical analysis results.

  11. Design and control of hybrid active power filters

    CERN Document Server

    Lam, Chi-Seng

    2014-01-01

    Design and Control of Hybrid Active Power Filters presents an overview of the current quality problems and their compensators. To get a balance between the system cost and performance, hybrid active power filters (HAPFs) are valuable. The book presents the coverage of resonance phenomena prevention capability, filtering performance and system robustness analysis of HAPF; nonlinear inverter current slope characteristics and their linear operation region requirement analysis of the hysteresis PWM for the HAPF; minimum inverter capacity design procedure of HAPF, adaptive dc-link voltage controller for the HAPF and the real design example of a 220V 10kVA HAPF, in which the system performance analysis method, minimum dc voltage deduction concept and adaptive dc voltage idea can be further extended into the other active compensators, such as APF, static synchronous compensator STATCOM, etc. This book will benefit researchers, graduate students, and electrical power engineers in the field of power-quality compensati...

  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. Use of dominant harmonic active filters in high power applications

    Science.gov (United States)

    Cheng, Po-Tai

    The application of power electronics equipment is increasing rapidly. It is estimated that 60% of electrical power will be processed by power electronics equipment by year 2000. These equipments typically require rectifiers for AC-DC power conversion. Due to their nonlinear nature, most rectifiers draw harmonic current from the utility grid. The harmonic current causes higher energy losses, and may excite resonance conditions in the utility grid. Harmonic standards such as IEEE 519 and IEC 1000-3-2 have been proposed to regulate the harmonic current and voltage levels. This work is to develop a dominant harmonic active filter (DHAF) to realize a cost-effective active filtering solution for nonlinear loads in the range of megawatt and above. The DHAF system achieves harmonic isolation at dominant harmonic frequencies, e.g. the 5th and 7th. This approach allows use of low switching frequency and small rating active filter inverters (1%--2% of the load MVA rating) for implementation. Review of conventional passive filters and various active filters based on high bandwidth PWM inverters is provided. The control theory of the DHAF system is presented. Comparison of the DHAF system and other dominant harmonic filtering approach is provided. Simulation results and laboratory prototype test results are presented to validate the effectiveness of the proposed DHAF system.

  14. Sliding Mode Controller for Three-Phase Hybrid Active Power Filter with Photovoltaic Application

    OpenAIRE

    Blorfan, Ayman; Merckle, Jean; Flieller, Damien; Wira, Patrice; Sturtzer, Guy

    2012-01-01

    International audience; This paper presents a new three-phase hybrid active power filter configuration that interconnects a passive high-pass filter in parallel with an active power filter and a photovoltaic system. The proposed configuration can improves the filtering performance of the conventional active power filter, as well as simultaneously supply the power from the photovoltaic arrays to the load and utility. This paper will describe the proposed hybrid active power filter control usin...

  15. Indirect control of a single-phase active power filter

    Directory of Open Access Journals (Sweden)

    Mihai CULEA

    2006-12-01

    Full Text Available The control of shunt active power filters using PWM inverters consists in generating a reference by separating, using different methods, the harmonics to be eliminated. The methods used are time-consuming and need dedicated control and signal processing equipments. To avoid these setbacks a new method is proposed in the paper. The active power filter is a current PWM rectifier with voltage output and with a capacitor on the DC side. The PWM rectifier is controlled so that the sum of its current and the load’s current is a sinusoid. The control block as well as simulation results are presented.

  16. Application of Discontinuous PWM Modulation in Active Power Filters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Rodriguez, Pedro

    2008-01-01

    Classical discontinuous pulsewidth modulations (DPWMs) may not be efficiently applied in active power filters (APFs), because it is hard to predict the peak values of the inverter current, and consequently it is difficult to calculate the position of the clamped interval, that minimizes the switc...

  17. Simulation and reliability analysis of shunt active power filter based on instantaneous reactive power theory

    Institute of Scientific and Technical Information of China (English)

    CUI Yu-long; LIU Hong; WANG Jing-qin; SUN Shu-guang

    2007-01-01

    This paper first discusses the operating principle ofinstantaneous reactive power theory. Then, the theory is introduced into shunt active power filter and its control scheme is studied. Finally, Matlab/Simulink power system toolbox is used to simulate the system. In the simulation model, as the most common harmonic source, 3-phase thyfistor bridge rectifier circuit is constructed.The simulation results before and after the shunt active filter was switched to the system corresponding to different firing angles of the thyristors are presented and analyzed, which demonstrate the practicability and reliability of the proposed shunt active filter scheme.

  18. Hybrid Active Filter with Variable Conductance for Harmonic Resonance Suppression in Industrial Power Systems

    DEFF Research Database (Denmark)

    Lee, Tzung-Lin; Wang, Yen-Ching; Li, Jian-Cheng

    2015-01-01

    -tuned passive filter and an active filter in series connection, both dc voltage and kVA rating of the active filter are dramatically decreased compared with the pure shunt active filter. In real application, this feature is very attractive since the active power filter with fully power electronics is very...... expensive. A reasonable trade-off between filtering performances and cost is to use the hybrid active filter. Design consideration are presented and experimental results are provided to validate effectiveness of the proposed method. Furthermore, this paper discusses filtering performances on line impedance...

  19. A new shunt DC active filter of power supply in a steady high magnetic field facility

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; LIU Xiao-Ning; WANG Can

    2011-01-01

    A DC active power filter is an indispensable part in a high power and high stability power supply system, especially in the power supply system of the Steady High Magnetic Field Facility, which requires that the current ripple should be limited to 50 parts per million. In view of the disadvantages of the series DC active power filter and shunt Pulse Width Modulation DC active filter, this paper puts forward a novel DC active filter by combining the advantages of the transistor regulator and the shunt type. The structure and principle of the new shunt linear active filter are introduced. Meanwhile, the design of several key components that construct the new shunt linear active filter is also analyzed. The simulation model and an experimental prototype of the shunt linear active filter are developed, and the results verify that the parameter design is reasonable and the shunt active filter has a good filter effect.

  20. Control strategies of active filters in the context of power conditioning

    DEFF Research Database (Denmark)

    Dan, Stan George; Benjamin, Doniga Daniel; Magureanu, R.;

    2005-01-01

    Active Power Filters have been intensively explored in the past decade. Various topologies and control schemes have been documented aiming at reducing the cost and improving the performance of the compensation system. Hybrid active filters inherit the efficiency of passive filters and the improved...... performance of active filters, and thus constitute a viable improved approach for harmonic compensation. In this paper a parallel hybrid filter is studied for current harmonic compensation. The hybrid filter is formed by a single tuned LC filter per phase and a small-rated power three-phase active filter...

  1. Instantaneous Power Theory with Fourier and Optimal Predictive Controller Design for Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Suksan Tiyarachakun

    2014-01-01

    Full Text Available This paper presents a novel harmonic identification algorithm of shunt active power filter for balanced and unbalanced three-phase systems based on the instantaneous power theory called instantaneous power theory with Fourier. Moreover, the optimal design of predictive current controller using an artificial intelligence technique called adaptive Tabu search is also proposed in the paper. These enhancements of the identification and current control parts are the aim of the good performance for shunt active power filter. The good results for harmonic mitigation using the proposed ideas in the paper are confirmed by the intensive simulation using SPS in SIMULINK. The simulation results show that the enhanced shunt active power filter can provide the minimum %THD (Total Harmonic Distortion of source currents and unity power factor after compensation. In addition, the %THD also follows the IEEE Std.519-1992.

  2. 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.

  3. Advanced nonlinear control of three phase series active power filter

    Directory of Open Access Journals (Sweden)

    Abouelmahjoub Y.

    2014-01-01

    Full Text Available The problem of controlling three-phase series active power filter (TPSAPF is addressed in this paper in presence of the perturbations in the voltages of the electrical supply network. The control objective of the TPSAPF is twofold: (i compensation of all voltage perturbations (voltage harmonics, voltage unbalance and voltage sags, (ii regulation of the DC bus voltage of the inverter. A controller formed by two nonlinear regulators is designed, using the Backstepping technique, to provide the above compensation. The regulation of the DC bus voltage of the inverter is ensured by the use of a diode bridge rectifier which its output is in parallel with the DC bus capacitor. The Analysis of controller performances is illustrated by numerical simulation in Matlab/Simulink environment.

  4. Adaptive Current Control Method for Hybrid Active Power Filter

    Science.gov (United States)

    Chau, Minh Thuyen

    2016-09-01

    This paper proposes an adaptive current control method for Hybrid Active Power Filter (HAPF). It consists of a fuzzy-neural controller, identification and prediction model and cost function. The fuzzy-neural controller parameters are adjusted according to the cost function minimum criteria. For this reason, the proposed control method has a capability on-line control clings to variation of the load harmonic currents. Compared to the single fuzzy logic control method, the proposed control method shows the advantages of better dynamic response, compensation error in steady-state is smaller, able to online control is better and harmonics cancelling is more effective. Simulation and experimental results have demonstrated the effectiveness of the proposed control method.

  5. An active trap filter for high-power voltage source converters

    DEFF Research Database (Denmark)

    Bai, Haofeng; Wang, Xiongfei; Loh, Poh Chiang;

    2015-01-01

    This paper proposes a power electronic based device to actively trap the switching current ripples for highpower converters. Control principle and system design of the active trap filter are discussed first. Comparisons of the active trap filter with LCL and LLCL filters are then carried out...... in time-domain simulations and experimental tests. The results demonstrate that the active trap filter not only provides more controllability and flexibility than the passive filters, but also mitigates the adverse effects of parameter shifts on harmonic filtering performance of passive filters....

  6. Indirect Control of a low power Single-Phase Active Power Filter

    Directory of Open Access Journals (Sweden)

    SILVIU EPURE

    2010-12-01

    Full Text Available This paper deals with a low power, single phase active filter used to compensate nonlinear loads. The filter uses the indirect control method and it is based on a particular connection between filter, polluting load and grid to avoid timeconsuming mathematic operations or signal processing computations and assures good rejection of harmonic currents injected by the nonlinear load into the grid. A scale model was first simulated in Simulink and then physically implemented. The paper presents simulation and experimental results, and highlight problems encountered during experiments.

  7. New hybrid active power filter for harmonic current suppression and reactive power compensation

    Science.gov (United States)

    Biricik, Samet; Cemal Ozerdem, Ozgur; Redif, Soydan; Sezai Dincer, Mustafa

    2016-08-01

    In the case of undistorted and balanced grid voltages, low ratio shunt active power filters (APFs) can give unity power factors and achieve current harmonic cancellation. However, this is not possible when source voltages are distorted and unbalanced. In this study, the cost-effective hybrid active power filter (HAPF) topology for satisfying the requirements of harmonic current suppression and non-active power compensation for industry is presented. An effective strategy is developed to observe the effect of the placement of power capacitors and LC filters with the shunt APF. A new method for alleviating the negative effects of a nonideal grid voltage is proposed that uses a self-tuning filter algorithm with instantaneous reactive power theory. The real-time control of the studied system was achieved with a field-programmable gate array (FPGA) architecture, which was developed using the OPAL-RT system. The performance result of the proposed HAPF system is tested and presented under nonideal supply voltage conditions.

  8. Evaluation of harmonic detection methods for active power filter applications

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Blaabjerg, Frede; Hansen, Steffan

    2005-01-01

    filter is to use a good method for current/voltage reference generation. There exist many implementations supported by different theories (either in time- or frequency-domain), which continuously debate their performances proposing ever better solutions. This paper gives a survey of the common used...... theories. Then, the work here proposes a simulation setup that decouples the harmonic reference generator from the active filter model and its controller. In this way the selected methods can be equally analyzed and compared with respect to their performance, which helps anticipating possible...... implementation issues. The conclusions are collected and a comparison is given at the end, which is useful in deciding the future hardware setup implementation. The comparison shows that the choice of numerical filtering is a key factor for obtaining good accuracies and dynamics for an active filter....

  9. DSP control of photovoltaic power generation system adding the function of shunt active power filter

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

    The growing number of power electronics-based equipment has created a problem on the quality of electric power supply since both high power industrial loads and domestic loads cause harmonics in the network voltage. Power quality problems can occur in the system or can be caused by the consumer. Active filter (AF) is widely used to compensate current harmonics and/or current imbalance of harmonic-producing loads. The power output of a photovoltaic (PV) system is directly affected by weather conditions. When alternating current (AC) power supply is required, power conversion by an inverter and an MPPT control is necessary. The proliferation of nonlinear loads such as inverter of PV power generation system can be treated as a harmonic source for the power distribution system. As such, the PV system combined with the function of the active filter system can be useful for the application in power distribution systems. This paper described a PV-AF system using DSP to prove that it is possible to combine AF theory to the three phase PV system connected to utility and verify it through experimental results. The paper described the control method of the PV-AF system, with reference to the photovoltaic power generation system, shunt active filter and PV-AF system. The experimental set-up was also presented. A laboratory system was designed and constructed to confirm the viability of the proposed PV-AF system. The test results revealed the stability and effectiveness of the proposed PV-AF system. 12 refs., 1 tabs., 12 figs.

  10. Neural network controlled three-phase four-wire shunt active power filter

    Energy Technology Data Exchange (ETDEWEB)

    Elmitwally, A.; Abdelkader, S. [Mansura University (Egypt); El-Kateb, M. [Bath University (United Kingdom). Dept. of Electronic and Electrical Engineering

    2000-03-01

    A three-phase four-wire shunt active power filter for harmonic mitigation and reactive power compensation in power systems supplying nonlinear loads is presented. Three adaptive linear neurons are used to tackle the desired three-phase filter current templates. Another feedforward three layer neural network is adopted to control the output filter compensating currents online. This is accomplished by producing the appropriate switching patterns of the converter's legs IGBTs. Adequate tracking of the filter current references is obtained by this method. The active filter inject the current required to compensate for the harmonic and reactive components of the line currents. Simulation results of the proposed active filter indicate a remarkable improvement in the source current waveforms. This is reflected in the enhancement of the unified power quality index defined. Also, the filter has exhibited quite a high dynamic response for step variations in the load current assuring its potential for real-time applications. (author)

  11. Adaptive Notch filter based active damping for power converters using LCL filters

    DEFF Research Database (Denmark)

    Ciobotaru, M.; Rossé, A.; Bede, L.;

    2016-01-01

    This paper proposes an active damping technique for grid-connected converters using inductor-capacitor-inductor (LCL) filters. The technique relies on a discrete-time adaptive notch filter (NF) which is able to adapt its resonance frequency and bandwidth in real-time. The tuning function of this ......This paper proposes an active damping technique for grid-connected converters using inductor-capacitor-inductor (LCL) filters. The technique relies on a discrete-time adaptive notch filter (NF) which is able to adapt its resonance frequency and bandwidth in real-time. The tuning function...

  12. A NEW METHOD TO CALCULATE COMPENSATION CURRENT IN PARALLEL ACTIVE POWER FILTER

    Directory of Open Access Journals (Sweden)

    Ahmet ALTINTAŞ

    2004-03-01

    Full Text Available Nowadays, active power filter plays an important role in reducing harmonic current and reactive power in power lines. The reliability and effectiveness of an active power filter depends basically on three characteristics. These are the modulation method, the design characteristics of the PWM modulator and the method implemented to generate compensation current. For the last one, there are many proposed methods. Most of them complicated and hence difficult to implement and adjust. In this study, a new method to calculate compensation current is improved and tested in single-phase parallel active power filter controlled by microcontroller. Experimental and simulation results are presented in the paper.

  13. Research on the filtering characteristic of single phase series hybrid active power filter based on fundamental magnetic flux compensation

    Science.gov (United States)

    Tian, Jun; Chen, Qiaofu; Zhang, Yuqi

    2012-12-01

    In this article, the PWM inverter works as a controlled fundamental current source in the single phase series hybrid active power filter (APF) based on fundamental magnetic flux compensation (FMFC). The series transformer can exhibit the self-impedance of primary winding to harmonic current, which forces harmonic current to flow into passive power filter. With the influence of harmonic current, the voltage of primary winding of transformer is a harmonic voltage, which makes the inverter output currents have a certain harmonic component, and it degrades the filtering characteristics. On the basis of PWM inverter, the mathematical model of series hybrid APF is established, and the filtering characteristics of single phase APF are analysed in detail. Three methods are gained to improve filtering characteristics: reasonably designing the inverter output filter inductance, increasing series transformer ratio and adopting voltage feed-forward control. Experimental results show that the proposed APF has greater validity.

  14. Active power filter for the reduction of the harmonic distortion and fundamental reactive power with improved dynamic response

    Energy Technology Data Exchange (ETDEWEB)

    Voncina, D.; Nastran, J.; Cajhen, R.; Nedeljkovic, D. [Ljubljana Univ. (Slovenia). Faculty of Electrical Engineering and Computer Science

    1995-12-31

    The parallel active power filter for nonlinear loads is described. First the method for extracting the fundamental active component from the load current, based on the combined analogue and digital signal processing is presented in detail. The load current is filtered by a precision analogue circuit. The phase and the amplitude of the load current fundamental component is passed to the microcontroller to calculate its active component. The implemented control principle provides fast response of the actual filter current. The results, obtained from the experimental circuit, illustrate the active filter`s performance in steady state and during load transients. 14 refs, 10 figs

  15. 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.

  16. 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.

  17. Modeling & Analysis of Shunt Active Power Filter Using IRP Theory Fed to Induction Drive

    Directory of Open Access Journals (Sweden)

    PABBISETTY SAI SUJATHA

    2014-10-01

    Full Text Available Utility distribution networks have sensitive industrial loads and critical commercial operations suffer from various types of outages and service interruptions which can cost significant financial losses. Because of sensitivity of consumers on power quality and advancement in power electronics. Active power filter technology is the most efficient way to compensate reactive power and cancel out low order harmonics generated by nonlinear loads. The shunt active power filter was considered to be the most basic configuration for the APF. This paper reviews the basic principle of shunt active power filter, along with the current tracking circuit based on the instantaneous reactive power theory and the main circuit performing as an inverter with PWM hysteresis control. The instantaneous active and reactive current component (id-iq method and instantaneous active and reactive power (p-q method are two control strategies which are extensively used in active filters. A shunt active filter based on the instantaneous active and reactive current component (id-iq method is proposed. This method aims to compensate harmonic and first harmonic unbalance. A Comprehensive control method is analyzed and a harmonic Compensation simulation is conducted, the result of which verifies The harmonic detection algorithm is well-proposed and the power Quality of the grid is overall-enhanced. The results are obtained using MATLAB/SIMULINK software.

  18. Implementation of FFT Algorithm using DSP TMS320F28335 for Shunt Active Power Filter

    Science.gov (United States)

    Patel, Pinkal Jashvantbhai; Patel, Rajesh M.; Patel, Vinod

    2016-07-01

    This work presents simulation, analysis and experimental verification of Fast Fourier Transform (FFT) algorithm for shunt active power filter based on three-level inverter. Different types of filters can be used for elimination of harmonics in the power system. In this work, FFT algorithm for reference current generation is discussed. FFT control algorithm is verified using PSIM simulation results with DLL block and C-code. Simulation results are compared with experimental results for FFT algorithm using DSP TMS320F28335 for shunt active power filter application.

  19. Passive Power Filters

    CERN Document Server

    Künzi, R

    2015-01-01

    Power converters require passive low-pass filters which are capable of reducing voltage ripples effectively. In contrast to signal filters, the components of power filters must carry large currents or withstand large voltages, respectively. In this paper, three different suitable filter struc tures for d.c./d.c. power converters with inductive load are introduced. The formulas needed to calculate the filter components are derived step by step and practical examples are given. The behaviour of the three discussed filters is compared by means of the examples. P ractical aspects for the realization of power filters are also discussed.

  20. Shunt hybrid active power filter for harmonic mitigation: A practical design approach

    Indian Academy of Sciences (India)

    Unnikrishnan A K; Chandira Sekaran E; Subhash Joshi T G; Manju A S; Aby Joseph

    2015-06-01

    The increasing importance of Power Quality problems has been responsible for several improvements in Active Power Filter (APF) typologies in the last decade. The increased cost and switching losses make a pure shunt APF economically impractical for high power applications. In higher power levels shunt Hybrid Active Power Filter (HAPF) has been reported to be a useful approach to eliminate current harmonics caused by nonlinear loads. This paper presents a control strategy and design criteria for transformer-less shunt HAPF with special attention to the integration of series passive filter. The paper also compares the performance improvement of passive harmonic filter when modified as shunt HAPF. Experimental results obtained verify the viability and effectiveness of the proposed design criteria and control algorithm.

  1. High performance active filtering solutions for modern aircraft power network

    OpenAIRE

    Liu, Jun yi

    2011-01-01

    In the past 2 decades the increasing intensive use of non-linear loads has resulted in a substantial reduction of power quality in electric power systems. Current harmonics produced by non-linear loads, such as power electronic converters and electrical drives cause a number of problems in power distribution networks. In more recent years this problem has affected also smaller distribution grids like for example in aircrafts, due to the so called "more electric aircraft" trend, consisting in ...

  2. DPC controlled three-phase active filter for power quality improvement

    Energy Technology Data Exchange (ETDEWEB)

    Chaoui, Abdelmadjid; Krim, Fateh [Laboratoire d' Electronique de Puissance et Commande Industrielle (LEPCI), Universite de Setif (Algeria); Gaubert, Jean-Paul; Rambault, Laurent [Laboratoire d' Automatique et d' Informatique Industrielle (LAII-ESIP), Universite de Poitiers (France)

    2008-10-15

    This paper presents a new control method entitled direct power control (DPC) for shunt active power filtering (5th, 7th, 11th,..) (SAPF), which is applied to eliminate line current harmonics and compensate reactive power. Its main goal is to rebuild active and reactive powers to be compared to references values using hysteresis control. The outputs of hysteresis controllers associated with a switching table, control the instantaneous active and reactive power by selecting the optimum switching state of the voltage source inverter (VSI). A theoretical analysis with a complete simulation of the system and experimental results are presented to prove the excellent performance of the proposed control technique. (author)

  3. Design of a multilevel Active Power Filter for More Electrical Airplane variable frequency systems

    Science.gov (United States)

    Guerreiro, Joel Filipe; Pomilio, Jose Antenor; Busarello, Tiago Davi Curi

    This paper presents the design and simulation of an Aeronautical Active Power Filter (AAPF) for a Variable Speed Variable Frequency (VSVF) advanced aircraft electric power system. The purposes of the AAPF are to mitigate current harmonics, to improve the source power factor and to mitigate the effects of unbalanced loads. Regarding the fact that the Aircraft Electrical Power System (AEPS) frequency may vary between 360 Hz and 900 Hz, and the load dynamics is often modified, an enhanced filtering technique is required. The designed AAPF topology is an asymmetrical multilevel inverter (AMI), which control strategy is based on the Conservative Power Theory (CPT) and synchronized by a Kalman Filter Phase-Locked Loop (KF-PLL). The above configuration renders the AAPF very robust and effective to its purpose. Accurate simulation results on Matlab/Simulink platform verify the feasibility of the proposed AAPF and the high performance of the control strategy during steady-state and dynamic operations.

  4. Control of a Shunt Active Power Filter with Neural Networks—Theory and Practical Results

    Science.gov (United States)

    Villalva, Marcelo G.; Filho, Ernesto Ruppert

    This paper presents theoretical studies and practical results obtained with a four-wire shunt active power filter fully controlled with neural networks. The paper is focused on a current compensation method based on adaptive linear elements (adalines), which are powerful and easy-to-use neural networks. The reader will find here an introduction about these networks, an explanatory section about the achievement of Fourier series with adalines, and the full description of an adaline-based selective current compensator. The paper also brings a quick discussion about the use of a feedforward neural network in the current controller of the active filter, as well as simulation and experimental results obtained with the prototype of an active power filter.

  5. A Series-LC-Filtered Active Damper with Grid Disturbance Rejection for AC Power-Electronics-Based Power Systems

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Pang, Ying; Loh, Poh Chiang;

    2015-01-01

    damper. Unlike an active power filter for mitigating low-frequency harmonics, the proposed damper dampens resonances at higher frequencies, whose values are dependent on interactions among multiple grid-connected converters and reactive elements of the system. Its control requirements are, therefore......-order resonant controller, in addition to the second-order resonant controller used for resonance damping. Experimental results obtained have confirmed the effectiveness of these controllers, and hence, the feasibility of the active damper.......This letter proposes an active damper with a series LC filter for suppressing resonances in an ac power-electronics-based power system. The added series filter capacitor helps to withstand most of the system voltage, hence, allowing a lower rated converter to be used for implementing the active...

  6. Power quality improvement using DPC controlled three-phase shunt active filter

    Energy Technology Data Exchange (ETDEWEB)

    Chaoui, Abdelmadjid [Laboratoire d' Automatique et d' Informatique Industrielle (LAII-ESIP), Universite de Poitiers (France); Gaubert, Jean-Paul; Krim, Fateh [Laboratoire d' Electronique de Puissance et Commande Industrielle (LEPCI), Universite de Setif (Algeria)

    2010-06-15

    This paper presents a new control method entitled direct power control (DPC) for shunt active power filter (APF), which is applied to eliminate line current harmonics and compensate reactive power. Its main goal is to rebuild active and reactive source powers to be compared to references values using hysteresis control. The active power reference is issue of DC-side of inverter and reactive power reference is set to zero for unity power factor. The outputs of hysteresis controllers associated with a switching table, control the instantaneous active and reactive power by selecting the optimum switching state of the voltage source inverter (VSI). A theoretical analysis with a complete simulation of the system and experimental results are presented to prove the excellent performance of the proposed technique. (author)

  7. A novel modular approach to active power-line harmonic filtering in distribution systems

    Science.gov (United States)

    El Shatshat, Ramadan A.

    The objective of this research is to develop an efficient and reliable modular active harmonic filter system to realize a cost-effective solution to the harmonic problem. The proposed filter system consists of a number CSC modules, each dedicated to filter a specific harmonic of choice (Frequency-Splitting Approach). The power rating of the modules will decrease and their switching frequency will increase as the order of the harmonic to be filtered is increased. The overall switching losses are minimized due to the selected harmonic elimination and balanced a "power rating"-"switching frequency" product. Two ADALINEs are proposed as a part of the filter controller for processing the signals obtained from the power-line. One ADALINE (the Current ADALINE) extracts the fundamental and harmonic components of the distorted current. The other ADALINE (the Voltage ADALINE) estimates the line voltage. The outputs of both ADALINEs are used to construct the modulating signals of the filter modules. The proposed controller decides which CSC filter module(s) is connected to the electric grid. The automated connection of the corresponding filter module(s) is based on decision-making rules in such a way that the IEEE 519-1992 limits are not violated. The information available on the magnitude of each harmonic component allows us to select the active filter bandwidth (i.e., the highest harmonic to be suppressed). This will result in more efficiency and higher performance. The proposed controller adjusts the I dc in each CSC module according to the present magnitude of the corresponding harmonic current. This results in optimum dc-side current value and minimal converter losses. The comparison of the proposed modular active filter scheme and the conventional one converter scheme on practical use in industry is presented. This comparison shows that the proposed solution is more economical, reliable and flexible compared to conventional one. High speed and accuracy of ADALINE, self

  8. Reduction of Switching Losses in Active Power Filters With a New Generalized Discontinuous-PWM Strategy

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Malinowski, M.;

    2008-01-01

    The classical discontinuous pulsewidth modulations (DPWMs) cannot be efficiently applied in active power filters (APFs) because it is difficult to predict the peak values of the inverter current. Consequently, it is difficult to calculate the optimal position of the clamped interval to minimize t...

  9. Frequency Response Analysis of Current Controllers for Selective Harmonic Compensation in Active Power Filters

    DEFF Research Database (Denmark)

    Lascu, C.; Asiminoaei, L.; Boldea, I.;

    2009-01-01

    This paper compares four current control structures for selective harmonic compensation in active power filters. All controllers under scrutiny perform the harmonic compensation by using arrays of resonant controllers, one for the fundamental and one for each harmonic of interest, in order to ach...

  10. Multi-Rate Fractional-Order Repetitive Control of Shunt Active Power Filter

    DEFF Research Database (Denmark)

    Xie, Chuan; Zhao, Xin; Savaghebi, Mehdi

    2017-01-01

    This paper presents a multi-rate fractional-order repetitive control (MRFORC) scheme for three-phase shunt active power filter (APF). The proposed APF control scheme includes an inner proportional-integral (PI) control loop with a sampling rate identical to switching frequency and an external plug-in...

  11. A control architecture to coordinate distributed generators and active power filters coexisting in a microgrid

    DEFF Research Database (Denmark)

    Hashempour, Mohammad M.; Savaghebi, Mehdi; Quintero, Juan Carlos Vasquez

    2016-01-01

    This paper proposes a control architecture of distributed generators (DGs) inverters and shunt active power filters (APFs) in microgrids to compensate voltage harmonics in a coordinated way. For this, a hierarchical control structure is proposed that includes two control levels. The primary (local...

  12. A Control Architecture to Coordinate Distributed Generators and Active Power Filters Coexisting in a Microgrid

    DEFF Research Database (Denmark)

    Hashempour, Mohammad M.; Firoozabadi, Mehdi Savaghebi; Quintero, Juan Carlos Vasquez

    2016-01-01

    This paper proposes a control architecture of distributed generators (DGs) inverters and shunt active power filters (APFs) in microgrids to compensate voltage harmonics in a coordinated way. For this, a hierarchical control structure is proposed that includes two control levels. The primary (local...

  13. Neuro-Fuzzy based Controller for a Three- Phase Four-Wire Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Mridul Jha

    2011-10-01

    Full Text Available This paper describes the application of a novel neuro-fuzzy based control strategy which is used in order to improve the Active Power Filter (APF dynamics to minimize the harmonics for wide range of variations of load current under various conditions. To improve dynamic behavior of a three phase four-wire shunt active power filter and its robustness under range of load variations, adaptive hysteresis band with instantaneous p-q theory is used with the inclusion of neural network filter for reference current generation and fuzzy logic controller for DC voltage control. The proposed control scheme for “split-capacitor” converter topology is simple and also capable of maintaining the compensated line currents balanced, irrespective of unbalancing in the source voltages & deviation in the capacitor voltages. The results presented in MATLAB-SIMULINK software in this paper clearly reflect the effectiveness of the proposed APF to meet the IEEE-519 standard recommendations on harmonic levels.

  14. Fundamental Active Current Adaptive Linear Neural Networks for Photovoltaic Shunt Active Power Filters

    Directory of Open Access Journals (Sweden)

    Muhammad Ammirrul Atiqi Mohd Zainuri

    2016-05-01

    Full Text Available This paper presents improvement of a harmonics extraction algorithm, known as the fundamental active current (FAC adaptive linear element (ADALINE neural network with the integration of photovoltaic (PV to shunt active power filters (SAPFs as active current source. Active PV injection in SAPFs should reduce dependency on grid supply current to supply the system. In addition, with a better and faster harmonics extraction algorithm, the SAPF should perform well, especially under dynamic PV and load conditions. The role of the actual injection current from SAPF after connecting PVs will be evaluated, and the better effect of using FAC ADALINE will be confirmed. The proposed SAPF was simulated and evaluated in MATLAB/Simulink first. Then, an experimental laboratory prototype was also developed to be tested with a PV simulator (CHROMA 62100H-600S, and the algorithm was implemented using a TMS320F28335 Digital Signal Processor (DSP. From simulation and experimental results, significant improvements in terms of total harmonic distortion (THD, time response and reduction of source power from grid have successfully been verified and achieved.

  15. Study on Soft Phase Locked Method to Solving the Synchronization Problem of Active Power Filter in Stand-alone Power Grid

    DEFF Research Database (Denmark)

    Zhuo, Fang; Wu, Longhui; Chen, Zhe

    2009-01-01

    Traditional LC filters can't work stably in small rating stand-alone power grid. So active power filter (APF) is becoming an important tool to solve the power quality problem in small rating stand-alone power grid. In most current detection algorithm of APF, it needs a synchronizing signal. First...

  16. Adaptive Current Control with PI-Fuzzy Compound Controller for Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Juntao Fei

    2013-01-01

    Full Text Available An adaptive control technology and PI-fuzzy compound control technology are proposed to control an active power filter (APF. AC side current compensation and DC capacitor voltage tracking control strategy are discussed and analyzed. Model reference adaptive controller for the AC side current compensation is derived and established based on Lyapunov stability theory; proportional and integral (PI fuzzy compound controller is designed for the DC side capacitor voltage control. The adaptive current controller based on PI-fuzzy compound system is compared with the conventional PI controller for active power filter. Simulation results demonstrate the feasibility and satisfactory performance of the proposed control strategies. It is shown that the proposed control method has an excellent dynamic performance such as small current tracking error, reduced total harmonic distortion (THD, and strong robustness in the presence of parameters variation and nonlinear load.

  17. Carrier phase shifted SPWM based on current sourced multi-modular converter for active power filter

    Institute of Scientific and Technical Information of China (English)

    王立乔; 李建林; 张仲超

    2004-01-01

    A novel current-source active power filter(APF)based on multi-modular converter with carrier phase-shifted SPWM(CPS-SPWM)technique is proposed.With this technique,the effect of equivalent high switching frequency converter is obtained with low switching frequency converter.It is very promising in current-source APF that adopt superconducting magnetic energy storage component.

  18. 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.

  19. Shunt Active-Power-Filter Topology Based on Parallel Interleaved Inverters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Aeloiza, E.

    2008-01-01

    In this paper, an interleaved active-power-filter concept with reduced size of passive components is discussed. The topology is composed of two pulsewidth-modulation interleaved voltage-source inverters connected together on the ac line and sharing the same dc-link capacitor. The advantages......, because the power sharing allows one to use a higher switching frequency in each inverter. This paper analyzes the design of the passive components and gives a practical and low-cost solution for the minimization of the circulation currents between the inverters, by using common-mode coils. Several...

  20. Research on a new active power filter topology based on chopper circuit

    CERN Document Server

    Xiaoling, Guo; Bo, Zhang; Jing, Zhang

    2015-01-01

    The active power filter (APF) is attracting more and more attention for its outstanding performance in current and voltage ripple compensation. As modern high-energy accelerators are demanding much more stringent current ripple guideline, the APF is introduced to the magnet power supply (MPS) in accelerator system. However, the conventional APF has a lot of shortages and drawbacks due to its traditional topology, such as complex structure, nonadjustable working voltage, requirement of power supply, and so on. This paper proposes a new topology of APF, which is working as two types of chopper circuits. This APF need not extra electricity, but to use the power of the MPS current ripple to realize ripple depressing. At the end of this paper, the experiment result proves its feasibility and effect.

  1. Different View on PQ Theory Used in the Control Algorithm of Active Power Filters

    Directory of Open Access Journals (Sweden)

    Rastislav Pavlanin

    2006-01-01

    Full Text Available The improvement of power quality is a frequently discussed issue, which still requires a considerable research effort to be devoted to the study of the problem. The aim of this paper is to describe some problems related to the control of switching compensators, commonly known as active power filters. It also includes some shortcomings of pq theory regarded as three phase instantaneous power theory. The term “shortcomings” means that the pq theory does not provide a proper description of power properties. Moreover the control algorithm based on this theory only achieves satisfactory results for sinusoidal balanced voltage system. Nevertheless it can still be considered a helpful approach to the problem under study. The simulation results presented in this paper illustrate the weaknesses of the pq theory.

  2. Shunt hybrid active power filter under nonideal voltage based on fuzzy logic controller

    Science.gov (United States)

    Dey, Papan; Mekhilef, Saad

    2016-09-01

    In this paper, a synchronous reference frame (SRF) method based on a modified phase lock loop (PLL) circuit is developed for a three-phase four-wire shunt hybrid active power filter (APF). Its performance is analysed under unbalanced grid conditions. The dominant lower order harmonics as well as reactive power can be compensated by the passive elements, whereas the active part mitigates the remaining distortions and improves the power quality. As different control methods show contradictory performance, fuzzy logic controller is considered here for DC-link voltage regulation of the inverter. Extensive simulations of the proposed technique are carried out in a MATLAB-SIMULINK environment. A laboratory prototype has been built on dSPACE1104 platform to verify the feasibility of the suggested SHAPF controller. The simulation and experimental results validate the effectiveness of the proposed technique.

  3. Real-Time Control of Shunt Active Power Filter under Distorted Grid Voltage and Unbalanced Load Condition Using Self Tuning Filter

    OpenAIRE

    2014-01-01

    In this paper, an alternative control method is proposed to improve the harmonic suppression efficiency of the active power filter in a distorted and an unbalanced power system to compensate for the perturbations caused by the unbalanced non-linear loads. The proposed method uses a self-tuning filter (STF) to process the grid voltage in order to provide a uniform reference voltage to obtain the correct angular position of the phase locked loop. Moreover, the required compensation currents are...

  4. Current control for a shunt hybrid active power filter using recursive integral PI

    Institute of Scientific and Technical Information of China (English)

    Wei ZHAO; An LUO; Ke PENG; Xia DENG

    2009-01-01

    This paper presents a current control method for a shunt hybrid active power filter(HAPF) using recursive integral Pl algorithm.The method improves the performance of the HAPF system by reducing the influence of detection accuracy,time delay of instruction current calculation and phase displacement of output filter.Fuzzy logic based set-point weighing algorithm is combined in the control scheme to enhance its robustness and anti-interference ability.The proposed algorithm is easy to implement for engineering applications and easy to compute.Experiment results have verified the validity of the proposed controller.Furthermore,the proposed recursive integral PI algorithm can also be applied in the control of periodic current as in AC drivers.

  5. Evaluation of reference current extraction methods for DSP implementation in active power filters

    Energy Technology Data Exchange (ETDEWEB)

    Vardar, K.; Akpinar, E.; Suergevil, T. [Dokuz Eylul University, Department of Electrical and Electronics Engineering, Kaynaklar Kampusu, 35160 Buca, Izmir (Turkey)

    2009-10-15

    Generation of current references constitutes an important part in the control of active power filters (APFs) used in power system, since any inaccuracy in reference currents yields to incorrect compensation. In this paper, harmonic detection methods for generating reference currents have been evaluated on the basis of three-phase balanced and unbalanced load currents processed in the digital signal processor (DSP). The advantages and disadvantages of several methods found in the literature have been discussed on the basis of simulation results. Three of these methods have been programmed in the TMS320F2812 digital signal processor (DSP) unit and their performances are evaluated from the viewpoint of practical considerations. Finally, instantaneous reactive power method to estimate the APF reference currents is implemented and its practical results obtained under balanced and unbalanced loads are given. (author)

  6. Simulation Research on a SVPWM Control Algorithm for a Four-Leg Active Power Filter

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper the topology of a four-leg shunt active-power filter (APF) is given.The APF compensates harmonic and reactive power in a three-phase four-wire system.The scheme adopted for control of the four-leg active power filter, a 3-Dimensional Pulse Width Modulation (PWM) technique, is presented.The theoretical deduction of a space vector PWM (SVPWM) algorithm is given in this paper.The paper also analyzes the distribution of the voltage-space vector of the four-leg converter in αβγ coordinates and describes methods to determine the location of the voltage-space vector and to calculate duration time.Finally, the algorithm is implemented in simulation; the results show that the total harmonic distortion (THD) of the three phase-current waveforms is reduced.The neutral wire current, after compensation, is about 0 A showing that the topology of the four-leg shunt APF is feasible and the proposed scheme is effective.

  7. A DSP-based active power filter for low voltage distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Shireen, Wajiha [University of Houston, Houston, TX 77204-4020 (United States); Tao, Li [Schlumberger Inc., Houston, TX (United States)

    2008-09-15

    The use of nonlinear loads, which inject undesired harmonic currents into low voltage distribution systems, is increasing rapidly. Active power filters are being considered as a potential candidate for solving harmonic problems in order to meet harmonic standards and guidelines. A new digital signal processor (DSP)-based control method for a single-phase active power filter (APF) is presented in this paper. Compared to conventional analog-based methods, the DSP-based solution provides a flexible and cheaper method to control the APF. The proposed scheme employs a carrier-based control that requires less feedback information compared to other reported solutions. Only one current sensor is used to sense the nonlinear load current and two voltage sensors to sense the input supply voltage and the dc bus voltage. The proposed method provides both harmonic elimination and power factor correction. The PSpice simulation and experiments using the DSP-based prototype are made to verify the feasibility of the method. (author)

  8. A New Synchronous Reference Frame-Based Method for Single-Phase Shunt Active Power Filters

    DEFF Research Database (Denmark)

    Monfared, Mohammad; Golestan, Saeed; Guerrero, Josep M.

    2013-01-01

    This paper deals with the design of a novel method in the synchronous reference frame (SRF) to extract the reference compensating current for single-phase shunt active power filters (APFs). Unlike previous works in the SRF, the proposed method has an innovative feature that it does not need...... the fictitious current signal. Frequency-independent operation, accurate reference current extraction and relatively fast transient response are other key features of the presented strategy. The effectiveness of the proposed method is investigated by means of detailed mathematical analysis. The results confirm...

  9. A New Generalized Discontinuous-PWM Strategy for Active Power Filters

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Rodriguez, Pedro; Blaabjerg, Frede

    2007-01-01

    losses in any operating point. This paper proposes a new discontinuous pulse width modulation strategy applied to shunt active power filters. The proposed modulation strategy detects the current vector position relative to the inverter voltage reference and determines instantaneously the optimum clamped...... duration on each phase. It achieves a clamped voltage pattern, with variable lengths depending on the magnitude of the inverter current. This property adaptively reduces the current stress and minimizes the inverter switching losses, regardless of its application. The proposed modulation strategy...

  10. Active power filter for medium voltage networks with predictive current control

    Energy Technology Data Exchange (ETDEWEB)

    Verne, Santiago A.; Valla, Maria I. [Laboratorio de Electronica Industrial, Control e Instrumentacion (LEICI), Facultad de Ingenieria, Universidad Nacional de La Plata and CONICET, La Plata (Argentina)

    2010-12-15

    A transformer less Shunt Active Power Filter (SAPF) for medium voltage distribution networks based on Multilevel Diode Clamped Inverter is presented in this paper. Converter current control is based on a Model Predictive strategy, which gives very fast current response. Also, the algorithm includes voltage balancing capability which is essential for proper converter operation. The presented current control algorithm is naturally applicable to converters with an arbitrary number of levels with reduced computational effort by virtue of the incorporation of switching restrictions which are necessary for reliable converter operation. The performance of the proposed algorithm is evaluated by means of computer simulations. (author)

  11. Active power filter for harmonic compensation using a digital dual-mode-structure repetitive control approach

    DEFF Research Database (Denmark)

    Zou, Zhixiang; Wang, Zheng; Cheng, Ming;

    2012-01-01

    This paper presents an digital dual-mode-structure repetitive control approach for the single-phase shunt active power filter (APF), which aims to enhance the tracking ability and eliminate arbitrary order harmonic. The proposed repetitive control scheme blends the characteristics of both odd......-harmonic repetitive control and even-harmonic repetitive control. Moreover, the convergence rate is faster than conventional repetitive controller. Additionally, the parameters have been designed and optimized for the dual-mode structure repetitive control to improve the performance of APF system. Experimental...... results on a laboratory setup are given to verify the proposed control scheme....

  12. Control System Design of Shunt Active Power Filter Based on Active Disturbance Rejection and Repetitive Control Techniques

    OpenAIRE

    Le Ge; Xiaodong Yuan; Zhong Yang

    2014-01-01

    To rely on joint active disturbance rejection control (ADRC) and repetitive control (RC), in this paper, a compound control law for active power filter (APF) current control system is proposed. According to the theory of ADRC, the uncertainties in the model and from the circumstance outside are considered as the unknown disturbance to the system. The extended state observer can evaluate the unknown disturbance. Next, RC is introduced into current loop to improve the steady characteristics. Th...

  13. An Improved Double Fuzzy PI Controller For Shunt Active Power Filter DC Bus Regulation

    Directory of Open Access Journals (Sweden)

    Nabil ELHAJ

    2015-06-01

    Full Text Available This paper targets to demonstrate the importance of the choice of the algorithm references detection to be applied with a double fuzzy PI corrector (DFPI for the control and the regulation of a shunt active power filter (SAPF DC bus voltage. In a previous work, the synchronous reference frame (SRF algorithm was applied and gave satisfactory results. In the present paper, the SRF is substituted by the positive sequence of the fundamental of the source voltage algorithm (PSF which offered better results regarding the power quality of the considered main utility feeding a variable DC RL load throughout a diode bridge. The results were carried out using computer simulation perfomed under MATLAB/Simulink environment. To make the obtained results more convenient, a comparison between the couples (SRF, PI, (PSF, PI, (SRF, DFPI, (PSF, DFPI is added to prove the effectiveness of the couple (PSF, DFPI in satisfying the compromise between a good regulation of the SAPF DC bus voltage and a good quality of filtering resulting in an improved quality of power.

  14. Hysteresis Current Control Based Shunt Active Power Filter for Six Pulse Ac/Dc Converter

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Pandey

    2017-02-01

    Full Text Available In this paper the simulation of Shunt Active power Filter using P-Q theory and PI controller has been presented. This SAPF compensates the harmonic currents drawn by three phase six pulse AC/DC converter. The process of compensation is done by calculating the instantaneous reactive power losses using p-q theory and the PI controller to reduce the ripple voltage of the dc capacitor of the PWM-VSI. This approach is different from conventional approach and provides very effective solution. In this simulation we use hysteresis band current controller (HCC for switching the VSI inverter. The simulation has been done for both steady state and transient conditions

  15. A Modular Cascaded Multilevel Inverter Based Shunt Hybrid Active Power Filter for Selective Harmonic and Reactive Power Compensation Under Distorted/Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    T. Demirdelen

    2016-10-01

    Full Text Available In recent years, shunt hybrid active power filters are being increasingly considered as a viable alternative to both passive filters and active power filters for compensating harmonics. In literature, their applications are restricted to balanced systems and low voltage applications and therefore not for industrial applications. This paper investigates the performance of a modular cascaded multilevel inverter based Shunt Hybrid Active Power Filter (SHAPF for reactive power compensation and selective harmonics elimination under distorted/unbalanced grid voltage conditions in medium voltage levels. In the proposed control method, reactive power compensation is achieved successfully with a perceptible amount and the performance results of harmonic compensation are satisfactory. Theoretical analysis and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for a proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

  16. Real time control of an active power filter under distorted voltage condition

    Directory of Open Access Journals (Sweden)

    Ahmed Safa

    2012-10-01

    Full Text Available

    This paper, presents three phase shunt active filter under distorted voltage condition, the active power filter control is based on the use of self-tuning filter (STF for reference current generation and on space vector PWM for generation of pulses. The dc capacitor voltage is controlled by a classical PI controller.  The diode rectifier feed RL load is taken as a nonlinear load. The self-tuning filter allows extracting directly the voltage and current fundamental components in the axis without phase locked loop (PLL under distorted voltage condition. The experiment analysis is made based on working under distorted voltage condition, and the total harmonic distortion of source current after compensation .Self tuning filter based extraction technique is good under distorted voltage conditions. The total harmonic distortion (THD of source current is fully reduced. The effectiveness of the method is theoretically studied and verified by experimentation.

  17. Permanent Magnet Synchronous Generator Driven Wind Energy Conversion System Based on Parallel Active Power Filter

    Directory of Open Access Journals (Sweden)

    FERDI Brahim

    2014-05-01

    Full Text Available This paper proposes a novel application of the instantaneous P-Q theory in a wind energy conversion system (WECS. The proposed WECS is formed by permanent magnet synchronous generator (PMSG wind turbine system connected to the grid through parallel active power filter (PAPF. PAPF uses the generated wind energy to feed loads connected at the point of common coupling (PPC, compensates current harmonics and injects the excess of this energy into the grid using P-Q theory as control method. To demonstrate the feasibility and the performance of the proposed control scheme, simulation of this wind system has been realized using MATLAB/SIMULINK software. Simulation results show the accuracy and validity of the proposed control scheme for the PMSGPAPF system.

  18. DSP Control of Line Hybrid Active Filter

    DEFF Research Database (Denmark)

    Dan, Stan George; Benjamin, Doniga Daniel; Magureanu, R.;

    2005-01-01

    Active Power Filters have been intensively explored in the past decade. Hybrid active filters inherit the efficiency of passive filters and the improved performance of active filters, and thus constitute a viable improved approach for harmonic compensation. In this paper a parallel hybrid filter ...

  19. Cooperative Control of Active Power Filters in Power Systems without Mutual Communication

    Directory of Open Access Journals (Sweden)

    Josef Tlustý

    2010-01-01

    Full Text Available The procedure for calculating controller parameters of the APFs implemented into a multibus industrial power system for harmonic voltage mitigation is presented. The node-voltage-detection control strategy is applied and the basic controller parameters are found under the condition that the demanded THD factors at the buses where the APFs are placed will be obtained. A cooperative control of several APFs without mutual communication is proposed, simulated, and experimentally verified. By tuning the controller gains without considering the power circuit parameters, all APFs used tend to share harmonic load currents approximately equally regardless of the operation modes of the nonlinear loads in different parts of the power system.

  1. Real-time modelling and simulation of an active power filter

    Energy Technology Data Exchange (ETDEWEB)

    Beaulieu, S.; Ouhrouche, M. [Quebec Univ., Chicoutimi, PQ (Canada); Dufour, C.; Allaire, P.F. [Opal RT Technologies Inc., Montreal, PQ (Canada)

    2007-07-01

    Power electronics converters generate harmonics and cause electromagnetic compatibility problems. Active power filter (APF) technology has advanced to the point that it can compensate for harmonics in electrical networks and provide reactive power and neutral current in AC networks. This paper presented a contribution in the design of a shunt APF for harmonics compensation in real-time simulation using the RT-LAB software package running on a simple personal computer. Real-time simulations were performed to validate the effectiveness of the proposed model. Several high-tech industries have adopted this tool for rapid control prototyping and for Hardware-in-the-Loop applications. The switching signals of the APF are determined by the hysteresis band current controller. The suitable current reference signals were determined by the algorithm based on synchronous reference frame. Real-time simulation runs showed good performance in harmonics compensation, thus satisfying the requirements of IEEE Standard 519-1992. The rate of total harmonic distortion for the source current decreased from 30 to 5 per cent. 12 refs., 1 tab., 9 figs.

  2. Analysis and Sliding Mode Control of Four-Wire Three-Leg Shunt Active Power Filter

    OpenAIRE

    Farid Hamoudi; Hocine Amimeur

    2015-01-01

    In this paper, the analysis and the sliding mode control application for a shunt active filter is presented. The active filter is based on a three-leg split-capacitor voltage source inverter which is used to compensate harmonics and unbalance in the phase currents, and therefore to cancel neutral current. The proposed sliding mode control is formulated from the multivariable state model established in dq0 frames. The selection of the sliding mode functions takes in account simultaneously, the...

  3. New controllability criteria for 3-phase 4-wire inverters applied to shunt active power filters

    OpenAIRE

    Perales Esteve, Manuel Ángel; Sánchez Segura, Juan Antonio; Torre, A. (Alberto) de la; Carrasco Solís, Juan Manuel; García Franquelo, Leopoldo; Terrón, L.

    2002-01-01

    In shunt active filter applications, the 3-phase 4-wire topology is frequently used when dealing with unbalanced loads containing zero sequence components. A new design criteria for this topology is presented, based on the well-known existing method for the 3-phase 3-wire system. Simulation and experimental results confirms the validity of this new criteria, providing an easy method for the design of the reactive elements involved in a shunt active filter.

  4. Application of Backstepping to the Virtual Flux Direct Power Control of Five-Level Three-Phase Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Bouzidi Mansour

    2014-03-01

    Full Text Available This paper proposes a virtual flux direct power control-space vector modulation combined with backstepping control for three-phase five-level neutral point clamped shunt active power filter. The main goal of the proposed active filtering system is to eliminate the unwanted harmonics and compensate fundamental reactive power drawn from the nonlinear loads. In this study, the voltage-balancing control of four split dc capacitors of the five-level active filter is achieved using five-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. The obtained results showed that, the proposed multilevel shunt active power filter with backstepping control can produce a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

  5. A novel modular approach to active power-line harmonic filtering in distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    El Shatshat, R.A.

    2001-07-01

    An efficient and reliable modular active harmonic filter system was developed as a cost-effective solution to the problem of harmonics. The newly developed filter system include several CSC modules that are each dedicated to filter a specific harmonic. Overall switching losses are minimized because selective harmonics is eliminated. Two ADALINEs are proposed for the filter controller. One extracts the fundamental and harmonic components of the distorted current, and the other estimates the line voltage. The main features of the new filter system are high speed, accuracy of ADALINE, self synchronizing harmonic tracking, intelligence and robustness of the controller, optimum dc value, and minimal converter losses. Simulation results were also presented to demonstrate the effectiveness of the system.

  6. 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.

  7. Shunt Active Filter in Damping Harmonics Propagation

    Directory of Open Access Journals (Sweden)

    BERBAOUI, B.

    2010-08-01

    Full Text Available This paper deals with a hybrid shunt active power filter applied on 500 kV HVDC, after a description of the causes and effects harmonic pollution which may damage equipments and interrupt electric power customers service; in this paper we present the deferent solutions of this problem among one has to study the two most recent types of filtering: passive and hybrid filter. The hybrid filter consists of active filter connected in shunt with passive filter. The hybrid shunt active filter proposed is based on three levels PWM inverter and characterized by detecting the harmonic current flowing into the passive filter and controlled by notch algorithm. This structure has been applied on a test HVDC power system, is presented as a technical solution makes it possible to eliminate the disadvantages from passive filtering, and also economic price of active filtering part. The simulation results justified the effectiveness of this type of filter face of the classic passive filter.

  8. Control System Design of Shunt Active Power Filter Based on Active Disturbance Rejection and Repetitive Control Techniques

    Directory of Open Access Journals (Sweden)

    Le Ge

    2014-01-01

    Full Text Available To rely on joint active disturbance rejection control (ADRC and repetitive control (RC, in this paper, a compound control law for active power filter (APF current control system is proposed. According to the theory of ADRC, the uncertainties in the model and from the circumstance outside are considered as the unknown disturbance to the system. The extended state observer can evaluate the unknown disturbance. Next, RC is introduced into current loop to improve the steady characteristics. The ADRC is used to get a good dynamic performance, and RC is used to get a good static performance. A good simulation result is got through choosing and changing the parameters, and the feasibility, adaptability, and robustness of the control are testified by this result.

  9. 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.

  10. A Lyapunov Stability Theory-Based Control Strategy for Three-Level Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Yijia Cao

    2017-01-01

    Full Text Available The three-phase three-wire neutral-point-clamped shunt active power filter (NPC-SAPF, which most adopts classical closed-loop feedback control methods such as proportional-integral (PI, proportional-resonant (PR and repetitive control, can only output 1st–25th harmonic currents with 10–20 kHz switching frequency. The reason for this is that the controller design must make a compromise between system stability and harmonic current compensation ability under the condition of less than 20 kHz switching frequency. To broaden the bandwidth of the compensation current, a Lyapunov stability theory-based control strategy is presented in this paper for NPC-SAPF. The proposed control law is obtained by constructing the switching function on the basis of the mathematical model and the Lyapunov candidate function, which can avoid introducing closed-loop feedback control and keep the system globally asymptotically stable. By means of the proposed method, the NPC-SAPF has compensation ability for the 1st–50th harmonic currents, the total harmonic distortion (THD and each harmonic content of grid currents satisfy the requirements of IEEE Standard 519-2014. In order to verify the superiority of the proposed control strategy, stability conditions of the proposed strategy and the representative PR controllers are compared. The simulation results in MATLAB/Simulink (MathWorks, Natick, MA, USA and the experimental results obtained on a 6.6 kVA NPC-SAPF laboratory prototype validate the proposed control strategy.

  11. Control of current inverters in decentral power systems as active filters; Regelung von Netzstromrichtern in dezentralen Energiesystemen als aktive Filter

    Energy Technology Data Exchange (ETDEWEB)

    Merfert, Igor; Lindemann, Andreas [Magdeburg Univ. (Germany). Lehrstuhl fuer Leistungselektronik

    2007-07-01

    Besides their main task, decentralized power generators can combine electric power generation with system services if the inverter has current capability to spare. This paper deals with the system services, power quality improvement and a reactive power compensation, in a fuel cell based decentralized electrical power generator. A control strategy and a practical realization are introduced. (orig.)

  12. Efficiency Considerations and Application Limits of Single-Phase Active Power Filter with Converters for Photoenergy Applications

    Directory of Open Access Journals (Sweden)

    Saša Sladić

    2011-01-01

    Full Text Available A new way of connecting PV sources to adaptive voltage active power filter (AV APF has been compared with classic approach including active power filter (APF. In standard active power filter applications a relatively high DC link voltage (500 V or even more with a buck converter or lower voltage (approx. 100 V with boost converter can be used. These two converters appear also in adaptive voltage circuit of AV APF, but in this case it is possible to achieve many different connections of DC source. Benefit of this approach is that the same circuit is used for improving switching conditions in APF and for connection of solar cells. It appears that these two functions support each other and a large variety of DC voltages and currents can be connected to AC mains. Experimental results confirm expectations of increased energy transfer from additional DC source to network, especially for DC voltages being lower than DC link voltage.

  13. An Efficient Space Vector Pulse Width Modulation with BFO Based Self Tuning PI Controller for Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    P. Saravanan

    2014-05-01

    Full Text Available This research study mainly focuses on using an efficient control strategy for extracting reference currents of shunt active filters under non linear load conditions. In recent decades, the utilization of highly automatic electric equipments has resulted in enormous economic loss. Thus, the power suppliers as well as the power consumers are very much concerned about the power quality issues and compensation approaches. In order to deal with this issue, Active Power Filter (APF has been considered as an attractive solution due to its significant harmonic compensation. But, the performance of APF is not consistent and is varies based on the output of the controller techniques. An efficient (id-id control strategy is used in this approach for attaining utmost profit from grid-interfacing inverters installed in transmission systems. The voltages are controlled through the PI controller which is further tuned by an optimization approach. Bacterial Forge Optimization (BFO is used in this approach for tuning the PI controller for the optimal value. The inverter used in this approach can be considered as a Shunt Active Power Filter (SAPF to compensate non linear load current harmonics. In order to improve the overall performance of the system, Space Vector Pulse Width Modulation (SVPWM is used in this proposed approach which regulates power frequency and produces good circularity through DC-AC part. SVPWM also eliminates the 3rd order harmonics and minimizes the 5th order harmonics effectively. The integration of (id-id control strategy and SVPWM has been proposed in this research study. Simulation results are carried out in MATLAB/Simulink and the performance of the proposed approach is compared with other control strategies. This research studies shows unique approach for attaining maximum benefits from RES with suppression of current harmonics.

  14. Capacity Calculation of Shunt Active Power Filters for Electric Vehicle Charging Stations Based on Harmonic Parameter Estimation and Analytical Modeling

    Directory of Open Access Journals (Sweden)

    Niancheng Zhou

    2014-08-01

    Full Text Available The influence of electric vehicle charging stations on power grid harmonics is becoming increasingly significant as their presence continues to grow. This paper studies the operational principles of the charging current in the continuous and discontinuous modes for a three-phase uncontrolled rectification charger with a passive power factor correction link, which is affected by the charging power. A parameter estimation method is proposed for the equivalent circuit of the charger by using the measured characteristic AC (Alternating Current voltage and current data combined with the charging circuit constraints in the conduction process, and this method is verified using an experimental platform. The sensitivity of the current harmonics to the changes in the parameters is analyzed. An analytical harmonic model of the charging station is created by separating the chargers into groups by type. Then, the harmonic current amplification caused by the shunt active power filter is researched, and the analytical formula for the overload factor is derived to further correct the capacity of the shunt active power filter. Finally, this method is validated through a field test of a charging station.

  15. A new compensation current real-time computing method for power active filter based on double linear construction algorithm

    Institute of Scientific and Technical Information of China (English)

    LI; Zicheng; SUN; Yukun

    2006-01-01

    Considering the detection principle that "when load current is periodic current, the integral in a cycle for absolute value of load current subtracting fundamental active current is the least", harmonic current real-time detection methods for power active filter are proposed based on direct computation, simple iterative algorithm and optimal iterative algorithm. According to the direct computation method, the amplitude of the fundamental active current can be accurately calculated when load current is placed in stable state. The simple iterative algorithm and the optimal iterative algorithm provide an idea about judging the state of load current. On the basis of the direct computation method, the simple iterative algorithm, the optimal iterative algorithm and precise definition of the basic concepts such as the true amplitude of the fundamental active current when load current is placed in varying state, etc., the double linear construction idea is proposed in which the amplitude of the fundamental active current at the moment of the sample is accurately calculated by using the first linear construction and the condition which disposes the next sample is created by using the second linear construction. On the basis of the double linear construction idea, a harmonic current real-time detection method for power active filter is proposed based on the double linear construction algorithm. This method has the characteristics of small computing quantity, fine real-time performance, being capable of accurately calculating the amplitude of the fundamental active current and so on.

  16. Design and Analysis of Sliding Mode Controller and Simplified Space Vector Modulation for Three Phase Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    S. Elangovan

    2014-07-01

    Full Text Available The main aim of this study is to control a multivariable coupled system by choosing sliding mode switching function. A Sliding mode control approach is developed to control a three phase three wire voltage source inverter operating as a shunt active power filter. Hence, no need to divide the system model developed in the synchronous ‘dq’ reference frame into two separate loops. Furthermore, the proposed control strategy allows a better stability and robustness over a wide range of operation. When sine PWM is used for generation of pulses for the switches, a variable switching nature is exhibited. The pulses for the active filter are fed by a Space Vector Modulation in order to have a constant switching of converter switches. But, the conventional space vector modulation, if implemented practically, needs a complicated algorithm which uses the trigonometric functions such as arctan, Sine and Cosine functions which in turn needs look up tables to store the pre-calculated trigonometric values. In this study, a very simplified algorithm is proposed for generating Space vector modulated pulse for all six switches without the use of look up tables and only by sensing the voltages and currents of the voltage source inverter acting as shunt active filter. The simulation using PSIM and MATLAB software verifies the results very well.

  17. Dynamic Harmonic and Reactive Power Compensation with an Adaptive Shunt Active Filter for Variable Speed Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    Sindhu M R

    2014-12-01

    Full Text Available Variable speed drives are mostly preferred in industries, while considering energy saving, smooth control, flexible operation and fast response. On the other hand, this equipment generates dynamic harmonic distortions in source currents and draws variable reactive power demand depending on variation in load condition. These distortions propagate throughout the system and affect all the loads connected to the point of common coupling. Hence a dynamic harmonic and reactive compensator is necessary to enhance power quality to meet current and voltage distortion limits at point of common coupling as per IEEE standard. The most common choice for adjustable speed drives in industries is three phase voltage source inverter based induction motor drives which uses PWM technique for voltage, frequency and current control. This paper presents harmonic analysis of an induction motor drive in an industrial plant and development of adaptive dynamic harmonic and reactive compensator to improve power quality. A digital controller which is programmed with adaptive Artificial Neural Network (ANN based control algorithm is used for controlling shunt active filter. The simulation and experimental results show that the adaptive shunt active filter provides effective harmonic and reactive compensation in the system under steady state and dynamic load conditions.

  18. On power consumption issues in FIR filters with application to communication receivers: complexity, word length, and switching activity

    Energy Technology Data Exchange (ETDEWEB)

    Havashki, Asghar

    2009-10-15

    channel estimation must be upheld, in particular at medium-to-high Channel Signal to Noise Ratios (CSNR). Furthermore, reducing the power consumption through word-length optimization, when realizing such estimators, is an attractive approach. Due to the characteristics of the input signal to such estimators, a special treatment of channel estimation error due to quantization of estimator filter coefficients is needed. In this thesis we investigate the impact of finite coefficient word length on channel estimator performance. A theoretical analysis of the increase in channel estimation error due to quantization of estimator coefficients is performed, and the behavior of this error in different fading environments and for different filter orders is studied. The power consumed in a channel estimator is also influenced by the switching activity in the input signal of the estimator. Characterizing the switching activity in the input signal, including how this activity changes in different environments, e.g., in the presence of noise, is a subject of the work performed in this thesis. In this study we give an expression for direct calculation of the correlation coefficient for the most significant bit in a signal, using the word-level correlation coefficient. We also derive expressions for accurately calculating the variance and word-level correlation coefficient for a correlated signal, when an additional noise of a given variance is added to the signal. This can be used to estimate the bit-level switching activity in a signal in the presence of noise, based on the Dual Bit Type (DBT) method. The impact the additional noise has on the switching activity of a correlated signal has also been studied. These results make it possible for a designer to model the actual input switching activity in different real life noisy environments, enabling realistic power consumption estimation. A study on switching activity reduction in estimator filters using a coefficient reordering method

  19. Evaluation of a Trapezoidal Predictive Controller for a Four-Wire Active Power Filter for Utility Equipment of Metro Railway, Power-Land Substations

    Directory of Open Access Journals (Sweden)

    Sergio Salas-Duarte

    2016-01-01

    Full Text Available The realization of an improved predictive current controller based on a trapezoidal model is described, and the impact of this technique is assessed on the performance of a 2 kW, 21.6 kHz, four-wire, Active Power Filter for utility equipment of Metro Railway, Power-Land Substations. The operation of the trapezoidal predictive current controller is contrasted with that of a typical predictive control technique, based on a single Euler approximation, which has demonstrated generation of high-quality line currents, each using a 400 V DC link to improve the power quality of an unbalanced nonlinear load of Metro Railway. The results show that the supply current waveforms become virtually sinusoidal waves, reducing the current ripple by 50% and improving its power factor from 0.8 to 0.989 when the active filter is operated with a 1.6 kW load. The principle of operation of the trapezoidal predictive controller is analysed together with a description of its practical development, showing experimental results obtained with a 2 kW prototype.

  20. Doubly Fed Induction Generator Based Wind Turbine Associated to a Shunt Active Power Filter for Current Harmonics Mitigation

    Directory of Open Access Journals (Sweden)

    Samira Dib,

    2011-04-01

    Full Text Available Integration of wind turbine based on doubly fed induction generator (DFIG into the electrical grid has become an important part of electrical generation in many countries and its importance is continuing to increase. The advantages of using a DFIG instead of other generators are already well known. A few of them are variousspeed generations, the decoupled control of active and reactive power and high power capacity. However, the ever-growing proliferation of power electronics based devices for source conditioning and motion control in modern industrial applications has increased the occurrence of harmonic currents in distribution systems. This harmonics have harmful and costly effects on DFIG such as, the increase of stator and rotor core losses and the increase of the operating temperature. In this paper, a shunt active power filter (SAPF is proposed to mitigate current harmonics generated by nonlinear loads and keeps the current at the point of common coupling (PCC sinusoidal. The simulation results using MATLAB/SIMULINK show a good performance of the SAPF for current harmonics mitigation.

  1. Second Order Generalized Integrator Based Reference Current Generation Method for Single-Phase Shunt Active Power Filters Under Adverse Grid Conditions

    DEFF Research Database (Denmark)

    Golestan, Saeed; Monfared, Mohammad; Guerrero, Josep M.

    2013-01-01

    The reference current generation (RCG) is a crucial part in the control of a shunt active power filter (APF). A variety of RCG techniques have been proposed in literature. Among these, the instantaneous reactive power theory, called pq theory, is probably the most widely used technique. The pq th...

  2. High Performance Current Controller for Selective Harmonic Compensation in Active Power Filters

    DEFF Research Database (Denmark)

    Lascu, Cristian; Asiminoaei, Lucian; Boldea, I.;

    2007-01-01

    computational effort. The proposed controller design is based on the pole-zero cancellation technique, taking into account the load transfer function at each harmonic frequency. Two design methods are provided, which give controller transfer functions with superior frequency response. The complete current...... controller is realized as the superposition of all individual harmonic controllers. The frequency response of the entire closed loop control is optimal with respect to filtering objectives, i.e., the system provides good overall stability and excellent selectivity for interesting harmonics. This conclusion...

  3. A Refined Self-Tuning Filter-Based Instantaneous Power Theory Algorithm for Indirect Current Controlled Three-Level Inverter-Based Shunt Active Power Filters under Non-sinusoidal Source Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Yap Hoon

    2017-02-01

    Full Text Available In this paper, a refined reference current generation algorithm based on instantaneous power (pq theory is proposed, for operation of an indirect current controlled (ICC three-level neutral-point diode clamped (NPC inverter-based shunt active power filter (SAPF under non-sinusoidal source voltage conditions. SAPF is recognized as one of the most effective solutions to current harmonics due to its flexibility in dealing with various power system conditions. As for its controller, pq theory has widely been applied to generate the desired reference current due to its simple implementation features. However, the conventional dependency on self-tuning filter (STF in generating reference current has significantly limited mitigation performance of SAPF. Besides, the conventional STF-based pq theory algorithm is still considered to possess needless features which increase computational complexity. Furthermore, the conventional algorithm is mostly designed to suit operation of direct current controlled (DCC SAPF which is incapable of handling switching ripples problems, thereby leading to inefficient mitigation performance. Therefore, three main improvements are performed which include replacement of STF with mathematical-based fundamental real power identifier, removal of redundant features, and generation of sinusoidal reference current. To validate effectiveness and feasibility of the proposed algorithm, simulation work in MATLAB-Simulink and laboratory test utilizing a TMS320F28335 digital signal processor (DSP are performed. Both simulation and experimental findings demonstrate superiority of the proposed algorithm over the conventional algorithm.

  4. An overview on hybrid active filters

    Energy Technology Data Exchange (ETDEWEB)

    Libano, Fausto B.; Uceda, Javier [Universidad Politecnica de Madrid (Spain). Division de Ingenieria Electronica; Simonetti, Domingos S.L. [Espirito Santo Univ., Vitoria, ES (Brazil). Dept. de Engenharia Eletrica

    1995-12-31

    This paper summarizes the main hybrid filter methods. A special attention is given to series active filter associations. Nowadays, an hybrid filtering is the preferred choice to improve line performance when feeding high-power non-linear loads. In addition, the use of an independent reference frame leads to a better response comparing to the initial proposition of p-q theory. A comparison of possible filter associations is given, presenting the expected function of each one. The work represents an interesting overview on the state-of-the-art of hybrid filters. (author) 16 refs., 8 figs., 2 tabs.

  5. Active imaging system with Faraday filter

    Science.gov (United States)

    Snyder, James J.

    1993-01-01

    An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

  6. Adaptive Hybrid Fuzzy-Proportional Plus Crisp-Integral Current Control Algorithm for Shunt Active Power Filter Operation

    Directory of Open Access Journals (Sweden)

    Nor Farahaida Abdul Rahman

    2016-09-01

    Full Text Available An adaptive hybrid fuzzy-proportional plus crisp-integral current control algorithm (CCA for regulating supply current and enhancing the operation of a shunt active power filter (SAPF is presented. It introduces a unique integration of fuzzy-proportional (Fuzzy-P and crisp-integral (Crisp-I current controllers. The Fuzzy-P current controller is developed to perform gain tuning procedure and proportional control action. This controller inherits the simplest configuration; it is constructed using a single-input single-output fuzzy rule configuration. Thus, an execution of few fuzzy rules is sufficient for the controller’s operation. Furthermore, the fuzzy rule is developed using the relationship of currents only. Hence, it simplifies the controller development. Meanwhile, the Crisp-I current controller is developed to perform integral control action using a controllable gain value; to improve the steady-state control mechanism. The gain value is modified and controlled using the Fuzzy-P current controller’s output variable. Therefore, the gain value will continuously be adjusted at every sample period (or throughout the SAPF operation. The effectiveness of the proposed CCA in regulating supply current is validated in both simulation and experimental work. All results have proven that the SAPF using the proposed CCA is capable to regulate supply current during steady-state and dynamic-state operations. At the same time, the SAPF is able to enhance its operation in compensating harmonic currents and reactive power. Furthermore, the implementation of the proposed CCA has resulted more stable dc-link voltage waveform.

  7. Control of a three-phase four-wire shunt-active power filter based on DC-bus energy regulation

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Teodorescu, Remus; Rodriguez, Pedro;

    2008-01-01

    stored in the DC bus and active power requirements on the APF. Harmonics and imbalances both on the utility voltage and load current have been considered and the power developed by the active power filter has been evaluated. This study allows designing a controller for the APF based on the regulation...... of the energy-state of its DC-bus. The method has been experimentally tested on a four leg APF based on a neutral-point-clamped DC bus. Such topology allowed the test of the most general case, including harmonics and imbalance in utility voltage and in load currents....

  8. 链式广义有源电力滤波器%Cascaded generalized active power filter

    Institute of Scientific and Technical Information of China (English)

    薛畅; 王建赜; 纪延超; 江滨浩

    2013-01-01

    为克服传统GAPF(generalized active power filter)实时性差、电压等级低、功耗大、只适合在低压小容量范围内应用等缺点,提出一种采用链式拓扑结构的GAPF,提高了装置的等效开关频率、电压等级、实时性和动态性能.详述了链式GAPF的拓扑结构、工作原理、控制方法及调制策略,建立了被控对象的小信号模型,给出了PI参数的整定原则和相间与相内电容电压的平衡方法.仿真与实验结果表明链式GAPF在实现综合补偿的基础上可有效降低输出电压的谐波含量和网侧滤波电抗的容量与功耗,适合在高压大功率领域中应用.%In order to overcome the shortcomings of traditional GAPF which has poor real - time perform ance , low voltage rate, high power consumption and only being suitable in low voltage and small capacity situations, a GAPF based on cascaded multilevel inverter is proposed which has higher equivalent switc hing frequency and voltage rating, better real-time and dynamic performance. Its topology, operating principle, control method and modulation strategy were discussed in detail. The small signal model of the controlled object was established. The setting principles of proportion integration (PI) parameters and the phase and individual balancing methods of capacitor voltages were presented. Simulation and experimen tal results show that cascaded GAPF can effectively reduce the harmonic content of output voltage and the capacity and power consumption of system side reactance while realizing comprehensive compensation, and is suitable in high voltage and power scope of application.

  9. 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%.

  10. Design of a Four-Branch LCL-Type Grid-Connecting Interface for a Three-Phase, Four-Leg Active Power Filter

    Directory of Open Access Journals (Sweden)

    Wu Cao

    2015-02-01

    Full Text Available Compared with the three-phase, two-split-capacitor active power filter (3P2C-APF, the three-phase, four-leg active power filter (3P4L-APF has been widely used in three-phase, four-wire grid utility for power quality control due to its numerous advantages, such as higher current output capability, particularly in phase N, lower current and easier voltage control on the DC-side. However, designing the grid-connecting interface, which is between the voltage source converter (VSC and grid utility, is rather difficult due to the higher requirement for current ripple filtering in phase N, cross-coupling in four phases and lack of relevant design methodology and specification. In this paper, a four-branch LCL-type (4B-LCL grid-connecting interface is proposed for 3P4L-APF, which features better current ripple filtering performance without decreasing the current output capability in all phases. First, this paper describes the mathematical models of 4B-LCL in the fully-complex-vector form from the zero and non-zero sequence perspective, resulting in two independent and uniform equivalent circuits without cross coupling terms. Then, the 4B-LCL parameter design method based on the most comprehensive performance index is proposed, including three main stages as the specification: performance index requirement determination, fulfillment of that requirement, and verification. Finally, the validity and effectiveness of the proposed design are proven by the simulated and experimental results of a 3P4L-APF with 4B-LCL.

  11. Research on hybrid power filter of 6 kV power grid in coal mine

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-feng; LI Jian

    2010-01-01

    Studied the harmonic control of the 6 kV power grid in a coal mine substation.Taking harmonic suppression and reactive power compensation into account, and complying with the economic and efficient technical line of the smart grid, a new hybrid active filter was proposed and applied to the power grid in the coal mine with the advantages such as large capacity, low cost and low loss. In order to improve detection speed and reduce the succeeding errors to improve the filtering performance of the active power filter,the DFT (Discrete Fourier Transform) sliding window algorithm based on coordinate transformation and improved hysteresis control method was proposed. The Matlab simulation results show that the hybrid active filter is satisfactory, can improve the grid power factor and can meet the requirements of improving the power quality in the coal mine.

  12. Active harmonic filtering using current-controlled, grid-connected DG units with closed-loop power control

    DEFF Research Database (Denmark)

    He, Jinwei; Li, Yun Wei; Blaabjerg, Frede;

    2014-01-01

    The increasing application of nonlinear loads may cause distribution system power quality issues. In order to utilize distributed generation (DG) unit interfacing converters to actively compensate harmonics, this paper proposes an enhanced current control approach, which seamlessly integrates...... system harmonic mitigation capabilities with the primary DG power generation function. As the proposed current controller has two well-decoupled control branches to independently control fundamental and harmonic DG currents, local nonlinear load harmonic current detection and distribution system harmonic...... voltage detection are not necessary for the proposed harmonic compensation method. Moreover, a closed-loop power control scheme is employed to directly derive the fundamental current reference without using any phase-locked loops (PLL). The proposed power control scheme effectively eliminates the impacts...

  13. A New Starting Method of the Hybrid Power Filter for Wind Power Generation Systems with Soft Starter

    Science.gov (United States)

    Yamada, Hiroaki; Hiraki, Eiji; Tanaka, Toshihiko

    This paper proposes a new method of starting the hybrid power filter for wind power generation systems with soft starter. In the proposed method, an active filter of the hybrid power filter behaves a resistor for the source current under the starting condition. Thus the inrush phenomena of the passive filter are perfectly suppressed. The basic principle of the proposed starting method is discussed, and then confirmed by digital computer simulation using PSCAD/EMTDC. Simulation results demonstrate that the proposed starting method can overcome the inrush currents for the passive filter, building up the dc voltage of the active filter.

  14. EMI filter techniques in power electronic converters

    Directory of Open Access Journals (Sweden)

    Fredy Edimer Hoyos Velasco

    2012-04-01

    Full Text Available This paper presents the results of EMI reduction techniques applied to power electronic converters. The techniques applied included shielding control and power signals, separating power system references regarding reference for instrumentation and measurement signals, implementing analog filters and configuring an appropriate switch trigger system for electronic power to decrease shifting EMI emissions to the maximum. This paper presents the results before and after applying the techniques to reduce interference. The results were also veryfied by using two real time control strategies rapid control prototyping (RCP.

  15. 有源电力滤波器在某数据中心的应用%Application of Active Power Filter to Data Center

    Institute of Scientific and Technical Information of China (English)

    刘小芳

    2012-01-01

    Burning out of capacitance compensation cabinet and trip failure of main breaker of low -voltage cabinet have happened for several times in the substation of a data center which has been put into operation. According to the field investigation, it is believed that the electric failures may be caused from excessive UPS configuration for the terminal computer, and harmonic pollution caused from using of a large number of LED lights. Effect of application of active power filter to the data center is introduced on the basis of field measurement of the harmonic data before and after setting of active power filter.%某已投入运行的数据中心变电所多次发生电容补偿柜烧坏及低压柜主断路器跳闸故障,作者现场考察认为故障可能是末端计算机所带UPS过多,以及大量使用LED灯导致的谐波污染而引起的电气故障。通过实测设置有源电力滤波器前后的谐波数据,说明有源电力滤波器在数据中心的应用效果。

  16. Ultra Low-Power Analog Median Filters

    Directory of Open Access Journals (Sweden)

    A. Diaz-Sanchez

    2013-09-01

    Full Text Available The design and implementation of three analog median filter topologies, whose transistors operate in the deep weak-inversion region, is described. The first topology is a differential pairs array, in which drain currents are driven into two nodes in a differential fashion, while the second topology is based on a wide range OTA, which is used to maximize the dynamic range. Finally, the third topology uses three range-extended OTAs. The proposed weak-inversion filters were designed and fabricated in ON Semiconductor 0.5 micrometer technology through MOSIS. Experimental results of three-input fabricated prototypes for all three topologies are show, where power consumptions of 90nW in the first case, and 270nW in the other two cases can be noticed. A dual power supply +/-1.5 Volts were used.

  17. 智能化数字有源电力滤波器的设计与实现%Design and Implementation of Intelligent Digital Active Power Filter

    Institute of Scientific and Technical Information of China (English)

    胡丽丽; 吴旭光; 董卫民

    2011-01-01

    为减少目前电力系统中的谐波与无功功率污染问题,提高电能的有效利用率,设计了一种能够去消谐波次数达31次和补偿无功功率的并联型智能化数字有源电力滤波器.简述了本系统的滤波原理和所要实现的功能,阐明了与液晶显示相结合的硬件和软件设计及多处理器之间的通信协议规范;原理样机的试验结果表明本设计能够达到所要求的技术指标.另外,软硬件设计为以后的二次开发预留了良好的接口.%To reduce the harmonics and reactive power pollution and improve the effective utilization of energy, an intelligent digital shunt active power filter is designed, which can eliminate harmonic up to 31 times and reduce the reactive power. Test results show that the principles of this system and the filtering functions are implemented. The design of the hardware and software with the liquid crystal display and the communication protocol in the multi-processor are described. Develop prototype test results show that the system meets the requirment of technical specifications. In addition, the hardware and software design provide a good condition for the future secondary development.

  18. 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.

  19. Spatial filters for high average power lasers

    Science.gov (United States)

    Erlandson, Alvin C

    2012-11-27

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second slit filter positioned between the second pair of cylindrical lenses.

  20. Reduction of dc-link capacitance for three-phase three-wire shunt active power filters

    DEFF Research Database (Denmark)

    Jin, Chi; Tang, Yi; Wang, Peng

    2013-01-01

    . This paper presents the concept of dc-link compensator (DLC) that aims to decouple the harmonic power from the dc-link of APF. With proper system sizing and design, most of the harmonic power can be eliminated by this DLC circuit and very small electrolytic capacitors or even film type capacitors can be used...... instead. Moreover, DLC itself is constructed with small passive components and features very simple circuit configuration. Experimental results are provided to show its effectiveness....

  1. 电力有源滤波器中谐波电流检测与仿真%The Harmonic Current Detecting and Simulation of Active Power Filter

    Institute of Scientific and Technical Information of China (English)

    高海洲; 叶天凤

    2012-01-01

    在电力有源滤波器设计中,谐波电流的实时检测是控制与补偿的关键技术环节。本文基于坐标变换和瞬时无功理论,得到谐波电流值。为了验证理论分析,进行不控整流桥带容性负载的非线性负载仿真。基于MATLAB/SIMULINK的仿真结果表明可以有效地得到电流中的基波和谐波成分。%In the design of active power filter,the real-time detection of harmonic current is the key techniques of control and compensation.In the paper,based on the theory of coordinate transformation and instantaneous reactive power,it gets the value of harmonic current.Meanwhile,to verify the theory's analysis,it uses MATLAB to simulate the nonlinear load which is the uncontrolled bridge rectifier with capacitive load.The simulation results show that the fundamental and harmonic components of the current can be effectively got.

  2. Dynamic Harmonic and Reactive Power Compensation with an Adaptive Shunt Active Filter for Variable Speed Induction Motor Drive

    OpenAIRE

    Sindhu M R; Aneesh P; Manjula G Nair; T N P Nambiar

    2014-01-01

    Variable speed drives are mostly preferred in industries, while considering energy saving, smooth control, flexible operation and fast response. On the other hand, this equipment generates dynamic harmonic distortions in source currents and draws variable reactive power demand depending on variation in load condition. These distortions propagate throughout the system and affect all the loads connected to the point of common coupling. Hence a dynamic harmonic and reactive compensator is necess...

  3. DC-pass filter design with notch filters superposition for CPW rectenna at low power level

    Science.gov (United States)

    Rivière, J.; Douyère, A.; Alicalapa, F.; Luk, J.-D. Lan Sun

    2016-03-01

    In this paper the challenging coplanar waveguide direct current (DC) pass filter is designed, analysed, fabricated and measured. As the ground plane and the conductive line are etched on the same plane, this technology allows the connection of series and shunt elements to the active devices without via holes through the substrate. Indeed, this study presents the first step in the optimization of a complete rectenna in coplanar waveguide (CPW) technology: key element of a radio frequency (RF) energy harvesting system. The measurement of the proposed filter shows good performance in the rejection of F0=2.45 GHz and F1=4.9 GHz. Additionally, a harmonic balance (HB) simulation of the complete rectenna is performed and shows a maximum RF-to-DC conversion efficiency of 37% with the studied DC-pass filter for an input power of 10 µW at 2.45 GHz.

  4. Novel Control Strategy for VSI and CSI Active Filters and Comparing These Two Types of Filters

    Directory of Open Access Journals (Sweden)

    Gholam Reza Arab

    2014-10-01

    Full Text Available Recently to eliminate the harmonics and improve the power factor of the power networks, much attention has been attracted to active filters. The advantages of these filters are lower volume and their better compensating characteristics than the passive filters. In conventional sliding mode controllers, the source current waveform is fluctuated in near to zero values. In this paper, using a new sliding technique, lower Total Harmonic Distortion (THD in source current is obtained and the current waveform is improved. As well as, two novel control strategies for two types of active filters, VSI and CSI is proposed and then these two types of filters are compared to reduce THD value of source current.The proposed controlled strategies are simulated by MATLAB/Simulink. The Simulation results confirm that the proposed strategies reduce the THD of source current more than other strategies, and active filter based on CSI has a better performance than active filter based on VSI with a dead time area (for avoiding short circuit of the source in high powers.

  5. Static DC to DC Power Conditioning-Active Ripple Filter, 1 MHZ DC to DC Conversion, and Nonlinear Analysis. Ph.D. Thesis; [voltage regulation and conversion circuitry for spacecraft power supplies

    Science.gov (United States)

    Sander, W. A., III

    1973-01-01

    Dc to dc static power conditioning systems on unmanned spacecraft have as their inputs highly fluctuating dc voltages which they condition to regulated dc voltages. These input voltages may be less than or greater than the desired regulated voltages. The design of two circuits which address specific problems in the design of these power conditioning systems and a nonlinear analysis of one of the circuits are discussed. The first circuit design is for a nondissipative active ripple filter which uses an operational amplifier to amplify and cancel the sensed ripple voltage. A dc to dc converter operating at a switching frequency of 1 MHz is the second circuit discussed. A nonlinear analysis of the type of dc to dc converter utilized in designing the 1 MHz converter is included.

  6. Digital notch filter based active damping for LCL filters

    DEFF Research Database (Denmark)

    Yao, Wenli; Yang, Yongheng; Zhang, Xiaobin

    2015-01-01

    . In contrast, the active damping does not require any dissipation elements, and thus has become of increasing interest. As a result, a vast of active damping solutions have been reported, among which multi-loop control systems and additional sensors are necessary, leading to increased cost and complexity....... In this paper, a notch filter based active damping without the requirement of additional sensors is proposed, where the inverter current is employed as the feedback variable. Firstly, a design method of the notch filter for active damping is presented. The entire system stability has then been investigated...... in the z-domain. Simulations and experiments are carried out to verify the proposed active damping method. Both results have confirmed that the notch filter based active damping can ensure the entire system stability in the case of resonances with a good system performance....

  7. DC-Link Capacitor Voltage Regulation for Three-Phase Three-Level Inverter-Based Shunt Active Power Filter with Inverted Error Deviation Control

    Directory of Open Access Journals (Sweden)

    Yap Hoon

    2016-07-01

    Full Text Available A new control technique known as inverted error deviation (IED control is incorporated into the main DC-link capacitor voltage regulation algorithm of a three-level neutral-point diode clamped (NPC inverter-based shunt active power filter (SAPF to enhance its performance in overall DC-link voltage regulation so as to improve its harmonics mitigation performances. In the SAPF controller, DC-link capacitor voltage regulation algorithms with either the proportional-integral (PI or fuzzy logic control (FLC technique have played a significant role in maintaining a constant DC-link voltage across the DC-link capacitors. However, both techniques are mostly operated based on a direct voltage error manipulation approach which is insufficient to address the severe DC-link voltage deviation that occurs during dynamic-state conditions. As a result, the conventional algorithms perform poorly with large overshoot, undershoot, and slow response time. Therefore, the IED control technique is proposed to precisely address the DC-link voltage deviation. To validate effectiveness and feasibility of the proposed algorithm, simulation work in MATLAB-Simulink and experimental implementation utilizing a TMS320F28335 Digital Signal Processor (DSP are performed. Moreover, conventional algorithms with PI and FLC techniques are tested too for comparison purposes. Both simulation and experimental results are presented, confirming the improvement achieved by the proposed algorithm in terms of accuracy and dynamic response in comparison to the conventional algorithms.

  8. Application of Self-adaptive Control in Active Power Filter%自适应控制在有源电力滤波器中的应用

    Institute of Scientific and Technical Information of China (English)

    顾雪晨

    2015-01-01

    自适应控制在工程和科技领域得到了越来越多的应用,当系统存在参数、结构以及环境的不确定因素时,自适应控制提供相应的自适应调节机制,通过调整控制器参数来获得期望的系统特性。本文在总结自适应控制的主要内容的基础上,以有源电力滤波器为例,分析自适应控制原理、设计方法和应用机理。%Self-adaptive control is widely applied in engineering and technology. When uncertain factors such as parameters, structure and operating environment exist, self-adaptive regulating mechanism will be provided correspondingly, and the control parameters can be adjusted automatically. Thus, expected systematic characteristic is obtained. In this paper, the fundamentals of self-adaptive control are concluded with its principle, design method and applying mechanism by taking active power filter as an example.

  9. 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.

  10. 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.

  11. Advanced Filters and Components for Power Applications

    Science.gov (United States)

    2006-08-31

    not in itself new. In fact, use of coupled magnetic windings in filters dates at least as far back as the 1920’s [4], and has continued up to the...IL CBig Network NetworkAnalyzer output- Figure 8.2: A test circuit for evaluating the filtering performance of magnetic components. The device under

  12. Design of active N-path filters

    NARCIS (Netherlands)

    Darvishi, Milad; Zee, van der Ronan; Nauta, Bram

    2013-01-01

    A design methodology for synthesis of active N-path bandpass filters is introduced. Based on this methodology, a 0.1-to-1.2 GHz tunable 6th-order N-path channel-select filter in 65 nm LP CMOS is introduced. It is based on coupling N-path filters with gyrators, achieving a “flat” passband shape and h

  13. High Power Combline Filter for Deep Space Applications

    Directory of Open Access Journals (Sweden)

    A. V. G. Subramanyam

    2014-01-01

    Full Text Available An S-band, compact, high power filter, for use in the Mars Orbiter Mission (MOM of Indian Space Research Organization (ISRO, has been designed and tested for multipaction. The telemetry, tracking, and commanding (TT&C transponder of MOM is required to handle continuous RF power of 200 W in the telemetry path besides simultaneously maintaining an isolation of greater than 145 dBc to its sensitive telecommand path. This is accomplished with the help of a complex diplexer, requiring high power, high rejection transmit path filter, and a low power receive path filter. To reduce the complexity in the multipaction-free design and testing, the transmit path filter of the diplexer is split into a low rejection filter integral to the diplexer and an external high rejection filter. This paper highlights the design and space qualification phases of this high rejection filter. Multipaction test results with 6 dB margin are also presented. Major concerns of this filter design are isolation, insertion loss, and multipaction. Mission performance of the on-board filter is normal.

  14. 有源电力滤波器双滞环电流控制新方法%A novel double hysteresis current control for active power filter

    Institute of Scientific and Technical Information of China (English)

    陈兆岭; 刘国海; 魏明洋

    2013-01-01

    To improve harmonic current tracking performance of shunt active power filter ( APF) based on double hysteresis current control strategy of voltage space vector, a novel 4-level α-β hysteresis comparator was proposed. The control strategy was directly implemented on α-β coordinates. The 4-level α-β hysteresis comparators were inputted current error vectors and outputted 4 state values to determine the location region of current error vectors. The differential relationship between reference voltages and reference currents was discretely calculated to determine the location region of reference voltage vectors. The optimum output switching vector at each instant was selected according to state values output of two 4-le-vel α-β hysteresis comparators and reference voltage vector. The compensatory current error was limited within the hysteresis width. APF models with constant load and variable load were established and simulated by Matlab/Simulink software. The results show that the proposed strategy can efficiently increase the utilization of DC bus with fast response. The total harmonic distortion of power grid current drops from 21.65% to 3. 11% , and the per phase switching number in one power supply cycle decreases from 342 of the conventional hysteresis control to 230 of the proposed method at steady state.%为了提高电压空间矢量双滞环电流控制方法在有源电力滤波器的谐波电流跟踪性能,提出了一种新颖的4段滞环比较器.直接在复平面上实施控制,4段滞环比较器输入误差电流矢量,输出4种状态值,可以确定误差电流矢量的空间分布,而将参考电压与电流之间的微分关系经离散化计算后得到参考电压矢量所在区域.根据两个4段滞环比较器的输出状态值与参考电压矢量的空间分布选择最佳的输出开关矢量,使补偿电流误差控制在滞环宽度以内.采用Matlab/Simulink仿真软件分别对负载不变和突变的情况仿真.结果表

  15. 具有APF功能的光伏并网发电系统的研究%A study of grid-connected photovoltaic power system with the function of active power filter

    Institute of Scientific and Technical Information of China (English)

    王春蕾; 张代润

    2012-01-01

    The grid connected photovoltaic (PV) power system with the function of active power filter (APF) was discussed. During the daytime, the system can provide not only PV grid-connected generation but also reactive power compensation and harmonic suppression which comes from the local nonlinear load. The system can continue to work as the APF at night. This compares to single photovoltaic system, which not only improves the utilization ratio of equipment but enhances the quality of power supply as well. In this paper, the structure of system, the method of reactive power and harmonic current closed-loop detection based on the theory of instantaneous reactive power with excellent robustness and dynamic response speed, combination of grid-connected current and current tracking are all discussed. Finally, the system is simulated with Matlab/simulink, and then the simulation results validate the feasibility of ' the system.%探讨了一种具有有源滤波器功能的光伏并网发电系统.该系统白天可有效地进行光伏并网发电,还可补偿或抑制本地非线性负载产生的无功和谐波,夜晚系统仍可作为APF继续工作.相对于单独的光伏并网系统,它不但提高了设备利用率,也改善了电网的供电质量.文章分析了系统的结构组成,还采用了具有较好鲁棒性和动态响应速度的、基于瞬时无功理论的闭环无功和谐波电流检测的方法,分析了并网电流的合成及其跟踪控制.最后,利用Matlab/Simulink对系统进行了仿真,验证了系统的可行性.

  16. Improving Industrial Energy Quality by an Active Current Filter

    Directory of Open Access Journals (Sweden)

    Reyes–Trujillo E

    2010-10-01

    Full Text Available The growing number of non-linear loads on industrial applications has produced an important impact on the quality of electric power supply due to the increasing of the voltage and current harmonic distortion, and low power factor. In order to solve this, arrangements of capacitors and reactors, known as passive filters have been used. However these filters may produce resonance problems with network impedance, over compensation of reactive power at fundamental frequency, and poor flexibility for dynamic compensation of different frequency harmonic components. As a solution to the problems mentioned above, the active filters have been developed, whose features can be adapted in a dynamic and adjustable way on the requirements of the system to compensate. This paper presents the modelling and simulation results of an active current filter, used to reduce the harmonic distortion and to improve the power factor in an electric industrial system. A six-pulse diode converter has been used as non-linear passive load. During the analysis, it was observed that the total current harmonic distortion (THD was reduced from 16.47% to 0.46%, and the power factor in the distribution bus has improved from 0.5 to 0.95.The waveforms of a three-phase thyristor converter with a DC machine as active non-linear load are shown.

  17. Parallel power electronics filters in three-phase four-wire systems principle, control and design

    CERN Document Server

    Wong, Man-Chung; Lam, Chi-Seng

    2016-01-01

    This book describes parallel power electronic filters for 3-phase 4-wire systems, focusing on the control, design and system operation. It presents the basics of power-electronics techniques applied in power systems as well as the advanced techniques in controlling, implementing and designing parallel power electronics converters. The power-quality compensation has been achieved using active filters and hybrid filters, and circuit models, control principles and operational practice problems have been verified by principle study, simulation and experimental results. The state-of-the-art research findings were mainly developed by a team at the University of Macau. Offering background information and related novel techniques, this book is a valuable resource for electrical engineers and researchers wanting to work on energy saving using power-quality compensators or renewable energy power electronics systems. .

  18. Design of Front Current Sampling Three-level Active Power Filter%电流采样前移三电平有源电力滤波器的设计

    Institute of Scientific and Technical Information of China (English)

    康劲松; 卢文建

    2012-01-01

    The structures, principles of traditional active power filter (APF) and PWM rectifier were researched respectively. The similarities and differences between their basic functions, topologies and control strategies were analyzed. According to their similarities, some changes and improvement in topologies of PWM rectifier were made to acquire the functions and features of an active power filter. This active power filter didn't need to sample the load current, but moved the current sampling point to the network side and took the corresponding space vector algorithm to ensure the network side with ideal current. Through establishing the model in Madab/Simulink, simulation results compared with the original APF have shown that the new structure of APF is effective.%文中分别对传统的有源电力滤波器(ActivePowerFilter,APF)和PWM(Pulse—widthModulation)整流器结构和原理进行研究,分析了它们基本功能、主电路拓扑结构、控制特性及策略的异同。根据二者的相似性对PWM整流器的拓扑结构加以转换和改进,使其衍生出具有有源电力滤波器的功能和特性。该有源电力滤波器不需要对负载的电流进行采样,而是将电流采样点前移到网侧,并通过相应的空间矢量算法以保证网侧具有较理想的电流。所得结论经过Matlab/Sirnulink仿真后,证实该有源电力滤波器结构的有效性。

  19. A Technique for Shunt Active Filter meld micro grid System

    Directory of Open Access Journals (Sweden)

    A. Lumani

    2015-08-01

    Full Text Available The proposed system presents a control technique for a micro grid connected hybrid generation system ith case study interfaced with a three phase shunt active filter to suppress the current harmonics and reactive power present in the load using PQ Theory with ANN controller. This Hybrid Micro Grid is developed using freely renewable energy resources like Solar Photovoltaic (SPV and Wind Energy (WE. To extract the maximum available power from PV panels and wind turbines, Maximum power point Tracker (MPPT has been included. This MPPT uses the “Standard Perturbs and Observe” technique. By using PQ Theory with ANN Controller, the Reference currents are generated which are to be injected by Shunt active power filter (SAPFto compensate the current harmonics in the non linear load. Simulation studies shows that the proposed control technique performs non-linear load current harmonic compensation maintaining the load current in phase with the source voltage.\\

  20. Power grid integration using Kalman filtering

    OpenAIRE

    Djerf, Magnus

    2012-01-01

    Renewable power sources with a relatively uneven or constant DC power production require synchronization methods to work with the current utility power grid. The solution to this synchronization problem has been solved with semiconductor based converters and advanced switching algorithms. To enable switching algorithms that work well with the grids amplitude, phase-shift and frequency, the current waveform has to be measured and estimated.    There are many sources of noise that will add dist...

  1. Filtering for increased power for microarray data analysis

    Directory of Open Access Journals (Sweden)

    Hess Ann M

    2009-01-01

    Full Text Available Abstract Background Due to the large number of hypothesis tests performed during the process of routine analysis of microarray data, a multiple testing adjustment is certainly warranted. However, when the number of tests is very large and the proportion of differentially expressed genes is relatively low, the use of a multiple testing adjustment can result in very low power to detect those genes which are truly differentially expressed. Filtering allows for a reduction in the number of tests and a corresponding increase in power. Common filtering methods include filtering by variance, average signal or MAS detection call (for Affymetrix arrays. We study the effects of filtering in combination with the Benjamini-Hochberg method for false discovery rate control and q-value for false discovery rate estimation. Results Three case studies are used to compare three different filtering methods in combination with the two false discovery rate methods and three different preprocessing methods. For the case studies considered, filtering by detection call and variance (on the original scale consistently led to an increase in the number of differentially expressed genes identified. On the other hand, filtering by variance on the log2 scale had a detrimental effect when paired with MAS5 or PLIER preprocessing methods, even when the testing was done on the log2 scale. A simulation study was done to further examine the effect of filtering by variance. We find that filtering by variance leads to higher power, often with a decrease in false discovery rate, when paired with either of the false discovery rate methods considered. This holds regardless of the proportion of genes which are differentially expressed or whether we assume dependence or independence among genes. Conclusion The case studies show that both detection call and variance filtering are viable methods of filtering which can increase the number of differentially expressed genes identified. The

  2. Power system harmonics and passive filter designs

    CERN Document Server

    Das, J C

    2015-01-01

    J.C. Das is a consultant of electrical power systems at Power Systems Studies, Inc., USA. He is Life Fellow of IEEE (UK), Fellow of IET (India), and has authored approximately sixty technical papers and published 190 study reports of real-world power systems. He is the author of three books including ARC Flash Hazard Analysis and Mitigation. He is a registered P.E. in the states of Georgia and Oklahoma, C.Eng. in UK, and Eur Ing in Europe. J. C. Das is also a member of CIGRE, Federation of European Engineers, and other technical associations and organizations.

  3. Detecting Power Voltage Dips using Tracking Filters - A Comparison against Kalman

    Directory of Open Access Journals (Sweden)

    STANCIU, I.-R.

    2012-11-01

    Full Text Available Due of its significant economical impact, Power-Quality (PQ analysis is an important domain today. Severe voltage distortions affect the consumers and disturb their activity. They may be caused by short circuits (in this case the voltage drops significantly or by varying loads (with a smaller drop. These two types are the PQ currently issues. Monitoring these phenomena (called dips or sags require powerful techniques. Digital Signal Processing (DSP algorithms are currently employed to fulfill this task. Discrete Wavelet Transforms, (and variants, Kalman filters, and S-Transform are currently proposed by researchers to detect voltage dips. This paper introduces and examines a new tool to detect voltage dips: the so-called tracking filters. Discovered and tested during the cold war, they can estimate a parameter of interest one-step-ahead based on the previously observed values. Two filters are implemented. Their performance is assessed by comparison against the Kalman filter?s results.

  4. Power and Aging Characterization of Digital FIR Filters Architectures

    DEFF Research Database (Denmark)

    Calimera, Andrea; Liu, Wei; Macii, Enrico;

    2012-01-01

    With technology scaling, newer metrics have been introduced, in addition to delay, area, and power dissipation, to characterize the behavior of digital systems. While dynamic and static power dissipation still remain the most serious concern at nanometer lengths (65nm and below), process-variatio......With technology scaling, newer metrics have been introduced, in addition to delay, area, and power dissipation, to characterize the behavior of digital systems. While dynamic and static power dissipation still remain the most serious concern at nanometer lengths (65nm and below), process......-variation, temperature and aging induced variations pose new challenges in the fabrication of the next generation of ICs. This work presents a detailed power and aging characterization of digital FIR filters in an industrial 45nm CMOS technology, and a design space exploration of different filter architectures...

  5. Sensory pollution from bag-type fiberglass ventilation filters: Conventional filter compared with filters containing various amounts of activated carbon

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Fadeyi, M.O.; Clausen, Geo

    2009-01-01

    (100 g/m(2)). Each filter was weighed at the beginning of the soiling period and after 3 and 6 months of service. Additionally, up- and down-stream ozone concentrations and filter pressure drops were measured monthly. Following 6 months of service, the air downstream of each of the combination filters......As ventilation filters accumulate particles removed from the airstream, they become emitters of sensory pollutants that degrade indoor air quality. Previously we demonstrated that an F7 bag-type filter that incorporates activated carbon (a "combination filter") reduces this adverse effect compared...... to an equivalent filter without carbon. The aim of the present study was to examine how the amount of activated carbon (AC) used in combination filters affects their ability to remove both sensory offending pollutants and ozone. A panel evaluated the air downstream of four different filters after each had...

  6. Ozone Removal by Filters Containing Activated Carbon: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William; Spears, Mike; Sullivan, Douglas; Mendell, Mark

    2009-09-01

    This study evaluated the ozone removal performance of moderate-cost particle filters containing activated carbon when installed in a commercial building heating, ventilating, and air conditioning (HVAC) system. Filters containing 300 g of activated carbon per 0.09 m2 of filter face area were installed in two 'experimental' filter banks within an office building located in Sacramento, CA. The ozone removal performance of the filters was assessed through periodic measurements of ozone concentrations in the air upstream and downstream of the filters. Ozone concentrations were also measured upstream and downstream of a 'reference' filter bank containing filters without any activated carbon. The filter banks with prefilters containing activated carbon were removing 60percent to 70percent of the ozone 67 and 81 days after filter installation. In contrast, there was negligible ozone removal by the reference filter bank without activated carbon.

  7. 基于自抗扰的并联有源电力滤波器优化控制策略%An Optimization Control Strategy for Parallel Active Power Filter Based on Active Disturbance Rejection

    Institute of Scientific and Technical Information of China (English)

    童成意; 刘朝华

    2012-01-01

    提出了一种并联型有源滤波器(APF)的自抗扰控制(ADRC)算法,同时利用改进的免疫粒子群算法对自抗扰控制器参数进行全局优化,利用小波变异增强了免疫克隆选择算法的动态优化性能,构建了一种基于免疫粒子群的并联有源电力滤波器自抗扰控制系统.实验结果表明,文中的控制策略不依赖于精确的对象模型,能够有效地抑制高频干扰对APF补偿性能的影响.控制算法能对有源电力滤波器进行有效控制,且具有较好的动态特性和鲁棒性.%The optimal active disturbance rejection control (ADRC) algorithm for paralleling active power filters (APF) is proposed. The improved immune particle swarm algorithm is employed to achieve the global optimization of the active disturbance rejection controller's parameters. The dynamic optimization performance of the immune clonal selection algorithm is further enhanced by the wavelet variation. Based on the immune particle swarm algorithm, a kind of active disturbance rejection control system for parallel APFs is constructed. Experimental results indicate that the proposed control algorithm does not depend on the precise model of controlled plant, and can restrain the negative effect of high frequency interference on the performance of APF compensators. In addition, the effective control for APF is achievable by the proposed algorithm with proved good dynamic characteristic and robustness.

  8. Low-power adaptive filter based on RNS components

    DEFF Research Database (Denmark)

    Bernocchi, Gian Luca; Cardarilli, Gian Carlo; Del Re, Andrea

    2007-01-01

    on the least mean squares (LMS) algorithm, is allowed. Previous work showed that the use of the residue number system (RNS) for the variable FIR filter grants advantages both in area and power consumption. On the other hand, the use of a binary serial implementation of the adaptation algorithm eliminates...... the need for complex scaling circuits in RNS. The advantages in terms of area and speed of the presented filter, with respect to its two's complement counterpart, are evaluated for implementations in standard cells....

  9. Hybrid LC filter for power electronic drives. Theory and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Dzhankhotov, V.

    2009-07-01

    Power electronic converter drives use, for the sake of high efficiency, pulse-width modulation that results in sequences of high-voltage high-frequency steep-edged pulses. Such a signal contains a set of high harmonics not required for control purposes. Harmonics cause reflections in the cable between the motor and the inverter leading to faster winding insulation ageing. Bearing failures and problems with electromagnetic compatibility may also result. Electrical du/dt filters provide an effective solution to problems caused by pulse-width modulation, thereby increasing the performance and service life of the electrical machines. It is shown that RLC filters effectively decrease the reflection phenomena in the cable. Improved (simple, but effective) solutions are found for both differential- and common-mode signals; these solutions use a galvanic connection between the RLC filter star point and the converter DC link. Foil chokes and film capacitors are among the most widely used components in high-power applications. In actual applications they can be placed in different parts of the cabinet. This fact complicates the arrangement of the cabinet and decreases the reliability of the system. In addition, the inductances of connection wires may prevent filtration at high frequencies. This thesis introduces a new hybrid LC filter that uses a natural capacitance between the turns of the foil choke based on integration of an auxiliary layer into it. The main idea of the hybrid LC filter results from the fact that both the foil choke and the film capacitors have the same roll structure. Moreover, the capacitance between the turns ('intra capacitance') of the foil inductors is the reason for the deterioration of their properties at high frequencies. It is shown that the proposed filter has a natural cancellation of the intra capacitance. A hybrid LC filter may contain two or more foil layers isolated from each other and coiled on a core. The core material can be

  10. 有源电力滤波器降低容量控制策略研究%Study on Control Strategy of Active Power Filter in Capacitance Minimizing

    Institute of Scientific and Technical Information of China (English)

    颜文旭; 纪志成; 谢林柏

    2012-01-01

    Shunt Active Power Filter ( APF) provides a way of harmonics suppression and reactive compensation for power systems, and its capacitance is identified as a very important factor for its application in the traditional power systems by power capacitors reactive power compensation. By analyzing the energy flows of APF and the key factors of APF capacitance, a novel control strategy is presented. While in the condition of power voltage distortion, the referenced compensation currents contains the fundamental active power and reactive power are achieved in model of power currents sinusoidal and APF capacitance minimized. An improved detection method for the fundamental positive sequence is put forward, which is applied in realizing the control strategy that decreases the APF currents and its loss, and then improves the efficiency. Simulations and experimental results indicate that the proposed control strategy has satisfactory performance in minimizing APF capacitance. It can be used to reduce the size of APF and potentially suppress harmonics in the traditional power distribution with reactive power compensation by power capacitors.%对有源电力滤波器(APF)能量流进行分析,得出决定APF容量的基本要素.针对复杂电源环境下APF的补偿目标,提出一种基于电源电流基波正弦化的降低容量控制策略,获取负载电流中的基波有功功率及基波无功功率,并获得补偿参考电流.为实现控制策略,提出适用于电源电压畸变情况下的三相电压基波正序检测的改进方法,减小APF变流电路总电流和自身损耗,提高了APF的效率.仿真和实验结果验证了该控制策略的正确性和有效性,对并联型APF的小型化及电力系统滤波改造具有实用的参考价值.

  11. Application of wide band harmonic active filters; Aplicacao de filtros ativos de harmonicos de banda larga

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Ian C. [Harmonics Solutions Co., Scotland (United Kingdom); Johnson, James R. [Schneider Electric (United States)

    2010-02-15

    Non linear charges causes problems such as flicker, harmonics, low displacement power factor and high inrush high currents. As the conventional technologies does not have capacity to face such problems, it is necessary specialized technologies such as the harmonic active filters with wide band logic. This paper presents four cases of difficult solution and analyses two types of active filter projects. (author)

  12. 改进型混合级联多电平有源电力滤波器的研究%Research on an improved hybrid cascade multilevel active power filter

    Institute of Scientific and Technical Information of China (English)

    高东辉; 杜少武; 张长征

    2014-01-01

    In order to reduce the active power loss and improve the compensation performance of high-voltage active power filter, an improved hybrid cascade multi-level topology is proposed, which is equivalent to series between voltage source and current source. The voltage source is constituted by hybrid cascade 27-level converter. The fundamental component of the output voltage offsets the high voltage power grid’s voltage, thus provides a low voltage situation for the current source. The current source is constituted by PWM converter, which has small rated power and high IGBT switching frequency, which makes the active power filter have excellent compensation performance. The main power of the APF is output by the square wave converter which has 50/60 Hz switching frequency, thus making the APF have small total loss. Theoretical analysis and simulation results show the effectiveness of the new topology.%针对高压有源电力滤波器,为了减小有功损耗且提高补偿性能,提出一种改进型混合级联多电平拓扑结构,等效为电压源与电流源相串联。电压源由混合级联27电平变换器构成,其输出电压的基波分量与高压配电网电压相抵消,从而为电流源的运行提供了很低的电压环境。电流源由 PWM 变换器构成,其额定功率很小,IGBT 开关频率较高,从而使得有源电力滤波器具有极好的补偿性能。有源电力滤波器的主要功率由开关频率50/60 Hz的方波变换器输出,从而使得有源电力滤波器的总损耗很小。理论分析与仿真结果证明了该新型拓扑结构的有效性。

  13. Digitally Controlled ’Programmable’ Active Filters.

    Science.gov (United States)

    1985-12-01

    Mitra, S. K., Analysis and Synthesis of Linear Active .. Networks, Wiley, New York, 1969. * 6. Sedra , A. S. and Smith , K. C., "A Second-Generation...Current Conveyor and its Applications," IEEE Trans. Circuit Theory, Vol. CT-17, pp. 132-134, 1970. 7. Sedra , A. S., "A New Approach to Active Network...CT-18, pp. 358-361, May 1971. 27. Hamilton, T. A., and Sedra , A. S., "Some New IJ Configurations for Active Filters," IEEE Trans. Circuit Tehory, Vol

  14. T Source Inverter Based Shunt Active Filter with LCL Passive Filter for the 415V 50 Hz Distribution systems

    Directory of Open Access Journals (Sweden)

    S. Sellakumar

    2015-06-01

    Full Text Available The inverter topology is being used as an active filter to reduce the harmonics in the power system [1]. The traditional voltage source or current source inverters are having the disadvantages of limited output voltage range hence it may not be able to supply enough compensating currents during heavy switching surges, Vulnerable to EMI noise and the devices gets damaged in either open or short circuit conditions and the main switching device of VSI and CSI are not interchangeable. The active filters are the type of DC-AC system with wide range of voltage regulation and integration of energy storages is often required. This cannot be achieved with conventional inverters and hence the impedance source inverters have been suggested. The T source inverters are basically impedance source inverters which can be used as an active filter in the power system. The MATLAB simulation is done and the results are discussed in this paper for both the types. The proposed dampening system is fully characterized by LCL based passive filters [6] and T source inverter based shunt active filter. The disturbances in the supply voltage and load current due to the non linear loads are observed in the simulation. The same is studied after connecting the designed hybrid shunt active filter in the distribution system. The simulation results obtained from the proposed method proves that it gives comparatively better THD value.

  15. Model Predictive Current Control for High-Power Grid-Connected Converters with Output LCL Filter

    DEFF Research Database (Denmark)

    Delpino, Hernan Anres Miranda; Teodorescu, Remus; Rodriguez, Pedro

    2009-01-01

    A model predictive control strategy for a highpower, grid connected 3-level neutral clamped point converter is presented. Power losses constraints set a limit on commutation losses so reduced switching frequency is required, thus producing low frequency current harmonics. To reduce these harmonics...... an LCL filter is used. The proposed control strategy allows control of the active and reactive power fed into the grid, reduce the switching frequency within acceptable operational margins and keep balance of the DC-link capacitor voltages while avoiding excitation of the filter resonance frequencies....

  16. 混合有源滤波器的复合控制研究%Complex control of hybrid active power filter

    Institute of Scientific and Technical Information of China (English)

    赵丽娜; 郭立杰; 李振明

    2012-01-01

    The working principle of the injection HAPF was analyzed, which could reduce the based voltage of active part and the capacity of active part, and effectively overcome switch device capacity and cost factor, more suitable for high pressure system. A composite control scheme through testing the power current and load current was presented. By controlling the above two values, the impedance series and parallel resonance of the system could be prevented, and thereby achieve the purpose of suppressing the harmonic.%分析了注入式混合有源滤波器的工作原理,它可以降低有源部分的基波分压,减少有源部分容量,更适用于高压系统,还可以有效地克服了开关器件容量和成本等因素的影响.提出了一种通过检测电网电流和负载谐波电流的复合控制方案.通过控制上述两个量来防止系统阻抗间可能的串并联谐振,而达到抑制电网谐波的目的.

  17. 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.

  18. New control algorithm for shunt active filters, based on self-tuned vector filter

    OpenAIRE

    Perales Esteve, Manuel Ángel; Mora Jiménez, José Luis; Carrasco Solís, Juan Manuel; García Franquelo, Leopoldo

    2001-01-01

    A new, improved, method for calculating the reference of a shunt active filter is presented. This method lays on a filter, which is able to extract the main component of a vector signal. This filter acts as a Phase-Locked Loop, capturing a particular frequency. The output of this filter is in phase with the frequency isolated, and has its amplitude. Simulation and experimental results confirms the validity of the proposed algorithm.

  19. Pre-research on hybrid cascaded multilevel high-voltage active power filter%混合级联多电平高压有源电力滤波器预研

    Institute of Scientific and Technical Information of China (English)

    刘洁; 黄海宏; 王海欣

    2015-01-01

    Aiming at high-voltage active power filter, in order to improve output power and get more levels with the same number of cascaded H bridges when the system adopts cascade structure , and also the relationship of switc-hing frequency and compensation characteristic is taken into consideration , a topology of hybrid cascaded multilevel is adopted.This active power filter consists of two parts that can be equivalent to voltage source and current source, respectively.They are connected in series, the current source is constituted by PWM converter;the voltage source is constituted by hybrid cascaded H bridge converter.The fundamental component of its output voltage counteracts grid voltage, so the current source can work in the environment of low voltage .It has low active power loss, and the switching frequency is higher, the compensation characteristic is better.The control strategy is simple and easy to implement.As the pre-research of high-voltage active power filter, MATLAB simulation and the experiment results in the condition of single-phase grid which the virtual value is 220V show the availability and practicability of the topology.%针对高压有源电力滤波器,为了采用级联结构时在相同的级联数目下可以获得更多的电平数,同时提高输出功率等级,并且考虑到开关频率和系统补偿特性关系,采用一种混合级联多电平拓扑结构。该有源电力滤波器由可以等效为电压源与电流源的两部分串联组成,电流源部分为传统的PWM变换器;电压源部分由3个H桥逆变器级联构成,其输出电压的基波分量可以抵消电网电压,因此电流源部分的PWM变换器交流侧承受的电压很低,有功损耗小,从而可以提高PWM变换器的开关频率,从而谐波抑制的效果更好。其控制策略简单,易于实现。作为高压大容量有源电力滤波器预研,在单相电网电压有效值220V条件下,通过MATLAB仿真和实验结果证

  20. Modeling and State feedback Control of Three-phase Active Power Filter on Switched System%三相 APF 的切换系统建模与状态反馈控制

    Institute of Scientific and Technical Information of China (English)

    殷文月; 程新功; 宗西举; 张静亮

    2015-01-01

    Three-phase active power filter (APF) is a typical switched affine system for the action of the power switch. The conventional modeling method is based on the linear system theory. Then a novel control procedure for three-phase APF based on switched affine system and quadratic stability is proposed. Firstly, the three-phase APF is built as the switched affine system model. Based on the sufficient condition for the quadratic stability of convex combination, the common Lyapunov function is selected. Then, the active region of the subsystems and switching rules can be defined to assess quadratic stability of the switched system, thus realizing the control of the compensation current and the DC side voltage. Finally, simulation and experimental results have good agreement with the theoretical analysis and demonstrate the validity of this approach.%功率开关的动作使得三相有源电力滤波器(active power filter,APF)成为一种典型切换仿射系统。因此提出了一种基于切换仿射模型和切换系统全局稳定理论的三相APF 的控制方法。首先建立三相 APF 切换仿射模型,为各个切换子系统选取合适的公共李亚普诺夫(Lyapunov)函数,据此划分各个子系统的运行域,构造基于状态反馈的切换规则保证系统在切换控制下二次稳定,从而实现了电流和电压的统一控制。最后仿真和实验结果与理论分析具有良好的一致性。

  1. PWM-Statcom system additionally having active filter function

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, K.; Kojima, H.; Yamamoto, I.; Hasegawa, M. [Chubu Univ., Kasugai Aichi (Japan); Ando, K. [Nitto Kogyo Corp., Nagakute, Aichi (Japan)

    2006-07-01

    The harmonic characteristics of static synchronous compensators (Statcom) were discussed with particular reference to the difference between symmetrical and asymmetrical modulation strategies that influence a quality of output waveform. The asymmetrical modulation strategy is the better approach in higher power factor applications such as alternating current (AC) motor drives. It was noted that in cases requiring a passive filter with a very large scale Statcom, a symmetrical modulation strategy is superior. Therefore, in this study, a symmetrical modulation was preferred for a neutral point clamped (NPC) pulse width modulation (PWM) inverter. Due to switching in a limited narrow frequency band, such output harmonics can be eliminated using a simple passive filter and harmonics such as the fifth and the seventh, can be suppressed using the proposed Statcom scheme in which the feedback signals for the fifth and seventh harmonics are injected into the Statcom. Using these feedback signals, the harmonics in the power system were significantly reduced. This result was also confirmed by simulation. It was concluded that, in addition to the proper operation of the Statcom, it is possible to perform an active filtering function . 10 refs., 1 tab., 9 figs.

  2. A new balancing three level three dimensional space vector modulation strategy for three level neutral point clamped four leg inverter based shunt active power filter controlling by nonlinear back stepping controllers.

    Science.gov (United States)

    Chebabhi, Ali; Fellah, Mohammed Karim; Kessal, Abdelhalim; Benkhoris, Mohamed F

    2016-07-01

    In this paper is proposed a new balancing three-level three dimensional space vector modulation (B3L-3DSVM) strategy which uses a redundant voltage vectors to realize precise control and high-performance for a three phase three-level four-leg neutral point clamped (NPC) inverter based Shunt Active Power Filter (SAPF) for eliminate the source currents harmonics, reduce the magnitude of neutral wire current (eliminate the zero-sequence current produced by single-phase nonlinear loads), and to compensate the reactive power in the three-phase four-wire electrical networks. This strategy is proposed in order to gate switching pulses generation, dc bus voltage capacitors balancing (conserve equal voltage of the two dc bus capacitors), and to switching frequency reduced and fixed of inverter switches in same times. A Nonlinear Back Stepping Controllers (NBSC) are used for regulated the dc bus voltage capacitors and the SAPF injected currents to robustness, stabilizing the system and to improve the response and to eliminate the overshoot and undershoot of traditional PI (Proportional-Integral). Conventional three-level three dimensional space vector modulation (C3L-3DSVM) and B3L-3DSVM are calculated and compared in terms of error between the two dc bus voltage capacitors, SAPF output voltages and THDv, THDi of source currents, magnitude of source neutral wire current, and the reactive power compensation under unbalanced single phase nonlinear loads. The success, robustness, and the effectiveness of the proposed control strategies are demonstrated through simulation using Sim Power Systems and S-Function of MATLAB/SIMULINK.

  3. A Performance Comparison Between Extended Kalman Filter and Unscented Kalman Filter in Power System Dynamic State Estimation

    DEFF Research Database (Denmark)

    Khazraj, Hesam; Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2016-01-01

    Dynamic State Estimation (DSE) is a critical tool for analysis, monitoring and planning of a power system. The concept of DSE involves designing state estimation with Extended Kalman Filter (EKF) or Unscented Kalman Filter (UKF) methods, which can be used by wide area monitoring to improve...... the stability of power system. State estimation with EKF and UKF methods can be used for monitoring and estimating the dynamic state variables of multi-machine power systems, which are generator rotor speed and rotor angle. This paper uses Powerfactory to solve power flow analysis of simulations, then a non......-linear state estimator is developed in MatLab to solve states by applying the unscented Kalman filter (UKF) and Extended Kalman Filter (EKF) algorithm. Finally, a DSE model is built for a 14 bus power system network to evaluate the proposed algorithm for the networks.This article will focus on comparing...

  4. Designing Asynchronous Circuits for Low Power: An IFIR Filter

    DEFF Research Database (Denmark)

    Nielsen, Lars Skovby; Sparsø, Jens

    1999-01-01

    by numerically small samples). Apart from the improved RAM design, these measures are only viable in an asynchronous design. The principles and techniques explained in this paper are of a general nature, and they apply to the design of asynchronous low-power digital signal-processing circuits in a broader......This paper addresses the design of asynchronous circuits for low power through an example: a filter bank for a digital hearing aid. The asynchronous design re-implements an existing synchronous circuit which is used in a commercial product. For comparison, both designs have been fabricated...... in the same 0.7 /spl mu/m CMOS technology. When processing typical data (less than 50 dB sound pressure), the asynchronous control and data-path logic, an improved RAM design, and by a mechanism that adapts the number range to the actual need (exploiting the fact that typical audio signals are characterized...

  5. Design Of EMI Filter For Flash Lamp Power Supply

    Directory of Open Access Journals (Sweden)

    Amrita Bhatt

    2015-08-01

    Full Text Available Abstract Conducted and radiated electromagnetic interference in embedded and VLSI systems have become important in recent years with increase in clock frequency and reduction in physical dimensions of interconnects. It is important to understand the noise components in terms of current paths and the mitigation techniques. Although the common mode and differential mode components of conducted noise are analyzed in the context of a power electronics system the analytical and theoretical techniques hold good for other domains as well such as embedded systems and VLSI. This paper deals with modelling design and development of an EMI filter for conducted mode noise in flash lamp power supply. Also a design procedure of EMI filters sustaining to the military standard 461E is presented and it is based on practical measurement of conducted emissions. Design procedure in this paper considers common mode and differential mode separately. The paper also consists of considerations for magnetic core material integrated common mode CM common mode choke size optimization and differential mode DM choke etc. Design examples are given and are experimentally verified.

  6. Design and control of an LCL-filter-based three-phase active rectifier

    DEFF Research Database (Denmark)

    Liserre, Marco; Blaabjerg, Frede; Hansen, Steffan

    2005-01-01

    This paper proposes a step-by-step procedure for designing the LCL filter of a front-end three-phase active rectifier. The primary goal is to reduce the switching frequency ripple at a reasonable cost, while at the same time achieving a high-performance front-end rectifier (as characterized...... by a rapid dynamic response and good stability margin). An example LCL filter design is reported and a filter has been built and tested using the values obtained from this design. The experimental results demonstrate the performance of the design procedure both for the LCL filter and for the rectifier...... a powerful tool to design an LCL-filter-based active rectifier while avoiding trial-and-error procedures that can result in having to build several filter prototypes....

  7. T Source Inverter Based Shunt Active Filter with LCL Passive Filter for the 415V 50 Hz Distribution systems

    OpenAIRE

    S. Sellakumar; Vijayakumar, M.

    2015-01-01

    The inverter topology is being used as an active filter to reduce the harmonics in the power system [1]. The traditional voltage source or current source inverters are having the disadvantages of limited output voltage range hence it may not be able to supply enough compensating currents during heavy switching surges, Vulnerable to EMI noise and the devices gets damaged in either open or short circuit conditions and the main switching device of VSI and CSI are not interchangeable. The active ...

  8. Study on SVPWM Control Method of Active Power Filter Based on Adaptive Parameters%自适应参数的有源电力滤波器SVPWM控制方法研究

    Institute of Scientific and Technical Information of China (English)

    朱宁辉; 白晓民; 董伟杰; 周子冠

    2012-01-01

    比较有源电力滤波器(active power filter,APF)两种常用空间矢量脉宽调制(space vector pulse width modulation,SVPWM)控制方法,两者计算时都用到补偿回路串联电抗器的参数,该参数精确程度对APF的补偿效果有一定的影响.针对这一问题,提出自适应参数的SVPWM控制策略.利用整体最小二乘法(total least squares,TLS)对电抗器的参数进行识别,结合次元分析(minor component analysis,MCA)线性神经元求解整体最小二乘法的超定方程,将修正后的电抗器参数再用于SVPWM算法中.为验证所提出自适应参数SVPWM算法的正确性,分别在Matlab仿真和试验平台上测量数据识别补偿回路中电抗器的参数,对比校正电抗器参数前后电源电流的畸变率.仿真和实验数据的分析结果表明了自适应参数SVPWM算法的合理性.%Two common space vector pulse width modulation (SVPWM) control strategies of active power filter (APF) were compared. In these two control strategies, the parameters of reactor in series compensation circuit are used. The accuracy of reactor parameters has a certain impact on the compensation effect of the APF. To solve this problem, the SVPWM control strategy based on adaptive parameters was proposed in this paper. The reactor parameters can be identified by total least square (TLS). Combined with minor component analysis (MCA) linear neurons, the over-determined equation of TLS can be solved. Then, the amended reactor parameters are calculated in SVPWM. In order to verify the correctness of the adaptive TLS-SVPWM algorithm, some experimental and calculation are conducted respectively in Matlab simulation and test platform. Through measuring data and identifying the reactor parameters of compensation branch, the distortion factors of source current are compared when reactor parameters are amended or not. The simulation results and experimental data analysis showed the rationality of the SVPWM algorithm.

  9. Four-branch Star Hybrid Power Filter for Three-phase Four-wire Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Teodorescu, Remus; Rodriguez, Pedro;

    2008-01-01

    This paper presents a new concept for filtering current harmonics in three-phase four-wire networks. The four-branch star (FBS) filtering topology presented in this work is characterized by a particular layout consisting of single-phase inductances and capacitors. Via this layout, a power filter...... results is conducted in order to verify and validate the good performance of the proposed four-branch star passive/hybrid power filter....

  10. Features of adsorbed radioactive chemical elements and their isotopes distribution in iodine air filters AU-1500 at nuclear power plants

    CERN Document Server

    Neklyudov, I M; Dikiy, N P; Ledenyov, O P; Lyashko, Yu V

    2013-01-01

    The main aim of research is to investigate the physical features of spatial distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU1500 in the forced exhaust ventilation systems at the nuclear power plant. The gamma activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU1500 iodine air filter, which was exposed to the bremsstrahlung gamma quantum irradiation, produced by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element 127I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granule...

  11. Partially resonant active filter using the digital PWM control circuit with the DSP

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, Hirofumi; Kurokawa, Fujio; Luo, Zongxin; Makino, Yutaka; Ishizuka, Yoichi [Nagasaki Univ. (Japan); Oshikata, Tetsuya [Shindengen Elect. Mfg. Co. Ltd. (Japan)

    2000-07-01

    The partially resonant active filter, as a pre-regulator, using the digital PWM control circuit with the DSP is proposed to improve the power factor and input current harmonic distortion factor. The steady-state and dynamic characteristics of this active filter are analysed and the relationship among the circuit parameters, variables and performance characteristics such as the pre-regulation of the output voltage, input power factor, input current harmonic distortion, boundaries of stability and so forth are defined. Using the partially resonant active filter, the high power efficiency over 91% is obtained and the high frequency switching noise is suppressed. Also, the digital control with the DSP is versatile and consequently, the power factor over 0.99 and total harmonic distortion factor less than 1% are easily realized. (orig.)

  12. Harmonic Current Detection Algorithm for Active Power Filter Based on Artifical Neutral Networks%基于人工神经网络谐波电流检测算法的电力有源滤波器

    Institute of Scientific and Technical Information of China (English)

    李智华; 刘振; 吕振彬

    2010-01-01

    有源滤波器的有效性在很大程度上依赖于是否能得到真实反映欲补偿的谐波分量的参考信号,因此,有源滤波器设计的关键问题之一就是研究一种好的电流检测算法.在分析并联型有源电力滤波器的工作原理、系统结构的基础上,给出一种新的神经网络的电流检测控制算法,结合此算法设计了三相并联有源电力滤波器(shunt active power filter, SAF).Matlab仿真结果显示,谐波总畸变率(total harmonic distortion,THD)明显降低,与理论分析一致,证实了该方法的有效性.

  13. HE CONTROL OF HYSTERESIS SPACE VECTOR OF PARALLEL ACTIVE POWER FILTER%并联型有源电力滤波器的滞环空间矢量控制

    Institute of Scientific and Technical Information of China (English)

    张润和; 武海涛; 杜超; 张丽荣

    2009-01-01

    本文分析了与滞环相结合的空间矢量PWM的基本控制原理,并将该方法应用到并联型有源电力滤波器的控制中.利用Matlab进行了仿真研究,结果表明有源滤波器在任一时刻输出的补偿电流均能实时地跟踪指令电流,有效减小电流补偿误差,达到消除非线性负载所引起的谐波电流对电网污染的目的.%An analysis on the basic control principle of space vector PWM combined with hysteresis is made and a method is devised for implementing the control over the parallel active power filter (APF).Results of simulation by means of Matlab show that the output compensation current given at any time can track the instruction current of the APF at real-time.Thus,the current compensation error can be reduced effectively.Consequently,the harmonic current pollution on the grid caused by nonlinear load is eliminated.

  14. Design and Analysis of Robust Active Damping for LCL Filters using Digital Notch Filters

    DEFF Research Database (Denmark)

    Yao, Wenli; Yang, Yongheng; Zhang, Xiaobin;

    2017-01-01

    Resonant poles of LCL filters may challenge the entire system stability especially in digital-controlled Pulse Width Modulation (PWM) inverters. In order to tackle the resonance issues, many active damping solutions have been reported. For instance, a notch filter can be employed to damp the reso......Resonant poles of LCL filters may challenge the entire system stability especially in digital-controlled Pulse Width Modulation (PWM) inverters. In order to tackle the resonance issues, many active damping solutions have been reported. For instance, a notch filter can be employed to damp...... the resonance, where the notch frequency should be aligned exactly to the resonant frequency of the LCL filter. However, parameter variations of the LCL filter as well as the time delay appearing in digital control systems will induce resonance drifting, and thus break this alignment, possibly deteriorating...... the original damping. In this paper, the effectiveness of the notch filter based active damping is firstly explored, considering the drifts of the resonant frequency. It is revealed that, when the resonant frequency drifts away from its nominal value, the phase lead or lag introduced by the notch filter may...

  15. A digital filter optimization method for low power digital wireless communication system

    OpenAIRE

    Tarumi, Kousuke; Tsujimoto, Taizo; Yasuura, Hiroto

    2003-01-01

    In this paper, we introduce a design method for a low power digital baseband processing circuit. In particular, we focus on a digital FIR(Finite Impulse Response) filter that is a part of the digital baseband processing. Because the digital filter contains large power consuming components, such as adders and multipliers. We propose a design method to reduce power consumption of the digital FIR filter circuit by optimizing bitwidth of inputs of the mutipliers and the adders. We found that the ...

  16. Application of wavelet transform in active power filter harmonic analysis%小波变换在有源电力滤波器谐波分析中的应用

    Institute of Scientific and Technical Information of China (English)

    梁东莺; 毛蔚

    2009-01-01

    In order to effectively analyze and resolve Active impedance transform, wavelet transform on the use of harmonic and inter harmonic detection methods are studied, and on this basis to explore the use of wavelet analysis to study the control of time-frequency characteristics of impedance and frequency characteristics of the basic principles of analysis of the use of wavelet transform to separate harmonic inter-harmonic wave with the algorithm, taking into account time and frequency domain resolution. The simulation results show that the method not only has the characteristics of high-resolution, but also can identify the APF time-frequency impedance chara-cteristics, it is very useful for harmonic analysis, in the active power filter harmonic inhibitory aspects, and it has providing a feasible solution.%为有效分析和解决有源阻抗变换,对使用小波变换检测谐波与间谐波的方法进行了研究,并在此基础上探讨了利用小波分析、研究时频阻抗的控制特性和频率特性的基本原理,提出了利用小波变换来分离谐波与间谐波的算法,并兼顾时域和频域的分辨率.仿真结果表明,该方法不仅具有高分辨率特性,能较好地找出APF的时频阻抗特性,可以较好地分析谐波,以使其跟踪特性最优,为有源电力滤波器谐波抑制提供了可行的解决途径.

  17. Kalman Filter Application to Symmetrical Fault Detection during Power Swing

    DEFF Research Database (Denmark)

    Khodaparast, Jalal; Silva, Filipe Miguel Faria da; Khederzadeh, M.;

    2016-01-01

    capability of Kalman Filter. The proposed index is calculated by assessing the difference between predicted and actual samples of impedance. The predicted impedance samples are obtained using Kalman filter and Taylor expansion, which is used in this paper to track the phasor precisely. Second order of Taylor...... expansion is used to decrease corrugation effect of impedance estimation and increase the reliability of proposed method. The instantaneous estimation and prediction capability of Kalman filter are two reasons for proposing utilizing Kalman filter....

  18. A Fault-Tolerance Method for Hysteresis SVPWM Based Active Power Filter%基于滞环SVPWM的有源电力滤波器故障容错方法

    Institute of Scientific and Technical Information of China (English)

    李国华; 汪玉凤; 高小朋; 宋雪萍; 刘阳

    2014-01-01

    To improve the fault tolerance ability of active power filter (APF), a hysteresis space vector pulse width modulation (SVPWM) strategy based fault tolerance method is proposed, that is, when inverter failure happens, the resultant vector of available voltage vector under fault condition is used to equivalently substitute the voltage vector selected by original control algorithm to ensure APF enable to keep working under fault condition. The essence of the proposed method is to perform tolerant control on the basis of original control algorithm, so the spare tolerant algorithm is not needed, thus the calculated amount is reduced. Besides, the values of voltage reference and impedance parameter are not to be estimated accurately, therefore the affect due to parameter estimation error can be overcome and the decoupling control of parameters can be implemented to enhance operational reliability of APF obviously. The effectiveness of the proposed method is validated by results of simulation and experiments.%为提高有源电力滤波器(active power filter,APF)的故障容错能力,提出了一种基于滞环空间矢量脉宽调制(space vector pulse width modulation,SVPWM)策略的APF故障容错方法。逆变器发生故障时,利用故障状态下有效电压矢量的合成矢量等效替代原控制算法选定的电压矢量,保证APF能在故障状态下继续工作。该方法是在原控制算法的基础上进行容错控制,不需要备用容错算法,降低了计算量。此外,该方法不需要精确估计参考电压值和阻抗参数值,克服了参数估计误差所带来的影响,而且可以实现参数的解耦控制,能够显著提高 APF 的工作可靠性。仿真和实验结果验证了该方法的有效性。

  19. An Improved Proportional Resonant Control Strategy in the Static Coordinate for Four-leg Active Power Filters%四桥臂有源滤波器在静止坐标系下的改进PR控制

    Institute of Scientific and Technical Information of China (English)

    周娟; 张勇; 耿乙文; 伍小杰

    2012-01-01

    有源电力滤波器(active power filter,APF)电流环控制要求补偿电流无误差地跟踪给定信号,传统的dq坐标系下P I控制很难消除稳态误差。采用并联的比例谐振(proportional resonant,PR)控制器,对不同频率的正弦分量进行跟踪控制,实现零稳态误差跟踪。针对电网频率波动和三相不平衡问题,在坐标系下采用改进PR控制器实现电流跟踪控制。在详细分析PR控制器各参数对性能指标影响的基础上,总结参数的调试方法,并给出控制器离散化方法。通过仿真与实验对所提控制策略进行验证,APF投入后,电网电流畸变率下降,中线电流有效值减小,负载和频率波动时仍有较好的补偿效果。该结果表明,所提的改进PR控制策略可以有效地抑制谐波,较好地解决三相不平衡问题,对负载突变和频率波动均有良好的适应性。%The current loop control of active power filters(APF) requires the compensation current to track the given signal without any error,while it is difficult to eliminate steady-state errors by using the traditional PI controller in the synchronous dq frame.In this paper,the proportion resonant(PR) controller was adopted to track the different frequency component,thus to obtain zero steady-state errors.As to the grid frequency fluctuation and the unbalanced problem of three-phase systems,the improved controller in the coordinate was proposed.On the basis of analyzing the effects of PR controller parameters on the performance index,the paper summarized the debugging methods of the parameters.And the Pre-Warped Tustin Transformation was used to discretize the controllers.The proposed strategy was verified through simulation and experiment results.The total harmonic distortion(THD) values of grid currents after filtering reduced and the root mean square value of the neutral current dropped.In addition,the compensating effects was still satisfying while load and

  20. 基于无差拍控制的有源电力滤波器直接电流控制研究%Research on Direct Current Control of Active Power Filter Based on Deadbeat Control

    Institute of Scientific and Technical Information of China (English)

    贺永平; 庄圣贤

    2015-01-01

    An improved method for direct current control of active power filter based on deadbeat control is proposed. Compared with the traditional current control method, the deadbeat control is carried out in the αβ coordinate system to avoid the serious coupling by dq transform. Fundamental component of load current is brought into the given value of source current, the system dynamic response is enhanced. The load current and the source voltage are feed-forward compensated to improve the compensation precision of the system. The simulation results show that the improved method has better dynamic performance than the conventional control method and also it can realize the selective compensation of load current between harmonics and reactive component.%提出一种基于无差拍控制的有源电力滤波器网侧电流直接控制方法。与传统网侧电流控制法相比,该方法的无差拍电流控制策略在αβ坐标系中实现,抑制了由dq变换引入的严重耦合;引入负载电流基波分量作为网侧电流的给定值,增强了系统的动态响应;对负载电流和电网电压进行前馈补偿,进一步提高了系统的补偿精度。仿真结果表明:改进方法比传统控制法具有更优越的动态性能,且可以实现APF对负载电流谐波分量和无功分量的选择性补偿。

  1. Predictive Current Control Strategy Based on ADALINE for Active Power Filter%基于ADALINE的有源电力滤波器预测电流控制策略

    Institute of Scientific and Technical Information of China (English)

    章兢; 于晶荣

    2009-01-01

    为有效补偿有源电力滤波器(APF)的控制延时, 提出一种基于自适应线性神经元(ADALINE)的APF预测电流控制策略.该策略通过ADALINE预测下一控制周期的参考电流, 根据两相静止坐标系下APF系统模型确定参考电压, 利用空间矢量脉宽调制(SVPWM)方法, 使APF输出电流快速、准确地跟踪参考电流.仿真与APF样机上的实际运行结果表明, 和采用传统无预测算法的SVPWM方法相比, 采用本文提出的预测电流控制策略, APF的稳态补偿精度和动态跟踪性能均明显提高.%In order to compensate control delay of active power filter (APF), a predictive current control strategy based on ADAptive LInear NEuron (ADALINE) for three-phase APF is proposed. Reference compensation current for next control cycle is calculated by current predictive algorithm based on ADALINE, and reference voltage is determined according to APF mathematical model in two-phase static coordinate system. The output current of APF can track to reference current quickly and exactly by space vector pulse width modulation (SVPWM) method. Simulation and experimental results on APF prototype demonstrate that, compared with APF of SVPWM control without predictive algorithm, APF with predictive current control strategy based on ADALINE has higher steady state compensation accuracy and better dynamic performance.

  2. A Low Power Linear Phase Digital FIR Filter for Wearable ECG Devices.

    Science.gov (United States)

    Lian, Yong; Yu, Jianghong

    2005-01-01

    In this paper we present a low power linear phase digital FIR filter which is a part of an ECG-on-Chip. The ECG-on-Chip can be embedded into clothing to acquire the electrocardiogram (ECG) signal and send a warning message to a mobile phone or PDA if an abnormal ECG is detected. The proposed new filter structure significantly reduces the arithmetic operations for each sample which in turn lowers the power consumption. The filter is developed based on the interpolated finite impulse filter technique and is very attractive for a low cost and low power VLSI implementation.

  3. 78 FR 44957 - Agency Information Collection Activities: BioWatch Filter Holder Log, Filter Holder Log DHS Form...

    Science.gov (United States)

    2013-07-25

    ... SECURITY Agency Information Collection Activities: BioWatch Filter Holder Log, Filter Holder Log DHS Form... maintenance of required documentation. The filter holder log form is part of the documentation required by federal law enforcement for the BioWatch Program. The filter holder log is required to create a...

  4. 有源滤波器的模糊阈值变环宽滞环电流跟踪控制策略%A fuzzy threshold mutative bandwidth hysteresis current tracking control method for active power filter

    Institute of Scientific and Technical Information of China (English)

    刘心旸; 王杰; 王昕; 姚钢

    2011-01-01

    A fuzzy threshold mutative bandwidth hysteresis current tracking control method for the Active Power Filter (APF) current tracking module is presented. Based on the construction of APF device model and the analysis of the variation of hysteresis width, the purpose to achieve a limited frequency of switching is reached by using an internal fuzzy controller to dynamically adjust the loop width of hysteresis comparator device. Compared with the traditional hysteresis method, the proposed method has more excellent dynamic response and tracking precision, taking full advantage of conduction capability of the power switches, moreover,a reduction of the maximum switching frequency ensures that the device operates safely. Finally, the current tracking efficiency of the method above and the harmonic compensating capability to nonlinear loads are demonstrated by the simulation and experiment results in this paper.This work is supported by National Natural Science Foundation of China (No. 60674035).%针对有源电力滤波器(APF)的电流跟踪功能模块,提出了一种模糊阈值变环宽滞环电流跟踪控制算法.在构建APF装置模型并分析滞环宽度变化规律的基础上,通过使用内部模糊控制器用以动态地调节滞环比较器的环宽,从而达到了限定开关频率的目的.该方法相比于传统滞环比较方法具有更好的跟踪精度和动态性能,充分利用了开关器件的导通能力;同时由于降低了最大开关频率,从而保证了装置的安全运行.通过仿真与实际实验结果进一步验证了该算法的电流跟踪效果以及对于非线性装置产生的系统谐波的补偿能力.

  5. Frequency Spectrum Based Low-Area Low-Power Parallel FIR Filter Design

    Directory of Open Access Journals (Sweden)

    Jin-Gyun Chung

    2002-09-01

    Full Text Available Parallel (or block FIR digital filters can be used either for high-speed or low-power (with reduced supply voltage applications. Traditional parallel filter implementations cause linear increase in the hardware cost with respect to the block size. Recently, an efficient parallel FIR filter implementation technique requiring a less-than linear increase in the hardware cost was proposed. This paper makes two contributions. First, the filter spectrum characteristics are exploited to select the best fast filter structures. Second, a novel block filter quantization algorithm is introduced. Using filter benchmarks, it is shown that the use of the appropriate fast FIR filter structures and the proposed quantization scheme can result in reduction in the number of binary adders up to 20%.

  6. Power Ramp Limitation capabilities of Large PV Power Plants with Active Power Reserves

    DEFF Research Database (Denmark)

    Bogdan, Craciun; Kerekes, Tamas; Sera, Dezso

    2017-01-01

    Power Ramp Limitation (PRL) is likely to become a requirement for large scale photovoltaic power plants (LPVPPs) in order to allow the increase of PV penetration levels. Especially in islands with reduced inertia capability, this problem is more stringent: high power ramp can be caused by either...... fast irradiance changes or other participant generators for example wind power, or loads. In order to compensate for the power mismatch, LPVPPs must use Active Power Reserve (APR), by either curtailment or auxiliary storage. The paper proposes a PRL control structure for dynamic APR sizing...... area of LPVPPs acts as filter against fast irradiance changes, the study reveals also the required plant size for which auxiliary storage is no longer needed in order to comply with PRL requirements – an important economical aspect....

  7. Filtered-X Affine Projection Algorithms for Active Noise Control Using Volterra Filters

    Directory of Open Access Journals (Sweden)

    Sicuranza Giovanni L

    2004-01-01

    Full Text Available We consider the use of adaptive Volterra filters, implemented in the form of multichannel filter banks, as nonlinear active noise controllers. In particular, we discuss the derivation of filtered-X affine projection algorithms for homogeneous quadratic filters. According to the multichannel approach, it is then easy to pass from these algorithms to those of a generic Volterra filter. It is shown in the paper that the AP technique offers better convergence and tracking capabilities than the classical LMS and NLMS algorithms usually applied in nonlinear active noise controllers, with a limited complexity increase. This paper extends in two ways the content of a previous contribution published in Proc. IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing (NSIP '03, Grado, Italy, June 2003. First of all, a general adaptation algorithm valid for any order of affine projections is presented. Secondly, a more complete set of experiments is reported. In particular, the effects of using multichannel filter banks with a reduced number of channels are investigated and relevant results are shown.

  8. Transistor-based filter for inhibiting load noise from entering a power supply

    Science.gov (United States)

    Taubman, Matthew S

    2013-07-02

    A transistor-based filter for inhibiting load noise from entering a power supply is disclosed. The filter includes a first transistor having an emitter coupled to a power supply, a collector coupled to a load, and a base. The filter also includes a first capacitor coupled between the base of the first transistor and a ground terminal. The filter further includes an impedance coupled between the base and a node between the collector and the load, or a second transistor and second capacitor. The impedance can be a resistor or an inductor.

  9. Design of the Trap Filter for the High Power Converters with Parallel Interleaved VSCs

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

    2014-01-01

    The power handling capability of the state-of-the-art semiconductor devices is limited. Therefore, the Voltage Source Converters (VSCs) are often connected in parallel to realize high power converter. The switching frequency semiconductor devices, used in the high power VSCs, is also limited. The...... to sink the dominant harmonic frequency components. The design procedure of the line filter is illustrated and the filter performance is also verified by performing the simulation and the experimental study....

  10. Systematic Design of the Lead-Lag Network Method for Active Damping in LCL-Filter Based Three Phase Converters

    DEFF Research Database (Denmark)

    Alzola, Rafael Pena; Liserre, Marco; Blaabjerg, Frede

    2014-01-01

    Three-phase active rectifiers guarantee sinusoidal input currents and unity power factor at the price of a high switching frequency ripple. To adopt an LCL-filter, instead of an L-filter, allows using reduced values for the inductances and so preserving dynamics. However, stability problems can...

  11. Stability analysis and active damping for LLCL-filter based grid-connected inverters

    DEFF Research Database (Denmark)

    Huang, Min; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    A higher order passive power filter (LLCL-filter) for the grid-tied inverter is becoming attractive for the industrial applications due to the possibility to reduce the cost of the copper and the magnetic material. To avoid the well-known stability problems of the LLCL-filter it is requested to use...... either passive or active damping methods. This paper analyzes the stability when damping is required and when damping is not necessary considering sampling and transport delay. Basic LLCL resonance damping properties of different feedback states are also studied. Then an active damping method which...... is using the capacitor current feedback for LLCL-filter is introduced. Based on this method, a design procedure for the control method is given. Last, both simulation and experimental results are provided to validate the theoretical analysis of this paper....

  12. Zero-sequence current decoupling control of three-phase four-wire active power filter%四桥臂有源滤波器零序电流解耦预测电流控制

    Institute of Scientific and Technical Information of China (English)

    王晓刚; 张杰

    2016-01-01

    针对应用于三相四线制系统中的三相四桥臂有源电力滤波器的特点,研究了一种基于零序电流解耦的预测电流控制方法,分析了零序电流解耦的原理,设计了控制系统。该方法有效地解除了第四桥臂和前三桥臂的耦合,对中线电流进行独立补偿,与三相三桥臂的控制方法兼容,简单易行,易于对三桥臂有源电力滤波器进行改造后应用于三相四线系统。仿真分析表明,与其他方法相比,基于零序电流解耦的预测电流控制可使有源电力滤波器获得更好的补偿性能,电源电流总谐波畸变率和中线电流正负峰值均达到最小。%Zero-sequence current decoupling based predictive current control of three-phase four-wire active power filter (APF)is studied based on the characteristics of three-phase four-leg APF.The principle of zero-se-quence decoupling is analyzed and the control system is designed.The control method eliminates the coupling between the first three legs and the fourth leg,and the neutral current is compensated independently.The meth-od is compatible with the control of three-phase three-leg APF and is simple to implement.It is easy to upgrade the three-leg APF to meet the three-phase four wire applications.Simulation analyses show that zero-sequence current decoupling based predictive current control achieves better compensation performance than other meth-ods,total harmonic distortion of supply currents and positive /negative amplitudes of neutral current are both with minimum.

  13. 一种新型自均压二极管钳位级联有源滤波器%A Novel Voltage Self-balance Diode-clamped Cascaded Multilevel Active Power Filter

    Institute of Scientific and Technical Information of China (English)

    高聪哲; 姜新建; 李永东

    2012-01-01

    A novel diode-clamped cascaded multilevel converter topology is proposed. The half bridge cascade cell is added a clamping diode to the DC-link capacitor, and it may provide an energy channel clamping in single direction for capacitor voltage. Via the clamping diodes, only the top and bottom cells of a phase arm need to be controlled to realize each cell' s capacitors voltage balance. Therefore, the DC-link voltage sensors of a phase arm are reduced to two, much less than that of traditional cascaded converter. A three-phase multilevel active power filter (APF) topology based on the proposed diode clamped cascaded multilevel converter topology is provided, and its control strategy is presented as well. A simulation model and an experiment prototype of seven-level diode-clamped cascaded multilevel APF are built. The simulation and experiment results show that the novel cascaded multilevel converter topology has good performance in voltage selbbalance control and harmonics compensation, and the control algorithm is easy and feasible.%提出一种新型二极管钳位级联多电平拓扑,在半桥单元拓扑上增加钳位二极管,为直流电容提供单向钳位通路。在该拓扑中,只需对阀体两端单元的直流电压进行控制就可实现均压控制,且每相阀体只需2个直流电压传感器,结构简单。将拓扑拓展到三相结构,提出了二极管钳位多电平有源滤波器(APF)拓扑及其控制方法。搭建了7电平二极管钳位多电平APF仿真模型和实验样机。实验结果表明,该拓扑自均压控制和谐波补偿效果良好,控制算法简易、可行。

  14. 神经网络自适应PI控制器在有源滤波器中的应用%Application of neural network adaptive PI controller in active power filter

    Institute of Scientific and Technical Information of China (English)

    冯亚琼; 王昕; 周荔丹; 郑益慧

    2011-01-01

    For current tracking control problems in active power filter (APF), a neural network adaptive PI (NNAPI) controller is designed. It combines the neural network technology with PI controller structure. It adopts the PI controller structurei which has the advantages of simple structure, short computing time and easy realization. Meanwhile > the neural network technology is used to make the output of APF be the PI controller parameters values under an optimal control law, and conduct an online real-time adaptive setting of the parameter values according to the error, thus to meet the requirements of full range working conditions and optimality. Simulation experiments show that NNAPI controller has quicker response speed and higher accuracy of compensation comparing with general PI controller. When NNAPI controller works, its total harmonic distortion rate of electric current and the current tracking error are reduced to around 55 percent of that using PI controller.%针对有源电力滤波器的电流跟踪控制问题,设计一种神经网络自适应PI控制器.该控制器将神经网络技术和PI控制器设计方法相结合,控制器采用PI控制器结构,具有结构简单、计算时间短、易于实现等优点.同时利用神经网络技术,使其输出作为最优控制规律下的PI控制器的参数值,并根据误差大小对控制器参数进行在线实时自适应整定,从而满足大工况、全工作条件和最优性的要求,仿真实验表明,神经网络自适应PI控制器较一般的PI控制器有更快的响应速度和更高的补偿精度,而且经过神经网络自适应PI控制器作用后,其电网电流的谐波畸变率和电流跟踪误差均降低到PI控制器的55%左右.

  15. 神经网络算法的改进及其在有源电力滤波器中的应用%Study on algorithm improvement of BP neural networks and its application in active power filter

    Institute of Scientific and Technical Information of China (English)

    马草原; 孙富华; 朱蓓蓓; 尹志超

    2015-01-01

    For current tracking control problems in active power filter (APF), a BP neural network adaptive PI controller based on improved gradient algorithm is designed. It combines the neural network technology with PI controller structure. Compared with the traditional PI controller, it has a simple structure, and easy to on-line adjustment. Meanwhile, in order to overcome the local minimum and slow convergence problem when using neural network algorithm to weight correction coefficient, the gradient algorithm is improved and the algebraic method instead of gradient descent method is used to solve the problem of the local minimum arise, and makes convergence faster. Simulation experiments show that the improved adaptive neural network PI controller has faster response and higher compensation accuracy, thus to make the system more stable, and the harmonic distortion of grid current is lower.%针对有源电力滤波器的电流跟踪控制问题,设计了一种基于改进梯度算法的BP神经网络自适应PI控制器。该控制器将神经网络技术与PI参数设计相结合,与传统的PI控制器相比,该控制器具有结构简单、易于在线调整等优点。同时,为了克服采用神经网络算法修正权值系数时,会存在局部极小、收敛速度慢的问题,对 BP 神经网络采用的梯度算法进行改进。利用代数法代替梯度下降法,从而解决了易出现局部极小问题,且使收敛速度更快。仿真实验表明,改进后的神经网络自适应PI控制器较传统的PI控制器有更快的响应速度和更高的补偿精度,从而使系统更稳定,而且电网电流的谐波畸变率更低。

  16. Temperature dependence of power handling capability of HTS filter with double-strip resonator

    Science.gov (United States)

    Sekiya, N.; Fujihara, K.

    2016-11-01

    We have investigated the temperature dependence of power handling capability of a high temperature superconducting filter with a double-strip resonator (DSR). The DSR structure consists of two coupled strips and the center pins of the SMA connector as feed line. We designed a four-pole DSR filter with the center frequency of 5 GHz and band width of 50 MHz. The filter was fabricated using two YBa2Cu3Oy thin films on CeO2-buffered r-Al2O3 substrates. The measured frequency responses of the filters were in reasonable agreement with the simulated ones. The measured power handling capability of the DSR filter at 35 K was 3.2 times higher than that of the filter at 70 K.

  17. Single-Phase LLCL-Filter-based Grid-Tied Inverter with Low-Pass Filter Based Capacitor Current Feedback Active damper

    DEFF Research Database (Denmark)

    Liu, Yuan; Wu, Weimin; Li, Yun;

    2016-01-01

    The capacitor-current-feedback active damping method is attractive for high-order-filter-based high power grid-tied inverter when the grid impedance varies within a wide range. In order to improve the system control bandwidth and attenuate the high order grid background harmonics by using the quasi....... In this paper, a low pass filter is proposed to be inserted in the capacitor current feedback loop op LLCL-filter based grid-tied inverter together with a digital proportional and differential compensator. The detailed theoretical analysis is given. For verification, simulations on a 2kW/220V/10kHz LLCL...

  18. Intrinsic dendritic filtering gives low-pass power spectra of local field potentials

    DEFF Research Database (Denmark)

    Lindén, Henrik; Pettersen, Klas H; Einevoll, Gaute T

    2010-01-01

    of contributions to the LFP from a single layer-5 pyramidal neuron and a single layer-4 stellate neuron receiving synaptic input. An intrinsic dendritic low-pass filtering effect of the LFP signal, previously demonstrated for extracellular signatures of action potentials, is seen to strongly affect the LFP power...... spectra, even for frequencies as low as 10 Hz for the example pyramidal neuron. Further, the LFP signal is found to depend sensitively on both the recording position and the position of the synaptic input: the LFP power spectra recorded close to the active synapse are typically found to be less low...... of the observed LFP. Two approximate schemes for calculating the LFP, the dipole approximation and the two-monopole approximation, are tested and found to be potentially useful for translating results from large-scale neural network models into predictions for results from electroencephalographic (EEG...

  19. 42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate respirators... RESPIRATORY PROTECTIVE DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.179 Non-powered air-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of...

  20. Method for Evaluating Insertion Loss of EMI Filter Connected to Semiconductor Power Converters

    Science.gov (United States)

    Tamate, Michio; Sasaki, Tamiko; Toba, Akio; Matsumoto, Yasushi; Wada, Keiji; Shimizu, Toshihisa

    In this paper, to design an EMI filter effectively, a method for insertion loss of an EMI filter connected to a semiconductor power converter is proposed. Conducted EMI noise that flows from the converter should conform to the regulations of an international commission, such as International Electrotechnical Commission (IEC). In order to conform to such regulations, EMI filters have to be connected to power converters. In general, the performance of the EMI filter is evaluated on the basis of the insertion loss of 50Ω measurement system. However, the impedance of the power converters is usually not set to 50Ω. As a result, the EMI filter design is often performed using a trial-and-error method because the noise reduction effect is different from the insertion loss. In this work, for simplicity, a power converter is considered to be a capacitor, instead of a stray capacitor. Then, a method for evaluating the insertion loss of an EMI filter connected to the power converter is proposed. This proposed method is employed using the 50Ω measurement system and the capacitance. The proposed method helps to design the EMI filter because the derived noise reduction effect corresponds to the experimental one.

  1. Active pre-filters for dc/dc Boost regulators

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Ramos-Paja

    2014-07-01

    Full Text Available This paper proposes an active pre-filter to mitigate the current harmonics generated by classical dc/dc Boost regulators, which generate current ripples proportional to the duty cycle. Therefore, high output voltage conditions, i.e., high voltage conversion ratios, produce high current harmonics that must be filtered to avoid damage or source losses. Traditionally, these current components are filtered using electrolytic capacitors, which introduce reliability problems because of their high failure rate. The solution introduced in this paper instead uses a dc/dc converter based on the parallel connection of the Boost canonical cells to filter the current ripples generated by the Boost regulator, improving the system reliability. This solution provides the additional benefits of improving the overall efficiency and the voltage conversion ratio. Finally, the solution is validated with simulations and experimental results.

  2. Monitoring active filters under automotive aging scenarios with embedded instrument

    NARCIS (Netherlands)

    Wan, Jinbo; Kerkhoff, Hans G.

    2012-01-01

    In automotive mixed-signal SoCs, the analogue/mixed-signal front-ends are of particular interest with regard to dependability. Because of the many electrical disturbances at the front-end, often (active) filters are being used. Due to the harsh environments, in some cases, degradation of these filte

  3. Development of active porous medium filters based on plasma textiles

    Science.gov (United States)

    Kuznetsov, Ivan A.; Saveliev, Alexei V.; Rasipuram, Srinivasan; Kuznetsov, Andrey V.; Brown, Alan; Jasper, Warren

    2012-05-01

    Inexpensive, flexible, washable, and durable materials that serve as antimicrobial filters and self-decontaminating fabrics are needed to provide active protection to people in areas regularly exposed to various biohazards, such as hospitals and bio research labs working with pathogens. Airlines and cruise lines need such material to combat the spread of infections. In households these materials can be used in HVAC filters to fight indoor pollution, which is especially dangerous to people suffering from asthma. Efficient filtering materials are also required in areas contaminated by other types of hazardous dust particulates, such as nuclear dust. The primary idea that guided the undertaken study is that a microplasma-generating structure can be embedded in a textile fabric to generate a plasma sheath ("plasma shield") that kills bacterial agents coming in contact with the fabric. The research resulted in the development of a plasma textile that can be used for producing new types of self-decontaminating garments, fabrics, and filter materials, capable of activating a plasma sheath that would filter, capture, and destroy any bacteriological agent deposited on its surface. This new material relies on the unique antimicrobial and catalytic properties of cold (room temperature) plasma that is benign to people and does not cause thermal damage to many polymer textiles, such as Nomex and polypropylene. The uniqueness of cold plasma as a disinfecting agent lies in the inability of bacteria to develop resistance to plasma exposure, as they can for antibiotics. Plasma textiles could thus be utilized for microbial destruction in active antimicrobial filters (for continuous decontamination and disinfection of large amounts of air) as well as in self-decontaminating surfaces and antibacterial barriers (for example, for creating local antiseptic or sterile environments around wounds and burns).

  4. Low Power and Low Leakage Implementation of RNS FIR Filters

    DEFF Research Database (Denmark)

    Cardarilli, Gian Carlo; Re, Andrea Del; Nannarelli, Alberto

    2005-01-01

    The CMOS technology scaling is leading to the integration of ever more complex systems on silicon. On the other hand, the shrinking of the devices and the reduction of the supply voltage have significantly increased the static power dissipation, that in power budgets of nanometer technologies, ca...

  5. Higher-order chaotic oscillator using active bessel filter

    DEFF Research Database (Denmark)

    Lindberg, Erik; Mykolaitis, Gytis; Bumelien, Skaidra;

    2010-01-01

    A higher-order oscillator, including a nonlinear unit and an 8th-order low-pass active Bessel filter is described. The Bessel unit plays the role of "three-in-one": a delay line, an amplifier and a filter. Results of hardware experiments and numerical simulation are presented. Depending on the pa...... on the parameters of the nonlinear unit the oscillator operates either in a one-scroll or two-scroll mode. Two positive Lyapunov exponents, found at larger values of the negative slopes of the nonlinear function, characterize the oscillations as hyperchaotic....

  6. Powered, air-purifying particulate respirator filter penetration by a DOP aerosol.

    Science.gov (United States)

    Martin, Stephen; Moyer, Ernest; Jensen, Paul

    2006-11-01

    In 1995, new certification requirements for all nonpowered, air-purifying particulate filter respirators were put in place when 42 CFR 84 replaced 30 CFR 11. However, the certification requirements for all other classes of respirators, including powered air-purifying respirators (PAPRs), were transferred to 42 CFR 84 from 30 CFR 11 without major changes. Since the inception of 42 CFR 84, researchers have learned that the efficiency of electrostatic filter media, in contrast with mechanical filter media, can be rapidly degraded by oil aerosols. Further, confusion may exist among respirator users, since electrostatic PAPR filters have the same magenta color assigned to high-efficiency filters for nonpowered particulate respirators that have been tested and certified for use against oil aerosols (i.e., P100 filters). Users may expect that the magenta color of certified PAPR filters indicates suitability for use against oil aerosols. This may not be the case. To illustrate the potential degradation of electrostatic PAPR filters, new filters certified under 42 CFR 84 were tested using a TSI model 8122 Automated Respirator Tester against charged and neutralized DOP aerosols with intermittent loading schedules. The performance of a magenta-colored electrostatic PAPR filter--one for which the manufacturer's user instructions appropriately indicates is not suitable for use in oily environments--was compared with the performance of several mechanical PAPR filters. In tests against both DOP aerosols, the electrostatic PAPR filter showed a significant decrease in performance at DOP loadings exceeding 400 mg, whereas mechanical filters showed no significant change in the performance except at extremely high loadings. The decreased performance of the electrostatic PAPR filter was found to be significantly greater when tested against a neutralized DOP aerosol when compared with a charged DOP aerosol. While laboratory tests show that the filtration efficiency of this electrostatic

  7. A high-power spatial filter for Thomson scattering stray light reduction

    Science.gov (United States)

    Levesque, J. P.; Litzner, K. D.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. S.

    2011-03-01

    The Thomson scattering diagnostic on the High Beta Tokamak-Extended Pulse (HBT-EP) is routinely used to measure electron temperature and density during plasma discharges. Avalanche photodiodes in a five-channel interference filter polychromator measure scattered light from a 6 ns, 800 mJ, 1064 nm Nd:YAG laser pulse. A low cost, high-power spatial filter was designed, tested, and added to the laser beamline in order to reduce stray laser light to levels which are acceptable for accurate Rayleigh calibration. A detailed analysis of the spatial filter design and performance is given. The spatial filter can be easily implemented in an existing Thomson scattering system without the need to disturb the vacuum chamber or significantly change the beamline. Although apertures in the spatial filter suffer substantial damage from the focused beam, with proper design they can last long enough to permit absolute calibration.

  8. Self-commissioning notch filter for active damping in three phase LCL-filter based grid converters

    DEFF Research Database (Denmark)

    Alzola, Rafael Pena; Liserre, Marco; Blaabjerg, Frede;

    2013-01-01

    challenge the LCL-filter stability. Active damping by using a notch filter on the reference voltage for the modulator is simple to implement and does not require additional sensors. With the notch frequency tuned for the resonant frequency the voltage reference does not contain any component susceptible...... of exciting the LCL-filter. However, the notch filter tuning requires considerable design effort and the variations in the resonance frequency limit the LCL-filter robustness. This paper proposes a simple tuning procedure for the notch filter that results in proper robustness. In order to cope with the grid...... inductance variations it is proposed to estimate the resonance frequency by means of Fourier analysis. The Goertzel algorithm, instead of the FFT, is used to reduce the calculation and memory requirements. Thus, the proposed self-commissioning notch filter results robust and consumes little computational...

  9. Energy-filtered Electron Transport Structures for Low-power Low-noise 2-D Electronics.

    Science.gov (United States)

    Pan, Xuan; Qiu, Wanzhi; Skafidas, Efstratios

    2016-10-31

    In addition to cryogenic techniques, energy filtering has the potential to achieve high-performance low-noise 2-D electronic systems. Assemblies based on graphene quantum dots (GQDs) have been demonstrated to exhibit interesting transport properties, including resonant tunnelling. In this paper, we investigate GQDs based structures with the goal of producing energy filters for next generation lower-power lower-noise 2-D electronic systems. We evaluate the electron transport properties of the proposed GQD device structures to demonstrate electron energy filtering and the ability to control the position and magnitude of the energy passband by appropriate device dimensioning. We also show that the signal-to-thermal noise ratio performance of the proposed nanoscale device can be modified according to device geometry. The tunability of two-dimensional GQD structures indicates a promising route for the design of electron energy filters to produce low-power and low-noise electronics.

  10. A review of DOE HEPA filter component test activities

    Energy Technology Data Exchange (ETDEWEB)

    Slawski, J.W.; Bresson, J.F. [Informatics Corp., Inc., Albuquerque, NM (United States); Scripsick, R.C. [Los Alamos National Lab., NM (United States)

    1997-08-01

    All HEPA filters purchased for installation in DOE nuclear facilities are required to be tested at a Filter Test Facility (FTF) prior to installation. The number of HEPA filters purchased by DOE has been reduced so much that the Hanford FTF was closed. From Fiscal Year (FY) 1992 to 1994, funding was not provided to the FTF Technical Support Group (TSG) at the Los Alamos National Laboratory. As a consequence, Round Robin Tests (RRTs), performed twice each year by the FTFs to assess constituency of test results among the FTFs, were not performed in FY 1992 and FY 1993. The Annual Reports of FTF test activities were not prepared for FY 1992 - 1995. Technical support provided to the FTFs was minimal. There is talk of closing a second FTF, and ongoing discussions as to whether DOE will continue to fund operation of the FTFs. In FY 1994, DOE Defense Programs commenced funding the TSG. RRT data for FY 1994 and 1995 have been entered into the database; the FY 1994 RRT report has been issued; and the FY 1995 RRT report is in progress. Data from semiannual reports have been retrieved and entered into the database. Standards related to HEPA filter test and procurement activities are now scheduled for issuance by FY 1996. Continuation of these activities depends on whether DOE will continue to support the HEPA filter test program. The history and activities of the FTFs and the TSG at Los Alamos have been reported at previous Air Cleaning Conferences. Data from the FY 1991 Annual Report of FTF activities was presented at the 1992 Air Cleaning Conference. Preparation of the Annual Reports was temporarily suspended in 1992. However, all of the FTF Semiannual report data have been retrieved and entered into the data base. This paper focuses primarily on the results of HEPA filter tests conducted by FTFs during FY 1992 - FY 1995, and the possible effects of the DOE program uncertainties on the quality of HEPA filters for installation at the DOE sites. 15 refs., 13 tabs.

  11. Implementation of High Performance Fir Filter Using Low Power Multiplier and Adder

    Directory of Open Access Journals (Sweden)

    Sweety Kashyap,

    2014-01-01

    Full Text Available The ever increasing growth in laptop and portable systems in cellular networks has intensified the research efforts in low power microelectronics. Now a day, there are many portable applications requiring low power and high throughput than ever before. Thus, low power system design has become a significant performance goal. So this paper is face with more constraints: high speed, high throughput, and at the same time, consumes as minimal power as possible. The Finite Impulse Response (FIR Filter is the important component for designing an efficient digital signal processing system. So, in this paper author trying, a FIR filter is constructing, which is efficient not only in terms of power and speed but also in terms of delay. When consider the elementary structure of an FIR filter, it is found that it is a combination of multipliers and delays, which in turn are the combination of adders. . This paper presents an efficient implementation and analysis for performance evaluation of multiplier and adder to minimize the consumption of energy during multiplication and addition methodology to improve the performance by compares different type of Multipliers and adder, respectively. By using, power comparison result of adders and multiplier, choice low power adder and multiplier to implementation of high performance FIR filter.

  12. Linear-phase delay filters for ultra-low-power signal processing in neural recording implants.

    Science.gov (United States)

    Gosselin, Benoit; Sawan, Mohamad; Kerherve, Eric

    2010-06-01

    We present the design and implementation of linear-phase delay filters for ultra-low-power signal processing in neural recording implants. We use these filters as low-distortion delay elements along with an automatic biopotential detector to perform integral waveform extraction and efficient power management. The presented delay elements are realized employing continuous-time OTA-C filters featuring 9th-order equiripple transfer functions with constant group delay. Such analog delay enables processing neural waveforms with reduced overhead compared to a digital delay since it does not requires sampling and digitization. It uses an allpass transfer function for achieving wider constant-delay bandwidth than all-pole does. Two filters realizations are compared for implementing the delay element: the Cascaded structure and the Inverse follow-the-leader feedback filter. Their respective strengths and drawbacks are assessed by modeling parasitics and non-idealities of OTAs, and by transistor-level simulations. A budget of 200 nA is used in both filters. Experimental measurements with the chosen filter topology are presented and discussed.

  13. Performance of a grid connected PV system used as active filter

    Energy Technology Data Exchange (ETDEWEB)

    Calleja, H. [Cenidet, Morelos (Mexico). Electronics Dept.; Jimenez, H. [IIE, Morelos (Mexico). Conventional Energy Sources Dept.

    2004-09-01

    In this paper, the performance of a grid connected photovoltaic (PV) system used as an active filter is presented. its main feature is the capability to compensate the reactive and harmonic currents drawn by nonlinear loads while simultaneously injecting into the grid the maximum power available from the cells. The system can also operate as a stand alone active filter. The system was connected to a 1 kW PV array and tested with the loads typically found in households: small motors, personal computers and electronic ballasts. The results show that the system can correct the power factor to values close to unity for all the cases tested, thereby improving the efficiency of the electric energy supply. (author)

  14. Reduction of power line interference in electrocardiographic signals by dual Kalman filtering

    Directory of Open Access Journals (Sweden)

    Luis David Avendaño Valencia

    2010-04-01

    Full Text Available This paper presents a filter for reducing powerline interference in electrocardiographic signals (ECG, based on dual parameter and state estimation using with a Kalman filter. Two models were used to represent power-line interference and ECG signal. Both models were combined to simulate the ECG signal whose state was estimated for separating the ECG signal from the interference. The proposed algorithm was fine-tuned and compared using a set of tests relying on the QT arrhythmia database. Tuning tests were done for tracking clean ECG; these results were used for setting the algorithm’s parameters for later filtering tests. Exhaustive filtering tests were carried out on artificially corrupted database registers for given signal to noise ratios; performance curves were thus obtained, leading to comparing the proposed algorithm with other filtering methods. The proposed algorithm was compared to an recursive infinite impulse response filter (IIR and a Kalman filter based on a simpler model. A filtering algorithm was thus obtained which is robust for changes in interference amplitude and keeps these properties for different types of ECG morphologies.

  15. Effect of a biological activated carbon filter on particle counts

    Institute of Scientific and Technical Information of China (English)

    Su-hua WU; Bing-zhi DONG; Tie-jun QIAO; Jin-song ZHANG

    2008-01-01

    Due to the importance of biological safety in drinking water quality and the disadvantages which exist in traditional methods of detecting typical microorganisms such as Cryptosporidium and Giardia,it is necessary to develop an alternative.Particle counts is a qualitative measurement of the amount of dissolved solids in water.The removal rate of particle counts was previously used as an indicator of the effectiveness of a biological activated carbon(BAC)filter in removing Cryptosporidium and Giardia.The particle counts in a BAC filter effluent over one operational period and the effects of BAC filter construction and operational parameters were investigated with a 10 m3/h pilot plant.The results indicated that the maximum particle count in backwash remnant water was as high as 1296 count/ml and it needed about 1.5 h to reduce from the maximum to less than 50 count/ml.During the standard filtration period,particle counts stay constant at less than 50 count/ml for 5 d except when influ-enced by sand filter backwash remnant water.The removal rates of particle counts in the BAC filter are related to characteristics of the carbon.For example,a columned carbon and a sand bed removed 33.3% and 8.5% of particles,respectively,while the particle counts in effluent from a cracked BAC filter was higher than that of the influent.There is no significant difference among particle removal rates with different filtration rates.High post-ozone dosage(>2 mg/L)plays an important role in particle count removal;when the dosage was 3 mg/L,the removal rates by carbon layers and sand beds decreased by 17.5% and increased by 9.5%,respectively,compared with a 2 mg/L dosage.

  16. Filter clogging and power loss issues while running a diesel engine with waste cooking oil

    Energy Technology Data Exchange (ETDEWEB)

    Bari, S.; Yu, C.W.; Lim, T.H. [Universiti Sains Malaysia, School of Mechanical Engineering, Penang (Malaysia)

    2003-07-01

    As with other vegetable oils, the high viscosity of waste cooking oil (WCO) poses some challenges to engine operation. One of them is filter clogging. In this research, it was found that heating to above 55 deg C was effective in preventing clogging. However, the head loss across the filter was about 6 times higher than that of diesel. Generally, the lower calorific values of vegetable oils are held responsible for the reduction in maximum power of the engine. While running with WCO, the maximum power of the engine was reduced by 10.9 per cent from that with diesel. Raising the fuel tank level and dividing the flow through two filters to compensate for the higher head loss across the filter reduced the maximum power loss to 5.0 and 8.8 per cent respectively. Therefore, higher head loss in the filter is also responsible for the loss of maximum power. In terms of combustion, WCO had a shorter ignition delay compared with diesel, resulting in a less intense premixed combustion phase. The CO and NO emissions were on the average 8.4 and 16.2 per cent higher than those for diesel. (Author)

  17. Active Finger Recognition from Surface EMG Signal Using Bayesian Filter

    Science.gov (United States)

    Araki, Nozomu; Hoashi, Yuki; Konishi, Yasuo; Mabuchi, Kunihiko; Ishigaki, Hiroyuki

    This paper proposed an active finger recognition method using Bayesian filter in order to control a myoelectric hand. We have previously proposed a finger joint angle estimation method based on measured surface electromyography (EMG) signals and a linear model. However, when we estimate 2 or more finger angles by this estimation method, the estimation angle of the inactive finger is not accurate. This is caused by interference of surface EMG signal. To solve this interference problem, we proposed active finger recognition method from the amplitude spectrum of surface EMG signal using Bayesian filter. To confirm the effectiveness of this recognition method, we developed a myoelectric hand simulator that implements proposed recognition algorithm and carried out real-time recognition experiment.

  18. Design and Simulation of a Shunt Active Filter in Application for Control of Harmonic Levels

    CERN Document Server

    Adrian, Gligor

    2010-01-01

    Nowadays, the active filters represent a viable alternative for controlling harmonic levels in industrial consumers electrical installations. It must be noted the availability of many different types of filter configurations that can be used but there is no standard method for rating the active filters. This paper focuses on describing the shunt active filter structure and design. The theoretical concepts underlying the design of shunt active filters are presented. To validate and highlight the performance of shunt active filters a Matlab-Simulink model was developed. Simulation results are also presented.

  19. FBD-Based Harmonic Current Detection Method for Active Power Filter%基于FBD法有源电力滤波器谐波电流检测方法

    Institute of Scientific and Technical Information of China (English)

    卢锋; 田铭兴

    2013-01-01

    Introduction was made to a kind of harmonic current detection method based on FBD (Fryze-Buchholz-Dpenbrock). Analy-sis was made to active power fundamental current, reactive power fundamental current, harmonic current, negative sequence fundamental current and any sub-harmonic current etc testing principles. The method used phase locked loop to generate reference voltage, to project load current to reference voltage, and to test various current components accurately via low-pass iflter, even under conditions of power net voltage distortion. Matlab/Simulink simulation results conifrm the feasibility and validity of the method.%介绍了一种基于FBD法的有源电力滤波器谐波电流检测方法,分析了基波有功电流和基波无功电流、谐波电流、基波负序电流和任意次谐波电流等的检测原理。该方法采用锁相环产生参考电压,将负载电流投影到参考电压上,通过低通滤波器可以准确检测出各种电流分量,并且在电网电压畸变情况下,该方法同样适用。Matlab/Simulink仿真结果证实了该方法的正确性和有效性。

  20. The steady-state performance of a controlled current active filter

    Energy Technology Data Exchange (ETDEWEB)

    Duke, R.M. (Univ. of Canterbury, Christchurch (New Zealand). Dept. of Electrical and Electronic Engineering); Round, S.D. (Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Electrical Engineering)

    1993-04-01

    An active filter that uses a high-frequency D-class asynchronous switching inverter for power system current distortion compensation is described. The distortion compensation technique involves deriving a signal corresponding to the distortion component of load current, and inverting and amplifying this signal for addition back to the supply current to cancel the load current distortion. A synthetic sinusoid is used to determine the distortion component in the time domain. Extensive computed and experimental results, illustrating the system's steady-state performance and ability to reduce the current harmonic distortion components, are presented. An intelligent controller is proposed to maintain the active filter's performance at the optimal operating point under varying load conditions.

  1. Gradient Descent Learning for Utility Current Compensation using Active Regenerative PWM Filter

    Directory of Open Access Journals (Sweden)

    R. Balamurugan

    2011-01-01

    Full Text Available Problem statement: Harmonic analysis is a primary matter of power quality assessment. Its main intention is to check the utility whether it is delivering the loads without any deviations in voltages and currents. The problem is due to proliferation of Electronic converters and power electronics which gave birth to numerous new applications, offering unmatched comfort to the customers. Approach: Harmonics should be maintained within the limits said in standards like IEEE 519 and others such as IEEE 1159 for safeguarding the utility. This was provided by many mitigation technologies like passive, shunt and series filtering, active conditioners, but they were lack of some demerits like huge cost, many controllers and circuit components. So for controlling the harmonic loads the converter with four quadrant characteristics was implemented and this converter act as shunt active filter as well as rectifier simultaneously without any additional circuitry. For having better harmonic reduction in addition, many controllers like p-q Theorem based controller, Fuzzy and gradient descent based neural network is also used. Results: The simulation results gives the compared source current wave forms for various controllers with individual harmonic mitigations. Conclusion: The pure utility current is obtained by using this intelligent neural filter without any additional components and without any extra controllers than the conventional methods.

  2. 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.

  3. 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

  4. Biquadratic Filter Applications Using a Fully-Differential Active-Only Integrator

    Directory of Open Access Journals (Sweden)

    H. A. Yildiz

    2013-04-01

    Full Text Available A new class of active filters, real active-only filters is described and possible implementation issues of these filters are discussed. To remedy these issues, a fully-differential active-only integrator block built around current controlled current conveyors is presented. The integration frequency of the proposed circuit is adjustable over a wide frequency range. As an application, a real active-only filter based on the classical two-integrator loop topology is presented and designed. The feasibility of this filter in a 0.35µm CMOS process is verified through SPECTRE simulation program in the CADENCE design tool.

  5. Operating experiences of the TESC BWE filter in the Escatron PFBC power plant

    Energy Technology Data Exchange (ETDEWEB)

    Tejedor, A.; Guilarte, R.; Nales, T.; Abellanal, I.

    1999-07-01

    A Ceramic Filter based on the TESC (Two Ends Supported Candle) concept by BWE has been operating since November 1997 at the 71 MWe Escatron PFBC Power Plant of ENDESA S.A. The Ceramic Filter is treating 1/9 of the combustion gases (this is 10.5 Kg/s), replacing a secondary cyclone, at temperatures ranging 750--820 C. The aim of this Project is to demonstrate the performance of a Ceramic Filter based on the TESC system, which keeps the ceramic elements working on compression by a pneumatic supporting system. The Escatron PFBC plant burns local lignites working under commercial conditions, and the objective is to optimize the main filtration parameters for these coals. The operating experience will permit evaluation of the design, the prediction of life expectancy of the materials used, while carrying out the tests needed to define commercial operating parameters. At present (December 1998) 4,420 hours of operation have been logged, 2,300 hours through the Ceramic Filter (mainly at full load) and the rest through a bypass cyclone system. The longest continuous Filter run lasted 687 hours, while the average run duration at the present test period is around 500 hours. Some problems regarding massive ash bridging due to the extremely sticky nature of the ash have been the main operating problem. Nevertheless, the operating results together with the very few candle failures (only in two of the runs) have proved that the TESC concept is right and a promising way to commercial hot gas filtration units. This paper describes the Escatron Filter Plant and reviews the operation experiences of the TESC Ceramic Filter at 71 MWe Escatron PFBC Plant.

  6. COMPARATIVE STUDY OF DIFFERENT KALMAN FILTER IMPLEMENTATIONS IN POWER SYSTEM STABILITY

    Directory of Open Access Journals (Sweden)

    H. H. Goh

    2014-01-01

    Full Text Available Voltage stability and voltage collapse issues have in recent years begun to constitute an unpleasant warning to the operational security of power systems. Many techniques have been investigated in order to predict the point of voltage collapse. However, there are still several restrictions due to the insufficiency of current system state information. Accompanied by the commencement of the Phasor Measurement Units (PMUs evolving technology, it donates a solution to enhance the existing power system state estimation. In consequence, the significances to develop preferable methods that would provide a preliminary warning before the voltage collapse had grabbed the attention. This study covers the forming of real-time system monitoring methods that able to provide a timely warning in the power system. The algorithms used to estimate the points of collapse are according to the theory that voltage instability is approximately linked to the maximum load ability of a transmission network. As a result, the critical operating conditions (peak of maximum deliverable power come when the system Thevenin impedance is equal to the load impedance. This study focuses specifically on research about the motivation and the application of different Kalman filter implementations such as Discrete Kalman Filter (DKF, Extended Kalman Filter (EKF and Unscented Kalman Filter (UKF are used to track the Thevenin parameters. Therefore, the implications of this research paper are to determine the robustness and reliability of the proposed tracking methods. As compared to previous studies, the tracking process is just mainly focused on DKF method only, while the novelty throughout this study is to compare the performances and efficiencies of different Kalman filters in determining the maximum load ability on the 2 different types of test systems. Accompanying, the parameters are utilized in real-time voltage instability estimator to discover the current system’s condition

  7. 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.

  8. Command Filtered Adaptive Fuzzy Neural Network Backstepping Control for Marine Power System

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2014-01-01

    Full Text Available In order to retrain chaotic oscillation of marine power system which is excited by periodic electromagnetism perturbation, a novel command-filtered adaptive fuzzy neural network backstepping control method is designed. First, the mathematical model of marine power system is established based on the two parallel nonlinear model. Then, main results of command-filtered adaptive fuzzy neural network backstepping control law are given. And the Lyapunov stability theory is applied to prove that the system can remain closed-loop asymptotically stable with this controller. Finally, simulation results indicate that the designed controller can suppress chaotic oscillation with fast convergence speed that makes the system return to the equilibrium point quickly; meanwhile, the parameter which induces chaotic oscillation can also be discriminated.

  9. A Sliding Mode Control for Four-Wire Shunt Active Filter

    Science.gov (United States)

    Hamoudi, Farid; Chaghi, Aziz; Adli, Mouloud; Amimeur, Hocine

    2011-09-01

    The present paper deals with the sliding mode control of a three-phase four-wire shunt active filter SAF, to improve phase-current waveform, neutral current mitigation and reactive power compensation in electric power distribution system. The sliding mode is formulated using elementary differential geometry, then the control vector is deduced from the sliding surface accessibility using the Lyapunov stability. The algorithm used to establish the current references for the sliding mode controller is based on the instantaneous real and imaginary power theory for four-wire system. It will be seen that this method permits to synthesis the control vector with simple manner, and finally, the obtained simulation results confirm that the above objectives are satisfied.

  10. 基于滑模控制的谐振阻抗型混合有源滤波系统控制技术%Control Technique of the Resonant Impedance Type Hybrid Active Power Filter Based on Sliding Mode Control

    Institute of Scientific and Technical Information of China (English)

    梁应昌

    2015-01-01

    基于滑模控制原理,针对矿用谐振阻抗型混合有源滤波系统( RITHAPF)控制技术进行深入研究,并对电网进行无功补偿和谐波抑制。利用开关函数建模法进行系统建模,给出RITHAPF的数学模型。通过对RITHAPF的等效模型的分析推导,提出了RITHAPF系统的收敛和稳定判据。结合离散指数趋近律对离散滑模控制的影响,将连续系统的指数趋近律方法推广到离散系统,证明离散指数趋近律滑模控制对系统摄动和外界干扰依然具有鲁棒性。进一步根据有源电力滤波器的离散数学模型,设计滑模离散数学模型。基于趋近律离散滑模变结构控制设计有源部分的电流跟踪控制器。结果表明,采用滑模控制的谐振阻抗型混合有源滤波器对矿用直流提升系统6 kV母线的无功功率和谐波电流补偿效果良好。%Based on principle of sliding mode control,the mine-used resonant impedance type hybrid active power filter system ( RITHAPF) control technology was further researched,and reactive power compensation and harmonic suppression on power grid were made. The switching function modeling method was adopted to make modeling and propose the mathematical model of RITHAPF. Through the derivation of RITHAPF equivalent model,a convergence and stability criterion was put for-ward for RITHAPF system. Combining the influence of discrete index reaching law on discrete sliding mode control,the reac-hing law index of the continuous system was extended to the discrete system,to prove that influence of the discrete index on the system perturbations and external disturbances is still robust. Furthermore,according to the discrete mathematical model of ac-tive power filter,the synovial discrete mathematical model is given. The active part current tracking controller was designed based on the reaching law of the discrete sliding mode control. The simulation results showed that the resonant impedance type

  11. Realization of Low Power High-Speed Channel Filters with Stringent Adjacent Channel Attenuation Specifications for Wireless Communication Receivers

    Science.gov (United States)

    Mathew, Jimson; Mahesh, R.; Vinod, A. P.; Lai, Edmund M.-K.

    Finite impulse response (FIR) filtering is the most computationally intensive operation in the channelizer of a wireless communication receiver. Higher order FIR channel filters are needed in the channelizer to meet the stringent adjacent channel attenuation specifications of wireless communications standards. The computational cost of FIR filters is dominated by the complexity of the coefficient multipliers. Even though many methods for reducing the complexity of filter multipliers have been proposed in literature, these works focused on lower order filters. This paper presents a coefficient-partitioning-based binary subexpression elimination method for realizing low power FIR filters. We show that the FIR filters implemented using proposed method consume less power and achieve speed improvement compared to existing filter implementations. Design examples of the channel filters employed in the Digital Advanced Mobile Phone System (D-AMPS) and Personal Digital Cellular (PDC) receivers show that the proposed method achieved 23% average reductions of full adder and power consumption and 23.3% reduction of delay over the best existing method. Synthesis results show that the proposed method offers average area reduction of 8% and power reduction of 22% over the best known method in literature.

  12. Interface of magnetoresistive converter of active power

    Directory of Open Access Journals (Sweden)

    A. I. Vytiaganets

    2009-10-01

    Full Text Available The vehicle and programmatic interfaces of magnetoresistive converter of active power are considered, the results of statistical treatment of the multiple measuring of active-power are analysed.

  13. Optical injection and spectral filtering of high-power UV laser diodes

    CERN Document Server

    Schäfer, V M; Tock, C J; Lucas, D M

    2015-01-01

    We demonstrate injection-locking of 120mW laser diodes operating at 397nm. We achieve stable operation with injection powers of ~100uW and a slave laser output power of up to 110mW. We investigate the spectral purity of the slave laser light via photon scattering experiments on a single trapped Ca40 ion. We show that it is possible to achieve a scattering rate indistinguishable from that of monochromatic light by filtering the laser light with a diffraction grating to remove amplified spontaneous emission.

  14. Multiple hormonal activities of UV filters and comparison of in vivo and in vitro estrogenic activity of ethyl-4-aminobenzoate in fish.

    Science.gov (United States)

    Kunz, Petra Y; Fent, Karl

    2006-10-12

    UV filters have been detected in surface water, wastewater and fish, and some of them are estrogenic in fish. At present, little is known about their additional hormonal activities in different hormonal receptor systems despite their increasing use and environmental persistence. Besides estrogenic activity, UV filters may have additional activities, both agonistic and antagonistic in aquatic organisms. In our study, we investigate a series of UV filters for multiple hormonal activities in vitro in human receptor systems and evaluate the predictive value of these findings for the activity in fish in vitro and in vivo. First we systematically analysed the estrogenic, antiestrogenic, androgenic, and antiandrogenic activity of 18 UV filters and one metabolite in vitro at non-cytotoxic concentrations with recombinant yeast systems carrying either a human estrogen (hERalpha) or androgen receptor (hAR). All 19 compounds elicited hormonal activities, surprisingly most of them multiple activities. We found 10 UV-filters having agonistic effects towards the hERalpha. Surprisingly, we identified for the first time six UV filters with androgenic activities and many of them having pronounced antiestrogenic and antiandrogenic activities. As much as 17 compounds inhibited 4,5-dihydrotestosterone activity in the hAR assay, while 14 compounds inhibited estradiol activity in the hERalpha assay, indicating antiandrogenic and antiestrogenic activity, respectively. In particular, the antiandrogenic activities of phenyl- and benzyl salicylate, benzophenone-1 and -2, and of 4-hydroxybenzophenone were higher than that of flutamide, a known hAR antagonist. In a second series of experiments, we investigated the predictive power of the hERalpha assay for aquatic organisms by further investigating the estrogenic UV filter ethyl 4-aminobenzoate (Et-PABA) in vitro and in vivo in fish. Et-PABA showed estrogenic activity in a recombinant yeast system carrying the rainbow trout estrogen receptor

  15. Physicochemical and sensory changes in aged sugarcane spirit submitted to filtering with activated carbon filter

    Directory of Open Access Journals (Sweden)

    Felipe Cimino Duarte

    2012-09-01

    Full Text Available Sugarcane spirit is a drink considered as a national symbol of Brazil. It is produced by large producers and by about 30 thousand small and medium home-distilling producers dispersed throughout the country. The copper originating from the home-distillers can become a serious problem since at high concentrations in beverages it may cause serious human health problems. Therefore, the objective of this study was to investigate the influence of the activated carbon used in commercial filters on the physicochemical and sensory characteristics of aged sugarcane spirit. Analyses of copper, dry extract, alcoholic degree, higher alcohols, volatile acids, aldehydes, esters, furfural, and methanol were performed. The sensory evaluation was performed by seven selected trained judges, who analyzed the yellow color, woody aroma and flavor, and intensity of alcoholic aroma and flavor of the cane spirit before and after the filtration process. The sensory tests were carried out using a 9 cm non-structured intensity scale. A reduction was observed in all compounds analyzed physicochemically, except for the esters, which increased after filtration. This increase is probably due to the esterification of the alcohols and acids present. According to the sensory results obtained, a reduction was observed in the intensity of the yellow color, aroma, and wood flavor characteristics, the major characteristics of the aging process.

  16. Alpha Stable Distribution Based Morphological Filter for Bearing and Gear Fault Diagnosis in Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Xinghui Zhang

    2015-01-01

    Full Text Available Gear and bearing play an important role as key components of rotating machinery power transmission systems in nuclear power plants. Their state conditions are very important for safety and normal operation of entire nuclear power plant. Vibration based condition monitoring is more complicated for the gear and bearing of planetary gearbox than those of fixed-axis gearbox. Many theoretical and engineering challenges in planetary gearbox fault diagnosis have not yet been resolved which are of great importance for nuclear power plants. A detailed vibration condition monitoring review of planetary gearbox used in nuclear power plants is conducted in this paper. A new fault diagnosis method of planetary gearbox gears is proposed. Bearing fault data, bearing simulation data, and gear fault data are used to test the new method. Signals preprocessed using dilation-erosion gradient filter and fast Fourier transform for fault information extraction. The length of structuring element (SE of dilation-erosion gradient filter is optimized by alpha stable distribution. Method experimental verification confirmed that parameter alpha is superior compared to kurtosis since it can reflect the form of entire signal and it cannot be influenced by noise similar to impulse.

  17. Stratification of nitrification activity in rapid sand filters for drinking water treatment

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Musovic, Sanin

    2013-01-01

    Rapid sand filters used in groundwater treatment remove ammonium, iron and manganese from the water. Ammonium is removed biologically by nitrifying microorganisms attached on the sand surface. Nitrification kinetics and activity is strongly affected by filter design and operation, which are the key...... parameters in process optimization. Nitrification optimization needs a detailed insight of the process and the way it takes place in the filter. Filters are often considered in a “black box” approach, where data are only available for influent and effluent and the entire filter is assumed homogenous. The aim...... of this study is to investigate nitrification activity in a rapid sand filter, with focus on its homogeneity and how it relates to filter performance. Two groundwater treatment plants in Denmark were selected for the experimental investigations. Plant 1 operates a single line of pre and after filters and has...

  18. H{infinity} Filtering for Dynamic Compensation of Self-Powered Neutron Detectors - A Linear Matrix Inequality Based Method -

    Energy Technology Data Exchange (ETDEWEB)

    Park, M.G.; Kim, Y.H.; Cha, K.H.; Kim, M.K. [Korea Electric Power Research Institute, Taejon (Korea)

    1999-07-01

    A method is described to develop and H{infinity} filtering method for the dynamic compensation of self-powered neutron detectors normally used for fixed incore instruments. An H{infinity} norm of the filter transfer matrix is used as the optimization criteria in the worst-case estimation error sense. Filter modeling is performed for both continuous- and discrete-time models. The filter gains are optimized in the sense of noise attenuation level of H{infinity} setting. By introducing Bounded Real Lemma, the conventional algebraic Riccati inequalities are converted into Linear Matrix Inequalities (LMIs). Finally, the filter design problem is solved via the convex optimization framework using LMIs. The simulation results show that remarkable improvements are achieved in view of the filter response time and the filter design efficiency. (author). 15 refs., 4 figs., 3 tabs.

  19. Creation of an iOS and Android Mobile Application for Inferior Vena Cava (IVC) Filters: A Powerful Tool to Optimize Care of Patients with IVC Filters.

    Science.gov (United States)

    Deso, Steven E; Idakoji, Ibrahim A; Muelly, Michael C; Kuo, William T

    2016-06-01

    Owing to a myriad of inferior vena cava (IVC) filter types and their potential complications, rapid and correct identification may be challenging when encountered on routine imaging. The authors aimed to develop an interactive mobile application that allows recognition of all IVC filters and related complications, to optimize the care of patients with indwelling IVC filters. The FDA Premarket Notification Database was queried from 1980 to 2014 to identify all IVC filter types in the United States. An electronic search was then performed on MEDLINE and the FDA MAUDE database to identify all reported complications associated with each device. High-resolution photos were taken of each filter type and corresponding computed tomographic and fluoroscopic images were obtained from an institutional review board-approved IVC filter registry. A wireframe and storyboard were created, and software was developed using HTML5/CSS compliant code. The software was deployed using PhoneGap (Adobe, San Jose, CA), and the prototype was tested and refined. Twenty-three IVC filter types were identified for inclusion. Safety data from FDA MAUDE and 72 relevant peer-reviewed studies were acquired, and complication rates for each filter type were highlighted in the application. Digital photos, fluoroscopic images, and CT DICOM files were seamlessly incorporated. All data were succinctly organized electronically, and the software was successfully deployed into Android (Google, Mountain View, CA) and iOS (Apple, Cupertino, CA) platforms. A powerful electronic mobile application was successfully created to allow rapid identification of all IVC filter types and related complications. This application may be used to optimize the care of patients with IVC filters.

  20. Fast Prediction of Differential Mode Noise Input Filter Requirements for FLyback and Boost Unity Power Factor Converters

    DEFF Research Database (Denmark)

    Andersen, Michael Andreas E.

    1997-01-01

    Two new and simple methods to make predictions of the differential mode (DM) input filter requirements are presented, one for flyback and one for boost unity power factor converters. They have been verified by measurements. They give the designer the ability to predict the DM input noise filter...

  1. LCL filter design for three-phase two-level power factor correction using line impedance stabilization network

    DEFF Research Database (Denmark)

    Kouchaki, Alireza; Nymand, Morten

    2016-01-01

    This paper presents LCL filter design method for three-phase two-level power factor correction (PFC) using line impedance stabilization network (LISN). A straightforward LCL filter design along with variation in grid impedance is not simply achievable and inevitably lead to an iterative solution...

  2. A High-Power Low-Loss Continuously Tunable Bandpass Filter With Transversely Biased Ferrite-Loaded Coaxial Resonators

    DEFF Research Database (Denmark)

    Acar, Öncel; Johansen, Tom Keinicke; Zhurbenko, Vitaliy

    2015-01-01

    This paper presents a technology for high-power lowlosscontinuously tunable RF filters demonstrated by the exampleof a two-pole coupled-resonator filter. The resonators are shortenedcoaxial cavities loaded with ferrite inserts, where an externallyapplied transverse dc magnetic bias controls...

  3. Development of adaptive IIR filtered-e LMS algorithm for active noise control

    Institute of Scientific and Technical Information of China (English)

    SUN Xu; MENG Guang; TENG Pengxiao; CHEN Duanshi

    2003-01-01

    Compared to finite impulse response (FIR) filters, infinite impulse response (IIR)filters can match the system better with much fewer coefficients, and hence the computationload is saved and the performance improves. Therefore, it is attractive to use IIR filters insteadof FIR filters in active noise control (ANC). However, filtered-U LMS (FULMS) algorithm, theIIR filter-based algorithm commonly used so far cannot ensure global convergence. A new IIRfilter based adaptive algorithm, which can ensure global convergence with computation loadonly slightly increasing, is proposed in this paper. The new algorithm is called as filtered-eLMS algorithm since the error signal of which need to be filtered. Simulation results show thatthe FELMS algorithm presents better performance than the FULMS algorithm.

  4. Interharmonics analysis of power signals with fundamental frequency deviation using Kalman filtering

    Energy Technology Data Exchange (ETDEWEB)

    Koese, Neslihan; Salor, Oezguel; Leblebicioglu, Kemal [TUBITAK UZAY, Power Electronics Group, TR 06531 Ankara (Turkey); METU, Electrical and Electronics Eng. Dept., TR 06531 Ankara (Turkey)

    2010-09-15

    In this paper a spectral decomposition-based method for interharmonic computation is proposed for power systems where the fundamental frequency fluctuates significantly. In the proposed method, the frequency domain components of the voltage waveform are obtained by Kalman filtering. Both the system fundamental frequency and the correct spectrum of the voltage waveform, and hence the exact interharmonics are obtained. The proposed method is tested with both simulated and field data obtained from different electric arc furnace (EAF) plants, where the system frequency deviates continuously due to the fluctuating load demands. Since the interharmonic frequencies are obtained by using Kalman filtering, no leakage effect of the DFT-based methods is involved in case of frequency deviations, which is an important advantage of the proposed method. (author)

  5. Particle capture in axial magnetic filters with power law flow model

    CERN Document Server

    Abbasov, T; Koksal, M

    1999-01-01

    A theory of capture of magnetic particle carried by laminar flow of viscous non-Newtonian (power law) fluid in axially ordered filters is presented. The velocity profile of the fluid flow is determined by the Kuwabara-Happel cell model. For the trajectory of the particle, the capture area and the filter performance simple analytical expressions are obtained. These expressions are valid for particle capture processes from both Newtonian and non-Newtonian fluids. For this reason the obtained theoretical results make it possible to widen the application of high-gradient magnetic filtration (HGMF) to other industrial areas. For Newtonian fluids the theoretical results are shown to be in good agreement with the experimental ones reported in the literature. (author)

  6. Particle capture in axial magnetic filters with power law flow model

    Science.gov (United States)

    Abbasov, T.; Herdem, S.; Köksal, M.

    1999-05-01

    A theory of capture of magnetic particle carried by laminar flow of viscous non-Newtonian (power law) fluid in axially ordered filters is presented. The velocity profile of the fluid flow is determined by the Kuwabara-Happel cell model. For the trajectory of the particle, the capture area and the filter performance simple analytical expressions are obtained. These expressions are valid for particle capture processes from both Newtonian and non-Newtonian fluids. For this reason the obtained theoretical results make it possible to widen the application of high-gradient magnetic filtration (HGMF) to other industrial areas. For Newtonian fluids the theoretical results are shown to be in good agreement with the experimental ones reported in the literature.

  7. Particle capture in axial magnetic filters with power law flow model

    Energy Technology Data Exchange (ETDEWEB)

    Abbasov, T.; Herdem, S.; Koksal, M. [Inonu University, Engineering Faculty, Department of Electrical and Electronics, Malatya (Turkey)

    1999-05-21

    A theory of capture of magnetic particle carried by laminar flow of viscous non-Newtonian (power law) fluid in axially ordered filters is presented. The velocity profile of the fluid flow is determined by the Kuwabara-Happel cell model. For the trajectory of the particle, the capture area and the filter performance simple analytical expressions are obtained. These expressions are valid for particle capture processes from both Newtonian and non-Newtonian fluids. For this reason the obtained theoretical results make it possible to widen the application of high-gradient magnetic filtration (HGMF) to other industrial areas. For Newtonian fluids the theoretical results are shown to be in good agreement with the experimental ones reported in the literature. (author)

  8. Simulation of an active filter for compensation of reactive power and suppression of harmonic currents in the phases and in the neuter of an unbalanced three-phase system of 4 wires; Simulacion de un filtro activo para compensacion de potencia reactiva y supresion de corrientes armonicas en las fases y en el neutro de un sistema trifasico de 4 kilos desbalanceado

    Energy Technology Data Exchange (ETDEWEB)

    Mino Aguilar, Gerardo

    1999-05-01

    In here it is presented a brief review of the state of art of power active filters used in the common coupling points between AC sources and nonlinear loads formed by static converters of AC/DC, for the suppression of harmonic currents and instantaneous compensation of the reactive power. Starting off from the active filters that affect only the three balanced currents of the three-phase systems of 3 wires, it is arrived at the subject of this thesis, whose objective is to solve the problem of the reactive compensation and suppression of harmonic currents in the three phases as well as in the neuter of the three-phase systems of 4 wires. The main contribution of this thesis is the design, analysis and simulation of an active filter that besides of suppressing the harmonic currents and compensating the power factor in the three phases of an unbalanced three-phase system, also has the capacity of removing the current that circulates in the neuter due to the unbalance of the phase currents. This design is based on the extension of the theory of the instantaneous reactive power that includes the existence of the zero sequence components of in the phase currents. It is set out in the thesis a novel filter based on an three-phase inverter of 4 branches, 3 branches of phase and one branch of neuter, that to the best knowledge of the author it has not been reported in the literature. Use is made of an extensive number of simulation results to prove the validity of this filter, whose behavior is superior to the filters for suppression of currents in the neuter existing in the literature, of which also a comparative study is presented. The thesis also includes a mathematical and graphical analysis of the symmetrical components in balanced and unbalanced systems in order to know the nature of the harmonic currents of zero sequence. It is included a section on causes and effects of the harmonic contamination problem. [Spanish] Se presenta un breve revision del estado del

  9. MACV/Radio integrated navigation for Mars powered descent via robust desensitized central difference Kalman filter

    Science.gov (United States)

    Lou, Taishan; Liu, Jie; Jin, Pan; Wang, Yan

    2017-01-01

    An innovative integrated navigation scheme based on MCAV/Radio measurement information during Mars powered descent phase, and a robust desensitized central difference Kalman filter (DCDKF) for systems with uncertain parameters or biases are proposed to improve the navigation descent accuracy. Based on the altitude and velocity information of the Miniature Coherent Altimeter and Velocimeter (MCAV), the radio-range information is added into the integrated navigation system to correct the horizontal position error of the vehicle during the Mars powered descent phase. Based the central difference transform, the sensitivity propagation of the state estimate errors in the DCDKF is described, and a designed desensitized cost function is minimized to obtain the gain matrix of the DCDKF. The performances of the innovative navigation scheme and the proposed DCDKF are all demonstrated by two Monte Carlo simulations with the Inertial Measurement Unit biases during the Mars power descent phase.

  10. A Self-commissioning Notch Filter for Active Damping in a Three-Phase LCL -Filter-Based Grid-Tie Converter

    DEFF Research Database (Denmark)

    Pena-Alzola, Rafael; Liserre, Marco; Blaabjerg, Frede

    2014-01-01

    LCL-filters are a cost-effective solution to mitigate harmonic current content in grid-tie converters. In order to avoid stability problems, the resonance frequency of LCL-filters can be damped with active techniques that remove dissipative elements but increase control complexity. A notch filter...... provides an effective solution, however tuning the filter requires considerable design effort and the variations in the grid impedance limit the LCL-filter robustness. This paper proposes a straightforward tuning procedure for a notch filter self-commissioning. In order to account for the grid inductance...

  11. Active Power Controls from Wind Power: Bridging the Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Ela, E.; Gevorgian, V.; Fleming, P.; Zhang, Y. C.; Singh, M.; Muljadi, E.; Scholbrook, A.; Aho, J.; Buckspan, A.; Pao, L.; Singhvi, V.; Tuohy, A.; Pourbeik, P.; Brooks, D.; Bhatt, N.

    2014-01-01

    This paper details a comprehensive study undertaken by the National Renewable Energy Laboratory, Electric Power Research Institute, and the University of Colorado to understand how the contribution of wind power providing active power control (APC) can benefit the total power system economics, increase revenue streams, improve the reliability and security of the power system, and provide superior and efficient response while reducing any structural and loading impacts that may reduce the life of the wind turbine or its components. The study includes power system simulations, control simulations, and actual field tests using turbines at NREL's National Wind Technology Center (NWTC). The study focuses on synthetic inertial control, primary frequency control, and automatic generation control, and analyzes timeframes ranging from milliseconds to minutes to the lifetime of wind turbines, locational scope ranging from components of turbines to large wind plants to entire synchronous interconnections, and additional topics ranging from economics to power system engineering to control design.

  12. Active and reactive power control of a current-source PWM-rectifier using space vectors

    Energy Technology Data Exchange (ETDEWEB)

    Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

    1997-12-31

    In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

  13. A low-power asynchronous data-path for a FIR filter bank

    DEFF Research Database (Denmark)

    Nielsen, Lars Skovby; Sparsø, Jens

    1996-01-01

    This paper describes a number of design issues relating to the implementation of low-power asynchronous signal processing circuits. Specifically, the paper addresses the design of a dedicated processor structure that implements an audio FIR filter bank which is part of an industrial application. ...... the implications it has on the choice of architecture, handshake-protocol, data-encoding, and circuit design. This includes a tagging scheme that divides the data-path into slices, and an asynchronous ripple carry adder that avoids a completion tree....

  14. Optimal Control for DC Side Voltage of Active Power Filter Based on Auto-Disturbance Rejection Control%基于自抗扰控制技术的有源电力滤波器直流侧电压优化控制

    Institute of Scientific and Technical Information of China (English)

    丁祖军; 刘保连; 张宇林

    2013-01-01

      直流侧电压的稳定控制是保证有源电力滤波器(active power filter,APF)正常工作的关键环节之一。对APF直流侧电压进行建模,在dq坐标系中分析了直流侧电压与d轴电流的数学关系,进而提出了 APF 直流侧电压自抗扰控制器的整体设计方法,给出了自抗扰控制器中的跟踪微分单元、扩张状态观测器和误差反馈单元的设计方法,并采用线性方法对该控制器进行优化,提高了响应速度与控制精度。仿真与试验结果验证了该设计方法的可行性。%  The stable control of DC side voltage is one of key links to ensure normal operation of active power filter (APF). The model of DC side voltage of APF is established and the mathematical relation between DC side voltage and d-axis current is analyzed in dq coordinate system, and then a total design method for auto disturbances rejection controller (ADRC) of DC side voltage of APF is proposed. The design method of tracking differentiator (TD), extended state observer (ECO) and error feedback unit of ADRC are given, and linear optimization is applied to the ADRC to improve its response speed and control accuracy. The feasibility of the proposed design method is validated by simulation and experimental results.

  15. Adaptive Controller for Vehicle Active Suspension Generated Through LMS Filter Algorithms

    Institute of Scientific and Technical Information of China (English)

    SUN Jianmin; SHU Gequn

    2006-01-01

    The least means squares (LMS) adaptive filter algorithm was used in active suspension system.By adjusting the weight of adaptive filter, the minimum quadratic performance index was obtained.For two-degree-of-freedom vehicle suspension model, LMS adaptive controller was designed.The acceleration of the sprung mass,the dynamic tyre load between wheels and road,and the dynamic deflection between sprung mass and unsprung mass were determined as the evaluation targets of suspension performance.For LMS adaptive control suspension, compared with passive suspension, acceleration power spectral density of sprung mass acceleration under the road input model decreased 8-10 times in high frequency resonance band or low frequency resonance band.The simulation results show that LMS adaptive control is simple and remarkably effective.It further proves that the active control suspension system can improve both the riding comfort and handling safety in various operation conditions, and the method is fit for the active control of the suspension system.

  16. LOW ACTIVITY WASTE FEED SOLIDS CARACTERIZATION AND FILTERABILITY TESTS

    Energy Technology Data Exchange (ETDEWEB)

    McCabe, D.; Crawford, C.; Duignan, M.; Williams, M.; Burket, P.

    2014-04-03

    The primary treatment of the tank waste at the DOE Hanford site will be done in the Waste Treatment and Immobilization Plant (WTP) that is currently under construction. The baseline plan for the WTP Pretreatment facility is to treat the waste, splitting it into High Level Waste (HLW) feed and Low Activity Waste (LAW) feed. Both waste streams are then separately vitrified as glass and sealed in canisters. The LAW glass will be disposed onsite in the Integrated Disposal Facility (IDF). There are currently no plans to treat the waste to remove technetium in the WTP Pretreatment facility, so its disposition path is the LAW glass. Options are being explored to immobilize the LAW portion of the tank waste, i.e., the LAW feed from the WTP Pretreatment facility. Removal of {sup 99}Tc from the LAW Feed, followed by off-site disposal of the {sup 99}Tc, would eliminate a key risk contributor for the IDF Performance Assessment (PA) for supplemental waste forms, and has potential to reduce treatment and disposal costs. Washington River Protection Solutions (WRPS) is developing some conceptual flow sheets for LAW treatment and disposal that could benefit from technetium removal. One of these flowsheets will specifically examine removing {sup 99}Tc from the LAW feed stream to supplemental immobilization. The conceptual flow sheet of the {sup 99}Tc removal process includes a filter to remove insoluble solids prior to processing the stream in an ion exchange column, but the characteristics and behavior of the liquid and solid phases has not previously been investigated. This report contains results of testing of a simulant that represents the projected composition of the feed to the Supplemental LAW process. This feed composition is not identical to the aqueous tank waste fed to the Waste Treatment Plant because it has been processed through WTP Pretreatment facility and therefore contains internal changes and recycle streams that will be generated within the WTP process. Although

  17. A Wideband Digital Predistorter for a Doherty Power Amplifier Using a Direct Learning Memory Effect Filter

    Science.gov (United States)

    Horiguchi, Kenichi; Matsunaga, Naoko; Yamauchi, Kazuhisa; Hayashi, Ryoji; Miyazaki, Moriyasu; Nojima, Toshio

    This paper presents a digital predistorter with a wideband memory effect compensator for a Doherty power amplifier (PA). A simple memory-predistortion model, which consists of a look-up-table (LUT) and an adaptive filter equalizing memory effects, and a new memory effect estimation algorithm using a direct-learning architecture are proposed. The proposed estimation algorithm has an advantage that a transfer function of a feedback circuit does not affect the learning process. The predistorter is implemented in a field programmable gate array (FPGA) and a digital signal processor (DSP). The transmitter has achieved distortion level of -50.8dBr at signal bandwidth away from the carrier, and PA module efficiency of 24% with output power of 43dBm at 2595MHz under a 20MHz-bandwidth orthogonal frequency division multiplexing (OFDM) signal using laterally diffused metal oxide semiconductor (LDMOS) FETs.

  18. A Review of Passive Power Filters for Three-Phase Grid-Connected Voltage-Source Converters

    DEFF Research Database (Denmark)

    Beres, Remus Narcis; Wang, Xiongfei; Liserre, Marco;

    2016-01-01

    with the utility grid are reviewed, and evaluated in terms of damping capability, stored energy in the passive components and power loss in the damping circuit. Additionally, the influences of different switching frequencies of power converters on the passive filter design are also discussed in the range of 1-15 k...

  19. Reduced Cost of Reactive Power in Doubly Fed Induction Generator Wind Turbine System With Optimized Grid Filter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2015-01-01

    through the rotor-side converter or the grid-side converter. This paper first compares the current ripples and supportive reactive power ranges between the conventional L and optimized LCL filter, if the reactive power is injected from the grid-side converter. Then, the loss distribution is evaluated both...

  20. Reduced Cost of Reactive Power in Doubly Fed Induction Generator Wind Turbine System with Optimized Grid Filter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2014-01-01

    the rotor-side converter or the grid-side converter. This paper firstly compares the current ripples and supportive reactive power ranges between the conventional L and optimized LCL filter, if the reactive power is injected from the grid-side converter. Then, the loss distribution is evaluated both...

  1. Power system damping - Structural aspects of controlling active power

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, O.

    1997-04-01

    Environmental and economical aspects make it difficult to build new power lines and to reinforce existing ones. The continued growth in demand for electric power must therefore to a great extent be met by increased loading of available lines. A consequence is that power system damping is reduced, leading to a risk of poorly damped power oscillations between the generators. This thesis proposes the use of controlled active loads to increase damping of such electro-mechanical oscillations. The focus is on structural aspects of controller interaction and of sensor and actuator placement. On-off control based on machine frequency in a single machine infinite bus system is analysed using energy function analysis and phase plane plots. An on-off controller with estimated machine frequency as input has been implemented. At a field test it damped oscillations of a 0.9 MW hydro power generator by controlling a 20kW load. The linear analysis uses two power system models with three and twenty-three machines respectively. Each damper has active power as output and local bus frequency or machine frequency as input. The power system simulator EUROSTAG is used both for generation of the linearized models and for time simulations. Measures of active power mode controllability and phase angle mode observability are obtained from the eigenvectors of the differential-algebraic models. The geographical variation in the network of these quantities is illustrated using the resemblance to bending modes of flexible mechanical structures. Eigenvalue sensitivities are used to determine suitable damper locations. A spring-mass equivalent to an inter-area mode provides analytical expressions, that together with the concept of impedance matching explain the structural behaviour of the power systems. For large gains this is investigated using root locus plots. 64 refs, 99 figs, 20 tabs

  2. Adaptive Fuzzy PID Based Control Strategy For 3Phase 4Wire Shunt Active Filter To Mitigate Current Harmonics Of Grid Interconnection Of Renewable Energy Based Distribution System

    Directory of Open Access Journals (Sweden)

    Kaleemullah

    2016-06-01

    Full Text Available This paper presents a new control strategy for controlling the shunt active power filter to compensate reactive power and to reduce the unwanted harmonics in the grid current. Shunt active filter act as a current source which is connected in parallel with a non-linear load and controlled to produce the required compensating current. The proposed control strategy is based on the fuzzy PID controller which is used for determining the reference compensating currents of the three-phase shunt active power filters. Simulations are carried out using MATLAB/SIMULINK to verify the performance of the proposed controller. The output shows the controller has fast dynamic response high accuracy of tracking DC voltage reference and robust to load parameters variations.

  3. Compensating active power imbalances in power system with large-scale wind power penetration

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Altin, Müfit

    2016-01-01

    penetration. This paper evaluates the impact oflarge-scale wind power integration on future power systems.An active power balance control methodology is usedfor compensating the power imbalances between thedemand and the generation in real time, caused by windpower forecast errors. The methodology......Large-scale wind power penetration can affectthe supply continuity in the power system. This is a matterof high priority to investigate, as more regulating reservesand specified control strategies for generation control arerequired in the future power system with even more highwind power...... for the balancepower control of future power systems with large-scalewind power integration is described and exemplified consideringthe generation and power exchange capacities in2020 for Danish power system....

  4. Modulation power of porous materials and usage as ripple filter in particle therapy.

    Science.gov (United States)

    Printz Ringbæk, Toke; Simeonov, Yuri; Witt, Matthias; Engenhart-Cabillic, Rita; Kraft, Gerhard; Zink, Klemens; Weber, Uli

    2017-04-07

    Porous materials with microscopic structures like foam, sponges, lung tissues and lung substitute materials have particular characteristics, which differ from those of solid materials. Ion beams passing through porous materials show much stronger energy straggling than expected for non-porous solid materials of the same thickness. This effect depends on the microscopic fine structure, the density and the thickness of the porous material. The beam-modulating effect from a porous plate enlarges the Bragg peak, yielding similar benefits in irradiation time reduction as a ripple filter. A porous plate can additionally function as a range shifter, which since a higher energy can be selected for the same penetration depth in the body reduces the scattering at the beam line and therefore improves the lateral fall-off. Bragg curve measurements of ion beams passing through different porous materials have been performed in order to determine the beam modulation effect of each. A mathematical model describing the correlation between the mean material density, the porous pore structure size and the strength of the modulation has been developed and a new material parameter called 'modulation power' is defined as the square of the Gaussian sigma divided by the mean water-equivalent thickness of the porous absorber. Monte Carlo simulations have been performed in order to validate the model and to investigate the Bragg peak enlargement, the scattering effects of porosity and the lateral beam width at the end of the beam range. The porosity is found to only influence the lateral scattering in a negligible way. As an example of a practical application, it is found that a 20 mm and 50 mm plate of Gammex LN300 performs similar to a 3 mm and 6 mm ripple filter, respectively, and at the same time can improve the sharpness of the lateral beam due to its multifunctionality as a ripple filter and a range shifter.

  5. Fast affine projections and the regularized modified filtered-error algorithm in multichannel active noise control

    NARCIS (Netherlands)

    Wesselink, J.M.; Berkhoff, A.P.

    2008-01-01

    In this paper, real-time results are given for broadband multichannel active noise control using the regularized modified filtered-error algorithm. As compared to the standard filtered-error algorithm, the improved convergence rate and stability of the algorithm are obtained by using an inner-outer

  6. 76 FR 42130 - Agency Information Collection Activities: BioWatch Filter Holder Log

    Science.gov (United States)

    2011-07-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Agency Information Collection Activities: BioWatch Filter Holder Log AGENCY: Department of... agent. ] Analysis Agency: Department of Homeland Security. Title: BioWatch Filter Holder Log. OMB...

  7. 76 FR 24504 - Agency Information Collection Activities: BioWatch Filter Holder Log

    Science.gov (United States)

    2011-05-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Agency Information Collection Activities: BioWatch Filter Holder Log AGENCY: Department of... submissions of responses. Analysis Agency: Department of Homeland Security, DHS. Title: BioWatch Filter...

  8. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  9. A Novel Method for the Current Harmonic Elimination of Industrial Power System Using Single Tuned Shunt Passive Filter

    Directory of Open Access Journals (Sweden)

    Mansoor Ahmed Soomro

    2012-01-01

    Full Text Available The automation of IPS (Industrial Power System has brought about several advantages of increased productivity and efficiency but it suffers from incompatible problems of overheating, noise, complexity etc, which disturb its smooth and fault tolerant implication. When the resonance condition is reached, these effects become detrimental and disturb the whole power system. The purpose of this research work is to include single tuned shunt type passive filter for harmonic elimination of the components used in industrial power system. For this purpose, MATLAB simulation using sim Power system tool has been used to analyze the effects of current harmonics. Third harmonic effects have been removed by the addition of six pulse converter technique. The simulation results show that implication of single tuned shunt (parallel connected passive filter removes effects of succeeding order current harmonics i.e. fifth, seventh and eleventh etc. which are causing substantial damage to industrial power system. The effects of current harmonics can be solved by installing without and with the application of proposed filter. Further, it is observed that these filters contribute in reduction of THD (Total Harmonic Current Distortion followed by improvement in power factor. These results are taken considering limits of IEEE 519-1992 standards.

  10. Wave-plate structures, power selective optical filter devices, and optical systems using same

    Science.gov (United States)

    Koplow, Jeffrey P [San Ramon, CA

    2012-07-03

    In an embodiment, an optical filter device includes an input polarizer for selectively transmitting an input signal. The device includes a wave-plate structure positioned to receive the input signal, which includes first and second substantially zero-order, zero-wave plates arranged in series with and oriented at an angle relative to each other. The first and second zero-wave plates are configured to alter a polarization state of the input signal passing in a manner that depends on the power of the input signal. Each zero-wave plate includes an entry and exit wave plate each having a fast axis, with the fast axes oriented substantially perpendicular to each other. Each entry wave plate is oriented relative to a transmission axis of the input polarizer at a respective angle. An output polarizer is positioned to receive a signal output from the wave-plate structure and selectively transmits the signal based on the polarization state.

  11. Development and evaluation of antimicrobial activated carbon fiber filters using Sophora flavescens nanoparticles.

    Science.gov (United States)

    Sim, Kyoung Mi; Kim, Kyung Hwan; Hwang, Gi Byoung; Seo, SungChul; Bae, Gwi-Nam; Jung, Jae Hee

    2014-09-15

    Activated carbon fiber (ACF) filters have a wide range of applications, including air purification, dehumidification, and water purification, due to their large specific surface area, high adsorption capacity and rate, and specific surface reactivity. However, when airborne microorganisms such as bacteria and fungi adhere to the carbon substrate, ACF filters can become a source of microbial contamination, and their filter efficacy declines. Antimicrobial treatments are a promising means of preventing ACF bio-contamination. In this study, we demonstrate the use of Sophora flavescens in antimicrobial nanoparticles coated onto ACF filters. The particles were prepared using an aerosol process consisting of nebulization-thermal drying and particle deposition. The extract from S. flavescens is an effective, natural antimicrobial agent that exhibits antibacterial activity against various pathogens. The efficiency of Staphylococcus epidermidis inactivation increased with the concentration of S. flavescens nanoparticles in the ACF filter coating. The gas adsorption efficiency of the coated antimicrobial ACF filters was also evaluated using toluene. The toluene-removal capacity of the ACF filters remained unchanged while the antimicrobial activity was over 90% for some nanoparticle concentrations. Our results provide a scientific basis for controlling both bioaerosol and gaseous pollutants using antimicrobial ACF filters coated with S. flavescens nanoparticles.

  12. A Novel Soft Switching PWM Power Frequency Converter with Non DC Smoothing Filter Link for Consumer High Frequency Induction Heating

    Science.gov (United States)

    Sugimura, Hisayuki; Muraoka, Hidekazu; Hiraki, Eiji; Hirota, Izuo; Yasui, Kenji; Omori, Hideki; Lee, Hyun-Woo; Nakaoka, Mutsuo

    In this paper, high frequency power converter without DC smoothing electrolytic capacitor filter link which convert the 100V/200Vrms and 60Hz single phase utility frequency AC power into a high frequency AC. This proposed high frequency AC power converter without electrolytic capacitor filter can operate under a principle of soft switching PWM based on a lossless capacitor snubber is proposed and demonstrated for consumer high frequency induction heating (IH). In particular, this high frequency power converter capable of producing a high frequency AC more than 20kHz is developed for consumer IH applications as hot water producer and steamer based on the specially designed spiral type IH-Dual Packs Heater (DPH), which includes the dual mode pulse modulation control scheme based on soft switching PWM for high output power setting and commercial frequency AC zero voltage soft switching pulse density modulation (PDM) for low output power settings. This developed high frequency power frequency converter using trench gate IGBTs is clarified on the basis of experimental and simulation results for its circuit operation of the utility frequency AC to high frequency AC frequency PWM power converter without the electrolytic capacitor bank DC filter link for the IH hot water and IH steamer. These IH appliances are based upon an innovative electromagnetic IH-DPH for fluid heating as heat exchanger in consumer pipeline. Finally, its power regulation characteristics, power conversion efficiency and harmonic current components characteristics including power factor in utility AC grid side are evaluated and discussed from an experimental point of view. The practical effectiveness of this utility frequency AC to high frequency AC soft switching high power frequency converter defined conveniently as high frequency soft switching cyclo-inverter is proved as one of the important products effective for next generation IH application all electricity power utilizations.

  13. Active cancellation of acoustical resonances with an FPGA FIR filter.

    Science.gov (United States)

    Ryou, Albert; Simon, Jonathan

    2017-01-01

    We present a novel approach to enhancing the bandwidth of a feedback-controlled mechanical system by digitally canceling acoustical resonances (poles) and anti-resonances (zeros) in the open-loop response via an FPGA FIR filter. By performing a real-time convolution of the feedback error signal with an inverse filter, we can suppress arbitrarily many poles and zeros below 100 kHz, each with a linewidth down to 10 Hz. We demonstrate the efficacy of this technique by canceling the ten largest mechanical resonances and anti-resonances of a high-finesse optical resonator, thereby enhancing the unity gain frequency by more than an order of magnitude. This approach is applicable to a broad array of stabilization problems including optical resonators, external cavity diode lasers, and scanning tunneling microscopes and points the way to applying modern optimal control techniques to intricate linear acoustical systems.

  14. Active Cancellation of Acoustical Resonances with an FPGA FIR Filter

    CERN Document Server

    Ryou, Albert

    2016-01-01

    We present a novel approach to enhancing the bandwidth of a feedback-controlled mechanical system by digitally canceling acoustical resonances (poles) and anti-resonances (zeros) in the open-loop response via an FPGA FIR filter. By performing a real-time convolution of the feedback error signal with an inverse filter, we can suppress arbitrarily many poles and zeros below 100 kHz, each with a linewidth down to 10 Hz. We demonstrate the efficacy of this technique by canceling the ten largest mechanical resonances and anti-resonances of a high-finesse optical resonator, thereby enhancing the unity gain frequency by more than an order of magnitude. This approach is applicable to a broad array of stabilization problems including optical resonators, external cavity diode lasers, and scanning tunneling microscopes, and points the way to applying modern optimal control techniques to intricate linear acoustical systems.es to intricate linear acoustical systems.

  15. Genetic Algorithm-Based Design of the Active Damping for an LCL-Filter Three-Phase Active Rectifier

    DEFF Research Database (Denmark)

    Liserre, Marco; Aquila, Antonio Dell; Blaabjerg, Frede

    2004-01-01

    of this filter is easily done, for a wide range of sampling frequencies, with the use of genetic algorithms. This method is used only for the optimum choice of the parameters in the filter, and an on-line implementation is not needed. Thus the resulting active damping solution does not need new sensors...

  16. 基于正余弦表的并联型有源电力滤波器指令电流生成方法%A Method Based on Sine and Cosine Table of Calculating Current Reference for Shunt Active Power Filters

    Institute of Scientific and Technical Information of China (English)

    卢超慧; 田铭兴

    2013-01-01

    提出了一种新的并联型有源电力滤波器指令电流生成方法.通过给定与电源电压基波正序分量同频率的正余弦表来提取电源电压的基波正序分量,再利用同步检测方法生成指令电流.该方法省却了锁相环电路,避免了锁相环电路的检测误差及延时问题,提高了检测的准确性;适用范围广,尤其是能适用于电源电压畸变和不对称条件下.理论推导和仿真结果都验证了该方法的正确性和可行性.%A new method to calculate the current reference for shunt active power filter (APF) is presented. The fundamental positive component of the supply voltage is obtained by given the sine and cosine table whose frequency is the same as the supply voltage fundamental positive component, generate the current reference with the synchronous detection method. The method obviates the phase-locked loop circuit, avoid the problem of the detection error and delay of the phase-locked loop circuit, the detection accuracy is improved; The proposed method works well under various load conditions, especially in the case of a distorted and asymmetric supply. The theoretical analysis and simulation results verify the validity and feasibility of the proposed method.

  17. 基于欧拉-拉格朗日模型的单相有源电力滤波器无源性控制新方法%A Novel Passivity-Based Control Algorithm for Single-Phase Active Power Filter Using Euler-Lagrange Model

    Institute of Scientific and Technical Information of China (English)

    张振环; 刘会金; 李琼林; 张全明

    2008-01-01

    有源电力滤波器(active power filter, APF)的控制方法是决定其补偿性能的关键因素之一.该文基于单相 APF 的Euler-Lagrange(EL)系统状态平均模型,提出了一种无源性控制新方法.该方法首先基于替代定理建立了考虑源阻抗和非线性负荷影响的单相 APFEL 系统状态平均模型,在此基础上设计了无源性间接控制律,确保对单相APF控制目标的渐近跟踪.由于在线计算直流电容指令电压波动量十分困难,在控制方法的执行中忽略波动量的影响,简化了控制方法的实现;此外,该方法还研究了所注入的阻尼大小对控制效果的影响以及 APF 内层控制过调制产生的原因,针对无源性控制律跟踪精度的要求与内层控制过调制限幅条件间的矛盾,通过构造模糊逻辑推理环节实现阻尼系数的在线调整,在满足内层控制限幅条件下确保跟踪精度和补偿效果.仿真结果验证了所提出方法的正确性和有效性.

  18. Commutation effect of Adjustable Speed Drives due to installation of active harmonic filters

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Kalaschnikow, Sergej; Hansen, Steffan;

    2011-01-01

    The success of designing an industrial installation with Active Filters depends on how precise the load profile of the application is known, because this determines the amount of harmonic currents to be compensated. However, once the Active Filter is added to the installation, the harmonic curren...... and sizing industrial Active Filter applications together with Adjustable Speed Drives. Examples of using the developed toolbox are given in the paper, supported with practical measurements....... the commutation behavior of Adjustable Speed Drives when their harmonic currents are compensated by a Shunt Active Filter. The method is formulated as an analytical computation algorithm verified by simulations. Further on the method is implemented in a Harmonic Calculation Toolbox which facilitates calculation...

  19. Power spectrum analysis of limb and disk spicule using Hinode Ca H line broadband filter

    CERN Document Server

    Tavabi, Ehsan

    2014-01-01

    We present observations of a solar quiet region obtained using Hinode Solar Optical telescope (SOT) in Ca II H line with broadband filter taken on November 2006. We study offlimb and on disk spicules to find a counterpart of limb spicule on the disk. This investigation shows a strong correspondence between the limb and near limb spicules (ondisk spicules that historically were called dark or bright mottles especially when observed in Halpha rather cool line) from the dynamical behavior (e.g., periodicity). An excellent time sequence of images obtained near the equatorial region with a cadence of 8 s was selected for analysis. 1D Fourier power spectra made at different positions on the disk and above the limb are shown. We take advantage of the so-called madmax operator to reduce effects of overlapping and improve the visibility of these hair like features. A definite signature with strong power in the 3 min. (5.5 mHz) and 5 min. (3.5 mHz) oscillations for both places exist. A full range of oscillations was fo...

  20. Development of Control Structure for Hybrid Wind Generators with Active Power Capability

    Directory of Open Access Journals (Sweden)

    Mehdi Niroomand

    2014-01-01

    Full Text Available A hierarchical control structure is proposed for hybrid energy systems (HES which consist of wind energy system (WES and energy storage system (ESS. The proposed multilevel control structure consists of four blocks: reference generation and mode select, power balancing, control algorithms, and switching control blocks. A high performance power management strategy is used for the system. Also, the proposed system is analyzed as an active power filter (APF with ability to control the voltage, to compensate the harmonics, and to deliver active power. The HES is designed with parallel DC coupled structure. Simulation results are shown for verification of the theoretical analysis.

  1. Towards low power N-Path filters for flexible RF-Channel selection

    NARCIS (Netherlands)

    Klumperink, Eric A.M.; Soer, Michiel C.M.; Struiksma, Remko E.; Vliet, van Frank E.; Nauta, Bram

    2015-01-01

    N-path filters can offer high-linearity high-Q channel selection filtering at a flexibly programmable RF center frequency, which is highly wanted for Software Defined Radio. Relying on capacitors and MOSFET switches, driven by digital non-overlapping clocks, N-path filters fit well to CMOS and benef

  2. Active carbon filter health condition detection with piezoelectric wafer active sensors

    Science.gov (United States)

    Bao, Jingjing; Giurgiutiu, Victor; Rubel, Glenn O.; Peterson, Gregory W.; Ball, Thomas M.

    2011-04-01

    The impregnated active carbon used in air purification systems degrades over time due to exposure to contamination and mechanical effects (packing, settling, flow channeling, etc.). A novel approach is proposed to detect contamination in active carbon filters by combining the electromechanical impedance spectroscopy (EMIS) and electrochemical impedance spectroscopy (ECIS). ECIS is currently being used to evaluate active carbon filtration material; however, it cannot differentiate the impedance changes due to chemical contamination from those due to mechanical changes. EMIS can detect impedance changes due to mechanical changes. For the research work presented in this paper, Piezoelectric wafer active sensor (PWAS) was used for the EMIS method. Some remarkable new phenomena were unveiled in the detection of carbon filter status. 1. PWAS EMIS can detect the presence of contaminants, such as water and kerosene in the carbon bed 2. PWAS EMIS can monitor changes in mechanical pressure that may be associated with carbon bed packing, settling and flow channeling 3. EMIS and ECIS measurements are consistent with each other and complimentary A tentative simplified impedance model was created to simulate the PWAS-carbon bed system under increasing pressure. Similar impedance change pattern was observed when comparing the simulation results with experimental data.

  3. 电力谐波滤波器设计与调试%Design and Debug for Powered Harmonic Filter

    Institute of Scientific and Technical Information of China (English)

    仇润鹤; 吴震春

    2001-01-01

    针对煤矿电网谐波特点,采用单调谐谐波滤波器滤除交流装置产生的谐波是一种经济而有效地方法。结合实例对谐波滤波器的设计和调试进行了详细的讨论和分析。%Aims at with regard to the characteristic of Mining Powered harmonics, this paper considers that employong single tume filter to eliminate harmonic of AC filter devices is a economical and effective method. The design and debug of powered harmonic filter are discussed and analyzed with a practical case in detail.

  4. Robust Active Damping Control of LCL Filtered Grid Connected Converter Based Active Disturbance Rejection Control

    DEFF Research Database (Denmark)

    Abdeldjabar, Benrabah; Xu, Dianguo; Wang, Xiongfei;

    2016-01-01

    This paper deals with the problem of LCL filter resonance in grid connected inverter control. The system equations are reformulated to allow the application of the active disturbance rejection control (ADRC). The resonance, assumed unknown, is treated as a disturbance, then estimated and mitigated....... By using this new robust control, a high level of performance is achieved with a minimum complexity in the controller design, and without any adaptive algorithm. It is demonstrated that the true quality of the control system is obtained by the proposed solution. Furthermore, it is shown that this control...... is robust against parameter variations and disturbances....

  5. Endotoxin release from biologically active bench-scale drinking water anthracite/sand filters

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, W.B.; Mayfield, C.I.; Huck, P.M. [University of Waterloo, Waterloo, ON (Canada). Dept. of Civil and Environmental Engineering

    2008-12-15

    Endotoxin release from biologically active dual-media (anthracite/sand) bench-scale drinking water filters was investigated. The biological filters were typically net producers of endotoxin during normal operation with mean concentrations increasing from 6 endotoxin units (EU)/mL to 16 EU/mL in filter influent and effluent, respectively. The filter operating condition resulting in the greatest release of endotoxin occurred upon shutdown and subsequent restart, with the highest observed filter effluent endotoxin concentration being 745 EU/mL in the first pore volume following the return of flow through the filter. Effluent samples collected following filter shutdowns were chlorinated to determine the effect of bacterial cell death on endotoxin release. Chlorination did not induce immediate 'dumping' of endotoxin, nor did holding the chlorinated samples for 5 d result in an increase in aqueous endotoxin concentration. In addition to endotoxin, measurable quantities of potassium were detected in the interstitial water in the biofilter during shutdown periods. In order to reduce potential risk to dialysis patients and humidifier users, it is recommended that, following even short biofilter shutdowns, filters should be immediately backwashed or, failing this, the first five pore volumes of effluent water be discharged to waste to allow endotoxin levels to return to pre-shutdown values.

  6. Activated charcoal filter effectively reduces p-benzosemiquinone from the mainstream cigarette smoke and prevents emphysema

    Indian Academy of Sciences (India)

    Neekkan Dey; Archita Das; Arunava Ghosh; Indu B Chatterjee

    2010-06-01

    In this paper, we have made a comparative evaluation of the cytotoxicity and pathophysiological effects of mainstream smoke from cellulose acetate (CA)-filtered cigarettes with that of charcoal-filtered cigarettes developed in our laboratory. Previously, we had demonstrated that the mainstream smoke from an Indian CA-filtered commercial cigarette contains p-benzosemiquinone (p-BSQ), a major, highly toxic, long-lived water-soluble radical. Here, we have examined 16 brands of different CA-filtered cigarettes including Kentucky research cigarettes, and observed that mainstream smoke from all the cigarettes contains substantial amounts of p-BSQ (100–200 g/cigarette). We also show that when the CA filter is replaced by a charcoal filter, the amount of p-BSQ in the mainstream smoke is reduced by 73–80%, which is accompanied by a reduction of carbonyl formation in bovine serum albumin to the extent of 70–90%. The charcoal filter also prevented cytotoxicity in A549 cells as evidenced by MTT assay, apoptosis as evidenced by FACS analysis, TUNEL assay, overexpression of Bax, activation of p53 and caspase 3, as well as emphysematous lung damage in a guinea pig model as seen by histology and morphometric analysis. The results indicate that the charcoal filter developed in our laboratory may protect smokers from cigarette smoke-induced cytotoxity, protein modification, apoptosis and emphysema.

  7. Power-ratio tunable dual-wavelength laser using linearly variable Fabry-Perot filter as output coupler.

    Science.gov (United States)

    Wang, Xiaozhong; Wang, Zhongfa; Bu, Yikun; Chen, Lujian; Cai, Guoxiong; Huang, Wencai; Cai, Zhiping; Chen, Nan

    2016-02-01

    For a linearly variable Fabry-Perot filter, the peak transmission wavelengths change linearly with the transverse position shift of the substrate. Such a Fabry-Perot filter is designed and fabricated and used as an output coupler of a c-cut Nd:YVO4 laser experimentally in this paper to obtain a 1062 and 1083 nm dual-wavelength laser. The peak transmission wavelengths are gradually shifted from 1040.8 to 1070.8 nm. The peak transmission wavelength of the Fabry-Perot filter used as the output coupler for the dual-wavelength laser is 1068 nm and resides between 1062 and 1083 nm, which makes the transmissions of the desired dual wavelengths change in opposite slopes with the transverse shift of the filter. Consequently, powers of the two wavelengths change in opposite directions. A branch power, oppositely tunable 1062 and 1083 nm dual-wavelength laser is successfully demonstrated. Design principles of the linear variable Fabry-Perot filter used as an output coupler are discussed. Advantages of the method are summarized.

  8. 一种适用于新型直接交交型有源滤波器的逐次分序谐波检测算法%A Harmonic Detection Method by Separated Sequence and Order Suitable for Novel Direct AC-AC Based Active Power Filters

    Institute of Scientific and Technical Information of China (English)

    吕自波; 李楚杉; 邓焰; 何湘宁; 谢瑞

    2015-01-01

    有源电力滤波器(active power filter,APF)是电力系统中实现谐波治理功能的一种新型变流设备。谐波检测作为APF 的关键技术之一,直接决定了其整体性能。针对近来出现的一类基于直接交交变换技术的 APF,提出一种新的谐波检测算法。该算法结合改进的滑窗离散傅里叶变换法以及对称分量法,实现对三相电网各次谐波的各序分量的独立的快速检测。新算法与传统方法相比具有简单快速的优势。尤其是当系统不平衡时,需要在每个谐波频率上对正序与负序分量分别检测的应用场合。此外,该算法同样可用于传统的 APF 中以实现快速的谐波检测。首先对新型直接交交型APF 进行简要的介绍,再详细推导新的谐波检测算法的原理,并将该算法与传统算法进行比较研究。然后基于新的谐波检测算法针,对新型APF提出一整套滤波控制解决方案。最后对新的谐波检测算法进行仿真验证,并在一台3kW新型 APF 样机上对其进行实验验证,仿真与实验结果证明了新算法的正确性与实用性。%Active Power Filter (APF) is a new kind of equipment used in power grids to realize harmonic control function. As a key technology in APF, the harmonic detection algorithm directly determines the overall performance of the system. A new harmonic detection algorithm was proposed for the newly emerging direct AC-AC based APF. It is based on the combination of an improved sliding-window discrete Fourier transform (ISDFT) and symmetrical component method (SCM), which can realize individual fast detection of each sequence components for different orders of harmonics. The algorithm is simpler and faster than the traditional detection ones. It is superior especially when the grid is unbalanced and large numbers of harmonics needs to be detected. Furthermore, the new method can also be used in traditional APF to get rapid harmonic

  9. Internal Porosity of Mineral Coating Supports Microbial Activity in Rapid Sand Filters for Groundwater Treatment

    DEFF Research Database (Denmark)

    Gülay, Arda; Tatari, Karolina; Musovic, Sanin

    2014-01-01

    A mineral coating develops on the filter grain surface when groundwater is treated via rapid sand filtration in drinking water production. The coating changes the physical and chemical properties of the filter material, but little is known about its effect on the activity, colonization, diversity...... prokaryotes in filter material with various degrees of mineral coating. We also examined the physical and chemical characteristics of the mineral coating. The amount of mineral coating correlated positively with the internal porosity, the packed bulk density, and the biologically available surface area......, and abundance of microbiota. This study reveals that a mineral coating can positively affect the colonization and activity of microbial communities in rapid sand filters. To understand this effect, we investigated the abundance, spatial distribution, colonization, and diversity of all and of nitrifying...

  10. Seasonal changes in the invertebrate community of granular activated carbon filters and control technologies.

    Science.gov (United States)

    Wang, Qing; You, Wei; Li, Xiaowei; Yang, Yufeng; Liu, Lijun

    2014-03-15

    Invertebrate colonization of granular activated carbon (GAC) filters in the waterworks is one of the most frequently occurring and least studied biological problems of water processing in China. A survey of invertebrate colonization of GAC filters was carried out weekly from October 2010 to December 2011 at a reservoir water treatment works in South China. Twenty-six kinds of invertebrates were observed. The abundance was as high as 5600ind.m(-3) with a mean of 860ind.m(-3). Large variations in abundance were observed among different seasons and before and after GAC filtration. The dominant organisms were rotifers and copepods. The average invertebrate abundance in the filtrate was 12-18.7 times of that in the pre-filtered water. Results showed that the GAC filters were colonized by invertebrates which may lead to a higher output of organisms in the filtrate than in the pre-filtered water. The invertebrate abundance in the GAC filters was statistically correlated with the water temperature. Seasonal patterns were observed. The invertebrate abundance grew faster in the spring and summer. Copepods were dominant in the summer while rotifers dominated in all other seasons of the year. There was a transition of small invertebrates (rotifers) gradually being substituted by larger invertebrates (copepods) from spring to summer. Control measures such as backwashing with chloric water, drying filter beds and soaking with saliferous water were implemented in the waterworks to reduce invertebrate abundances in the GAC filters. The results showed that soaking with saliferous water (99%, reduction in percent) was best but drying the filter beds (84%) was more economical. Soaking filter beds with 20g/L saliferous water for one day can be implemented in case of emergency. In order to keep invertebrate abundance in the acceptable range, some of these measures should be adopted.

  11. A new state-space model for three-phase systems for Kalman filtering with application to power quality estimation

    Science.gov (United States)

    Phan, Anh Tuan; Ho, Duc Du; Hermann, Gilles; Wira, Patrice

    2015-12-01

    For power quality issues like reducing harmonic pollution, reactive power and load unbalance, the estimation of the fundamental frequency of a power lines in a fast and precise way is essential. This paper introduces a new state-space model to be used with an extended Kalman filter (EKF) for estimating the frequency of distorted power system signals in real-time. The proposed model takes into account all the characteristics of a general three-phase power system and mainly the unbalance. Therefore, the symmetrical components of the power system, i.e., their amplitude and phase angle values, can also be deduced at each iteration from the proposed state-space model. The effectiveness of the method has been evaluated. Results and comparisons of online frequency estimation and symmetrical components identification show the efficiency of the proposed method for disturbed and time-varying signals.

  12. An LLCL Power Filter for Single-Phase Grid-Tied Inverter

    DEFF Research Database (Denmark)

    Wu, Weimin; He, Yuanbin; Blaabjerg, Frede

    2012-01-01

    . Particularly, it can attenuate the switching-frequency current ripple components much better than an LCL filter, leading to a decrease in the total inductance and volume. Furthermore, by decreasing the inductance of a grid-side inductor, it raises the characteristic resonance frequency, which is beneficial...... to the inverter system control. The parameter design criteria of the proposed LLCL filter is also introduced. The comparative analysis and discussions regarding the traditional LCL filter and the proposed LLCL filter have been presented and evaluated through experiment on a 1.8-kW-single-phase grid-tied inverter...

  13. Filterability of membrane bioreactor (MBR) sludge: impacts of polyelectrolytes and mixing with conventional activated sludge.

    Science.gov (United States)

    Yigit, Nevzat O; Civelekoglu, Gokhan; Cinar, Ozer; Kitis, Mehmet

    2010-01-01

    The main objective of this work was to investigate the filterability of MBR sludge and its mixture with conventional activated sludge (CAS). In addition, the impacts of type and dose of various polyelectrolytes, filter type and sludge properties on the filterability of both MBR and Mixed sludges were determined. Specific cake resistance (SCR) measured by the Buchner funnel filtration test apparatus and the solids content of the resulting sludge cake were used to assess the dewaterability of tested sludges. The type of filter paper used in Buchner tests affected the results of filterability for MBR, CAS and Mixed sludges. SCR values and optimum polyelectrolyte doses increased with increasing MLSS concentrations in the MBR, which suggested that increase in MLSS concentrations accompanied by increases in EPS and SMP concentrations and a shift toward smaller particles caused poorer dewaterability of the MBR sludge. The significant differences observed among the filterability of CAS and MBR sludges suggested that MLSS alone is not a good predictor of sludge dewaterability. Combining CAS and MBR sludges at different proportions generally improved their dewaterability. Combining MBR sludges having typically high MLSS and EPS concentrations with CAS having much lower MLSS concentrations may be an option for full-scale treatment plants experiencing sludge dewaterability problems. Better filterability and higher cake dry solids were achieved with cationic polyelectrolytes compared to anionic and non-ionic ones for all sludge types tested.

  14. SUPPRESSING CONDUCTED EMI FROM A DC/DC HIGH POWER CONVERTER BASED ON MIXED-MODE FILTER

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Conducted electromagnetic interference (EMI) from a 7.5kVA DC/DC high power converter is investigated to agree with EN class A. Here in some passive methods of suppressing conducted EM Noise, such as mixed-mode (MM) EMI filters, snubbing circuits and other means, are used. Based on measurement, the sources of noise are detected with the characteristics analyzed in detail. The MM EMI filters is valuable means with which low-frequency part and some of the high frequency part of conducted EM Noise can be efficiently reduced. How to lay out the MM filters on both sides of the converter is outlined in detail. In addition, multiple grounding and RDC snubbing circuits are employed to improve the performance in high frequency. The experimental results confirm the methods adopted.

  15. 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.

  16. Activated soil filters for removal of biocides from contaminated run-off and waste-waters

    DEFF Research Database (Denmark)

    Bester, Kai; Banzhaf, Stefan; Burkhardt, Michael

    2011-01-01

    Building facades can be equipped with biocides to prevent formation of algal, fungal and bacterial films. Thus run-off waters may contain these highly active compounds. In this study, the removal of several groups of biocides from contaminated waters by means of an activated soil filter was studied....... A technical scale activated vertical soil filter (biofilter) with different layers (peat, sand and gravel), was planted with reed (Phragmites australis) and used to study the removal rates and fate of hydrophilic to moderate hydrophobic (log Kow 1.8–4.4) biocides and biocide metabolites such as: Terbutryn...

  17. Hybrid recursive active filters for duplexing in RF transmitter front-ends

    Science.gov (United States)

    Gottardo, Giuseppe; Donati, Giovanni; Musolff, Christian; Fischer, Georg; Felgentreff, Tilman

    2016-08-01

    Duplex filters in modern base transceiver stations shape the channel in order to perform common frequency division duplex operations. Usually, they are designed as cavity filters, which are expensive and have large dimensions. Thanks to the emerging digital technology and fast digital converters, it is possible to transfer the efforts of designing analog duplex filters into digital numeric algorithms applied to feedback structures, operating on power. This solution provides the shaping of the signal spectrum directly at the output of the radio frequency (RF) power amplifiers (PAs) relaxing the transmitter design especially in the duplexer and in the antenna sections. The design of a digital baseband feedback applied to the analog power RF amplifiers (hybrid filter) is presented and verified by measurements. A model to describe the hybrid system is investigated, and the relation between phase and resonance peaks of the resulting periodic band-pass transfer function is described. The stability condition of the system is analyzed using Nyquist criterion. A solution involving a number of digital feedback and forward branches is investigated defining the parameters of the recursive structure. This solution allows the closed loop system to show a periodic band pass with up to 500 kHz bandwidth at the output of the RF amplifier. The band-pass magnitude reaches up to 17 dB selectivity. The rejection of the PA noise in the out-of-band frequencies is verified by measurements. The filter is tested with a modulated LTE (Long Term Evolution) signal showing an ACPR (Adjacent Channel Power Ratio) enhancement of 10 dB of the transmitted signal.

  18. Comparison of in vitro and in vivo estrogenic activity of UV filters in fish.

    Science.gov (United States)

    Kunz, Petra Y; Galicia, Hector F; Fent, Karl

    2006-04-01

    In this work, we evaluate whether in vitro systems are good predictors for in vivo estrogenic activity in fish. We focus on UV filters being used in sunscreens and in UV stabilization of materials. First, we determined the estrogenic activity of 23 UV filters and one UV filter metabolite employing a recombinant yeast carrying the estrogen receptor of rainbow trout (rtERalpha) and made comparisons with yeast carrying the human hERalpha for receptor specificity. Benzophenone-1 (BP1), benzophenone-2 (BP2), 4,4-dihydroxybenzophenone, 4-hydroxybenzophenone, 2,4,4-trihydroxy-benzophenone, and phenylsalicylate showed full dose-response curves with maximal responses of 81-115%, whereas 3-benzylidene camphor (3BC), octylsalicylate, benzylsalicylate, benzophenone-3, and benzophenone-4 displayed lower maximal responses of 15-74%. Whereas the activity of 17beta-estradiol was lower in the rtERalpha than the hERalpha assay, the activities of UV filters were similar or relatively higher in rtERalpha, indicating different relative binding activities of both ER. Subsequently, we analyzed whether the in vitro estrogenicity of eight UV filters is also displayed in vivo in fathead minnows by the induction potential of vitellogenin after 14 days of aqueous exposure. Of the three active compounds in vivo, 3BC induced vitellogenin at lower concentrations (435 microg/l) than BP1 (4919 microg/l) and BP2 (8783 microg/l). The study shows, for the first time, estrogenic activities of UV filters in fish both in vitro and in vivo. Thus we propose that receptor-based assays should be used for in vitro screening prior to in vivo testing, leading to environmental risk assessments based on combined, complementary, and appropriate species-related assays for hormonal activity.

  19. 级联式有源电力滤波器控制策略及实验研究%Experiment studies and control method of high power acitve power filter using cascaded multilevel converter

    Institute of Scientific and Technical Information of China (English)

    陈敏洁; 陈峻岭; 李耀华; 王平

    2014-01-01

    针对由级联式多电平变换器为主电路的有源电力滤波器,其主电路中直流电容相互独立,如果没有有效控制措施,这些独立的电容电压会产生不平衡,严重威胁装置的安全、稳定运行。本论文提出一种有效控制策略,不仅具有良好的补偿效果,而且保证了主电路中各级联单元直流侧电容电压恒定和均衡。为了验证所提控制方法和控制策略,本文搭建了两级级联式有源电力滤波器,实验结果表明,该系统具有良好的滤波性能,同时也保证了各级联单元直流侧电容电压恒定和均衡,进一步表明本文所提方法的有效性和正确性。%High⁃power applications of cascaded multilevel inverter to active power filters ( APF) is hindered by the problem of keeping capacitor voltage balance while retaining good filtering performances. This paper proposes a no⁃vel control method with capacitor voltage balancing control for high power active power filters ( APF) using casca⁃ded multilevel converter. This method not only can balance the capacitor voltages of cascaded multilevel converter using for APF, but also has the better filtering characters. Firstly, the system topology of APF using cascaded mul⁃tilevel converter is described in detail. Secondly, the control method of APF using cascaded multilevel converter is discussed. Thirdly, a laboratory prototype of the APF based on five⁃level cascaded multilevel inverter is built, rated at 100kVA, to verify the capacitors voltage regulation and the harmonic filtering performance. Lastly, the experi⁃mental waveforms show that good filtering characteristics of the APF are achieved and the capacitor voltage is also controlled and balanced by using the proposed control methods.

  20. IIR filtering based adaptive active vibration control methodology with online secondary path modeling using PZT actuators

    Science.gov (United States)

    Boz, Utku; Basdogan, Ipek

    2015-12-01

    Structural vibrations is a major cause for noise problems, discomfort and mechanical failures in aerospace, automotive and marine systems, which are mainly composed of plate-like structures. In order to reduce structural vibrations on these structures, active vibration control (AVC) is an effective approach. Adaptive filtering methodologies are preferred in AVC due to their ability to adjust themselves for varying dynamics of the structure during the operation. The filtered-X LMS (FXLMS) algorithm is a simple adaptive filtering algorithm widely implemented in active control applications. Proper implementation of FXLMS requires availability of a reference signal to mimic the disturbance and model of the dynamics between the control actuator and the error sensor, namely the secondary path. However, the controller output could interfere with the reference signal and the secondary path dynamics may change during the operation. This interference problem can be resolved by using an infinite impulse response (IIR) filter which considers feedback of the one or more previous control signals to the controller output and the changing secondary path dynamics can be updated using an online modeling technique. In this paper, IIR filtering based filtered-U LMS (FULMS) controller is combined with online secondary path modeling algorithm to suppress the vibrations of a plate-like structure. The results are validated through numerical and experimental studies. The results show that the FULMS with online secondary path modeling approach has more vibration rejection capabilities with higher convergence rate than the FXLMS counterpart.

  1. Characterization of activated carbon fiber filters for pressure drop, submicrometer particulate collection, and mercury capture.

    Science.gov (United States)

    Hayashi, T; Lee, T G; Hazelwood, M; Hedrick, E; Biswas, P

    2000-06-01

    The use of activated carbon fiber (ACF) filters for the capture of particulate matter and elemental Hg is demonstrated. The pressure drop and particle collection efficiency characteristics of the ACF filters were established at two different face velocities and for two different aerosols: spherical NaCl and combustion-generated silica particles. The clean ACF filter specific resistance was 153 kg m-2 sec-1. The experimental specific resistance for cake filtration was 1.6 x 10(6) sec-1 and 2.4 x 10(5) sec-1 for 0.5- and 1.5-micron mass median diameter particles, respectively. The resistance factor R was approximately 2, similar to that for the high-efficiency particulate air filters. There was a discrepancy in the measured particle collection efficiencies and those predicted by theory. The use of the ACF filter for elemental Hg capture was illustrated, and the breakthrough characteristic was established. The capacity of the ACF filter for Hg capture was similar to other powdered activated carbons.

  2. DE optimized fuzzy PID controller with derivative filter for LFC of multi source power system in deregulated environme

    Directory of Open Access Journals (Sweden)

    Rabindra Kumar Sahu

    2015-06-01

    Full Text Available In this paper, Differential Evolution (DE optimized fuzzy PID controller with derivative Filter (PIDF is proposed for Load Frequency Control (LFC of a deregulated power system with multi-source power generation and interconnected via parallel AC/DC transmission links. To get an accurate insight of the LFC problem, important physical constraints such as time delay and GRC are considered. The performance of proposed controller is evaluated at all possible power transactions that take place in a deregulated power market. The improvement in dynamic performance of the power system with DC link in parallel with AC tie-line is also assessed. Further, sensitivity analysis is performed by varying the system parameters and operating load conditions from their nominal values. It is observed from the simulation results that the optimum gains of the proposed controller need not be reset even if the system is subjected to wide variation in loading condition and system parameters.

  3. Low power, chip-based stimulated Brillouin scattering microwave photonic filter with ultrahigh selectivity

    CERN Document Server

    Marpaung, David; Pagani, Mattia; Pant, Ravi; Choi, Duk-Yong; Luther-Davies, Barry; Madden, Steve J; Eggleton, Benjamin J

    2014-01-01

    Highly selective and reconfigurable microwave filters are of great importance in radio-frequency signal processing. Microwave photonic (MWP) filters are of particular interest, as they offer flexible reconfiguration and an order of magnitude higher frequency tuning range than electronic filters. However, all MWP filters to date have been limited by trade-offs between key parameters such as tuning range, resolution, and suppression. This problem is exacerbated in the case of integrated MWP filters, blocking the path to compact, high performance filters. Here we show the first chip-based MWP band-stop filter with ultra-high suppression, high resolution in the MHz range, and 0-30 GHz frequency tuning. This record performance was achieved using an ultra-low Brillouin gain from a compact photonic chip and a novel approach of optical resonance-assisted RF signal cancellation. The results point to new ways of creating energy-efficient and reconfigurable integrated MWP signal processors for wireless communications an...

  4. Active micromachines: Microfluidics powered by mesoscale turbulence

    CERN Document Server

    Thampi, Sumesh P; Shendruk, Tyler N; Golestanian, Ramin; Yeomans, Julia M

    2016-01-01

    Dense active matter, from bacterial suspensions and microtubule bundles driven by motor proteins to cellular monolayers and synthetic Janus particles, is characterised by mesoscale turbulence, the emergence of chaotic flow structures. By immersing an ordered array of symmetric rotors in an active fluid, we introduce a microfluidic system that exploits spontaneous symmetry breaking in mesoscale turbulence to generate work. The lattice of rotors self-organises into a spin-state where neighbouring discs continuously rotate in permanent alternating directions due to combined hydrodynamic and elastic effects. Our virtual prototype demonstrates a new research direction for the design of micromachines powered by the nematohydrodynamic properties of active turbulence.

  5. Impacts of backwashing on granular activated carbon filters for advanced wastewater treatment.

    Science.gov (United States)

    Frank, Joshua; Ruhl, Aki Sebastian; Jekel, Martin

    2015-12-15

    The use of granular activated carbon (GAC) in fixed bed filters is a promising option for the removal of organic micropollutants (OMP) from wastewater treatment plant effluents. Frequent backwashing of the filter bed is inevitable, but its effect on potential filter stratification is not well understood yet and thus has been evaluated in the present study for two commercial GAC products. Backwashing of GAC filters was simulated with 10 or 100 filter bed expansions of 20 or 100% at backwash velocities of 12 and 40 m/h, respectively. Five vertical fractions were extracted and revealed a vertical stratification according to grain sizes and material densities. Sieve analyses indicated increasing grain sizes towards the bottom for one GAC while grain sizes of the other GAC were more homogeneously distributed throughout the filter bed. The apparent densities of the top sections were significantly lower than that of the bottom sections of both products. Comparative long term fixed bed adsorption experiments with the top and bottom sections of the stratified GAC showed remarkable differences in breakthrough curves of dissolved organic carbon, UV light absorption at 254 nm wavelength (UVA254) and OMP. GAC from the upper section showed constantly better removal efficiencies than GAC from the bottom section, especially for weakly adsorbing OMP such as sulfamethoxazole. Furthermore correlations between UVA254 reductions and OMP removals were found.

  6. How does an fMRI voxel sample the neuronal activity pattern: compact-kernel or complex spatiotemporal filter?

    Science.gov (United States)

    Kriegeskorte, Nikolaus; Cusack, Rhodri; Bandettini, Peter

    2010-02-01

    Recent studies suggested that fMRI voxel patterns can convey information represented in columnar-scale neuronal population codes, even when spatial resolution is insufficient to directly image the patterns of columnar selectivity (Kamitani and Tong, 2005; Haynes and Rees, 2005). Sensitivity to subvoxel-scale pattern information, or "fMRI hyperacuity," would greatly enhance the power of fMRI when combined with pattern information analysis techniques (Kriegeskorte and Bandettini, 2007). An individual voxel might weakly reflect columnar-level information if the columns within its boundaries constituted a slightly unbalanced sample of columnar selectivities (Kamitani and Tong, 2005), providing a possible mechanism for fMRI hyperacuity. However, Op de Beeck (2009) suggests that a coarse-scale neuronal organization rather than fMRI hyperacuity may explain the presence of the information in the fMRI patterns. Here we argue (a) that the present evidence does not rule out fMRI hyperacuity, (b) that the mechanism originally suggested for fMRI hyperacuity (biased sampling by averaging within each voxel's boundaries; Kamitani and Tong, 2005) will only produce very weak sensitivity to fine-grained pattern information, and (c) that an alternative mechanism (voxel as complex spatiotemporal filter) is physiologically more accurate and promises stronger sensitivity to fine-grained pattern information: We know that each voxel samples the neuronal activity pattern through a unique fine-grained structure of venous vessels that supply its blood oxygen level-dependent signal. At the simplest level, the drainage domain of a venous vessel may sample the neuronal pattern with a selectivity bias (Gardner, 2009; Shmuel et al., 2009). Beyond biased drainage domains, we illustrate with a simple simulation how temporal properties of the hemodynamics (e.g., the speed of the blood in the capillary bed) can shape spatial properties of a voxel's filter (e.g., how finely structured it is). This

  7. Wireless power pad with local power activation for portable devices

    NARCIS (Netherlands)

    Waffenschmidt, E.; Zheglov, V.

    2007-01-01

    Wireless power transfer by magnetic induction offers a simple to use way to recharge mobile devices like e.g. mobile phone, music players or medical sensors. As shown by a previous report and an existing Power Pad demonstrator, wireless inductive power transfer is possible with a good power efficien

  8. Problems in creation of modern air inlet filters of power gas turbine plants in Russia and methods of their solving

    Science.gov (United States)

    Mikhaylov, V. E.; Khomenok, L. A.; Sherapov, V. V.

    2016-08-01

    The main problems in creation and operation of modern air inlet paths of gas turbine plants installed as part of combined-cycle plants in Russia are presented. It is noted that design features of air inlet filters shall be formed at the stage of the technical assignment not only considering the requirements of gas turbine plant manufacturer but also climatic conditions, local atmospheric air dustiness, and a number of other factors. The recommendations on completing of filtration system for air inlet filter of power gas turbine plants depending on the facility location are given, specific defects in design and experience in operation of imported air inlet paths are analyzed, and influence of cycle air preparation quality for gas turbine plant on value of operating expenses and cost of repair works is noted. Air treatment equipment of various manufacturers, influence of aerodynamic characteristics on operation of air inlet filters, features of filtration system operation, anti-icing system, weather canopies, and other elements of air inlet paths are considered. It is shown that nonuniformity of air flow velocity fields in clean air chamber has a negative effect on capacity and aerodynamic resistance of air inlet filter. Besides, the necessity in installation of a sufficient number of differential pressure transmitters allowing controlling state of each treatment stage not being limited to one measurement of total differential pressure in the filtration system is noted in the article. According to the results of the analysis trends and methods for modernization of available equipment for air inlet path, the importance of creation and implementation of new technologies for manufacturing of filtering elements on sites of Russia within the limits of import substitution are given, and measures on reliability improvement and energy efficiency for air inlet filter are considered.

  9. Monitoring Biological Activity at Geothermal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Peter Pryfogle

    2005-09-01

    The economic impact of microbial growth in geothermal power plants has been estimated to be as high as $500,000 annually for a 100 MWe plant. Many methods are available to monitor biological activity at these facilities; however, very few plants have any on-line monitoring program in place. Metal coupon, selective culturing (MPN), total organic carbon (TOC), adenosine triphosphate (ATP), respirometry, phospholipid fatty acid (PLFA), and denaturing gradient gel electrophoresis (DGGE) characterizations have been conducted using water samples collected from geothermal plants located in California and Utah. In addition, the on-line performance of a commercial electrochemical monitor, the BIoGEORGE?, has been evaluated during extended deployments at geothermal facilities. This report provides a review of these techniques, presents data on their application from laboratory and field studies, and discusses their value in characterizing and monitoring biological activities at geothermal power plants.

  10. SOGI-based capacitor voltage feedback active damping in LCL-filtered grid converters

    DEFF Research Database (Denmark)

    Xin, Zhen; Wang, Xiongfei; Loh, Poh Chiang;

    2015-01-01

    The capacitor voltage feedback active damping control is an attractive way to suppress LCL-filter resonance especially for the systems where the capacitor voltage is used for grid synchronization, since no extra sensors are added. The derivative is the core of the capacitor voltage feedback active...... derivative is more suited for capacitor voltage feedback active damping control. Experimental results validate the effectiveness of the proposed method....

  11. EVALUATING DEGREE OF ACTIVE POWER LOSSES REDUCTION IN THE ELECTRIC POWER LINES WITH REACTIVE POWER COMPENSATION

    Directory of Open Access Journals (Sweden)

    V. N. Radkevich

    2016-01-01

    Full Text Available The paper considers evaluation procedure for the degree of active power losses reduction in the power transmission lines under 1 kV and 6–10 kV of the systems of electric power supply of industrial enterprises with compensating installations mounted at the side of the customer. The capacitor installations conform to the applied voltage level and factor in dielectric losses in the capacitors. The voltage at the compensating device terminal changes from 0.95 to 1.05 of the capacitors nominal voltage. The study did not account for reactive power losses in the line, nor did it for its charge capacity, conditioned by relative shortness of the cable lines generally operating in the mains of industrial enterprises. For this reason, the quantities of reactive power being consumed and generated by the transmission line are negligible and do not significantly affect the reactive power flux. The researchers obtain functional relations that allow estimating the degree of power loss reduction in the transmission line factoring in its explicit initial data. They perform mathematical analysis of the obtained functional relations and study the function by means of derivatives. The function extremum points are found as well as the intervals of its increment and decrement. A graphical research of the obtained functional relation is performed. It is ascertained that reduction of the active power losses is contingent on the line and the capacitor-installation engineering factors, the electrical energy consumer reactive load value as well as the voltage applied to the capacitor installation. The functional relations presented in the article can be employed in scoping calculation necessary for decision making on the reactive power compensation in systems of the industrial facilities electric power supply. Their account will allow a more accurate estimate of technical and economic effect of the capacitor bank installation in the electrical mains under 1 kV and 6

  12. Passivity enhancement by series LC filtered active damper with zero current reference

    DEFF Research Database (Denmark)

    Bai, Haofeng; Wang, Xiongfei; Blaabjerg, Frede

    2016-01-01

    stability analysis of grid converters in the weak grid. Based on the impedance model of the series LC filtered active damper, the real part of its output admittance is investigated and shown to be able to enhance the passivity of the admittance of the converters seen by the grid. Finally, simulation...

  13. Passivity Enhancement of Grid-Tied Converters by Series LC-Filtered Active Damper

    DEFF Research Database (Denmark)

    Bai, Haofeng; Wang, Xiongfei; Loh, Poh Chiang;

    2017-01-01

    The series LC-filtered active damper can be used for stabilizing a grid converter tied to the non-ideal grid. Its operation principle is to mimic a damping resistance at the resonance frequencies appearing in the grid. However, the selection of the damping resistance has not been fully analyzed i...

  14. Active Damping of LLCL-Filter Resonance Based on LC-Trap Voltage or Current Feedback

    DEFF Research Database (Denmark)

    Huang, Min; Wang, Xiongfei; Loh, Poh Chiang;

    2016-01-01

    . Active damping is presently more efficient, and can easily be realized by feeding back a state variable. For the LCL-filter, the variable is usually its middle capacitor current. However, with computational delays considered, a simple proportional damper cannot be used with the capacitor current. Instead...

  15. Grid-Voltage-Feedforward Active Damping for Grid-Connected Inverter with LCL Filter

    DEFF Research Database (Denmark)

    Lu, Minghui; Wang, Xiongfei; Blaabjerg, Frede;

    2016-01-01

    For the grid-connected voltage source inverters, the feedforward scheme of grid voltage is commonly adopted to mitigate the current distortion caused by grid background voltages harmonics. This paper investigates the grid-voltage-feedforward active damping for grid connected inverter with LCL fil...... for Phase Locked Loop (PLL). Simulation and experiment results are provided for verifying the theoretical analyses....... filter. It reveals that proportional feedforward control can not only fulfill the mitigation of grid disturbance, but also offer damping effects on the LCL filter resonance. Digital delays are intrinsic to digital controlled inverters; with these delays, the feedforward control can be equivalent...

  16. One watt gallium arsenide class-E power amplifier with a thin-film bulk acoustic resonator filter embedded in the output network

    Directory of Open Access Journals (Sweden)

    Kyle Holzer

    2015-05-01

    Full Text Available Integration of a class-E power amplifier (PA and a thin-film bulk acoustic wave resonator (FBAR filter is shown to provide high power added efficiency in addition to superior out-of-band spectrum suppression. A discrete gallium arsenide pseudomorphic high-electron-mobility transistor is implemented to operate as a class-E amplifier from 2496 to 2690 MHz. The ACPF7041 compact bandpass FBAR filter is incorporated to replace the resonant LC tank in a traditional class-E PA. To reduce drain voltage stress, the supply choke is replaced by a finite inductance. The fabricated PA provides up to 1 W of output power with a peak power added efficiency (PAE of 58%. The improved out-of-band spectrum filtering is compared to a traditional class-E with discrete LC resonant filtering. Such PAs can be combined with linearisation techniques to reduce out-of-band emissions.

  17. Power spectra of active galactic nuclei

    Institute of Scientific and Technical Information of China (English)

    WANG TaiShan; WU YuXiang; LIU Yuan

    2009-01-01

    The power spectral densities (PSDs) for a sample of active galactic nuclei (AGNs) are analyzed in both the frequency domain and the time domain. We find for each object that for broadband noise a character timescale-bifurcation timescale of Fourier and time-domain PSD exists in the 103-106 s range,below which the time-domain power spectrum is systematically higher than the corresponding Fourier spectrum. The relationship between bifurcation timescale, AGN mass and luminosity is studied. Compared with the fact that similar phenomena have been found for Galactic black hole candidates (GBHs)with bifurcation timescale ~0.1 s but not for accreting neutron stars, our finding indicates that AGNs and GBHs have common intrinsic nature in rapid X-ray variability with a character time parameter scaled with their masses.

  18. Power spectra of active galactic nuclei

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The power spectral densities(PSDs)for a sample of active galactic nuclei(AGNs)are analyzed in both the frequency domain and the time domain.We find for each object that for broadband noise a character timescale-bifurcation timescale of Fourier and time-domain PSD exists in the 10 3 -10 6 s range, below which the time-domain power spectrum is systematically higher than the corresponding Fourier spectrum.The relationship between bifurcation timescale,AGN mass and luminosity is studied.Compared with the fact that similar phenomena have been found for Galactic black hole candidates(GBHs) with bifurcation timescale~0.1 s but not for accreting neutron stars,our finding indicates that AGNs and GBHs have common intrinsic nature in rapid X-ray variability with a character time parameter scaled with their masses.

  19. Relationship between %dd(10)x and stopping-power ratios for flattening filter free accelerators: a Monte Carlo study.

    Science.gov (United States)

    Xiong, Guoming; Rogers, D W O

    2008-05-01

    The relationship between the photon beam quality specifier %dd(10)x and the Spencer-Attix water water to air restricted mass collision stopping-power ratio, (L/rho))air(water), is studied using Monte Carlo simulation with realistic beams in contrast to the previously used realistic but uniform spectra from an isotropic point source. The differences between accelerators with and without flattening filters are investigated since flattening filter free accelerators appear to be useful for IMRT. Our results show that the standard relationship between %dd(10)x and (L/rho)air(water), which is used in the TG-51 protocol to calculate the quality conversion factor kQ, is acceptable for beams with or without a flattening filter with a maximum error of 0.4%, although a fit to the new data would reduce the maximum error to 0.2%. Reasons for differences between the individual values of %dd(10)x and (L/ rho)air(water) with and without a flattening filter are studied. Specifically the differences due to the softening of the beam, the change in shape of the profile, and the inclusion of radial variations in the photon energy spectra, are investigated. It is shown that if TPR10(20) is used as a beam quality specifier, there are two different relationships between TPR10(20) and (L/rho)air(water) which differ by 0.4%-1%. When using TPR10(20) as a beam quality specifier in a beam without a flattening filter, one should subtract 0.5% from the value of kQ for a given value of TPR10(20).

  20. Ultra-Fast Tracking Power Supply with 4th order Output Filter and Fixed-Frequency Hysteretic Control

    DEFF Research Database (Denmark)

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

    2008-01-01

    A practical solution is presented for the design of a non-isolated DC/DC power converter with very low output ripple voltage and very fast output voltage step response. The converter is intended for use as an envelope tracking power supply for an RFPA (Radio Frequency Power Amplifier) in a Tetra2...... base station. A simple and effective fixed-frequency hysteretic control scheme for the converter (buck with 4th order output filter) is developed and analyzed. The proposed approach is verified experimentally by a 500W output prototype, capable of delivering any voltage in the range of 10-30V within 10......μs with 10mVpp of output ripple and efficiencies in the 88- 95% range....

  1. Design of Optimized Low Power and Area Efficient Digital FIR Filter using Modified Group Structures based Square Root Carry Select Adder

    Directory of Open Access Journals (Sweden)

    S. Murugeswari

    2015-01-01

    Full Text Available In Digital Signal Processing, Finite Impulse Response (FIR filter is mostly used for communications and radar applications. The Performance of FIR filter depends on Multiplier and adder circuits used in filter. To reduce the dynamic power consumption and chip size, different multiplier and adder combinations are used in order to improve the overall performance of FIR filter. The Low Power Modified Square Root Carry Select Adder (M-SQRT CSLA is presented in this study by introducing half adders instead of full adders. The proposed M-SQRT CSLA has been designed to reduce dynamic power consumption. Hence the modified SQRT CSLA is applied into Wallace multiplier for addition process after the partial product generation stage. MAC unit of the Digital FIR filter is designed by using modified Wallace multipliers and M-SQRT CSLA. Further the Group 2, Group 3; Group 4 and Group5 structures of SQRT CSLA were constructed using half adders only. Comparison between proposed SQRT CSLA and Modified Carry Save Adder (MCSA has been done with reference to the Area, Power and Delay. It is proved that the proposed SQRT CSLA consumes less area and power than all other methods. Simulation is performed by Modelsim6.3c and Synthesis process is done by Xilinx 10.1. The simulation result shows that digital filter with proposed SQRT CSLA occupies less area and consumes low power.

  2. Physical features of small disperse coal dust fraction transportation and structurization processes in iodine air filters of absorption type in ventilation systems at nuclear power plants

    CERN Document Server

    Ledenyov, Oleg P; Poltinin, P Ya; Fedorova, L I

    2012-01-01

    The research on the physical features of transportation and structurization processes by the air-dust aerosol in the granular filtering medium with the cylindrical coal adsorbent granules in an air filter of the adsorption type in the heating ventilation and cooling (HVAC) system at the nuclear power plant is completed. The physical origins of the coal dust masses distribution along the absorber with the granular filtering medium with the cylindrical coal granules during the air-dust aerosol intake process in the near the surface layer of absorber are researched. The quantitative technical characteristics of air filtering elements, which have to be considered during the optimization of air filters designs for the application in the ventilation systems at the nuclear power plants, are obtained.

  3. Step by Step Design of a High Order Power Filter for Three-Phase Three-Wire Grid-connected Inverter in Renewable Energy System

    DEFF Research Database (Denmark)

    Huang, Min; Blaabjerg, Frede; Yang, Yongheng;

    2013-01-01

    Traditionally, when designing an LCL-filter, a three-phase inverter is simplified as a single-phase inverter for analysis and the output phase voltage is used to calculate the inverter-side current harmonics and to design inverter-side inductor. However, for a three-phase three-wire grid-tied sys...... method of the high order power filter is introduced. Simulations are carried out to verify the accuracy and the validity of the proposed methods through a 6 kW, 380V/50 Hz grid-connected inverter model with three different types of high order power filters....

  4. Low power consumption and continuously tunable all-optical microwave filter based on an opto-mechanical microring resonator.

    Science.gov (United States)

    Liu, Li; Yang, Yue; Li, Zhihua; Jin, Xing; Mo, Wenqin; Liu, Xing

    2017-01-23

    We propose and experimentally demonstrate a continuously tunable all-optical microwave filter using a silicon opto-mechanical microring resonator (MRR). By finely adjusting the pump light with submilliwatt power level, transmission spectrum of the MRR could be continuously shifted based on the nonlinear effects, including the opto-mechanical effect and thermo-optic effect. Therefore, in the case of optical single sideband (OSSB) modulation, the frequency intervals between the optical carrier (near one MRR resonance) and the corresponding resonance could be flexibly manipulated, which is the critical factor to achieve continuously tunable microwave photonic filter (MPF). In the experiment, the central frequency of the MPF could be continuously tuned from 6 GHz to 19 GHz with the pump power lower than -2.5 dBm. The proposed opto-mechanical device is competent to process microwave signals with dominant advantages, such as compact footprint, all-optical control and low power consumption. In the future, using light to control light, the opto-mechanical structure on silicon platforms might have many other potential applications in microwave systems, such as microwave switch.

  5. Simulation of mercury capture by activated carbon injection in incinerator flue gas. 2. Fabric filter removal.

    Science.gov (United States)

    Scala, F

    2001-11-01

    Following a companion paper focused on the in-duct mercury capture in incinerator flue gas by powdered activated carbon injection, this paper is concerned with the additional mercury capture on the fabric filter cake, relevant to baghouse equipped facilities. A detailed model is presented for this process, based on material balances on mercury in both gaseous and adsorbed phases along the growing filter cake and inside the activated carbon particles,taking into account mass transfer resistances and adsorption kinetics. Several sorbents of practical interest have been considered, whose parameters have been evaluated from available literature data. The values and range of the operating variables have been chosen in order to simulate typical incinerators operating conditions. Results of simulations indicate that, contrary to the in-duct removal process, high mercury removal efficiencies can be obtained with moderate sorbent consumption, as a consequence of the effective gas/sorbent contacting on the filter. Satisfactory utilization of the sorbents is predicted, especially at long filtration times. The sorbent feed rate can be minimized by using a reactive sorbent and by lowering the filter temperature as much as possible. Minor benefits can be obtained also by decreasing the sorbent particle size and by increasing the cleaning cycle time of the baghouse compartments. Reverse-flow baghouses were more efficient than pulse-jet baghouses, while smoother operation can be obtained by increasing the number of baghouse compartments. Model results are compared with available relevant full scale data.

  6. Incremental Activation Detection for Real-Time fMRI Series Using Robust Kalman Filter

    Directory of Open Access Journals (Sweden)

    Liang Li

    2014-01-01

    Full Text Available Real-time functional magnetic resonance imaging (rt-fMRI is a technique that enables us to observe human brain activations in real time. However, some unexpected noises that emerged in fMRI data collecting, such as acute swallowing, head moving and human manipulations, will cause much confusion and unrobustness for the activation analysis. In this paper, a new activation detection method for rt-fMRI data is proposed based on robust Kalman filter. The idea is to add a variation to the extended kalman filter to handle the additional sparse measurement noise and a sparse noise term to the measurement update step. Hence, the robust Kalman filter is designed to improve the robustness for the outliers and can be computed separately for each voxel. The algorithm can compute activation maps on each scan within a repetition time, which meets the requirement for real-time analysis. Experimental results show that this new algorithm can bring out high performance in robustness and in real-time activation detection.

  7. Incremental activation detection for real-time fMRI series using robust Kalman filter.

    Science.gov (United States)

    Li, Liang; Yan, Bin; Tong, Li; Wang, Linyuan; Li, Jianxin

    2014-01-01

    Real-time functional magnetic resonance imaging (rt-fMRI) is a technique that enables us to observe human brain activations in real time. However, some unexpected noises that emerged in fMRI data collecting, such as acute swallowing, head moving and human manipulations, will cause much confusion and unrobustness for the activation analysis. In this paper, a new activation detection method for rt-fMRI data is proposed based on robust Kalman filter. The idea is to add a variation to the extended kalman filter to handle the additional sparse measurement noise and a sparse noise term to the measurement update step. Hence, the robust Kalman filter is designed to improve the robustness for the outliers and can be computed separately for each voxel. The algorithm can compute activation maps on each scan within a repetition time, which meets the requirement for real-time analysis. Experimental results show that this new algorithm can bring out high performance in robustness and in real-time activation detection.

  8. Conversion of sand filters into activated carbon filters at the La Presa (Valencia) water works; Conversion de filtros de arena porcarbon activo en la ETAP de La Presa (Valencia)

    Energy Technology Data Exchange (ETDEWEB)

    Macian Cervera, V. J.; Monforte Monleon, L.; Ribera Orts, R.; Suris Jorda, J. I.; Klee, J. M.

    2007-07-01

    To improve the water quality at potable water treatment plant of La P esa (Valencia), the sand filters have been replaced for activated carbon filters. In the following review the results and conclusions of the direct sand filter conversion into activated carbon filters will be presented. The leads to a simple and fast solution to odour and taste removal, as well as dissolved organic matter, without investments in works at the water works. (Author)

  9. 电子式电能表中滤波器的设计%Design of the Electronic Power Meter Filter

    Institute of Scientific and Technical Information of China (English)

    孙国菊; 袁金晶; 朱德省; 张健辉

    2012-01-01

    The measurement accuracy of power meters is very important as it is related to trade settlement.Based on analyzing the metrological algorithm of electronic power meters,the paper proposes an improved measurement methodology for impulse types of load conditions.Different types of digital filters will be studied using the MATLAB Digital filter tool FDA Tool (Filter design & Analysis tool).The results show that in cases of harmonic and impulse load conditions,active energy can he measured within an error range of ± 1%,whereas fundamental energy error within ± 0.1%,thus verifying the effectiveness of the presented method.%电能表计量结果涉及到贸易结算,计量准确性至关重要.本文在电子式电能表电能计量算法分析的基础上,对动态负载下计量算法误差较大提出了改进方法.在MATLAB仿真软上使用专门的数字滤波器设计工具FDA Tool设计数字滤波器.结果显示在有谐波和动态负荷情况下有功电能误差在±1%范围内,基波电能误差在±0.1%范围内,从而验证本文提供方法的有效性.

  10. Output Filter Design for a Novel Dual-Input PV-Wind Power Converter by Energy Balance Principle

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2016-09-01

    Full Text Available In this paper, a detailed and systematic derivation of the output filter in a novel dual-input photovoltaic (PV-wind converter (DIPWC is presented. The theoretical derivation is based on an energy balance principle. While the DIPWC operates in steady state, the amount of charged energy of the output filter will be equal to that of the energy pumped away within one switching cycle. From this zero net change in energy, the minimum value of the output filter can be found. With the determined value, the DIPWC is able to operate in continuous conduction for high power applications. The developed procedure of the inductance determination can be applied to other types of dual-input converters. Therefore, it makes significant contributions to the design toward a green-energy, multi-input converter. To verify the correctness of the mathematical analysis, the DIPWC—with the derived output inductance—is built and tested. Practical measurements and results have verified the inductance determination.

  11. Removal of Toluene at Low Concentration with Activated Carbon Filter : Adsorption Analysis using Tenax Tube and TD-GCMSD

    OpenAIRE

    Shan, Chi-En

    2016-01-01

    Various studies have demonstrated the usefulness of adsorption of activated carbon on VOCs removal. Large porosity and high adsorption allows activated carbon to remove very small particles. This project was commissioned by the company name Genano Oy to test the activated carbon filter in their air purifier and hence to provide a database for the company. The purpose of this thesis was to study the effectiveness of impregnated activated carbon filter on toluene removal. Experiment was co...

  12. Active slag filters-simple and sustainable phosphorus removal from wastewater using steel industry byproduct.

    Science.gov (United States)

    Pratt, C; Shilton, A

    2010-01-01

    Active filtration, where effluent is passed through a reactive substrate such as steel slag, offers a simple and cost-effective option for removing phosphorus (P) from effluent. This work summarises a series of studies that focused on the world's only full-scale active slag filter operated through to exhaustion. The filter achieved 75% P-removal during its first 5 years, reaching a retention capacity of 1.23 g P/kg slag but then its performance sharply declined. Scanning electron microscopy, X-ray diffraction, X-ray fluorescence, and chemical extractions revealed that P sequestration was primarily achieved via adsorption onto iron (Fe) oxyhydroxides on the slag's surface. It was concluded that batch equilibrium tests, whose use has been repeatedly proposed in the literature, cannot be used as an accurate predictor of filter adsorption capacity because Fe oxyhydroxides form via chemical weathering in the field, and laboratory tests don't account for this. Research into how chemical conditions affect slag's P retention capacity demonstrated that near-neutral pH and high redox are optimal for Fe oxyhydroxide stability and overall filter performance. However, as Fe oxyhydroxide sites fill up, removal capacity becomes exhausted. Attempts to regenerate P removal efficiency using physical techniques proved ineffective contrary to dogma in the literature. Based on the newly-developed understanding of the mechanisms of P removal, chemical regeneration techniques were investigated and were shown to strip large quantities of P from filter adsorption sites leading to a regenerated P removal efficiency. This raises the prospect of developing a breakthrough technology that can repeatedly remove and recover P from effluent.

  13. 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

  14. LCL-Filter Design for Robust Active Damping in Grid-Connected Converters

    DEFF Research Database (Denmark)

    Pena-Alzola, Rafael; Liserre, Marco; Blaabjerg, Frede;

    2014-01-01

    Grid-connected converters employ LCL-filters, instead of simple inductors, because they allow lower inductances while reducing cost and size. Active damping, without dissipative elements, is preferred to passive damping for solving the associated stability problems. However, large variations...... in the grid inductance may compromise system stability, and this problem is more severe for parallel converters. This situation, typical of rural areas with solar and wind resources, calls for robust LCL-filter design. This paper proposes a design procedure with remarkable results under severe grid inductance...... variation. The procedure considers active damping using lead-lag network and capacitor current feedback. Passive damping is also discussed. The design flow, with little iteration and no complex algorithms, selects the proper ratios between the switching and resonance frequency, the grid and converter...

  15. Active plasmonic band-stop filters based on graphene metamaterial at THz wavelengths.

    Science.gov (United States)

    Wei, Zhongchao; Li, Xianping; Yin, Jianjun; Huang, Rong; Liu, Yuebo; Wang, Wei; Liu, Hongzhan; Meng, Hongyun; Liang, Ruisheng

    2016-06-27

    Active plasmonic band-stop filters based on single- and double-layer doped graphene metamaterials at the THz wavelengths are proposed and investigated numerically by using the finite-difference time-domain (FDTD) method. The metamaterial unit cell structure is composed of two parallel graphene nanoscale ribbons. Simulated results exhibit that significant resonance wavelength shifts can be achieved with a slight variation of the doping concentration of the graphene ribbons. Besides, the asymmetry double-layer graphene metamaterial device has two apparent filter dips while the symmetry single-, double-layer and asymmetry single-layer graphene metamaterial devices just only one. The metamaterials with symmetry single-layer and asymmetry double-layer graphene can be used as a high-sensitivity refractive sensor with the sensitivity up to 5100 nm/RIU and a two-circuit switch, respectively. These prospects pave the way towards ultrafast active graphene-based plasmonic devices for THz applications.

  16. Digital Realization of Capacitor-Voltage Feedback Active Damping for LCL-Filtered Grid Converters

    DEFF Research Database (Denmark)

    Xin, Zhen; Wang, Xiongfei; Loh, Poh Chiang;

    2015-01-01

    The capacitor voltage of an LCL-filter can also be used for active damping, if it is fed back for synchronization. By this way, an extra current sensor can be avoided. Compared with the existing active damping techniques designed with capacitor current feedback, the capacitor voltage feedback....... To overcome their drawbacks, a new derivative method is then proposed, based on the non-ideal generalized integrator. The performance of the proposed derivative has been found to match the ideal “s” function closely. Active damping based on capacitor voltage feedback can therefore be realized accurately...

  17. Thermal Filters for the ATHENA X-IFU: Ongoing Activities Toward the Conceptual Design

    Science.gov (United States)

    Barbera, Marco; Argan, A.; Bozzo, E.; Branduardi-Raymont, G.; Ciaravella, A.; Collura, A.; Cuttaia, F.; Gatti, F.; Jimenez Escobar, A.; Lo Cicero, U.; Lotti, S.; Macculi, C.; Mineo, T.; Nuzzo, F.; Paltani, S.; Parodi, G.; Piro, L.; Rauw, G.; Sciortino, L.; Sciortino, S.; Villa, F.

    2016-08-01

    ATHENA is the L2 mission selected by ESA to pursue the science theme "Hot and Energetic Universe." One of the two focal plane instruments is the X-ray Integral Field Unit, an array of TES microcalorimeters operated at T RF electromagnetic interferences on TES sensors and SQUID electronics, and to protect the detector from contamination. This paper reviews the ongoing activities driving the design of the X-IFU thermal filters.

  18. Wind Powering America FY07 Activities Summary

    Energy Technology Data Exchange (ETDEWEB)

    2008-02-01

    The Wind Powering America FY07 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 30 state wind working groups (welcoming Georgia and Wisconsin in 2007) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 140 members of national and state public and private sector organizations from 39 U.S. states and Canada attended the 6th Annual WPA All-States Summit in Los Angeles in June. WPA's emphasis remains on the rural agricultural sector, which stands to reap the significant economic development benefits of wind energy development. Additionally, WPA continues its program of outreach, education, and technical assistance to Native American communities, public power entities, and regulatory and legislative bodies.

  19. Optically powered active sensing system for Internet Of Things

    Science.gov (United States)

    Gao, Chen; Wang, Jin; Yin, Long; Yang, Jing; Jiang, Jian; Wan, Hongdan

    2014-10-01

    Internet Of Things (IOT) drives a significant increase in the extent and type of sensing technology and equipment. Sensors, instrumentation, control electronics, data logging and transmission units comprising such sensing systems will all require to be powered. Conventionally, electrical powering is supplied by batteries or/and electric power cables. The power supply by batteries usually has a limited lifetime, while the electric power cables are susceptible to electromagnetic interference. In fact, the electromagnetic interference is the key issue limiting the power supply in the strong electromagnetic radiation area and other extreme environments. The novel alternative method of power supply is power over fiber (PoF) technique. As fibers are used as power supply lines instead, the delivery of the power is inherently immune to electromagnetic radiation, and avoids cumbersome shielding of power lines. Such a safer power supply mode would be a promising candidate for applications in IOT. In this work, we built up optically powered active sensing system, supplying uninterrupted power for the remote active sensors and communication modules. Also, we proposed a novel maximum power point tracking technique for photovoltaic power convertors. In our system, the actual output efficiency greater than 40% within 1W laser power. After 1km fiber transmission and opto-electric power conversion, a stable electric power of 210mW was obtained, which is sufficient for operating an active sensing system.

  20. Wind Powering America FY06 Activities Summary

    Energy Technology Data Exchange (ETDEWEB)

    2007-02-01

    The Wind Powering America FY06 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 29 state wind working groups (welcoming New Jersey, Indiana, Illinois, and Missouri in 2006) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 120 members of national and state public and private sector organizations from 34 states attended the 5th Annual WPA All-States Summit in Pittsburgh in June.

  1. Capacitor Current Feedback-Based Active Resonance Damping Strategies for Digitally-Controlled Inductive-Capacitive-Inductive-Filtered Grid-Connected Inverters

    DEFF Research Database (Denmark)

    Lorzadeh, Iman; Askarian Abyaneh, Hossein; Savaghebi, Mehdi

    2016-01-01

    Inductive-capacitive-inductive (LCL)-type line filters are widely used in grid-connected voltage source inverters (VSIs), since they can provide substantially improved attenuation of switching harmonics in currents injected into the grid with lower cost, weight and power losses than their L......-type counterparts. However, the inclusion of third order LCL network complicates the current control design regarding the system stability issues because of an inherent resonance peak which appears in the open-loop transfer function of the inverter control system near the control stability boundary. To avoid...... passive (resistive) resonance damping solutions, due to their additional power losses, active damping (AD) techniques are often applied with proper control algorithms in order to damp the LCL filter resonance and stabilize the system. Among these techniques, the capacitor current feedback (CCF) AD has...

  2. Transient Control of Synchronous Machine Active and Reactive Power in Micro-grid Power Systems

    Science.gov (United States)

    Weber, Luke G.

    There are two main topics associated with this dissertation. The first is to investigate phase-to-neutral fault current magnitude occurring in generators with multiple zero-sequence current sources. The second is to design, model, and tune a linear control system for operating a micro-grid in the event of a separation from the electric power system. In the former case, detailed generator, AC8B excitation system, and four-wire electric power system models are constructed. Where available, manufacturers data is used to validate the generator and exciter models. A gain-delay with frequency droop control is used to model an internal combustion engine and governor. The four wire system is connected through a transformer impedance to an infinite bus. Phase-to-neutral faults are imposed on the system, and fault magnitudes analyzed against three-phase faults to gauge their severity. In the latter case, a balanced three-phase system is assumed. The model structure from the former case - but using data for a different generator - is incorporated with a model for an energy storage device and a net load model to form a micro-grid. The primary control model for the energy storage device has a high level of detail, as does the energy storage device plant model in describing the LC filter and transformer. A gain-delay battery and inverter model is used at the front end. The net load model is intended to be the difference between renewable energy sources and load within a micro-grid system that has separated from the grid. Given the variability of both renewable generation and load, frequency and voltage stability are not guaranteed. This work is an attempt to model components of a proposed micro-grid system at the University of Wisconsin Milwaukee, and design, model, and tune a linear control system for operation in the event of a separation from the electric power system. The control module is responsible for management of frequency and active power, and voltage and reactive

  3. Convergence analysis of the Filtered-U LMS algorithm for active noise control in case perfect cancellation is not possible

    NARCIS (Netherlands)

    Fraanje, P.R.; Verhaegen, M.; Doelman, N.J.

    2003-01-01

    The Filtered-U LMS algorithm, proposed by Eriksson for active noise control applications, adapts the coefficients of an infinite-impulse response controller. Conditions for global convergence of the Filtered-U LMS algorithm were presented by Wang and Ren (Signal Processing, 73 (1999) 3) and Mosquera

  4. Active damping of LLCL-filter resonance based on LC-trap voltage and capacitor current feedback

    DEFF Research Database (Denmark)

    Huang, Min; Wang, Xiongfei; Loh, Poh Chiang;

    2015-01-01

    . In this paper, different feedback coefficients like the proportional, derivative, integral, high pass and low pass feedback coefficients of the filter capacitor current and the LC-trap circuit voltage are investigated for damping the filter resonance. Active damping methods are analyzed by using the concept...

  5. Modulation power of porous materials and usage as ripple filter in particle therapy

    Science.gov (United States)

    Printz Ringbæk, Toke; Simeonov, Yuri; Witt, Matthias; Engenhart-Cabillic, Rita; Kraft, Gerhard; Zink, Klemens; Weber, Uli

    2017-04-01

    Porous materials with microscopic structures like foam, sponges, lung tissues and lung substitute materials have particular characteristics, which differ from those of solid materials. Ion beams passing through porous materials show much stronger energy straggling than expected for non-porous solid materials of the same thickness. This effect depends on the microscopic fine structure, the density and the thickness of the porous material. The beam-modulating effect from a porous plate enlarges the Bragg peak, yielding similar benefits in irradiation time reduction as a ripple filter. A porous plate can additionally function as a range shifter, which since a higher energy can be selected for the same penetration depth in the body reduces the scattering at the beam line and therefore improves the lateral fall-off. Bragg curve measurements of ion beams passing through different porous materials have been performed in order to determine the beam modulation effect of each. A mathematical model describing the correlation between the mean material density, the porous pore structure size and the strength of the modulation has been developed and a new material parameter called ‘modulation power’ is defined as the square of the Gaussian sigma divided by the mean water-equivalent thickness of the porous absorber. Monte Carlo simulations have been performed in order to validate the model and to investigate the Bragg peak enlargement, the scattering effects of porosity and the lateral beam width at the end of the beam range. The porosity is found to only influence the lateral scattering in a negligible way. As an example of a practical application, it is found that a 20 mm and 50 mm plate of Gammex LN300 performs similar to a 3 mm and 6 mm ripple filter, respectively, and at the same time can improve the sharpness of the lateral beam due to its multifunctionality as a ripple filter and a range shifter.

  6. Filtered x-ray diode diagnostics fielded on the Z-accelerator for source power measurements

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, G.A.; Deeney, C.; Cuneo, M. [and others

    1998-06-02

    Filtered x-ray diode, (XRD), detectors are used as primary radiation flux diagnostics on Sandia`s Z-accelerator, which generates nominally a 200 TW, 2 MJ, x-ray pulse. Given such flux levels and XRD sensitivities the detectors are being fielded 23 meters from the source. The standard diagnostic setup and sensitivities are discussed. Vitreous carbon photocathodes are being used to reduce the effect of hydrocarbon contamination present in the Z-machine vacuum system. Nevertheless pre- and post-calibration data taken indicate spectrally dependent changes in the sensitivity of these detectors by up to factors up to 2 or 3.

  7. Detecting Low-Power RF Signals Using a Multimode Optoelectronic Oscillator and Integrated Optical Filter

    Science.gov (United States)

    2010-02-01

    output is connected to an erbium-doped fiber amplifier ( EDFA ) and the amplified signal is sent to a photodetector. Part of the detected electrical...1 dB below threshold at 1 GHz with a photocurrent of 20.2 mA. The mode spacing is 5.2 MHz, limited by the long length of fiber in the EDFA . We inject...insertion loss. The optical signal after the filter is then amplified by an EDFA and measured at an ESA. The RF gain of the different RF tones was measured

  8. Simplified greywater treatment systems: Slow filters of sand and slate waste followed by granular activated carbon.

    Science.gov (United States)

    Zipf, Mariah Siebert; Pinheiro, Ivone Gohr; Conegero, Mariana Garcia

    2016-07-01

    One of the main actions of sustainability that is applicable to residential, commercial, and public buildings is the rational use of water that contemplates the reuse of greywater as one of the main options for reducing the consumption of drinking water. Therefore, this research aimed to study the efficiencies of simplified treatments for greywater reuse using slow sand and slow slate waste filtration, both followed by granular activated carbon filters. The system monitoring was conducted over 28 weeks, using analyses of the following parameters: pH, turbidity, apparent color, biochemical oxygen demand (BOD), chemical oxygen demand (COD), surfactants, total coliforms, and thermotolerant coliforms. The system was run at two different filtration rates: 6 and 2 m(3)/m(2)/day. Statistical analyses showed no significant differences in the majority of the results when filtration rate changed from 6 to 2 m(3)/m(2)/day. The average removal efficiencies with regard to the turbidity, apparent color, COD and BOD were 61, 54, 56, and 56%, respectively, for the sand filter, and 66, 61, 60, and 51%, respectively, for the slate waste filter. Both systems showed good efficiencies in removing surfactants, around 70%, while the pH reached values of around 7.80. The average removal efficiencies of the total and thermotolerant coliforms were of 61 and 90%, respectively, for the sand filter, and 67 and 80%, respectively, for the slate waste filter. The statistical analysis found no significant differences between the responses of the two systems, which attest to the fact that the slate waste can be a substitute for sand. The maximum levels of efficiency were high, indicating the potential of the systems, and suggesting their optimization in order to achieve much higher average efficiencies.

  9. A Component-Minimized Single-Phase Active Power Decoupling Circuit with Reduced Current Stress to Semiconductor Switches

    DEFF Research Database (Denmark)

    Tang, Yi; Blaabjerg, Frede

    2015-01-01

    This letter proposes a novel circuit topology which can realize the power decoupling function without adding additional active switches into the circuit. The dc-link capacitor of a full bridge rectifier is split into two identical parts and the midpoint is connected to one leg through a filter...

  10. High temperature superconductors in satellite communications. High power microwave resonators and filters in planar HTSC technology. Final report; Hochtemperatur-Supraleiter-Systeme in der Satellitenkommunikation. Leistungstaugliche Hochfrequenz-Resonatoren und -Filter in planarer HTSL-Technologie. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Baumfalk, A.; Kaiser, T.; Kolesov, S.; Chaloupka, H.; Piel, H.; Hein, M.

    1999-07-31

    Goal of the R and D project was the development of miniaturized HTSC resonators and filters. The work was divided into two main packages: ({alpha}) Systematic investigations of thin film samples, manufactured by partners of the common project as well as the development of characterization methods. ({beta}) Considerations of all relevant topics related to the design and manufacturing of high power filters with given specifications. The power handling capability of thin films is the most challenging issue in film production. A large variation in film quality could be observed that can cause problems in the realization of HTSC components. Employing the introduced concept of edge current free disk and ring resonators, high power HTSC filters can be realized with an improvement of 400 in power handling capability compared to other HTSC resonator types. During optimization of the unloaded quality factor, dielectric losses were identified to be the limiting factor. Two-pole, four-pole Chebyshev and four pole elliptic filters were developed and characterized and showed low loss and high power handling capability. (orig.) [German] Die Zielsetzung des F und E-Vorhabens war es, stark miniaturisierte leistungstaugliche Resonatoren und Filter auf der Basis von Hochtemperatur-supraleitenden Duennfilmen zu entwickeln. Die Arbeiten gliederten sich in zwei Teilbereiche: Einerseits wurden Methoden zur Hochfrequenz-Charakterisierung der zugrundeliegenden HTSL-Schichten entwickelt und systematische Untersuchungen an Proben schichtherstellender Verbundpartner durchgefuehrt. Andererseits wurden alle relevanten Teilprobleme zur Entwicklung hochleistungstauglicher Filter bearbeitet und entsprechende Problemloesungen entwickelt. Bei der Schichtherstellung stellte sich die geforderte Leistungstragfaehigkeit der HTSL-Schichten als besondere Herausforderung dar. Es wurde eine grosse Streuung der Filmqualitaet beobachtet, wodurch die Realisierung von Bauelementen erschwert werden kann. Die

  11. Power factor compensation with lossless linear filters is equivalent to (weighted) power equalization and a new cyclo–dissipativity characterization

    NARCIS (Netherlands)

    Puerto-Flores, Dunstano del; Ortega, Romeo; Scherpen, Jacquelien M.A.

    2009-01-01

    Recently, it has been established that the problem of power factor compensation for nonlinear loads with non-sinusoidal source voltage can be recast in terms of the property of cyclo–dissipativity. Using this framework the classical capacitor and inductor compensators can be interpreted in terms of

  12. Elimination of Harmonic Force and Torque in Active Magnetic Bearing Systems with Repetitive Control and Notch Filters

    Directory of Open Access Journals (Sweden)

    Xiangbo Xu

    2017-04-01

    Full Text Available Harmonic force and torque, which are caused by rotor imbalance and sensor runout, are the dominant disturbances in active magnetic bearing (AMB systems. To eliminate the harmonic force and torque, a novel control method based on repetitive control and notch filters is proposed. Firstly, the dynamics of a four radial degrees of freedom AMB system is described, and the AMB model can be described in terms of the translational and rotational motions, respectively. Next, a closed-loop generalized notch filter is utilized to identify the synchronous displacement resulting from the rotor imbalance, and a feed-forward compensation of the synchronous force and torque related to the AMB displacement stiffness is formulated by using the identified synchronous displacement. Then, a plug-in repetitive controller is designed to track the synchronous feed-forward compensation adaptively and to suppress the harmonic vibrations due to the sensor runout. Finally, the proposed control method is verified by simulations and experiments. The control algorithm is insensitive to the parameter variations of the power amplifiers and can precisely suppress the harmonic force and torque. Its practicality stems from its low computational load.

  13. Indoor Air Contaminant Adsorption By Palm Shell Activated Carbon Filter – A Proposed Study

    Directory of Open Access Journals (Sweden)

    Leman A.M

    2016-01-01

    Full Text Available Indoor air contaminant is a public issue. High Volatile Organic Compound (VOC, Carbon monoxide (CO, Carbon dioxide (CO2, and particulate matter is becoming main issue that needs to solve. Therefore, this study focus on improving indoor air quality by using activated carbon (AC for Ventilation and Air-Conditioning (VAC. It investigated because AC is widely explored but developing AC as a filter for VAC is not developed yet. The AC prepared by physical and chemical activation process and combination both of process and it was activated by H3PO4 and NaOH. Characterization and analysis process are consists of water content, ash content, bulk density, adsorption capacity, iodine number and indoor air filtering analysis. Treated activated carbon potential in achieving higher surface area of the structure to the range of 950 to 1150 m2/g for gas phase application. The higher surface area will adsorb more air pollution. Maintained properties of activated carbon such as hardness, density, pore, extractable ash, particle size (12 by 40 mesh and pH are becoming the main concern in achieving high quality of activated carbon.

  14. Active notch filter network with variable notch depth, width and frequency

    Science.gov (United States)

    Black, J. M. (Inventor)

    1980-01-01

    An active notch filter having independently adjustable notch frequency, width, and depth is provided by three equal capacitors connected in series with an operational amplifier (connected in a voltage follower configuration), a potentiometer across the series connected capacitors for notch depth adjustment, and a potentiometer (for notch frequency connected across the center capacitor); with its tap connected to receive a voltage feedback signal from a variable voltage divider comprised of another potentiometer for notch width. Adjusting the voltage dividing potentiometer will independently set the notch width, and adjusting the tap on the potentiometer across the center capacitor will independently adjust the notch frequency of the filter. A second operational amplifier connected in a voltage follower configuration may be used to connect the voltage divider output to the adjustable tap of the potentiometer across the center capacitor.

  15. Highly Accurate Derivatives for LCL-Filtered Grid Converter with Capacitor Voltage Active Damping

    DEFF Research Database (Denmark)

    Xin, Zhen; Loh, Poh Chiang; Wang, Xiongfei;

    2016-01-01

    The middle capacitor voltage of an LCL-filter, if fed back for synchronization, can be used for active damping. An extra sensor for measuring the capacitor current is then avoided. Relating the capacitor voltage to existing popular damping techniques designed with capacitor current feedback would...... are then proposed, based on either second-order or non-ideal generalized integrator. Performances of these derivatives have been found to match the ideal “s” function closely. Active damping based on capacitor voltage feedback can therefore be realized accurately. Experimental results presented have verified...

  16. Development of biomass in a drinking water granular active carbon (GAC) filter.

    Science.gov (United States)

    Velten, Silvana; Boller, Markus; Köster, Oliver; Helbing, Jakob; Weilenmann, Hans-Ulrich; Hammes, Frederik

    2011-12-01

    Indigenous bacteria are essential for the performance of drinking water biofilters, yet this biological component remains poorly characterized. In the present study we followed biofilm formation and development in a granular activated carbon (GAC) filter on pilot-scale during the first six months of operation. GAC particles were sampled from four different depths (10, 45, 80 and 115 cm) and attached biomass was measured with adenosine tri-phosphate (ATP) analysis. The attached biomass accumulated rapidly on the GAC particles throughout all levels in the filter during the first 90 days of operation and maintained a steady state afterward. Vertical gradients of biomass density and growth rates were observed during start-up and also in steady state. During steady state, biomass concentrations ranged between 0.8-1.83 x 10(-6) g ATP/g GAC in the filter, and 22% of the influent dissolved organic carbon (DOC) was removed. Concomitant biomass production was about 1.8 × 10(12) cells/m(2)h, which represents a yield of 1.26 × 10(6) cells/μg. The bacteria assimilated only about 3% of the removed carbon as biomass. At one point during the operational period, a natural 5-fold increase in the influent phytoplankton concentration occurred. As a result, influent assimilable organic carbon concentrations increased and suspended bacteria in the filter effluent increased 3-fold as the direct consequence of increased growth in the biofilter. This study shows that the combination of different analytical methods allows detailed quantification of the microbiological activity in drinking water biofilters.

  17. Highly efficient terahertz wave filter for high-power laser beam separation

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Bo; Cai, Bin, E-mail: bullcai@gmail.com, E-mail: ymzhu@usst.edu.cn; Zhu, YiMing, E-mail: bullcai@gmail.com, E-mail: ymzhu@usst.edu.cn [Engineering Research Center of Optical Instruments and Systems, Ministry of Education, and Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai 200093 (China); Tang, Jun [Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064 (China)

    2014-12-01

    In this study, we design and fabricate a two-layer device based on the Rayleigh scattering theory for effectively separating high-energy pump-laser-generated terahertz (THz) waves. The basic layer is comprised of cyclo olefin polymer and silicon nanoparticles, which can obstruct the propagation of the 800-nm, high-energy pump laser through scattering and absorption effects while permitting THz waves to pass through. In order to improve the laser damage threshold of the basic layer, an additional layer, which is composed of hollow silica nanoparticles, is used to diffuse the incident high-energy laser beam. Through this two-layer structure, a high 800-nm laser threshold and highly transparent THz region filter are fabricated.

  18. Catalytic diesel particulate filters reduce the in vitro estrogenic activity of diesel exhaust.

    Science.gov (United States)

    Wenger, Daniela; Gerecke, Andreas C; Heeb, Norbert V; Naegeli, Hanspeter; Zenobi, Renato

    2008-04-01

    An in vitro reporter gene assay based on human breast cancer T47D cells (ER-CALUX) was applied to examine the ability of diesel exhaust to induce or inhibit estrogen receptor (ER)-mediated gene expression. Exhaust from a heavy-duty diesel engine was either treated by iron- or copper/iron-catalyzed diesel particulate filters (DPFs) or studied as unfiltered exhaust. Collected samples included particle-bound and semivolatile constituents of diesel exhaust. Our findings show that all of the samples contained compounds that were able to induce ER-mediated gene expression as well as compounds that suppressed the activity of the endogenous hormone 17beta-estradiol (E2). Estrogenic activity prevailed over antiestrogenic activity. We found an overall ER-mediated activity of 1.63 +/- 0.31 ng E2 CALUX equivalents (E2-CEQs) per m(3) of unfiltered exhaust. In filtered exhaust, we measured 0.74 +/- 0.07 (iron-catalyzed DPF) and 0.55 +/- 0.09 ng E2-CEQ m(-3) (copper/iron-catalyzed DPF), corresponding to reductions in estrogenic activity of 55 and 66%, respectively. Our study demonstrates that both catalytic DPFs lowered the ER-mediated endocrine-disrupting potential of diesel exhaust.

  19. Catalytic diesel particulate filters reduce the in vitro estrogenic activity of diesel exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Wenger, Daniela; Gerecke, Andreas C.; Heeb, Norbert V. [Laboratory for Analytical Chemistry, Empa, Swiss Federal Laboratories for Materials Testing and Research, Duebendorf (Switzerland); Naegeli, Hanspeter [University of Zurich-Vetsuisse, Institute of Pharmacology and Toxicology, Zurich (Switzerland); Zenobi, Renato [ETH Zurich, Department of Chemistry and Applied Biosciences, Zurich (Switzerland)

    2008-04-15

    An in vitro reporter gene assay based on human breast cancer T47D cells (ER-CALUX {sup registered}) was applied to examine the ability of diesel exhaust to induce or inhibit estrogen receptor (ER)-mediated gene expression. Exhaust from a heavy-duty diesel engine was either treated by iron- or copper/iron-catalyzed diesel particulate filters (DPFs) or studied as unfiltered exhaust. Collected samples included particle-bound and semivolatile constituents of diesel exhaust. Our findings show that all of the samples contained compounds that were able to induce ER-mediated gene expression as well as compounds that suppressed the activity of the endogenous hormone 17{beta}-estradiol (E2). Estrogenic activity prevailed over antiestrogenic activity. We found an overall ER-mediated activity of 1.63 {+-} 0.31 ng E2 CALUX equivalents (E2-CEQs) per m{sup 3} of unfiltered exhaust. In filtered exhaust, we measured 0.74 {+-} 0.07 (iron-catalyzed DPF) and 0.55 {+-} 0.09 ng E2-CEQ m{sup -3} (copper/iron-catalyzed DPF), corresponding to reductions in estrogenic activity of 55 and 66%, respectively. Our study demonstrates that both catalytic DPFs lowered the ER-mediated endocrine-disrupting potential of diesel exhaust. (orig.)

  20. Design and Simulation for EMI Filter of 60 W RGB LED Power Supply%60 WRGB LED电源的EMI滤波器设计与仿真

    Institute of Scientific and Technical Information of China (English)

    张明准; 秦会斌; 胡艳蕊

    2016-01-01

    The mechanism and hazard of EMI(Electromagnetic Interference,EMI)of a 60 W Red,Green,and Blue leds(Red,Green,and Blue Light-emitting Diode,RGB LED)power supply was introduced. A low cost EMI filter with simple structure was designed. A PSpice model of EMI filter was built,and parameters of EMI filter designed were simulated according to the PSpice model. The EMI filter was used in a prototype of RGB LED power supply , and EMI test result for LED power supply with EMI filter circuit verify the validity of proposed EMI filter.%介绍了一款60 W红,绿,蓝发光二极管(Red,Green and Blue Light-Emitting Diode,RGB LED)驱动电源电磁干扰EMI (Electromagnetic Interference)产生的机理及危害,设计了一种结构简单的低成本抗传导EMI滤波电路。通过PSpice软件建模,对所设计的滤波电路进行仿真实验。所设计的EMI滤波电路使用在RGB LED电源样机上,对样机进行了传导EMI测试,测试结果验证了所设计的EMI滤波电路具有25 dB的裕量。

  1. 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.

  2. FILTER COMPONENT ASSESSMENT--CERAMIC CANDLES--

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Alvin

    2004-04-23

    Efforts at Siemens Westinghouse Power Corporation (SWPC) have been focused on development of hot gas filter systems as an enabling technology for advanced coal and biomass-based gas turbine power generation applications. SWPC has been actively involved in the development of advanced filter materials and component configuration, has participated in numerous surveillance programs characterizing the material properties and microstructure of field tested filter elements, and has undertaken extended, accelerated filter life testing programs. This report summarizes the results of SWPC's filter component assessment efforts, identifying the performance and stability of porous monolithic, fiber reinforced, and filament wound ceramic hot gas candle filters, potentially for {ge}3 years of viable pressurized fluidized-bed combustion (PFBC) service operating life.

  3. An implicit evolution scheme for active contours and surfaces based on IIR filtering.

    Science.gov (United States)

    Delibasis, Konstantinos K; Asvestas, Pantelis A; Kechriniotis, Aristides I; Matsopoulos, George K

    2014-05-01

    In this work, we present an approach for implementing an implicit scheme for the numerical solution of the partial differential equation of the evolution of an active contour/surface. The proposed scheme is applicable to any variant of the traditional active contour (AC), irrespectively of the calculation of the image-based force field and it is readily applicable to explicitly parameterized active surfaces (AS). The proposed approach is formulated as an infinite impulse response (IIR) filtering of the coordinates of the contour/surface points. The poles of the filter are determined by the parameters controlling the shape of the active contour/surface. We show that the proposed IIR-based implicit evolution scheme has very low complexity. Furthermore, the proposed scheme is numerically stable, thus it allows the convergence of the AC/AS with significantly fewer iterations than the explicit evolution scheme. It also possesses the separability property along the two parameters of the AS, thus it may be applied to deformable surfaces, without the need to store and invert large sparse matrices. We implemented the proposed IIR-based implicit evolution scheme in the Vector Field Convolution (VFC) AC/AS using synthetic and clinical volumetric data. We compared the segmentation results with those of the explicit AC/AS evolution, in terms of accuracy and efficiency. Results show that the VFC AC/AS with the proposed IIR-based implicit evolution scheme achieves the same segmentation results with the explicit scheme, with considerably less computation time.

  4. Filtered-X Radial Basis Function Neural Networks for Active Noise Control

    Directory of Open Access Journals (Sweden)

    Bambang Riyanto

    2004-05-01

    Full Text Available This paper presents active control of acoustic noise using radial basis function (RBF networks and its digital signal processor (DSP real-time implementation. The neural control system consists of two stages: first, identification (modeling of secondary path of the active noise control using RBF networks and its learning algorithm, and secondly neural control of primary path based on neural model obtained in the first stage. A tapped delay line is introduced in front of controller neural, and another tapped delay line is inserted between controller neural networks and model neural networks. A new algorithm referred to as Filtered X-RBF is proposed to account for secondary path effects of the control system arising in active noise control. The resulting algorithm turns out to be the filtered-X version of the standard RBF learning algorithm. We address centralized and decentralized controller configurations and their DSP implementation is carried out. Effectiveness of the neural controller is demonstrated by applying the algorithm to active noise control within a 3 dimension enclosure to generate quiet zones around error microphones. Results of the real-time experiments show that 10-23 dB noise attenuation is produced with moderate transient response.

  5. On Power Factor Improvement by Lossless Linear Filters under Nonlinear Nonsinusoidal Conditions

    NARCIS (Netherlands)

    Puerto-Flores, D. del; Ortega, R.; Scherpen, J.M.A.

    2011-01-01

    Recently, it has been established that the problem of power factor compensation for nonlinear loads with nonsinusoidal source voltage can be recast in terms of the property of cyclodissipativity. The purpose of this brief note is to review and to illustrate the application of this framework to the p

  6. Increasing input power dynamic range of SOA by shifting the transparent wavelength of tunable optical filter

    DEFF Research Database (Denmark)

    Yu, Jianjun; Jeppesen, Palle

    2001-01-01

    is only 2-3 ps long. The input power dynamic range (IPDR) can be strongly increased by shifting the TOF and the direction of the shifted transparent wavelength is different for 10 Gb/s return-to-zero (RZ) or nonreturn-to-zero (NRZ) signals. The transparent wavelength of the TOF should be shifted...

  7. On Power Factor Improvement by Lossless Linear Filters in the Nonlinear Nonsinusoidal Case

    NARCIS (Netherlands)

    Puerto-Flores, Dunstano del; Scherpen, Jacquelien M.A.; Ortega, Romeo

    2010-01-01

    Recently, it has been established that the problem of power factor compensation (PFC) for nonlinear loads with non-sinusoidal source voltage can be recast in terms of the property of cyclodissipativity. Using this framework we study the PFC for nonlinear loads containing a memoryless nonlinearity. W

  8. Line filter design of parallel interleaved VSCs for high power wind energy conversion systems

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

    2015-01-01

    The Voltage Source Converters (VSCs) are often connected in parallel in a Wind Energy Conversion System (WECS) to match the high power rating of the modern wind turbines. The effect of the interleaved carriers on the harmonic performance of the parallel connected VSCs is analyzed in this paper...

  9. Ultra low-power biomedical signal processing: an analog wavelet filter approach for pacemakers

    NARCIS (Netherlands)

    Pavlík Haddad, S.A.

    2006-01-01

    The purpose of this thesis is to describe novel signal processing methodologies and analog integrated circuit techniques for low-power biomedical systems. Physiological signals, such as the electrocardiogram (ECG), the electroencephalogram (EEG) and the electromyogram (EMG) are mostly non-stationary

  10. Application of High Order X-LMS Filter for Active Noise Control

    Directory of Open Access Journals (Sweden)

    N.V.K.Mahalakshmi

    2014-06-01

    Full Text Available In this paper active noise is controlled by using higher order X-LMS (least mean square filter. This technique is based on X-NLMS (normalized least mean square, also known as traditional acoustic noise cancellation (ANC scheme. It cancels the wideband noise from the corrupted speech signal. The active noise reducing headphone is probably the most successful application of active control of sound – the technology of cancelling sound with sound i.e., by using anti-noise signal. This report presents an outlined technical review of noise cancellation in headphones. The principles of passive noise attenuation are presented after which active attenuation is introduced showing how the two complement the attenuation performance. In real-time environment, the number of different applications in which adaptive techniques are being successfully used that are echo cancellation, equalization of dispersive channels, system identification, signal enhancement, noise cancelling and control.

  11. Active Power Flow Optimization of Industrial Power Supply with Regard to the Transmission Line Conductor Heating

    Directory of Open Access Journals (Sweden)

    Leyzgold D.Yu.

    2015-04-01

    Full Text Available This article studies the problem of the transmission line conductor heating effect on the active power flows optimization in the local segment of industrial power supply. The purpose is to determine the optimal generation rating of the distributed power sources, in which the power flow values will correspond to the minimum active power losses in the power supply. The timeliness is the need to define the most appropriate rated power values of distributed sources which will be connected to current industrial power supply. Basing on the model of active power flow optimization, authors formulate the description of the nonlinear transportation problem considering the active power losses depending on the transmission line conductor heating. Authors proposed a new approach to the heating model parameters definition based on allowable current loads and nominal parameters of conductors as part of the optimization problem. Analysis of study results showed that, despite the relatively small active power losses reduction to the tune 0,45% due to accounting of the conductors heating effect for the present configuration of power supply, there are significant fluctuations in the required generation rating in nodes of the network to 9,32% within seasonal changes in the outer air temperature. This fact should be taken into account when selecting the optimum power of distributed generation systems, as exemplified by an arbitrary network configuration.

  12. Analog Electronic Filters Theory, Design and Synthesis

    CERN Document Server

    Dimopoulos, Hercules G

    2012-01-01

    Filters are essential subsystems in a huge variety of electronic systems. Filter applications are innumerable; they are used for noise reduction, demodulation, signal detection, multiplexing, sampling, sound and speech processing, transmission line equalization and image processing, to name just a few. In practice, no electronic system can exist without filters. They can be found in everything from power supplies to mobile phones and hard disk drives and from loudspeakers and MP3 players to home cinema systems and broadband Internet connections. This textbook introduces basic concepts and methods and the associated mathematical and computational tools employed in electronic filter theory, synthesis and design.  This book can be used as an integral part of undergraduate courses on analog electronic filters. Includes numerous, solved examples, applied examples and exercises for each chapter. Includes detailed coverage of active and passive filters in an independent but correlated manner. Emphasizes real filter...

  13. Tunable add-drop filter using an active whispering gallery mode microcavity

    CERN Document Server

    Monifi, Faraz; Yang, Lan

    2013-01-01

    An add-drop filter (ADF) fabricated using a whispering gallery mode resonator has different crosstalks for add and drop functions due to non-zero intrinsic losses of the resonator. Here, we show that introducing gain medium in the resonator and optically pumping it below the lasing threshold not only allows loss compensation to achieve similar and lower crosstalks but also tunability in bandwidth and add-drop efficiency. For an active ADF fabricated using an erbium-ytterbium co-doped microsphere, we achieved 24-fold enhancement in the intrinsic quality factor, 3.5-fold increase in drop efficiency, bandwidth tunability of 35 MHz and a crosstalk of only 2%.

  14. Stability Improvements of an LCL-filter based Three-phase Active Rectifier

    DEFF Research Database (Denmark)

    Liserre, Marco; Dell'Aquila, Antonio; Blaabjerg, Frede

    2002-01-01

    for the ac inductors making them expensive and bulky. Moreover the dynamic of the system becomes poor with so high value of inductance. On the contrary to adopt an LCL-filter configuration allows to use reduced values of the inductances (preserving dynamic) and to reduce the switching frequency pollution......, both passive (based on the use of resistors) and active (based on the modification of the control algorithm), is studied using the z-plane root locus approach and looking to dynamic performances and losses. In fact it is necessary to verify the dynamic effects by the introduction of damping resistors...

  15. Enhanced Stability of Capacitor-Current Feedback Active Damping for LCL-Filtered Grid Converters

    DEFF Research Database (Denmark)

    Xin, Zhen; Wang, Xiongfei; Loh, Poh Chiang;

    2015-01-01

    The proportional capacitor-current feedback active damping method has been widely used to suppress the LCL-filter resonance. However, the time delay in the damping control loop may lead to non-minimum phase or even unstable responses when the resonance frequency varies in a wide range. To improve...... the robustness of damping, this paper proposes an improved damping controller with the capacitor current feedback loop, which is based on the second-order generalized integrator, instead of a proportional gain, which can effectively mitigate the detrimental effect of the time delay. Robustness of the proposed...

  16. High-performance feedback-type active damping of LCL-filtered voltage source converters

    DEFF Research Database (Denmark)

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

    2015-01-01

    Active damping of LCL-filter resonance based on single-state feedback control is widely used with voltage source converters. Its robustness against grid impedance variation has always been a major concern with its controller design. To deal with this issue, this paper begins by developing......, but ensures also a robust stabilization against the grid parameters variations. For illustration, the approach is applied to design three single-state feedback-damping schemes, and their damping robustness are compared under both inductive and resonant grid impedances. Experimental results validate...

  17. Lightweight MAC-Spoof Detection Exploiting Received Signal Power and Median Filtering

    DEFF Research Database (Denmark)

    Papini, Davide

    2011-01-01

    IEEE 802.11 networks are subject to MAC-spoof attacks. An attacker can easily steal the identity of a legitimate station, even Access Points, thus enabling him to take full control over network basic mech- anisms or even access restricted resources. In this paper we propose a method to detect...... this kind of attack based on signal power monitoring. The main contribution of our work is the introduction of a median l- ter that enables the detection of the attack by looking at the variance of the signal power. We take into account two types of references for the samples, time and number of frames......, and compare their detection capabilities. Our experimental results show that the spoong attack is successfully detected with both type of references. Moreover the median lter helps to reject false positives....

  18. 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...

  19. Theoretical Studies of Active Power/angle Sub-matrix in Power Flow Jacobian for Power System Analysis

    Institute of Scientific and Technical Information of China (English)

    CAO Guo-yun; ZHANG Qing; CHUNG T S; CHEN Chen

    2008-01-01

    Properties of the active power/angle sub-matrix in the power flow Jacobian for power system analysis are studied. The sub-matrix is a dominant and irreducible matrix under very general conditions of power systems, so that it is invertible. Also the necessary conditions for its singularity are given. These theoretical rsuts can be used to clarify the ambiguous understanding of the sub-matrix in current literature, and also provide the theoretical foundations for the applications based on reduced power flow Jacobian. Numerical simulation on the IEEE 118-bus power system is used to illustrate our results.

  20. 高性能CIC抽取滤波器研究与设计%Design of High-powered CIC Decimator Filter

    Institute of Scientific and Technical Information of China (English)

    刘立; 向新

    2013-01-01

    In view of the problem of high pass band distortion and low stop band attenuation of CIC decimation filter in the sampling rata conversion system, a high-powered CIC decimator filter is proposed in this paper by using the technology of compensate filter and non-recursive parallel structure. Simulation results show that the proposed filter is more excellent on the stop band attenuation and pass band distortion contact with traditional CIC filter, CIC-Cosine filter and ISOP-CIC filter. Therefore, it is more appropriate in the sampling rata conversion system which has stricter require on magnitude performance.%针对采样率变换系统中CIC抽取滤波器存在通带失真较大和阻带衰减较小的问题,提出一种高性能CIC抽取滤波器的设计方法,该方法采用补偿滤波器技术和非递归并行结构.仿真结果表明,通带失真与阻带衰减特性明显优于传统的CIC,CIC-Cosine,ISOP-CIC等滤波器.因此,适用于对幅频特性要求较高的采样率变换系统.

  1. Digital filtering techniques applied to electric power systems protection; Tecnicas de filtragem digital aplicadas a protecao de sistemas eletricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Brito, Helio Glauco Ferreira

    1996-12-31

    This work introduces an analysis and a comparative study of some of the techniques for digital filtering of the voltage and current waveforms from faulted transmission lines. This study is of fundamental importance for the development of algorithms applied to digital protection of electric power systems. The techniques studied are based on the Discrete Fourier Transform theory, the Walsh functions and the Kalman filter theory. Two aspects were emphasized in this study: Firstly, the non-recursive techniques were analysed with the implementation of filters based on Fourier theory and the Walsh functions. Secondly, recursive techniques were analyzed, with the implementation of the filters based on the Kalman theory and once more on the Fourier theory. (author) 56 refs., 25 figs., 16 tabs.

  2. Programmable Power-of-two RNS Scaler and its Application to a QRNS Polyphase Filter

    DEFF Research Database (Denmark)

    Cardarilli, Gian Carlo; Re, Andrea Del; Nannarelli, Alberto;

    2005-01-01

    . This basic operation is not easily implementable in the Residue Number System (RNS) due to its non positional nature. A number of different algorithms have been presented in the literature for the RNS scaling. In this paper, several RNS dynamic reduction techniques have been analyzed and the selected one......The scaling operation, i.e. the division by a constant factor followed by rounding, is a commonly used technique for reducing the dynamic range in Digital Signal Processing (DSP) systems. Usually, the constant is a power of two, and the implementation of the scaling is reduced to a right shift...

  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. Kalman filter for onboard state of charge estimation and peak power capability analysis of lithium-ion batteries

    Science.gov (United States)

    Dong, Guangzhong; Wei, Jingwen; Chen, Zonghai

    2016-10-01

    To evaluate the continuous and instantaneous load capability of a battery, this paper describes a joint estimator for state-of-charge (SOC) and state-of-function (SOF) of lithium-ion batteries (LIB) based on Kalman filter (KF). The SOC is a widely used index for remain useful capacity left in a battery. The SOF represents the peak power capability of the battery. It can be determined by real-time SOC estimation and terminal voltage prediction, which can be derived from impedance parameters. However, the open-circuit-voltage (OCV) of LiFePO4 is highly nonlinear with SOC, which leads to the difficulties in SOC estimation. To solve these problems, this paper proposed an onboard SOC estimation method. Firstly, a simplified linearized equivalent-circuit-model is developed to simulate the dynamic characteristics of a battery, where the OCV is regarded as a linearized function of SOC. Then, the system states are estimated based on the KF. Besides, the factors that influence peak power capability are analyzed according to statistical data. Finally, the performance of the proposed methodology is demonstrated by experiments conducted on a LiFePO4 LIBs under different operating currents and temperatures. Experimental results indicate that the proposed approach is suitable for battery onboard SOC and SOF estimation.

  5. A Robust Pre-Filter and Power Loading Design for Time Reversal UWB Systems over Time-Correlated MIMO Channels

    Directory of Open Access Journals (Sweden)

    Sajjad Alizadeh

    2014-04-01

    Full Text Available Conventional Time Reversal (TR technique suffers from performance degradation in time varying Multiple-Input Multiple-Output Ultra-Wideband (MIMO-UWB systems due to outdating Channel State Information (CSI over time progressions. That is, the outdated CSI degrades the TR performance significantly in time varying channels. The correlation property of time correlated channels can improve the TR performance against other traditional TR designs. Based on this property, at first, we propose a robust TR-MIMO-UWB system design for a time-varying channel in which the CSI is updated only at the beginning of each block of data where the CSI is assumed to be known. As the channel varies over time, pre-processor blindly pre-equalizes the channel during the next symbol time by using the correlation property. Then, a novel recursive power allocation strategy is derived over time-correlated time-varying TR-MIMO-UWB channels. We show that the proposed power loading technique, considerably improves the BER performance of TR-MIMO-UWB system in imperfect CSI with robust pre-filter. The proposed algorithms lead to a cost-efficient CSI updating procedure for the TR optimization. Simulation results are provided to confirm the new design performance against traditional method.

  6. Novel Low-Power Switched-Current Matched Filter for Direct-Sequence Code-Division-Multiple-Access Wireless Communication

    Science.gov (United States)

    Togura, Kenji; Kubota, Koji; Nakase, Hiroyuki; Masu, Kazuya; Tsubouchi, Kazuo

    2000-04-01

    We have proposed the current-cut switched-current matched filter (CC-SIMF) with a low power consumption of less than 10 mW for mobile terminals in direct-sequence code-division-multiple-access. The parallel SIMF configuration is proposed for the reduction of the current transfer error accumulation in the conventional serial SIMF@. In order to evaluate the fundamental operation of the parallel SIMF, we have designed and fabricated a 32-chip parallel SIMF using 0.8-μm complementary-metal-oxide-semiconductor (CMOS) technology. The autocorrelation performance of a 32-chip orthogonal m-sequence has been clearly observed to be more than 5 Mcps. The measured dynamic range is improved to 12 dB as compared with that of the conventional SIMF, even though each current memory cell has a current transfer error of over 10% per chip. Since the current sources in the parallel SIMF can be reduced to be one-third of those in the serial SIMF, the power consumption of the parallel SIMF can be reduced to one-third of that of the serial SIMF.

  7. Digital Filters for Low Frequency Equalization

    DEFF Research Database (Denmark)

    Tyril, Marni; Abildgaard, J.; Rubak, Per

    2001-01-01

    Digital filters with high resolution in the low-frequency range are studied. Specifically, for a given computational power, traditional IIR filters are compared with warped FIR filters, warped IIR filters, and modified warped FIR filters termed warped individual z FIR filters (WizFIR). The results...... indicate that IIR filters are the most effective in a number of situations....

  8. Evaluation and Certification of Ambersorb 4652 for use in Activated Carbon Ion Exchange Filters for the International Space Station

    Science.gov (United States)

    Adam, Niklas; Cox, Trey; Larner, Katherine; Carter, Donald; Kouba, Coy

    2017-01-01

    In order to reduce the infiltration of dimethylsilanediol (DMSD) and other organosilicon containing species through the Multifiltration Beds (MF Beds), an alternate activated carbon was found to replace the obsolete Barnabey Cheney 580-26 activated carbon. The carbon that removed the most organosilicon compounds in testing1 was a synthetic activated carbon named Schunk 4652 which later became Ambersorb 4652. Since activated carbon has a large capacity for iodine (I2), and is used in the Activated Carbon Ion Exchange (ACTEX) filters on the International Space Station (ISS), testing was performed on the Ambersorb 4652 carbon to determine the effectiveness of the material for use in ACTEX filters to remove iodine. This work summarizes the testing and the certification of Ambersorb 4652 for use in the ACTEX filters for the ISS.

  9. Sensitivity analysis of an LCL-filter-based three-phase active rectifier via a virtual circuit approach

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Chiarantoni, Ernesto; Aquila, Antonio Dell’;

    2004-01-01

    , to the grid side stiffness and to the parameters of the controller has never been detailed considered. In this paper the experimental results of an LCL-filter-based three-phase active rectifier are analysed with the circuit theory approach. A ?virtual circuit? is synthesized in role of the digital controller...... and of the feedback filters to have an homogenous model that allows a sensitivity analysis which is rigorous and straightforward for the industry....

  10. Study of Active Disturbance Rejection Controller on Filtering%ESO抑制扰动特性的研究

    Institute of Scientific and Technical Information of China (English)

    赵秀元

    2011-01-01

    Active disturbance rejection controlling technique on filtering is presented, and some examples given. The results show that it has fine filtering characters to high frequency noises.%给出了自抗扰控制技术用于滤波的研究结果,提供了一些仿真实例.结果表明,这种新型的控制技术对高频噪声具有较好的滤波特性.

  11. A Low Power/Area Digital FIR Filter Design Based on PRF Framework

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel DSP to ASIC (Application Specific Integrated Circuit) architecture desig n methodology is presented in this paper for reducing power/area consumption. Traditional methods always focus on optimizing hardware structure or algorithm sep arately. The authors propose a new method called PRF (ParallelingReducing-Fol-ding) framework to combine hardware optimization with algorithm simplification. In the first step,paralleling, unfolding technology is applied to divide one data path into several channels and expose the redundancy of the algorithm. In the second step, reducing,decoupling theory is used to reduce computational complexity.In the last step, folding, timemultiplexing method is used to merge similar components. As an exoteric methodology framework, many optimization methods can be integrated into the PRF framework.To optimize a 3N taps FIR (Fincte Impact Response)and obtain a content result,PRF methodology framework is applied.

  12. Collaborative filtering for brain-computer interaction using transfer learning and active class selection.

    Directory of Open Access Journals (Sweden)

    Dongrui Wu

    Full Text Available Brain-computer interaction (BCI and physiological computing are terms that refer to using processed neural or physiological signals to influence human interaction with computers, environment, and each other. A major challenge in developing these systems arises from the large individual differences typically seen in the neural/physiological responses. As a result, many researchers use individually-trained recognition algorithms to process this data. In order to minimize time, cost, and barriers to use, there is a need to minimize the amount of individual training data required, or equivalently, to increase the recognition accuracy without increasing the number of user-specific training samples. One promising method for achieving this is collaborative filtering, which combines training data from the individual subject with additional training data from other, similar subjects. This paper describes a successful application of a collaborative filtering approach intended for a BCI system. This approach is based on transfer learning (TL, active class selection (ACS, and a mean squared difference user-similarity heuristic. The resulting BCI system uses neural and physiological signals for automatic task difficulty recognition. TL improves the learning performance by combining a small number of user-specific training samples with a large number of auxiliary training samples from other similar subjects. ACS optimally selects the classes to generate user-specific training samples. Experimental results on 18 subjects, using both k nearest neighbors and support vector machine classifiers, demonstrate that the proposed approach can significantly reduce the number of user-specific training data samples. This collaborative filtering approach will also be generalizable to handling individual differences in many other applications that involve human neural or physiological data, such as affective computing.

  13. Social power and approach-related neural activity

    NARCIS (Netherlands)

    M.A.S. Boksem (Maarten); R. Smolders (Ruud); D. de Cremer (David)

    2009-01-01

    textabstractIt has been argued that power activates a general tendency to approach whereas powerlessness activates a tendency to inhibit. The assumption is that elevated power involves reward-rich environments, freedom and, as a consequence, triggers an approach-related motivational orientation and

  14. A novel spatiotemporal muscle activity imaging approach based on the Extended Kalman Filter.

    Science.gov (United States)

    Wang, Jing; Zhang, Yingchun; Zhu, Xiangjun; Zhou, Ping; Liu, Chenguang; Rymer, William Z

    2012-01-01

    A novel spatiotemporal muscle activity imaging (sMAI) approach has been developed using the Extended Kalman Filter (EKF) to reconstruct internal muscle activities from non-invasive multi-channel surface electromyogram (sEMG) recordings. A distributed bioelectric dipole source model is employed to describe the internal muscle activity space, and a linear relationship between the muscle activity space and the sEMG measurement space is then established. The EKF is employed to recursively solve the ill-posed inverse problem in the sMAI approach, in which the weighted minimum norm (WMN) method is utilized to calculate the initial state and a new nonlinear method is developed based on the propagating features of muscle activities to predict the recursive state. A series of computer simulations was conducted to test the performance of the proposed sMAI approach. Results show that the localization error rapidly decreases over 35% and the overlap ratio rapidly increases over 45% compared to the results achieved using the WMN method only. The present promising results demonstrate the feasibility of utilizing the proposed EKF-based sMAI approach to accurately reconstruct internal muscle activities from non-invasive sEMG recordings.

  15. Active Learning: A PowerPoint Tutorial

    Science.gov (United States)

    Gareis, Elisabeth

    2007-01-01

    Individual or group presentations are common assignments in business communication courses, and many students use PowerPoint slides as audiovisual support. Frequently, curriculum constraints don't allow instructors much time to teach effective design and delivery of presentation graphics in their courses; guidelines in the form of minilectures or…

  16. Filter Paper Inspired Zinc Oxide Nanomaterials with High Photocatalytic Activity for Degradation of Methylene Orange

    Directory of Open Access Journals (Sweden)

    Huang Liu

    2016-01-01

    Full Text Available Nanometer-sized zinc oxide (ZnO has been synthesized through sol-gel method with natural cellulose substance (commercial filter paper as template. The structure of zinc oxide nanomaterial was characterized by nitrogen adsorption-desorption and XRD. The morphology was observed by SEM and TEM. The results show that the hexagonal wurtzite phase is actually the only crystal phase in the sample and the product faithfully inherits the hierarchical morphology and the complex network structure of the original filter paper, which is composed of many randomly intersecting zinc oxide microfibers and nanosheets with lots of close stacked particles adsorbed on the surface. Moreover, these zinc oxide nanomaterials possess abundant mesoporous structure with an average pore diameter of ca. 21 nm and a wide pore size distribution (3–30 nm. Due to the strong absorption ability in the UV range, the zinc oxide nanomaterial prepared by this method displays significantly high photocatalytic activity for degrading methyl orange. In a short period of 20 minutes, the zinc oxide nanomaterial has degraded about 50% of the original MO, and the MO dye is fully degraded after UV irradiation for 80 minutes.

  17. Active listening room compensation for massive multichannel sound reproduction systems using wave-domain adaptive filtering.

    Science.gov (United States)

    Spors, Sascha; Buchner, Herbert; Rabenstein, Rudolf; Herbordt, Wolfgang

    2007-07-01

    The acoustic theory for multichannel sound reproduction systems usually assumes free-field conditions for the listening environment. However, their performance in real-world listening environments may be impaired by reflections at the walls. This impairment can be reduced by suitable compensation measures. For systems with many channels, active compensation is an option, since the compensating waves can be created by the reproduction loudspeakers. Due to the time-varying nature of room acoustics, the compensation signals have to be determined by an adaptive system. The problems associated with the successful operation of multichannel adaptive systems are addressed in this contribution. First, a method for decoupling the adaptation problem is introduced. It is based on a generalized singular value decomposition and is called eigenspace adaptive filtering. Unfortunately, it cannot be implemented in its pure form, since the continuous adaptation of the generalized singular value decomposition matrices to the variable room acoustics is numerically very demanding. However, a combination of this mathematical technique with the physical description of wave propagation yields a realizable multichannel adaptation method with good decoupling properties. It is called wave domain adaptive filtering and is discussed here in the context of wave field synthesis.

  18. Autonomous Navigation for Autonomous Underwater Vehicles Based on Information Filters and Active Sensing

    Directory of Open Access Journals (Sweden)

    Tianhong Yan

    2011-11-01

    Full Text Available This paper addresses an autonomous navigation method for the autonomous underwater vehicle (AUV C-Ranger applying information-filter-based simultaneous localization and mapping (SLAM, and its sea trial experiments in Tuandao Bay (Shangdong Province, P.R. China. Weak links in the information matrix in an extended information filter (EIF can be pruned to achieve an efficient approach-sparse EIF algorithm (SEIF-SLAM. All the basic update formulae can be implemented in constant time irrespective of the size of the map; hence the computational complexity is significantly reduced. The mechanical scanning imaging sonar is chosen as the active sensing device for the underwater vehicle, and a compensation method based on feedback of the AUV pose is presented to overcome distortion of the acoustic images due to the vehicle motion. In order to verify the feasibility of the navigation methods proposed for the C-Ranger, a sea trial was conducted in Tuandao Bay. Experimental results and analysis show that the proposed navigation approach based on SEIF-SLAM improves the accuracy of the navigation compared with conventional method; moreover the algorithm has a low computational cost when compared with EKF-SLAM.

  19. Autonomous navigation for autonomous underwater vehicles based on information filters and active sensing.

    Science.gov (United States)

    He, Bo; Zhang, Hongjin; Li, Chao; Zhang, Shujing; Liang, Yan; Yan, Tianhong

    2011-01-01

    This paper addresses an autonomous navigation method for the autonomous underwater vehicle (AUV) C-Ranger applying information-filter-based simultaneous localization and mapping (SLAM), and its sea trial experiments in Tuandao Bay (Shangdong Province, P.R. China). Weak links in the information matrix in an extended information filter (EIF) can be pruned to achieve an efficient approach-sparse EIF algorithm (SEIF-SLAM). All the basic update formulae can be implemented in constant time irrespective of the size of the map; hence the computational complexity is significantly reduced. The mechanical scanning imaging sonar is chosen as the active sensing device for the underwater vehicle, and a compensation method based on feedback of the AUV pose is presented to overcome distortion of the acoustic images due to the vehicle motion. In order to verify the feasibility of the navigation methods proposed for the C-Ranger, a sea trial was conducted in Tuandao Bay. Experimental results and analysis show that the proposed navigation approach based on SEIF-SLAM improves the accuracy of the navigation compared with conventional method; moreover the algorithm has a low computational cost when compared with EKF-SLAM.

  20. Co-generation system with integrated functions of active filter; Sistema de cogeneracion con funciones de filtro activo integradas

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Grajales, Humberto Raul

    2002-07-15

    Without question, the electrical energy is the form of energy more widely used in the economic and social activities of our modern world. For that reason, it is possible to say that the electricity generating and distributing companies assume two challenges of present relevant preoccupation. One is to generate with greater efficiency, less costs and with a minimum impact on the environment. The second is to fulfill the quality of the provision, that has gotten to be an important point as much for the users as for the companies that distribute the electrical energy, and that is reflected in more efficient distribution and consumption of energy. The thesis work that is presented, describes a photovoltaic system (PVS) interconnected to the electric network that helps to surpass the mentioned challenges. This PSV has the function of receiving the power generated by the solar energy delivered by an array of PV cells; to operate in the maximum point of power of the cells (for greater advantage of the collected energy); to condition it to an alternating signal, within the normative technical parameters for the electrical interconnection established by the company; (Comision Federal de Electricidad in Mexico); and to inject it to the electric network in order to compensate reactive power (active filtering) demanded by lineal and non-lineal loads, reducing the contamination of the electric network; in addition to compensating the active power in demand peaks of maximum electrical energy. The system works as active filter throughout day, which allows that the power installed capacity by the equipment takes advantage to the maximum and not only during the period of the day in which the solar radiation is available. The main advantages that are obtained are: simple, robust implementation and high immunity to the parameters variation. In the active filter functions, the necessary reference signals to modulate the inverter, are obtained using the cancellation technique of

  1. Benefit-cost analysis of commercially available activated carbon filters for indoor ozone removal in single-family homes.

    Science.gov (United States)

    Aldred, J R; Darling, E; Morrison, G; Siegel, J; Corsi, R L

    2016-06-01

    This study involved the development of a model for evaluating the potential costs and benefits of ozone control by activated carbon filtration in single-family homes. The modeling effort included the prediction of indoor ozone with and without activated carbon filtration in the HVAC system. As one application, the model was used to predict benefit-to-cost ratios for single-family homes in 12 American cities in five different climate zones. Health benefits were evaluated using disability-adjusted life-years and included city-specific age demographics for each simulation. Costs of commercially available activated carbon filters included capital cost differences when compared to conventional HVAC filters of similar particle removal efficiency, energy penalties due to additional pressure drop, and regional utility rates. The average indoor ozone removal effectiveness ranged from 4 to 20% across the 12 target cities and was largely limited by HVAC system operation time. For the parameters selected in this study, the mean predicted benefit-to-cost ratios for 1-inch filters were >1.0 in 10 of the 12 cities. The benefits of residential activated carbon filters were greatest in cities with high seasonal ozone and HVAC usage, suggesting the importance of targeting such conditions for activated carbon filter applications.

  2. Comparative ecophysiology of active zoobenthic filter feeding, essence of current knowledge

    Science.gov (United States)

    Riisgård, H. U.; Larsen, P. S.

    2000-12-01

    The present contribution gives an overview of current knowledge of a comprehensive and steadily growing research field. The first section deals with water pumping and particle retention mechanisms in ciliary and muscular filter feeders. The second section examines the biological filter pumps in order to assess adaptation to the environment. Filter-feeding benthic invertebrates have evolved filter pumps to solve common basic problems. This has led to a large degree of similarity between otherwise distant standing species, which makes comparative studies interesting and important. The present review of zoobenthic filter feeding aims at accentuating such recognition.

  3. Fast filtering false active subspaces for efficient high dimensional similarity processing

    Institute of Scientific and Technical Information of China (English)

    WANG GuoRen; YU Ge; XIN JunChang; ZHAO YuHai; ZHANG EnDe

    2009-01-01

    The query space of a similarity query is usually narrowed down by pruning inactive query subspaces which contain no query results and keeping active query subspaces which may contain objects corre-sponding to the request. However, some active query subspaces may contain no query results at all, those are called false active query subspaces. It is obvious that the performance of query processing degrades in the presence of false active query subspaces. Our experiments show that this problem becomes seriously when the data are high dimensional and the number of accesses to false active sub-spaces increases as the dimensionality increases. In order to solve this problem, this paper proposes a space mapping approach to reducing such unnecessary accesses. A given query space can be re-fined by filtering within its mapped space. To do so, a mapping strategy called maxgap is proposed to improve the efficiency of the refinement processing. Based on the mapping strategy, an index structure called MS-tree and algorithms of query processing are presented in this paper. Finally, the performance of MS-tree is compared with that of other competitors in terms of range queries on a real data set.

  4. Active Power Regulation based on Droop for AC Microgrid

    DEFF Research Database (Denmark)

    Li, Chendan; Coelho, Ernane A. A.; Firoozabadi, Mehdi Savaghebi

    2015-01-01

    In this paper, two different control strategies are proposed to address the active power regulation issue in AC microgrids. The principle of power regulation in the droop controller is firstly introduced. Frequency scheduling and droop gain scheduling on top of droop control is proposed to succes......In this paper, two different control strategies are proposed to address the active power regulation issue in AC microgrids. The principle of power regulation in the droop controller is firstly introduced. Frequency scheduling and droop gain scheduling on top of droop control is proposed...

  5. Novel Algorithm for Active Noise Control Systems Based on Frequency Selective Filters

    Institute of Scientific and Technical Information of China (English)

    Hong-liang ZHAO

    2010-01-01

    A novel algorithm for active noise control systems based on frequency selective filters (FSFANC)is presented in the paper.The FSFANC aims at the m lti-tonal noise attenuation problem.One FSFANC system copes with one of the tonal components,and several FSFANC systems can nun independently in parallel to cancel the selected multiple tones.The proposed algorithm adopts a simple structrue with only two coefficients that can be explained as the real and imaginary parts of the structure to modelthesecondary path,and estimates the secondary path by injecting sinusoidal identification signals.Theoretical analysis and laboratory experiments show that the proposed algorithm possesses some advantages,such as simpler stricture,less computational burden,greater stability,and fast canverging speed.

  6. Voltage Quality Enhancement and Fault Current Limiting with Z-Source based Series Active Filter

    Directory of Open Access Journals (Sweden)

    F. Gharedaghi

    2011-11-01

    Full Text Available In this study, series active filter or dynamic voltage restorer application is proposed for reduction of downstream fault current in addition to voltage quality enhancement. Recently, the application of Z-source inverter is proposed in order to optimize DVR operation. This inverter makes DVR to operate appropriately when the energy storage device’s voltage level severely falls. Here, the Z-source inverter based DVR is proposed to compensate voltage disturbance at the PCC and to reduce the fault current in downstream of DVR. By calculating instantaneous current magnitude in synchronous frame, control system recognizes if the fault exists or not, and determines whether DVR should compensate voltage disturbance or try to reduce the fault current. The proposed system is simulated under voltage sag and swell and short circuit conditions. The simulation results show that the system operates correctly under voltage sag and short circuit conditions.

  7. Sustainable Buildings. Using Active Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, M. Keith [Univ. of Louisville, KY (United States); Barnett, Russell [Univ. of Louisville, KY (United States)

    2015-04-20

    The objective of this project is to promote awareness and knowledge of active solar energy technologies by installing and monitoring the following demonstration systems in Kentucky: 1) Pool heating system, Churchill Park School, 2) Water heating and daylighting systems, Middletown and Aiken Road Elementary Schools, 3) Photovoltaic street light comparison, Louisville Metro, 4) up to 25 domestic water heating systems across Kentucky. These tasks will be supported by outreach activities, including a solar energy installer training workshop and a Kentucky Solar Energy Conference.

  8. Communication Systems and Study Method for Active Distribution Power systems

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    Due to the involvement and evolvement of communication technologies in contemporary power systems, the applications of modern communication technologies in distribution power system are becoming increasingly important. In this paper, the International Organization for Standardization (ISO....... The suitability of the communication technology to the distribution power system with active renewable energy based generation units is discussed. Subsequently the typical possible communication systems are studied by simulation. In this paper, a novel method of integrating communication system impact into power...... system simulation is presented to address the problem of lack of off-shelf research tools on the power system communication. The communication system is configured and studied by the OPNET, and the performance of an active distribution power system integrated with the communication system is simulated...

  9. Controlling of crustacean zooplankton reproduction in biological activated carbon (BAC) filters by strengthen operation and management of conventional process

    Institute of Scientific and Technical Information of China (English)

    LIU Li-jun; ZHANG Jin-song; LI Xiao-wei; HE Jun-guo

    2010-01-01

    To counter the mass reproduction and penetration of crustacean zooplankton in Biological Activated Carbon (BAC) filters which may result in the presence of organisms in potable water and water pollution,this paper analyzed the factors affecting organisms' reproduction in BAC filters.A comparative study was performed on the density and composition of crustacean zooplankton of the concerned water treatment units of two advanced water plants (Plant A and B) which with the same raw water and the same treatment technique in southern China.The results obtained show that the crustaceans' density and composition was very different between the sand filtered water of Plant A and Plant B.which Harpacticoida bred sharply in the sediment tanks and penetrated sand filter into BAC falters was the primary reason of crustaceans reproduce in BAC filters of Plant A.For prevention of the organisms reproduction in BAC,some strengthen measures was taken including pre-chlorination,cleaning coagulation tanks and sediment tanks completely,increasing sludge disposal frequency to stop organisms enter BAC filters,and the finished water quality was improved and enhanced.

  10. The Control of Transmitted Power in an Active Isolation System

    DEFF Research Database (Denmark)

    Elliott, S.J.; Gardonio, P.; Pinnington, R.J.

    1997-01-01

    and distributed active mounts, and these models can be connected together to produce an overall theoretical description of a realistic active isolation system. Total transmitted power has been found to be an excellent criterion to quantify the effect of various control strategies in this model in which...... the contributions to the transmitted power in the various degrees of freedom can be clearly understood. It has also been found, however, that an active control system which minimises a practical estimate of transmitted power, calculated from the product of the axial forces and velocities under the mounts, can give...... a very poor performance in terms of reducing the total transmitted power, and can even increase it under some circumstances. Such a control system was also found to be very sensitive to measurement errors and the presence of flanking paths, which give rise to the phenomena of 'power circulation'. A more...

  11. Requirements Specication for Ampliers and Power Supplies in Active Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Jensen, Lasse Crone; Petersen, Lars Press

    2014-01-01

    This work aims to provide designers with a method to develop a requirements specication for power supplies and ampliers in active loudspeakers. The motivation is to avoid over-sizing and unnecessary cost. A realistic estimation of the power supplied during playback of audio in a given loudspeaker...

  12. Facilities of management magnetoresistive transformer of active power

    Directory of Open Access Journals (Sweden)

    Val. S. Vuntesmeri

    2009-03-01

    Full Text Available Management facilities are considered, spectral composition is certain and the form of коммутируемого signal of magnetoresistive transformer of active power is rotined.

  13. Unified active and reactive power modulation of HVDC transmission systems

    Science.gov (United States)

    Grund, C. E.; Pohl, R. V.

    1981-11-01

    The power modulation of a high voltage direct current (HVDC) system for stabilization of an ac/dc network was investigated. It was found that simultaneous modulation of both dc current and voltage was more effective than just current modulation by itself, since the dc voltage modulation could be used to minimize the reactive power changes resulting from a change of the dc current. This helps stabilize the ac busbar voltages at the converters, which reduces undesirable load flow changes to voltage dependent ac loads, thus improving the effectiveness of the dc power modulation. This unified modulation control concept was evaluated by means of digital computer studies as well as a special purpose HVDC simulator. Several combined ac/dc power transmission systems were synthesized for testing of different modulation controller concepts. An optimum controller design incorporating a linear quadratic control algorithm with full state feedback was first studied. This provided a basis for comparison of suboptimal controller designs utilizing reduced state feedback and a Kalman filter state reconstruction technique.

  14. Active power reserves evaluation in large scale PVPPs

    DEFF Research Database (Denmark)

    Crăciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso

    2013-01-01

    contribute to the total amount of Frequency Containment Reserves (FCR) required by TSOs, reserves which are released during transients. To realize this PVPPs have to operate below their maximum available power and operate in Frequency Sensitive Mode (FSM). The reserve can also be used to fulfill future grid...... of the ancillary services have to be shared by the renewable plants. The main focus of the proposed paper is to technically and economically analyze the possibility of having active power reserves in large scale PV power plants (PVPPs) without any auxiliary storage equipment. The provided reserves should...... codes (GCs) requirements such as Power Ramp Limitation (PRL) during high slopes of irradiance....

  15. DESIGN OF LOW-VOLTAGE AND LOW-POWER FULLY INTEGRATED FILTER BASED ON LOG-DOMAIN CURRENT-MODE INTEGRATOR

    Institute of Scientific and Technical Information of China (English)

    Li Shutao; Wang Yaonan; Wu Jie

    2001-01-01

    In this paper a novel log-domain current-mode integrator based on MOS transistors in subthreshold is proposed. The integrator's time-constant is tunable by varying a reference bias current. By use of the integrator, a fifth-order Chebyshev lowpass filter with 0.1dB ripples is designed. The simulation results demonstrate that the proposed filter has such advantages as low power supply(1.5V), very low power dissipation (μW level), nearly ideal frequency response, very small sensitivity to components in passband, and adjustable cut-off frequency over a wide range.The circuit is composed of NMOS transistors and grounded capacitors which make it suitable for fully integrated circuit implementation.

  16. Real-time Kalman filter implementation for active feedforward control of time-varying broadband noise and vibrations

    NARCIS (Netherlands)

    Ophem, S. van; Berkhoff, A.P.

    2012-01-01

    Tracking behavior and the rate of convergence are critical properties in active noise control applications with time-varying disturbance spectra. As compared to the standard filtered-reference Least Mean Square (LMS) algorithm, improved convergence can be obtained with schemes based on preconditioni

  17. Active noise control with fast array recursive least squares filters using a parallel implementation for numerical stability

    NARCIS (Netherlands)

    Berkhoff, A.P.; Ophem, S. van

    2015-01-01

    Noise reduction in feedforward active noise control systems with a rapidly changing primary path requires rapid convergence and fast tracking. This can be accomplished with a fast-array Kalman method which uses an efficient rotation matrix technique to calculate the filter parameters. However, finit

  18. Ceramic fiber filter technology

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, B.L.; Janney, M.A.

    1996-06-01

    Fibrous filters have been used for centuries to protect individuals from dust, disease, smoke, and other gases or particulates. In the 1970s and 1980s ceramic filters were developed for filtration of hot exhaust gases from diesel engines. Tubular, or candle, filters have been made to remove particles from gases in pressurized fluidized-bed combustion and gasification-combined-cycle power plants. Very efficient filtration is necessary in power plants to protect the turbine blades. The limited lifespan of ceramic candle filters has been a major obstacle in their development. The present work is focused on forming fibrous ceramic filters using a papermaking technique. These filters are highly porous and therefore very lightweight. The papermaking process consists of filtering a slurry of ceramic fibers through a steel screen to form paper. Papermaking and the selection of materials will be discussed, as well as preliminary results describing the geometry of papers and relative strengths.

  19. On Variable Reverse Power Flow-Part I: Active-Reactive Optimal Power Flow with Reactive Power of Wind Stations

    Directory of Open Access Journals (Sweden)

    Aouss Gabash

    2016-02-01

    Full Text Available It has recently been shown that using battery storage systems (BSSs to provide reactive power provision in a medium-voltage (MV active distribution network (ADN with embedded wind stations (WSs can lead to a huge amount of reverse power to an upstream transmission network (TN. However, unity power factors (PFs of WSs were assumed in those studies to analyze the potential of BSSs. Therefore, in this paper (Part-I, we aim to further explore the pure reactive power potential of WSs (i.e., without BSSs by investigating the issue of variable reverse power flow under different limits on PFs in an electricity market model. The main contributions of this work are summarized as follows: (1 Introducing the reactive power capability of WSs in the optimization model of the active-reactive optimal power flow (A-R-OPF and highlighting the benefits/impacts under different limits on PFs. (2 Investigating the impacts of different agreements for variable reverse power flow on the operation of an ADN under different demand scenarios. (3 Derivation of the function of reactive energy losses in the grid with an equivalent-π circuit and comparing its value with active energy losses. (4 Balancing the energy curtailment of wind generation, active-reactive energy losses in the grid and active-reactive energy import-export by a meter-based method. In Part-II, the potential of the developed model is studied through analyzing an electricity market model and a 41-bus network with different locations of WSs.

  20. Parasitic Effects of Grounding Paths on Common-Mode EMI Filter's Performance in Power Electronics Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuo [ORNL; Maillet, Yoann [Virginia Polytechnic Institute and State University (Virginia Tech); Wang, Fei [ORNL; Lai, Rixin [General Electric; Luo, Fang [Virginia Polytechnic Institute and State University (Virginia Tech); Boroyevich, Dushan [Virginia Polytechnic Institute and State University (Virginia Tech)

    2010-01-01

    High-frequency common-mode (CM) electromagnetic-interference (EMI) noise is difficult to suppress in electronics systems. EMI filters are used to suppress CM noise, but their performance is greatly affected by the parasitic effects of the grounding paths. In this paper, the parasitic effects of the grounding paths on an EMI filter's performance are investigated in a motor-drive system. The effects of the mutual inductance between two grounding paths are explored. Guidelines for the grounding of CM EMI filters are derived. Simulations and experiments are finally carried out to verify the theoretical analysis.

  1. Design and feasibility of high temperature nanoparticle fluid filter in hybrid thermal/photovoltaic concentrating solar power

    Science.gov (United States)

    DeJarnette, Drew; Brekke, Nick; Tunkara, Ebrima; Hari, Parameswar; Roberts, Kenneth; Otanicar, Todd

    2015-09-01

    A nanoparticle fluid filter used with concentrating hybrid solar/thermal collector design is presented. Nanoparticle fluid filters could be situated on any given concentrating system with appropriate customized engineering. This work shows the design in the context of a trough concentration system. Geometric design and physical placement in the optical path was modeled using SolTrace. It was found that a design can be made that blocks 0% of the traced rays. The nanoparticle fluid filter is tunable for different concentrating systems using various PV cells or operating at varying temperatures.

  2. Generalized stability regions of current control for LCL-filtered grid-connected converters without passive or active damping

    DEFF Research Database (Denmark)

    Tang, Yi; Yoon, Changwoo; Zhu, Rongwu;

    2015-01-01

    This paper investigates the stability regions of current control for LCL-filtered grid-connected converters, where no active or passive damping is required to stabilize the closed-loop control system. It is already identified in the literature that if the LCL resonance frequency is placed within 1...... the resonance frequency could be larger than 1/2 of the sampling frequency, and derives the complete stability regions for both grid and converter current control. Interestingly, it is found that for any given LCL-filter design, there will always be one stable current control design without any damping, which...

  3. Aerosol-phase Activity of Iodine Captured from a Triiodide Resin Filter on Fine Particles Containing an Infectious Virus

    Science.gov (United States)

    2015-01-01

    AFCEC-CX-TY-TP-2014-0019 AEROSOL-PHASE ACTIVITY OF IODINE CAPTURED FROM A TRIIODIDE RESIN FILTER ON FINE PARTICLES CONTAINING AN INFECTIOUS VIRUS ... Virus (POSTPRINT) FA4819-11-C-0003 X13SY002 X0E7 (QL102007) D.A. Harnish,** B.K. Heimbuch,** C. Balzli,* A. Lumley,** K. Kinney,** E. Rudico,# and J.D...from a triiodide resin filter on fine particles containing an infectious virus B.K. Heimbuch1, D.A. Harnish1, C. Balzli2,*, A. Lumley1, K. Kinney1 and

  4. 基于级联有源滤波器与静止无功补偿器的综合补偿控制方案%A Universal Compensation Control Scheme Based on Cascade Active Power Filter and Static Var Compensator

    Institute of Scientific and Technical Information of China (English)

    高聪哲; 姜新建; 李永东

    2012-01-01

    How to keep system stability and optimize var compensation capability is the key issue in the combined system based on cascade multilevel active power filter(CS-APF) and static var compensator(SVC).A universal control strategy is proposed for the combined system.For the SVC,a feed forward control for the compensation of positive sequence reactive component and negative sequence component of the load is adopted.The network susceptance(with no components of CS-APF) feedback control is applied to decrease the compensation error.For the CS-APF control,a feed forward control of harmonic compensation for thyristor control reactor(TCR) and the load is applied.The network harmonic current feedback control is applied to decrease the compensation error.The fixed capacitor(in SVC) current component is removed from the network current feedback control loop of CS-APF to improve the stability of the combined system.The var compensation capability of CS-APF is enabled to optimize the performance of SVC.Moreover,a novel pre-calculation method for the TCR harmonic current detection is proposed.According to the triggering angle of the thyristor in TCR and the network voltage phase,the harmonic current is constructed with no time delay.Finally,the simulation and experimental results show that: 1)the system stability is high without closed loop between the control of CS-APF and SVC;2)the real-time harmonic compensation of TCR is realized;3)the system responsibility is quick;and 4)the capability of var compensation of SVC is improved.%级联多电平有源滤波器(CS-APF)与静止无功补偿器(SVC)同时运行存在稳定性及无功补偿控制优化等问题。文中提出一种统一控制策略,结合SVC和CS-APF的功能特点,使SVC对负载正序无功分量及负序分量的补偿进行前馈控制和电网电纳(不包含CS-APF分量)反馈控制;CS-APF对晶闸管相控电抗器(TCR)与电网负载谐波的补偿进行前馈

  5. A simple approach to calculate active power of electrosurgical units

    Directory of Open Access Journals (Sweden)

    André Luiz Regis Monteiro

    Full Text Available Abstract Introduction: Despite of more than a hundred years of electrosurgery, only a few electrosurgical equipment manufacturers have developed methods to regulate the active power delivered to the patient, usually around an arbitrary setpoint. In fact, no manufacturer has a method to measure the active power actually delivered to the load. Measuring the delivered power and computing it fast enough so as to avoid injury to the organic tissue is challenging. If voltage and current signals can be sampled in time and discretized in the frequency domain, a simple and very fast multiplication process can be used to determine the active power. Methods This paper presents an approach for measuring active power at the output power stage of electrosurgical units with mathematical shortcuts based on a simple multiplication procedure of discretized variables – frequency domain vectors – obtained through Discrete Fourier Transform (DFT applied on time-sampled voltage and current vectors. Results Comparative results between simulations and a practical experiment are presented – all being in accordance with the requirements of the applicable industry standards. Conclusion An analysis is presented comparing the active power analytically obtained through well-known voltage and current signals against a computational methodology based on vector manipulation using DFT only for time-to-frequency domain transformation. The greatest advantage of this method is to determine the active power of noisy and phased out signals with neither complex DFT or ordinary transform methodologies nor sophisticated computing techniques such as convolution. All results presented errors substantially lower than the thresholds defined by the applicable standards.

  6. Retention of titanium dioxide nanoparticles in biological activated carbon filters for drinking water and the impact on ammonia reduction.

    Science.gov (United States)

    Liu, Zhiyuan; Yu, Shuili; Park, Heedeung; Liu, Guicai; Yuan, Qingbin

    2016-06-01

    Given the increasing discoveries related to the eco-toxicity of titanium dioxide (TiO2) nanoparticles (NPs) in different ecosystems and with respect to public health, it is important to understand their potential effects in drinking water treatment (DWT). The effects of TiO2 NPs on ammonia reduction, ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in biological activated carbon (BAC) filters for drinking water were investigated in static and dynamic states. In the static state, both the nitrification potential and AOB were significantly inhibited by 100 μg L(-1) TiO2 NPs after 12 h (p  0.05). In the dynamic state, different amounts of TiO2 NP pulses were injected into three pilot-scale BAC filters. The decay of TiO2 NPs in the BAC filters was very slow. Both titanium quantification and scanning electron microscope analysis confirmed the retention of TiO2 NPs in the BAC filters after 134 days of operation. Furthermore, the TiO2 NP pulses considerably reduced the performance of ammonia reduction. This study identified the retention of TiO2 NPs in BAC filters and the negative effect on the ammonia reduction, suggesting a potential threat to DWT by TiO2 NPs.

  7. Assessment of multiple hormone activities of a UV-filter (octocrylene) in zebrafish (Danio rerio).

    Science.gov (United States)

    Zhang, Qiuya Y; Ma, Xiaoyan Y; Wang, Xiaochang C; Ngo, Huu Hao

    2016-09-01

    In this study, zebrafish (Danio rerio) were exposed to a UV-filter-octocrylene (OCT) with elevated concentrations for 28 d. The total body accumulation of OCT in zebrafish was found to reach 2321.01 ("L" level), 31,234.80 ("M" level), and 70,593.38 ng g(-1) ("H" level) when the average OCT exposure concentration was controlled at 28.61, 505.62, and 1248.70 μg L(-1), respectively. Gross and histological observations as well as RT-qPCR analysis were conducted to determine the effects of OCT accumulation on zebrafish. After exposure, the gonad-somatic index and percentage of vitellogenic oocytes were found to increase significantly in the ovaries of female zebrafish at the H accumulation level. Significant up-regulation of esr1 and cyp19b were observed in the gonads, as well as vtg1 in the livers for both female and male zebrafish. At M and H accumulation levels, apparent down-regulation of ar was observed in the ovaries and testis of the female and male zebrafish, respectively. Although the extent of the effects on zebrafish differed at different accumulation levels, the induction of vtg1 and histological changes in the ovaries are indications of estrogenic activity and the inhibition of esr1 and ar showed antiestrogenic and antiandrogenic activity, respectively. Thus, as OCT could easily accumulate in aquatic life such as zebrafish, one of its most of concern hazards would be the disturbance of the histological development and its multiple hormonal activities.

  8. Clarifying the role of activated charcoal filters in preparing an anaesthetic workstation for malignant hyperthermia-susceptible patients.

    Science.gov (United States)

    Bilmen, J G; Gillies, R I

    2014-01-01

    Malignant hyperthermia (MH) is a life-threatening condition caused by exposure of susceptible individuals to volatile anaesthetics or suxamethonium. MH-susceptible individuals must avoid exposure to these drugs, so accurate and reproducible processes to remove residual anaesthetic agents from anaesthetic workstations are required. Activated charcoal filters (ACFs) have been used for this purpose. ACFs can reduce the time for preparing an anaesthetic workstation for MH patients. Currently, the only commercially available ACFs are the Vapor-Clean$trade; (Dynasthetics, Salt Lake City, UT, USA) filters which retail at approximately AUD$130 per set of two, both of which are to be used in a single anaesthetic. Anaesthetic workstations were saturated with anaesthetic vapours and connected to a Miran ambient air analyser (SapphRe XL, ThermoScientific, Waltham, MA, USA) to measure vapour concentration. Various scenarios were tested in order to determine the most economical configurations of machine flushing, component change and activated charcoal filter use. We found that placement of filters in an unprepared, saturated circuit was insufficient to safely prepare an anaesthetic workstation. Following flushing of the anaesthetic workstation with high-flow oxygen for 90 seconds, a circuit and soda lime canister change and the placement of an ACF on the inspiratory limb, we were able to safely prepare a workstation in less than three minutes. A single filter on the inspiratory limb was able to maintain a clean circuit for 12 hours, with gas flows dropped from 10 lpm to 3 lpm after 90 minutes or removal of the filter after 90 minutes if high gas flows were maintained.

  9. Active Photonic crystal fibers for high power applications

    DEFF Research Database (Denmark)

    Olausson, Christina Bjarnal Thulin

    . This plays an important role in high power lasers and ampliers with respect to efficiency, packaging, and thermal handling. The third part of the work has involved developing tools for characterizing the mode quality and stability of large core bers. Stable, single-mode bers with larger cores are essential......The photonic crystal ber technology provides means to realize bers optimized for high power operation, due to the large single-mode cores and the unique design exibility of the microstructure. The work presented in this thesis focuses on improving the properties of active photonic crystal bers...... for high power ber lasers and ampliers, and on adding new functionality to the fibers - all with the purpose of pushing the technology towards high powers. The first part of the work has been to investigate photo darkening, the mitigation of which is crucial in the quest for higher powers. The work has...

  10. Active Power Deficit Estimation in Presence of Renewable Energy Sources

    DEFF Research Database (Denmark)

    Hoseinzadeh, Bakhtyar; Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2015-01-01

    following outage of SMs during cascading events. Therefore, the active power deficit following the disturbance/s may not be properly estimated by existing conventional System Frequency Response (SFR) methods in which the total inertia of the power system is required to be known. In this paper, the actual......The inertia of the power system is reduced in the presence of Renewable Energy Sources (RESs) due to their low or even no contribution in the inertial response as it is inherently available in the Synchronous Machines (SMs). The total inertia of the grid becomes unknown or at least uncertain...... active power deficit is estimated independent of grid inertia, type and number of occurred cascading events after each Load Shedding (LS) stage using shed load amount, pre-shed and post-shed Rate of Change of Frequency (ROCOF). Numerical simulations conducted on IEEE 39 bus standard test system in Dig...

  11. High Power VCSEL Device with Periodic Gain Active Region

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    High power vertical cavity surface emitting lasers(VCSEKLs) with large aperture have been fabricated through improving passivation, lateral oxidation and heat dissipation techniques. Different from conventional three quantum well structures, a periodic gain active region with nine quantum wells was incorporated into the VCSEL structure, with which high efficiency and high power operation were expected. The nine quantum wells were divided into three groups with each of them located at the antinodes of the ca...

  12. Nuclear power development and nuclear data activities in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Gui Ah Auu [Malaysian Institute for Nuclear Technology Research, Ministry of Science, Technology and the Environment, Selangor (Malaysia)

    1999-03-01

    In this paper, research activities on nuclear power requirement carried out jointly by MINT and other organizations are described. Also discussed are activities on neutronics such as TRIGA reactor fuel management, storage pool criticality, and reactor fuel transfer cask calculations. In addition, recent work on radiation transport activities in MINT such as skyshine and photon phantom dose calculations using the MCNP and MRIPP computer codes are presented. Finally, nuclear data measurement works by researchers in Malaysian universities are described. (author)

  13. Junction temperature estimation for an advanced active power cycling test

    DEFF Research Database (Denmark)

    Choi, Uimin; Blaabjerg, Frede; Jørgensen, S.

    2015-01-01

    estimation method using on-state VCE for an advanced active power cycling test is proposed. The concept of the advanced power cycling test is explained first. Afterwards the junction temperature estimation method using on-state VCE and current is presented. Further, the method to improve the accuracy......On-state collector-emitter voltage (VCE) is a good indicator to determine the wear-out condition of power device modules. Further, it is a one of the Temperature Sensitive Electrical Parameters (TSEPs) and thus can be used for junction temperature estimation. In this paper, the junction temperature...

  14. Autonomous Active and Reactive Power Distribution Strategy in Islanded Microgrids

    DEFF Research Database (Denmark)

    Wu, Dan; Tang, Fen; Guerrero, Josep M.;

    2014-01-01

    This paper proposes an autonomous active and reactive power distribution strategy that can be applied directly on current control mode (CCM) inverters, being compatible as well with conventional droop-controlled voltage control mode (VCM) converters. In a microgrid, since renewable energy sources...... in a distributed way. Real-time hardware-in-the-loop results are presented to verify the proposed control strategy.......This paper proposes an autonomous active and reactive power distribution strategy that can be applied directly on current control mode (CCM) inverters, being compatible as well with conventional droop-controlled voltage control mode (VCM) converters. In a microgrid, since renewable energy sources...

  15. Validation of Power Requirement Model for Active Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Madsen, Anders Normann; Bjerregaard, Ruben

    2015-01-01

    The actual power requirement of an active loudspeaker during playback of music has not received much attention in the literature. This is probably because no single and simple solution exists and because a complete system knowledge from input voltage to output sound pressure level is required....... There are however many advantages that could be harvested from such knowledge like size, cost and efficiency improvements. In this paper a recently proposed power requirement model for active loudspeakers is experimentally validated and the model is expanded to include the closed and vented type enclosures...

  16. Contributions to the development of microwave active circuits: metamaterial dual-band active filters and broadband differential low-noise amplifier

    OpenAIRE

    García Pérez, Óscar Alberto

    2011-01-01

    New telecommunication systems require electronic components with increasing performance. Microwave active circuits are not an exception. In fact, these active devices (such as amplifiers, active filters, oscillators, mixers, switches, modulators, etc.) are a key part of any modern communication device and, in many cases, the components that greatly limit the overall system performance. During the last decades, engineers have been improving the performance and operation capabilities of such ac...

  17. Use of alpha spectroscopy for conducting rapid surveys of transuranic activity on air sample filters and smears.

    Science.gov (United States)

    Hayes, Robert B; Peña, Adan M; Goff, Thomas E

    2005-08-01

    This paper demonstrates the utility of a portable alpha Continuous Air Monitor (CAM) as a bench top scalar counter for multiple sample types. These include using the CAM to count fixed air sample filters and radiological smears. In counting radiological smears, the CAM is used very much like a gas flow proportional counter (GFPC), albeit with a lower efficiency. Due to the typically low background in this configuration, the minimum detectable activity for a 5-min count should be in the range of about 10 dpm which is acceptably below the 20 dpm limit for transuranic isotopes. When counting fixed air sample filters, the CAM algorithm along with other measurable characteristics can be used to identify and quantify the presence of transuranic isotopes in the samples. When the radiological control technician wants to take some credit from naturally occurring radioactive material contributions due to radon progeny producing higher energy peaks (as in the case with a fixed air sample filter), then more elaborate techniques are required. The techniques presented here will generate a decision level of about 43 dpm for such applications. The calibration for this application should alternatively be done using the default values of channels 92-126 for region of interest 1. This can be done within 10 to 15 min resulting in a method to rapidly evaluate air filters for transuranic activity. When compared to the 1-h count technique described by , the technique presented in the present work demonstrates a technique whereby more than two thirds of samples can be rapidly shown (within 10 to 15 min) to be within regulatory compliant limits. In both cases, however, spectral quality checks are required to insure sample self attenuation is not a significant bias in the activity estimates. This will allow the same level of confidence when using these techniques for activity quantification as is presently available for air monitoring activity quantification using CAMs.

  18. Active control of radiated sound power from a baffled, rectangular panel

    DEFF Research Database (Denmark)

    Mørkholt, Jakob

    1996-01-01

    with an array of eleven microphones in front of the panel, is very close to minimising the actual radiated sound power. Practical experiments where such an array estimate has been minimised using the filtered X LMS algorithm have shown that substantial reductions of radiated sound power can be obtained over...

  19. Monte Carlo simulations of ripple filters designed for proton and carbon ion beams in hadrontherapy with active scanning technique

    Energy Technology Data Exchange (ETDEWEB)

    Bourhaleb, F; Givehchi, N; Iliescu, S; Rosa, A La; Pecka, A; Peroni, C [Dipartimento di Fisica Sperimentale, Universita' di Torino, Via P. Giuria 1, Torino 10125 (Italy); Attili, A; Cirio, R; Marchetto, F; Donetti, M; Garella, M A; Giordanengo, S; Pardo, J [INFN, Sezione di Torino, Via P. Giuria 1, Torino 10125 (Italy); Cirrone, P [INFN, Laboratori Nazionali del Sud, Via S.Sofia 62, Catania 95125 (Italy)], E-mail: bourhaleb@to.infn.it

    2008-02-01

    Proton and carbon ion beams have a very sharp Bragg peak. For proton beams of energies smaller than 100 MeV, fitting with a gaussian the region of the maximum of the Bragg peak, the sigma along the beam direction is smaller than 1 mm, while for carbon ion beams, the sigma derived with the same technique is smaller than 1 mm for energies up to 360 MeV. In order to use low energy proton and carbon ion beams in hadrontherapy and to achieve an acceptable homogeneity of the spread out Bragg peak (SOBP) either the peak positions along the beam have to be quite close to each other or the longitudinal peak shape needs to be broaden at least few millimeters by means of a properly designed ripple filter. With a synchrotron accelerator in conjunction with active scanning techniques the use of a ripple filter is necessary to reduce the numbers of energy switches necessary to obtain a smooth SOBP, leading also to shorter overall irradiation times. We studied the impact of the design of the ripple filter on the dose uniformity in the SOBP region by means of Monte Carlo simulations, implemented using the package Geant4. We simulated the beam delivery line supporting both proton and carbon ion beams using different energies of the beams. We compared the effect of different kind of ripple filters and their advantages.

  20. Active current control in wind power plants during grid faults

    DEFF Research Database (Denmark)

    Martinez, Jorge; Kjær, Phillip C.; Rodriguez, Pedro;

    2010-01-01

    , wind turbines usually have solutions that enable the turbines to control the generation of reactive power during faults. This paper addresses the importance of using an optimal injection of active current during faults in order to fulfil these grid codes. This is of relevant importance for severe......Modern wind power plants are required and designed to ride through faults in electrical networks, subject to fault clearing. Wind turbine fault current contribution is required from most countries with a high amount of wind power penetration. In order to comply with such grid code requirements...... faults, causing low voltages at the point of common coupling. As a consequence, a new wind turbine current controller for operation during faults is proposed. It is shown that to achieve the maximum transfer of reactive current at the point of common coupling, a strategy for optimal setting of the active...

  1. Calculation methods of reactivity using derivatives of nuclear power and Filter fir; Metodos para o calculo da reatividade usando derivadas da potencia nuclear e o filtro FIR

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Daniel Suescun

    2007-07-01

    This work presents two new methods for the solution of the inverse point kinetics equation. The first method is based on the integration by parts of the integral of the inverse point kinetics equation, which results in a power series in terms of the nuclear power in time dependence. Applying some conditions to the nuclear power, the reactivity is represented as first and second derivatives of this nuclear power. This new calculation method for reactivity has special characteristics, amongst which the possibility of using different sampling periods, and the possibility of restarting the calculation, after its interruption associated it with a possible equipment malfunction, allowing the calculation of reactivity in a non-continuous way. Apart from this reactivity can be obtained with or without dependency on the nuclear power memory. The second method is based on the Laplace transform of the point kinetics equations, resulting in an expression equivalent to the inverse kinetics equation as a function of the power history. The reactivity can be written in terms of the summation of convolution with response to impulse, characteristic of a linear system. For its digital form the Z-transform is used, which is the discrete version of the Laplace transform. In this method it can be pointed out that the linear part is equivalent to a filter named Finite Impulse Response (Fir). The Fir filter will always be, stable and non-varying in time, and, apart from this, it can be implemented in the non-recursive way. This type of implementation does not require feedback, allowing the calculation of reactivity in a continuous way. The proposed methods were validated using signals with random noise and showing the relationship between the reactivity difference and the degree of the random noise. (author)

  2. Power spectrum analysis for optical tweezers. II: Laser wavelength dependence of parasitic filtering, and how to achieve high bandwidth

    DEFF Research Database (Denmark)

    Berg-Sørensen, Kirstine; Peterman, Erwin J G; Weber, Tom

    2006-01-01

    In a typical optical tweezers detection system, the position of a trapped object is determined from laser light impinging on a quadrant photodiode. When the laser is infrared and the photodiode is of silicon, they can act together as an unintended low-pass filter. This parasicit effect is due to ...

  3. Design and performance of an EMI filter to reduce conducted EMI in an isolated full bridge buck converter power supply

    Institute of Scientific and Technical Information of China (English)

    Abdolreza Esmaeli; SUN Li; ZHAO Ke; JIANG Bao-jun

    2005-01-01

    EMI Filter Design and Performance for isolated full bridge buck converter is developed in this paper.In order to design a high performance EMI filter, many issues need to be considered beforehand. Some important issues including accurate model of converter components, parasitic elements, its effect on EMI noise and impedance mismatch are included in this paper. A numerical prediction of EMI/EMC has the potential to evaluate EMI performances at the design stage and before prototyping. It can also help reduce the post-prototype EMC cost by minimizing late redesign and modifications of a design implementation. Saber simulator is used to analyze the EMI noises and EMI filter's performance. Conducted EMI noise measurement and EMI filter design of isolated full bridge buck converter has been achieved while successfully satisfying the FCC class B limits in the frequency range from 150 kHz to 30 MHz. Simulation results are compared with experimental data and the effectiveness of the EMI simulation approach is demonstrated.

  4. Reduction of Carbon Dioxide in Filtering Facepiece Respirators with an Active-Venting System: A Computational Study

    OpenAIRE

    2015-01-01

    During expiration, the carbon dioxide (CO2) levels inside the dead space of a filtering facepiece respirator (FFR) increase significantly above the ambient concentration. To reduce the CO2 concentration inside the dead space, we attach an active lightweight venting system (AVS) comprising a one-way valve, a blower and a battery in a housing to a FFR. The achieved reduction is quantified with a computational-fluid-dynamics model that considers conservation of mass, momentum and the dilute spec...

  5. A tunable Butterworth low-pass filter with digitally controlled DDCC

    Directory of Open Access Journals (Sweden)

    Y. S. Hwang

    2013-06-01

    Full Text Available This paper presents a 6th-order tunable Butterworth low-pass active filter with Digitally Controlled Differential Difference Current Conveyor (DDCC. This active filter is synthesized using the systematic method of voltage-mode linear transformation (VMLT which enables the filter use fewer active components, grounded capacitors and grounded resistors to avoid the parasitical effects. The bandwidth of the filter can be tuned by digital switches to adjust the output current of the DDCC. The specifications of the filter are based on 3G standard, and the filter is controlled by 8-bits digital signals. The tunable bandwidth of the filter is from 12 KHz to 2.6 MHz. The filter chip layout is realized by TSMC 0.18 um CMOS 1P6M mixed-mode technology. The supply voltage is 1.8V and the power consumption is 3.6 mW.

  6. Enhancing filterability of activated sludge from landfill leachate treatment plant by applying electrical field ineffective on bacterial life.

    Science.gov (United States)

    Akkaya, Gulizar Kurtoglu; Sekman, Elif; Top, Selin; Sagir, Ece; Bilgili, Mehmet Sinan; Guvenc, Senem Yazici

    2017-03-09

    The aim of this study is to investigate filterability enhancement of activated sludge supplied form a full-scale leachate treatment plant by applying DC electric field while keeping the biological operational conditions in desirable range. The activated sludge samples were received from the nitrification tank in the leachate treatment plant of Istanbul's Odayeri Sanitary Landfill Site. Experimental sets were conducted as laboratory-scale batch studies and were duplicated for 1A, 2A, 3A, 4A, and 5A of electrical currents and 2, 5, 10, 15, and 30 min of exposure times under continuous aeration. Physicochemical parameters such as temperature, pH, and oxidation reduction potential in the mixture right after each experimental set and biochemical parameters such as chemical oxygen demand, total phosphorus, and ammonia nitrogen in supernatant were analyzed to define the sets that remain in the range of ideal biological operational conditions. Later on, sludge filterability properties such as capillary suction time, specific resistance to filtration, zeta potential, and particle size were measured for remaining harmless sets. Additionally, cost analyses were conducted in respect to energy and electrode consumptions. Application of 2A DC electric field and 15-min exposure time was found to be the most favorable conditions to enhance filterability of the landfill leachate-activated sludge.

  7. 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

  8. Joint Estimation of the Electric Vehicle Power Battery State of Charge Based on the Least Squares Method and the Kalman Filter Algorithm

    Directory of Open Access Journals (Sweden)

    Xiangwei Guo

    2016-02-01

    Full Text Available An estimation of the power battery state of charge (SOC is related to the energy management, the battery cycle life and the use cost of electric vehicles. When a lithium-ion power battery is used in an electric vehicle, the SOC displays a very strong time-dependent nonlinearity under the influence of random factors, such as the working conditions and the environment. Hence, research on estimating the SOC of a power battery for an electric vehicle is of great theoretical significance and application value. In this paper, according to the dynamic response of the power battery terminal voltage during a discharging process, the second-order RC circuit is first used as the equivalent model of the power battery. Subsequently, on the basis of this model, the least squares method (LS with a forgetting factor and the adaptive unscented Kalman filter (AUKF algorithm are used jointly in the estimation of the power battery SOC. Simulation experiments show that the joint estimation algorithm proposed in this paper has higher precision and convergence of the initial value error than a single AUKF algorithm.

  9. Active noise control of forced and induced draft fans in power generating plants

    Energy Technology Data Exchange (ETDEWEB)

    Eldada, M.V.

    1985-05-01

    A study was carried out into active noise reduction of forced draft fans in power generation plants. Active noise reduction involves detecting noise, inverting the phase and re-introducing the anti-phase signal into the duct to cancel the noise through destructive interference. Acoustic pressure transfer functions were meaured in-situ along a cross section of a 15 ft diameter fan inlet. A computer modal analysis program was written and used to analyze the field data. It was found that in frequencies between ca 5 Hz and 45 Hz the energy propagates mainly in the plane wave mode, while in higher frequencies the energy was carried mainly by higher order propagation modes. The project objective was to cancel noise up to a frequency of 130 Hz, but current technology restricted active cancellation to plane waves only. Three alternatives were considered: install a feed forward active noise control system to cancel noise at frequencies below 45 Hz; conduct research on active noise control of higher order propagation modes in ducts; or install a feed back active noise control system and a duct splitter in order to cancel noise between 30 and 130 Hz. It was recommended that the third option be selected as the next phase of the research project, which would comprise a 20 ft duct splitter and microphones, filters, amplifiers, loudspekers and cabinets. 6 refs., 12 figs.

  10. A Fruit Fly-Optimized Kalman Filter Algorithm for Pushing Distance Estimation of a Hydraulic Powered Roof Support through Tuning Covariance

    Directory of Open Access Journals (Sweden)

    Lin Zhang

    2016-10-01

    Full Text Available To measure the pushing distance of a hydraulic-powered roof support, and reduce the cost from a non-reusable displacement sensor embedded in pushing a hydraulic cylinder, an inertial sensor is used to measure the pushing distance, and a Kalman filter is applied to process the inertial data. To obtain better estimation performance, an improved fruit fly optimization algorithm (IFOA is proposed to tune the parameters of the Kalman filter, processing noise covariance Q and observation noise covariance R. The key procedures of the proposed method, including state-space model, fitness function, and Kalman filter implementation, are presented. Finally, an artificial signal is utilized to verify the feasibility of the proposed method, and the tuning results of other algorithms, particle swarm optimization (PSO, genetic algorithm (GA, basic FOA, and 3D-FOA are compared. The proposed method is also applied in the pushing distance estimation scenario. The simulation and application results prove the effectiveness and superiority of the proposed method.

  11. Dependence of beam emittance on plasma electrode temperature and rf-power, and filter-field tuning with center-gapped rod-filter magnets in J-PARC rf-driven H{sup −} ion source

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, A., E-mail: akira.ueno@j-parc.jp; Koizumi, I.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Yamazaki, S.; Oguri, H. [J-PARC Center, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan)

    2014-02-15

    The prototype rf-driven H{sup −} ion-source with a nickel plated oxygen-free-copper (OFC) plasma chamber, which satisfies the Japan Proton Accelerator Research Complex (J-PARC) 2nd stage requirements of a H{sup −} ion beam current of 60 mA within normalized emittances of 1.5 π mm mrad both horizontally and vertically, a flat top beam duty factor of 1.25% (500 μs × 25 Hz) and a life-time of more than 50 days, was reported at the 3rd international symposium on negative ions, beams, and sources (NIBS2012). The experimental results of the J-PARC ion source with a plasma chamber made of stainless-steel, instead of nickel plated OFC used in the prototype source, are presented in this paper. By comparing these two sources, the following two important results were acquired. One was that the about 20% lower emittance was produced by the rather low plasma electrode (PE) temperature (T{sub PE}) of about 120 °C compared with the typically used T{sub PE} of about 200 °C to maximize the beam current for the plasma with the abundant cesium (Cs). The other was that by using the rod-filter magnets with a gap at each center and tuning the gap-lengths, the filter-field was optimized and the rf-power necessary to produce the J-PARC required H{sup −} ion beam current was reduced typically 18%. The lower rf-power also decreases the emittances.

  12. STUDY ON FAST TRANSVERSAL FILTER (FTF)ALGORITHM FOR ACTIVE CONTROL OF STRUCTURAL RESPONSE (ACSR) OF HELICOPTER

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Vibration suppression is one of the most important tasks for helicopter research. ACSR (Active Control of Structural Response) in time domain has turned out to be an effective technique to deal with this issue. In this paper, based on Least Square Principle and ACSR Principle, a multichannel delayed filtered-x FTF (Fast Transversal Filter) algorithm is developed for suppressing helicopter vibration. In order to keep the algorithm running in a stable and efficient state, DRR (Desired Response Reconstruction) technique is developed and a Constraint Stabilization Technique is firstly presented for the developed algorithm. Computer simulations are conducted on attenuating helicopter vibration and remarkable vibration reductions are achieved. The results demonstrate good properties of the obtained FTF algorithm in stability, robustness, convergence speed, tracking capability, etc.. They also show that time delay and DRR technique play important and effective roles in keeping ACSR system working efficiently.

  13. Analysis of Signal Transition Activity in FIR Filters Implemented by Parallel Multiplier Accumulator Based on Modified Booth Algorithm

    Directory of Open Access Journals (Sweden)

    T.S. Udhaya Suriya

    2014-03-01

    Full Text Available The MAC architecture is used in real time digital s ignal processing and multimedia information processing which requires high throughput. A novel method to estimate the transition activity at the nodes of a multiplier accumulator architecture based on modified booth algorithm implementing finite impulse response filter is prop osed in this paper. The input signals are described by a stationary Gaussian process and the transition activity per bit of a signal word is modeled according to the dual bit type (DBT model. This estimation is based on the mathematical formulation by multiplexing mechanism on the breakpoints of the DBT model.

  14. Remotely serviced filter and housing

    Science.gov (United States)

    Ross, M.J.; Zaladonis, L.A.

    1987-07-22

    A filter system for a hot cell comprises a housing adapted for input of air or other gas to be filtered, flow of the air through a filter element, and exit of filtered air. The housing is tapered at the top to make it easy to insert a filter cartridge holds the filter element while the air or other gas is passed through the filter element. Captive bolts in trunnion nuts are readily operated by electromechanical manipulators operating power wrenches to secure and release the filter cartridge. The filter cartridge is adapted to make it easy to change a filter element by using a master-slave manipulator at a shielded window station. 6 figs.

  15. Cochlear power flux as an indicator of mechanical activity.

    Science.gov (United States)

    Diependaal, R J; de Boer, E; Viergever, M A

    1987-09-01

    The question of whether one can conclude just from basilar membrane (BM) vibration data that the cochlea is an active mechanical system is addressed. To this end, a method is developed which computes the power flux through a channel cross section of a short-wave cochlear model from a given BM vibration pattern. The power flux is an important indicator of mechanical activity because a rise in this function corresponds to creation of mechanical energy. The power flux method is applied to BM velocity patterns as measured by Johnstone and Yates [J. Acoust. Soc. Am. 55, 584-587 (1974)] and by Sellick et al. [Hear. Res. 10, 101-108 (1983)] in the guinea pig and by Robles et al. [Peripheral Auditory Mechanisms, edited by J.B. Allen, J.L. Hall, A.E. Hubbard, S.T. Neely, and A. Tubis (Springer, New York, 1986a), pp. 121-128, and J. Acoust. Soc. Am. 80, 1364-1374 (1986b)] in the chinchilla. Before the calculations are performed, the BM data are interpolated and smoothed in order to avoid numerical errors as a result of too few and noisy data points. The choice of the smoothing method influences the computed power flux function considerably. Nevertheless, the calculations appear to make a clear distinction between the "old" data, showing broad BM tuning (Johnstone and Yates, 1974), and the "new" data, in which the response is much more peaked (Sellick et al., 1983; Robles et al., 1986a, b). The former do not give rise to a significant increase of the power flux; the latter do, although less convincingly for the Sellick et al. (1983) data than for the Robles et al. (1986a,b) data. It is thus concluded that the recently obtained, sharply tuned BM responses reflect the presence of mechanical activity in the cochlea.

  16. Active dehydration impairs upper and lower body anaerobic muscular power.

    Science.gov (United States)

    Jones, Leon C; Cleary, Michelle A; Lopez, Rebecca M; Zuri, Ron E; Lopez, Richard

    2008-03-01

    We examined the effects of active dehydration by exercise in a hot, humid environment on anaerobic muscular power using a test-retest (euhydrated and dehydrated) design. Seven subjects (age, 27.1 +/- 4.6 years; mass, 86.4 +/- 9.5 kg) performed upper and lower body Wingate anaerobic tests prior to and after a 1.5-hour recovery from a heat stress trial of treadmill exercise in a hot, humid environment (33.1 +/- 3.1C = 55.1 +/- 8.9% relative humidity) until a 3.1 +/- 0.3% body mass loss was achieved. Dehydration was confirmed by a significant body mass loss (P dehydrated compared to the euhydrated condition. Compared to the euhydrated condition, the dehydrated condition mean power was significantly (P = 0.014) decreased 7.17% in the upper body and 19.20% in the lower body. Compared to the euhydrated condition, the dehydrated condition peak power was significantly (P = 0.013) decreased 14.48% in the upper body and 18.36% in the lower body. No significant differences between the euhydrated and dehydrated conditions were found for decrease in power output (P = 0.219, power = 0.213). Our findings suggest that dehydration of 2.9% body mass decreases the ability to generate upper and lower body anaerobic power. Coaches and athletes must understand that sports performance requiring anaerobic strength and power can be impaired by inadequate hydration and may contribute to increased susceptibility to musculoskeletal injury.

  17. Application of active power sensitivity to frequency and voltage variations on load shedding

    Energy Technology Data Exchange (ETDEWEB)

    Girgis, Adly A. [Clemson University, 303 Riggs Hall, Clemson, SC 29634-0915 (United States); Mathure, Shruti [ITC Holdings, MI (United States)

    2010-03-15

    The occurrence of a large disturbance in a power system can lead to a decline in the system frequency and bus voltages due to a real and reactive power deficiency or due to the formation of islands with generation-load imbalance. Load shedding is an emergency control action that can prevent a blackout in the power system by relieving the overload in some parts of the system. This paper shows that rate of change of frequency can be utilized to determine the magnitude of generation-load imbalance, while the rate of change of voltage with respect to active power can be utilized to identify the sensitive bus for load shedding. The frequency, voltages and their rate of change can be obtained by means of measurements in real-time from various devices such as digital recorders or phasor measurement units or these parameters can be estimated from the voltage data by other means such as an optimal estimation method like Kalman filtering. The rate of change of system frequency, along with the equivalent system inertia may be used to estimate the magnitude of the disturbance prior to each load shedding step. The buses with a higher rate of change of voltage may be identified as the critical ones for load shedding and load can be first shed at these buses, depending on the change in the power flow at each bus. This application is tested on the IEEE 30 bus system and the preliminary results demonstrate that it is feasible to be used in load shedding to restore system voltage and frequency. (author)

  18. Application of Active Power Curve of Motor in Situ

    Institute of Scientific and Technical Information of China (English)

    Wang Dexi

    1996-01-01

    @@ Introduction Previously, inferring output of gearbox, checking and adjusting balance, and inferring quite accurate diagram of work have been achieved by revolution. The characteristic data of motor, I.e., the relationships between motor revolution and torque, and electric current, and efficiency,are needed for these methods. But it is difficult to realize because there are too many types of motors in oilfields. For this reason, the motor active power recorder was developed by engineers of Daqing Oil Fields. It is unnecessary to change the electric circuit or switch off the motor in measuring motor revolution. The negative value of active power can be measured by recorder. It is more direct and effective than using motor revolution to analyze the problems above.

  19. 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.

  20. Voltage Unbalance and Harmonic Compensation in Microgrids by Cooperation of Distributed Generators and Active Power Filters

    DEFF Research Database (Denmark)

    Hashempour, Mohammad M.; Savaghebi, Mehdi; Quintero, Juan Carlos Vasquez

    2016-01-01

    , selective virtual impedance and voltage/current regulators. Based on the secondary control, at first voltage harmonic compensation and voltage unbalance compensation of point of common coupling (PCC), that might includes sensitive loads, is carried out by DGs. Voltage compensation of PCC by DGs may cause...... severe voltage distortion at DGs terminals. Thus, the coordinated control is used to mitigate the voltage distortion to the defined maximum allowable value at DGs terminals. Evaluation of the proposed hierarchical control is carried out by a simulation study....

  1. Zero loss magnetic metamaterials using powered active unit cells.

    Science.gov (United States)

    Yuan, Yu; Popa, Bogdan-Ioan; Cummer, Steven A

    2009-08-31

    We report the design and experimental measurement of a powered active magnetic metamaterial with tunable permeability. The unit cell is based on the combination of an embedded radiofrequency amplifier and a tunable phase shifter, which together control the response of the medium. The measurements show that a negative permeability metamaterial with zero loss or even gain can be achieved through an array of such metamaterial cells. This kind of active metamaterial can find use in applications that are performance limited due to material losses.

  2. Analysis and experimental verification of new power flow control for grid-connected inverter with LCL filter in microgrid.

    Science.gov (United States)

    Gu, Herong; Guan, Yajuan; Wang, Huaibao; Wei, Baoze; Guo, Xiaoqiang

    2014-01-01

    Microgrid is an effective way to integrate the distributed energy resources into the utility networks. One of the most important issues is the power flow control of grid-connected voltage-source inverter in microgrid. In this paper, the small-signal model of the power flow control for the grid-connected inverter is established, from which it can be observed that the conventional power flow control may suffer from the poor damping and slow transient response. While the new power flow control can mitigate these problems without affecting the steady-state power flow regulation. Results of continuous-domain simulations in MATLAB and digital control experiments based on a 32-bit fixed-point TMS320F2812 DSP are in good agreement, which verify the small signal model analysis and effectiveness of the proposed method.

  3. [Occupational radiation exposures during maintenance activities at nuclear power plants].

    Science.gov (United States)

    Imahori, A

    1987-11-01

    Occupational exposures at nuclear power plants occur mostly during maintenance activities rather than during routine reactor operation. In this paper, statistical summaries of occupational exposures during routine maintenance activities for the years 1982-84 at nuclear power plants in Japan are presented, including comparison of the exposure levels by reactor type and by plant age. Average annual collective doses per reactor for BWRs and PWRs are 7.30 man-Sv and 2.84 man-Sv, respectively, and 78% and 89% of annual doses are incurred during maintenance activities. Average annual outage days of BWRs and PWRs for routine maintenance are 102 d and 97 d. Annual collective doses per reactor, most of which occur during maintenance activities, usually increase with plant age. Higher collective doses are observed for routine maintenance performed on older reactors as compared to newer reactors, especially in BWRs. Collective doses accrued during respective routine maintenance activities have a significant correlation with duration of maintenance and number of workers involved in maintenance.

  4. The Shoebox activity: a powerful tool for learning

    Directory of Open Access Journals (Sweden)

    Hobley, Janet

    2011-06-01

    Full Text Available This article explores an activity that has been used in many different training contexts from Initial Teacher Training (ITT, Advanced Learning Coach (ALC training through to different ‘in–house’ training sessions and explains how it has been adapted by other teachers for their own contexts and how the learners themselves experience it. The activity is explained in practice and then linked to the theory of reflective practice to show how it can support and extend learners’ thinking about themselves, their different roles and their individual teaching. Different perspectives have been drawn on as reflections on the activity and the work includes both tutor and learner comments about undertaking the activity. Their contributions together with personal reflections show the power of the idea from a simple icebreaker to something more profound that contributes to personal development and learning.

  5. Enhancement of nuclease P1 production by Penicillium citrinum YL104 immobilized on activated carbon filter sponge.

    Science.gov (United States)

    Zhao, Nan; Ren, Hengfei; Li, Zhenjian; Zhao, Ting; Shi, Xinchi; Cheng, Hao; Zhuang, Wei; Chen, Yong; Ying, Hanjie

    2015-02-01

    The efficiency of current methods for industrial production of the enzyme nuclease P1 is limited. In this study, we sought to improve fermentation methods for the production of nuclease P1. An immobilized fermentation system using an activated carbon filter sponge as a carrier was used for the production of nuclease P1. In an airlift internal loop reactor (ALR), the fermentation performance of three different fermentation modes, including free-cell fermentation, repeated-batch fermentation, and semi-continuous immobilized fermentation, were compared. The fermentation kinetics in the fermentation broth of the three fermentation modes, including dissolved oxygen (DO), pH value, cell concentration, residual sugar concentration, and enzyme activity, were tested. The productivity of semi-continuous immobilized fermentation reached 8.76 U/mL/h, which was 33.3 and 80.2% higher than that of repeated-batch fermentation and free-cell fermentation, respectively. The sugar consumption of free-cell, repeated-batch, and semi-continuous immobilized fermentations was 41.2, 30.8, and 25.9 g/L, respectively. These results showed that immobilized-cell fermentation by using Penicillium citrinum with activated carbon filter sponge in an ALR was advantageous for nuclease P1 production, especially in the semi-continuous immobilized fermentation mode. In spite of the significant improvement in nuclease P1 production in semi-continuous immobilized fermentation mode, the specific activity of nuclease P1 was almost equal among the three fermentation modes.

  6. Design and analysis of tilt integral derivative controller with filter for load frequency control of multi-area interconnected power systems.

    Science.gov (United States)

    Kumar Sahu, Rabindra; Panda, Sidhartha; Biswal, Ashutosh; Chandra Sekhar, G T

    2016-03-01

    In this paper, a novel Tilt Integral Derivative controller with Filter (TIDF) is proposed for Load Frequency Control (LFC) of multi-area power systems. Initially, a two-area power system is considered and the parameters of the TIDF controller are optimized using Differential Evolution (DE) algorithm employing an Integral of Time multiplied Absolute Error (ITAE) criterion. The superiority of the proposed approach is demonstrated by comparing the results with some recently published heuristic approaches such as Firefly Algorithm (FA), Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) optimized PID controllers for the same interconnected power system. Investigations reveal that proposed TIDF controllers provide better dynamic response compared to PID controller in terms of minimum undershoots and settling times of frequency as well as tie-line power deviations following a disturbance. The proposed approach is also extended to two widely used three area test systems considering nonlinearities such as Generation Rate Constraint (GRC) and Governor Dead Band (GDB). To improve the performance of the system, a Thyristor Controlled Series Compensator (TCSC) is also considered and the performance of TIDF controller in presence of TCSC is investigated. It is observed that system performance improves with the inclusion of TCSC. Finally, sensitivity analysis is carried out to test the robustness of the proposed controller by varying the system parameters, operating condition and load pattern. It is observed that the proposed controllers are robust and perform satisfactorily with variations in operating condition, system parameters and load pattern.

  7. Low Power, Small Form Factor, High Performance EVA Radio Employing Micromachined Contour Mode Piezoelectric Resonators and Filters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In Phase I Harmonic Devices proposes to investigate the feasibility of a low-power, low-volume, lightweight, frequency agile, and fault tolerant EVA radio based on...

  8. Fully characterization of an active optical filter based on an equivalent-phase-shifted DFB-SOA

    Science.gov (United States)

    Deng, Ye; Li, Ming; Shi, Nuannuan; Tang, Jian; Sun, Shuqian; Zhang, Lihong; Li, Wei; Zhu, Ninghua

    2016-10-01

    A fully characterization of an active optical filter based on an equivalent-phase-shifted DFB-SOA has been theoretically analyzed and experimentally demonstrated in this paper. By employing an optical vector network analyzer (OVNA), transmission characteristics of the equivalent-phase-shifted DFB-SOA are obtained. The influences of driven current on transmission characteristics of the equivalent-phase-shifted DFB-SOA are also investigated. In addition to the advantage of integration, the proposed equivalent-phase-shifted DFB-SOA also shows significant application in design of photonic devices for all-optical signal processing and computing.

  9. DOE HEPA filter test program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    This standard establishes essential elements of a Department of Energy (DOE) program for testing HEPA filters to be installed in DOE nuclear facilities or used in DOE-contracted activities. A key element is the testing of HEPA filters for performance at a DOE Filter Test Facility (FTF) prior to installation. Other key elements are (1) providing for a DOE HEPA filter procurement program, and (2) verifying that HEPA filters to be installed in nuclear facilities appear on a Qualified Products List (QPL).

  10. Statistically-Efficient Filtering in Impulsive Environments: Weighted Myriad Filters

    Directory of Open Access Journals (Sweden)

    Gonzalez Juan G

    2002-01-01

    Full Text Available Linear filtering theory has been largely motivated by the characteristics of Gaussian signals. In the same manner, the proposed Myriad Filtering methods are motivated by the need for a flexible filter class with high statistical efficiency in non-Gaussian impulsive environments that can appear in practice. Myriad filters have a solid theoretical basis, are inherently more powerful than median filters, and are very general, subsuming traditional linear FIR filters. The foundation of the proposed filtering algorithms lies in the definition of the myriad as a tunable estimator of location derived from the theory of robust statistics. We prove several fundamental properties of this estimator and show its optimality in practical impulsive models such as the -stable and generalized- . We then extend the myriad estimation framework to allow the use of weights. In the same way as linear FIR filters become a powerful generalization of the mean filter, filters based on running myriads reach all of their potential when a weighting scheme is utilized. We derive the "normal" equations for the optimal myriad filter, and introduce a suboptimal methodology for filter tuning and design. The strong potential of myriad filtering and estimation in impulsive environments is illustrated with several examples.

  11. Powerful Outflows and Feedback from Active Galactic Nuclei

    CERN Document Server

    King, Andrew

    2015-01-01

    Active Galactic Nuclei (AGN) represent the growth phases of the supermassive black holes in the center of almost every galaxy. Powerful, highly ionized winds, with velocities $\\sim 0.1- 0.2c$ are a common feature in X--ray spectra of luminous AGN, offering a plausible physical origin for the well known connections between the hole and properties of its host. Observability constraints suggest that the winds must be episodic, and detectable only for a few percent of their lifetimes. The most powerful wind feedback, establishing the $M -\\sigma$ relation, is probably not directly observable at all. The $M - \\sigma$ relation signals a global change in the nature of AGN feedback. At black hole masses below $M-\\sigma$ feedback is confined to the immediate vicinity of the hole. At the $M-\\sigma$ mass it becomes much more energetic and widespread, and can drive away much of the bulge gas as a fast molecular outflow.

  12. Aerosol hygroscopicity and cloud droplet activation of extracts of filters from biomass burning experiments

    Science.gov (United States)

    Carrico, Christian M.; Petters, Markus D.; Kreidenweis, Sonia M.; Collett, Jeffrey L.; Engling, Guenter; Malm, William C.

    2008-04-01

    In this laboratory closure study, we compare sub- and supersaturated water uptake properties for aerosol particles possessing a range of hygroscopicity. Measurements for water sub-saturated conditions used a hygroscopic tandem differential mobility analyzer (HTDMA). Simultaneously, measurements of particle critical supersaturation were conducted on the same sample stream with a continuous flow cloud condensation nuclei (CCN) counter. For these experiments, we used filter-collected samples of biomass smoke generated in the combustion of two common wildland fire fuels, western sagebrush and Alaskan duff core. Extractions of separate sections of the filter were performed using two solvents, ultrapure water and methanol. The extracts were subsequently atomized, producing aerosols having a range of hygroscopic responses. HTDMA and CCN measurements were fit to a single-parameter model of water uptake, in which the fit parameter is denoted κ, the hygroscopicity parameter. Here, for the four extracts we observed mean values of the hygroscopicity parameter of 0.06 CCN-derived values of κ for each experiment agreed within approximately 20%. Applicability of the κ-parameterization to other multicomponent aerosols relevant to the atmosphere remains to be tested.

  13. Airborne Laser Scanning (ALS) point cloud ground filtering for area of an active landslide (Doren, Western Austria)

    Science.gov (United States)

    Brodić, Nenad; Cvijetinović, Željko; Milenković, Milutin; Dorninger, Peter; Mitrović, Momir

    2014-05-01

    Ground filtering of point cloud is the primary step required for Digital Terrain Model (DTM) generation. The procedure is especially interesting for forested areas, since LiDAR systems can measure terrain elevation under vegetation cover with a high level of penetration. This work analyzes the potential of ALS data ground filtering for area of an active landslide. The results of ALS filtering, for example, may improve geomorphological and motion-detection studies. ALS data was collected during flight campaign 2011 under leaf-off conditions for Doren region, Vorarlberg, Western Austria. In this area, non-ground objects are mostly low vegetation such as shrubs, small trees etc. The vegetation is more dense in lower part of the landslide where erosion is smaller. Vegetation points can be removed based on the hypothesis that these are significantly higher than their neighboring points. However, in case of steep terrain, ground points may have the same heights as vegetation points, and thus, local slope should be considered. Also, if terrain roughness increases, the classification may become even more complex. Software system OPALS (Orientation and Processing of Airborne Laser Scanning data, Vienna University of Technology) was used for processing the ALS data. Labeling ground points has been made using physical and geometrical attributes (parameters) of ALS points. Also additional attributes were calculated in order to improve extraction. Since bare ground surface is usually smooth and continuous unlike vegetation, standard deviation of local elevations was used as roughness measure to differentiate these surfaces. EchoRatio (ER) was adopted as a measure of surface penetrability, while number of echoes and differentiation between echoes (EchoNumber) were also deployed in filtering. Since the ground points are measurements from bare-earth that are usually the lowest surface features in a local area, normalized height was defined as a rank of neighboring points

  14. Observational Signatures of Galactic Winds Powered by Active Galactic Nuclei

    CERN Document Server

    Nims, Jesse; Faucher-Giguere, Claude-Andre

    2014-01-01

    We predict the observational signatures of galaxy scale outflows powered by active galactic nuclei (AGN). Most of the emission is produced by the forward shock driven into the ambient interstellar medium (ISM) rather than by the reverse shock. AGN powered galactic winds with energetics suggested by phenomenological feedback arguments should produce spatially extended 1-10 keV X-ray emission of 10^(41-44) erg/s, significantly in excess of the spatially extended X-ray emission associated with normal star forming galaxies. The presence of such emission is a direct test of whether AGN outflows significantly interact with the ISM of their host galaxy. We further show that even radio quiet quasars should have a radio luminosity comparable to or in excess of the far infrared-radio correlation of normal star forming galaxies. This radio emission directly constrains the total kinetic energy flux in AGN-powered galactic winds. Radio emission from AGN wind shocks can also explain the recently highlighted correlations be...

  15. Filtering bleb activation in the early post-operative period after fistulizing surgery

    Directory of Open Access Journals (Sweden)

    S. Yu. Petrov

    2014-10-01

    Full Text Available The article presents a case report of a patient with a cystic bleb in the early postoperative period after trabeculectomy. Patient complained of discomfort in a recently (4 weeks operated eye. Medical regimen administered previously had been taken irregularly. Biomicroscopy revealed a high, encapsulated cystic bleb with thin walls and hyperemia. Intraocular pressure at the moment of examination was 27 mmHg. Local hypotensive therapy had been neglected by the patient. A local anti-inflammatory (tobramycin / dexamethasone fixed combination and hypotensive (brimonidine / timolol fixed combination therapy was administered. 24 hours later, when intraocular pressure decreased to 20 mmHg, a needle revision procedure was conducted for partial bleb wall destruction and subconjunctival injection of dexamethasone, fluorouracil and ranibizumab. During the next day examination the bleb was diffuse, with less hyperemia and an abundance of conjunctival microcysts in the central bleb’s zone. Intraocular pressure was 10.2 mmHg. No choroidal detachment was noted during ophthalmoscopy and OCT examination. The patient continued anti-inflammatory therapy. Another needling procedure with the same drug combination was repeated two weeks after due to an increased hyperemia. At the end of the four-week follow-up period the filtering bleb remained diffuse and the intraocular pressure was 13.2 mmHg. Dexamethasone drops were prescribed to be instilled 1‑2 times a day for a month. This case report demonstrates the method of restoring a functioning filtering bleb by the needle revision with antiinflammatory, cytostatic and anti-VEGF therapy for prolonging the hypotensive effect of a trabeculectomy in the presence of wound healing.

  16. Filtering bleb activation in the early post-operative period after fistulizing surgery

    Directory of Open Access Journals (Sweden)

    S. Yu. Petrov

    2014-01-01

    Full Text Available The article presents a case report of a patient with a cystic bleb in the early postoperative period after trabeculectomy. Patient complained of discomfort in a recently (4 weeks operated eye. Medical regimen administered previously had been taken irregularly. Biomicroscopy revealed a high, encapsulated cystic bleb with thin walls and hyperemia. Intraocular pressure at the moment of examination was 27 mmHg. Local hypotensive therapy had been neglected by the patient. A local anti-inflammatory (tobramycin / dexamethasone fixed combination and hypotensive (brimonidine / timolol fixed combination therapy was administered. 24 hours later, when intraocular pressure decreased to 20 mmHg, a needle revision procedure was conducted for partial bleb wall destruction and subconjunctival injection of dexamethasone, fluorouracil and ranibizumab. During the next day examination the bleb was diffuse, with less hyperemia and an abundance of conjunctival microcysts in the central bleb’s zone. Intraocular pressure was 10.2 mmHg. No choroidal detachment was noted during ophthalmoscopy and OCT examination. The patient continued anti-inflammatory therapy. Another needling procedure with the same drug combination was repeated two weeks after due to an increased hyperemia. At the end of the four-week follow-up period the filtering bleb remained diffuse and the intraocular pressure was 13.2 mmHg. Dexamethasone drops were prescribed to be instilled 1‑2 times a day for a month. This case report demonstrates the method of restoring a functioning filtering bleb by the needle revision with antiinflammatory, cytostatic and anti-VEGF therapy for prolonging the hypotensive effect of a trabeculectomy in the presence of wound healing.

  17. A new three-component signal model to objectively select power Doppler wall filter cut-off velocity for quantitative microvascular imaging

    Science.gov (United States)

    Elfarnawany, Mai; Lacefield, James C.

    2013-03-01

    The wall-filter selection curve (WFSC) method was developed to automatically select cut-off velocities for high-frequency power Doppler imaging. Selection curves are constructed by plotting color pixel density (CPD) as a function of wall filter cut-off velocity. A new three-component mathematical model is developed to guide the design of an online implementation of the method for in vivo imaging. The model treats Doppler imaging as a signal detection task in which the scanner must distinguish intravascular pixels from perivascular and extravascular pixels and includes a cost function to identify the optimum cut-off velocity that provides accurate vascular quantification and minimizes the effect of color pixel artifacts on visualization of vascular structures. The goodness of fit of the three-component model to flow-phantom data is significantly improved compared to a previous two-component model (F test, p new model indicate that selection curves should be sampled using at least 100 cut-off velocities to ensure robust performance of the automated WFSC method and determine an upper bound on CPD variability that ensures reliable vascular quantification accuracy, defined as CPD within 5% of the reference vascular volume fraction. Results of the simulations also provide evidence that limiting the selection of the cut-off velocity to a binary choice between the middle and right end of the characteristic interval is sufficient to meet the quantification accuracy goal. The model provides an intuitive, empirical description of the relationship between system settings and blood-flow detection performance in power Doppler imaging.

  18. Model Identification of Unmanned Powered Parafoil Based on Subspace Observer/Kalman Filter Identification%基于SOKID的无人动力伞模型辨识

    Institute of Scientific and Technical Information of China (English)

    谢志刚; 陈自力

    2011-01-01

    Unmanned Powered Parafoil( UPP)of special flight characteristics is studied, and establish a 9-DOF nonlinear dynamic e-quation. A observer/kalman filter identification(OKID)method and advanced subspace observer/kalman filter identification(OKID)is researched. Using the flight data, the longitudinal slate space models of UPP is identified and derived, and the identified model pitch angle response characters and identified precision are also analysed. The consistent and effective of the identification method are verified in a simulation experiment, and the validity of the identified longitudinal model is also tested in the fly.%对具有独特飞行特性的无人动力伞(Unmanned Powered Parafoil,UPP)进行了研究,建立了无人动力伞九自由度非线性动力学方程,研究了观测器/卡尔曼滤波辨识算法和改进的子空间观测器/卡尔曼滤波辨识算法.根据系统的飞行数据,辨识得到系统的纵向状态空间模型,分析了两种辨识模型的俯仰角响应特性和辨识精度.仿真结果表明子空间观测器/卡尔曼滤波辨识算法的一致和有效估计,能有效辨识无人动力伞的纵向动态模型.

  19. A Wolf Pack Algorithm for Active and Reactive Power Coordinated Optimization in Active Distribution Network

    Science.gov (United States)

    Zhuang, H. M.; Jiang, X. J.

    2016-08-01

    This paper presents an active and reactive power dynamic optimization model for active distribution network (ADN), whose control variables include the output of distributed generations (DGs), charge or discharge power of energy storage system (ESS) and reactive power from capacitor banks. To solve the high-dimension nonlinear optimization model, a new heuristic swarm intelligent method, namely wolf pack algorithm (WPA) with better global convergence and computational robustness, is adapted so that the network loss minimization can be achieved. In this paper, the IEEE33-bus system is used to show the effectiveness of WPA technique compared with other techniques. Numerical tests on the modified IEEE 33-bus system show that WPA for active and reactive multi-period optimization of ADN is exact and effective.

  20. Analysis of active damping of LCL filter used in single-phase PV system in discrete domain

    Science.gov (United States)

    Zhang, Ningyun; Tang, Houjun; Yao, Chen

    2015-06-01

    Sampling and computational delay are necessary in digital control, though they may alter the characteristics of the actual controlled plant when considered in the discrete domain. Accordingly, this article establishes a mathematical model of a single-phase grid-connected inverter with an LCL filter in the discrete domain. Three active damping control delay times: 0, ?, ? are analysed, considering the influences introduced by digital control of the plant. Further, the range of the capacitor current feedback coefficient used in active damping control is derived to guarantee that the controlled plant does not have poles outside the unit circle. Using Nyquist diagrams, the proper proportional-resonant (PR) controller parameters can be intuitively determined. The theoretical analysis is verified using MATLAB and a 3 kW laboratory prototype based on a digital signal processor (TMS320F2808).

  1. Impact of titanium dioxide nanoparticles on the bacterial communities of biological activated carbon filter intended for drinking water treatment.

    Science.gov (United States)

    Zhiyuan, Liu; Shuili, Yu; Heedeung, Park; Qingbin, Yuan; Guicai, Liu; Qi, Li

    2016-08-01

    Titanium dioxide nanoparticles (TiO2 NPs) are inevitably present in the aquatic environment owing to their increasing production and use. However, knowledge of the potential effects of TiO2 NPs on the treatment of drinking water is scarce. Herein, the effects of two types of anatase TiO2 NPs (TP1, 25 nm; TP2, 100 nm) on the bacterial community in a biological activated carbon (BAC) filter were investigated via quantitative polymerase chain reaction (Q-PCR) analysis, ATP quantification, and 454 pyrosequencing analysis. Both TP1 and TP2 significantly inhibited the bacterial ATP level (p < 0.01) and induced a decrease in the abundance of bacterial 16S rDNA gene copies at doses of 0.1 and 100 mg L(-1). Simultaneously, the diversity and evenness of the bacterial communities were considerably reduced. The relative abundances of bacteria annotated to OTUs from Nitrospira class and Betaproteobacteria class decreased upon TiO2 NP treatment, whereas those of Bacilli class and Gammaproteobacteria class increased. TiO2 NP size showed a greater effect on the bacterial composition than did the dose based on Bray-Curtis distances. These findings identified negative effects of TiO2 NPs on the bacterial community in the BAC filter. Given the fact that BAC filters are used widely in drinking water treatment plants, these results suggested a potential threat by TiO2 NP to drinking water treatment system.

  2. A Multi-Functional Power Electronic Converter in Distributed Generation Power Systems

    DEFF Research Database (Denmark)

    Chen, Zhe; Blaabjerg, Frede; Pedersen, John Kim

    2005-01-01

    This paper presents a power electronic converter which is used as an interface for a distributed generation unit/energy storage device, and also functioned as an active power compensator in a hybrid compensation system. The operation and control of the converter have been described. An example...... and passive filters connected to each distorting load or distributed generation (DG) unit. The passive filters are distributely located to remove major harmonics and provide reactive power compensation. The active power electronic filter corrects the system unbalance, removes the remaining harmonic components...... of the converter interfacing a wind power generation unit is also given. The power electronic interface performs the optimal operation in the wind turbine system to extract the maximum wind power, while it also plays a key role in a hybrid compensation system that consists of the active power electronic converter...

  3. Optimal filtering

    CERN Document Server

    Anderson, Brian D O

    2005-01-01

    This graduate-level text augments and extends beyond undergraduate studies of signal processing, particularly in regard to communication systems and digital filtering theory. Vital for students in the fields of control and communications, its contents are also relevant to students in such diverse areas as statistics, economics, bioengineering, and operations research.Topics include filtering, linear systems, and estimation; the discrete-time Kalman filter; time-invariant filters; properties of Kalman filters; computational aspects; and smoothing of discrete-time signals. Additional subjects e

  4. A Systematic Method for Designing a PR Controller and Active Damping of the LCL Filter for Single-Phase Grid-Connected PV Inverters

    Directory of Open Access Journals (Sweden)

    Ningyun Zhang

    2014-06-01

    Full Text Available The Proportional Resonant (PR current controller provides gains at a certain frequency (resonant frequency and eliminates steady state errors. Therefore, the PR controller can be successfully applied to single grid-connected PV inverter current control. On the contrary, a PI controller has steady-state errors and limited disturbance rejection capability. Compared with the L- and LC filters, the LCL filter has excellent harmonic suppression capability, but the inherent resonant peak of the LCL filter may introduce instability in the whole system. Therefore, damping must be introduced to improve the control of the system. Considering the controller and the LCL filter active damping as a whole system makes the controller design method more complex. In fact, their frequency responses may affect each other. The traditional trial-and-error procedure is too time-consuming and the design process is inefficient. This paper provides a detailed analysis of the frequency response influence between the PR controller and the LCL filter regarded as a whole system. In addition, the paper presents a systematic method for designing controller parameters and the capacitor current feedback coefficient factor of LCL filter active-damping. The new method relies on meeting the stable margins of the system. Moreover, the paper also clarifies the impact of the grid on the inverter output current. Numerical simulation and a 3 kW laboratory setup assessed the feasibility and effectiveness of the proposed method.

  5. Nuclear Power: Entering the Stage of Active Development

    Institute of Scientific and Technical Information of China (English)

    Xu Lianyi; Zhu Li

    2009-01-01

    @@ Development course Since 1970 when the construction preparation of Qinshan No. 1 Nuclear Power Plant started, China's nuclear power industry has grown out of nothing, and then adjusted the step from moderate development to vigorous development. In this course, China's nuclear power equipment manufacturing industry has also been unceasingly developing and strengthening itself with the construction of nuclear power plants one by one.

  6. A Lower Power Channel Selective Filter for Multi-Frequency Multi-Mode Receiver%一种多频多模接收机低功耗信道选择滤波器

    Institute of Scientific and Technical Information of China (English)

    谢淼; 任旭; 马聪; 张润曦; 赖宗声

    2012-01-01

    Based on GSMC 0.18 jim RF CMOS process, a low-power 8active RC channel selective filter was designed for multi-frequency/multi-mode receiver. The filter achieved a tunable cut-off frequency ranging from 200 kHz to 10 MHz, which covers all frequency bands from GSM, UHF RFID, TD-SCDMA to IEEE 802. lla/b/ g. An operational amplifier with variable GBW was proposed to optimize power consumption in different modes. The channel selective filter for both I &. Q channels occupied a chip area of 1. 5 mm X 0. 36 mm. The circuit had an input reference noise of 20 nV/

  7. The suppression of star formation by powerful active galactic nuclei

    CERN Document Server

    Page, M J; Vieira, J D; Altieri, B; Amblard, A; Arumugam, V; Aussel, H; Babbedge, T; Blain, A; Bock, J; Boselli, A; Buat, V; Castro-Rodr'iguez, N; Cava, A; Chanial, P; Clements, D L; Conley, A; Conversi, L; Cooray, A; Dowell, C D; Dubois, E N; Dunlop, J S; Dwek, E; Dye, S; Eales, S; Elbaz, D; Farrah, D; Fox, M; Franceschini, A; Gear, W; Glenn, J; Griffin, M; Halpern, M; Hatziminaoglou, E; Ibar, E; Isaak, K; Ivison, R J; Lagache, G; Levenson, L; Lu, N; Madden, S; Maffei, B; Mainetti, G; Marchetti, L; Nguyen, H T; O'Halloran, B; Oliver, S J; Omont, A; Panuzzo, P; Papageorgiou, A; Pearson, C P; Perez-Fournon, I; Pohlen, M; Rawlings, J I; Rigopoulou, D; Riguccini, L; Rizzo, D; Rodighiero, G; Roseboom, I G; Rowan-Robinson, M; Portal, M Sanchez; Schulz, B; Scott, Douglas; Seymour, N; Shupe, D L; Smith, A J; Stevens, J A; Trichas, M; Tugwell, K E; Vaccari, M; Valtchanov, I; Viero, M; Vigroux, L; Wang, L; Ward, R; Wright, G; Xu, C K; Zemcov, M

    2013-01-01

    The old, red stars which constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly from accretion onto black holes. It is widely suspected, but unproven, that the tight correlation in mass of the black hole and stellar components results from the AGN quenching the surrounding star formation as it approaches its peak luminosity. X-rays trace emission from AGN unambiguously, while powerful star-forming galaxies are usually dust-obscured and are brightest at infrared to submillimetre wavelengths. Here we report observations in the submillimetre and X-ray which show that rapid star formation was common in the host galaxies of AGN when the Universe was 2-6 Gyrs old, but that the most vigorous star formation is not observed around black holes above an X-ray luminosity of 10^44 erg/s. This suppression of star formation in the host galaxies of powerful AGN ...

  8. The Suppression of Star Formation by Powerful Active Galactic Nuclei

    Science.gov (United States)

    Dwek, E.

    2012-01-01

    The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight corre1ation between the mass of the black hole and the mas. of the stellar bulge results from the AGN quenching the surrounding star formation as it approaches its peak luminosity. X-rays trace emission from AGN unambiguously, whereas powerful star-forming ga1axies are usually dust-obscured and are brightest at infrared and submillimeter wavelengths. Here we report submillimetre and X-ray observations that show that rapid star formation was common in the host galaxies of AGN when the Universe was 2-6 billion years old, but that the most vigorous star formation is not observed around black holes above an X-ray luminosity of 10(exp 44) ergs per second. This suppression of star formation in the host galaxy of a powerful AGN is a key prediction of models in which the AGN drives an outflow, expe11ing the interstellar medium of its host and transforming the galaxy's properties in a brief period of cosmic time.

  9. Aspects of tests and assessment of filtering materials used for respiratory protection against bioaerosols. Part I: type of active substance, contact time, microorganism species.

    Science.gov (United States)

    Majchrzycka, Katarzyna; Gutarowska, Beata; Brochocka, Agnieszka

    2010-01-01

    This paper presents the results of a study on antimicrobial activity of polymer filter nonwovens produced by needle-punching or melt-blowing with an addition of disinfecting agents. The first part of the paper discusses how the biocidal activity of nonwovens is a function of the active agent added to the nonwovens, the duration of the contact of microorganisms with nonwovens and the type of microorganisms. The types of fibres and disinfecting agents had a considerable effect on the biocidal activity of nonwovens. The biocidal effect of nonwovens increased with the duration of their contact with microorganisms. Fibre activity differed considerably depending on the species of the microorganism. The microorganisms most sensitive to biocidal activity of the active filter nonwoven were S. aureus, M. flavus and E. coli. There were no biocidal effects on spore-forming bacterium B. subtilis.

  10. 自适应滤波在有源消声中的应用%Application of adaptive filter in active noise control

    Institute of Scientific and Technical Information of China (English)

    于华民; 朱海潮; 施引; 吴正国

    2001-01-01

    从分析有源消声的难点出发,综述了自适应滤波算法在有源消声中的应用,给出了相应的实例.对自适应滤波在有源消声中应用的未来发展趋势作了展望.%With focus on the difficulties of ANC(active noise control), the application of adaptive filter in active noise control is reviewed, and some practical examples are also displayed. Finally, prospect of adaptive filter in ANC is proposed.

  11. Nuclear Power:Entering the Stage of Active Development

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Development course Since 1970 when the construction preparation of Qinshan No.1 Nuclear Power Plant started,China's nuclear power industry has grown out of nothing,and then adjusted the step from moderate development to vigorous development.In this course,China's nuclear power equipment manufacturing industry has also been unceasingly developing and strengthening itself with the construction of nuclear power plants one by one.

  12. Line Impedance Estimation Using Active and Reactive Power Variations

    DEFF Research Database (Denmark)

    Timbus, Adrian Vasile; Rodriguez, Pedro; Teodorescu, Remus;

    2007-01-01

    This paper proposes an estimation method of power system impedance based on power variations caused by a distributed power generation system (DPGS) at the point of common coupling (PCC). The proposed algorithm is computationally simple and uses the voltage variations at the point of common coupling...... (PCC) caused by the variations of the power delivered to utility network to derive the value of grid impedance. Accurate estimation of both resistive and inductive part of the impedance is obtained, as the results presented show....

  13. A Test Circuit with Microstrip Filter for Microwave Power Device%微波功率器件的滤波器测试电路

    Institute of Scientific and Technical Information of China (English)

    罗卫军; 陈晓娟; 刘果果; 刘新宇; 王晓燕; 方测宝; 郭伦春; 王晓亮

    2007-01-01

    With the principles of microwave circuits and semiconductor device physics, three kinds of microwave power device test circuits are designed and simulated, whose properties are evaluated by a parameter network analyzer within the frequency range from 3 to 8GHz. The simulated results verify that the test circuit with stepped-impedance filter bias network has a larger bandwidth than that with the radial stub. A microstrip interdigital capacitor is used in the third test circuit to replace the DC block,however,which does not show its advantage during the test frequency band. Based on the simulated results, the stepped-impedance filter test circuit can be used to evaluate microwave power devices in the whole C band,namely from 4 to 8GHz.%在微波电路原理和半导体器件物理的基础上,设计和模拟了三种用于微波功率器件的测试电路,并且设计了与之配套的测试夹具.采用矢量网络分析仪对该测试电路和夹具,在3~8GHz范围内进行了小信号测试.模拟和测试结果表明,采用阶梯阻抗滤波器偏置网络的测试电路性能较好,比采用扇形线偏置网络的测试电路具有更宽的带宽.该滤波器偏置电路能够用来在整个C波段,即在4~8GHz内对微波功率器件进行测试.但是,微带叉指耦合电容没有起到取代贴片隔直电容的目的,原因是该结构对参数精度要求高,而PCB制作工艺无法满足这个要求.

  14. Mosquito knock-down and adulticidal activities of essential oils by vaporizer, impregnated filter paper and aerosol methods

    Directory of Open Access Journals (Sweden)

    M. Ramar

    2014-09-01

    Full Text Available Essential oils from 12 medicinal plants were evaluated by three different bioassay methods (Vaporizer, Filter paper and Aerosol for Knock-down and adulticidal efficacy on the filarial vector mosquito, Culex quinquefasciatus. Based on screening results the effective plants were selected for investigating Knock-down and adulticidal potential against adult female of the laboratory-reared mosquito species, Cx. quinquefasciatus. In vaporizer bioassay method four different doses (1.25, 2.5, 5 and 10% were used. Four different doses (0.625, 1.25, 2.5 and 10% were used both filter paper (cm2 and aerosol (cm3 bioassay methods. Five essential oils (calamus, camphor, citronella, clove and eucalyptus were identified as potential treatments in vaporizer bioassay. The result showed that the knock down time decreased with increased concentration in clove oil treatment; the Knock-down time (KT 50 = 46.1 ± 0.1, 38.5 ± 0.1, 30.7 ± 0.2, and 20.1 ± 0.1 minutes was recorded at 1.25, 2.5, 5 and 10% /cm3 respectively. In filter paper method nine essential oils were identified as potential treatments. After 1 hr exposure period clove oil recorded the lowest median Knock-down time (KT50 which was calculated as 9.15 ± 0.1min/cm2. Followed by citronella (KT50 =11.4 ± 0.1 min and eucalyptus (KT50 =11.4 ±0.1min oils since they recorded lower median Knock-down time. All the twelve essential oils were identified as potential treatments in aerosol activity. The lethal time decreased when the concentration increased. At 5 % concentration the median lethal time (LT50 for clove oil was calculated as (LT50=3.80 ± 0.1minutes. The Cinnamon oil was effective which recorded (LT50 = 1.99 mins as median lethal time. Camphor (LT50 =19.6± 0.1 min oil were found to be less toxic by aerosol method. These results suggest that clove oil and cinnamon oil have the potential to be used as a eco-friendly approach for the control of the major important filaria vector Cx. quinquefasciatus

  15. Fabrication of Activated Rice Husk Charcoal by Slip Casting as a Hybrid Material for Water Filter Aid

    Science.gov (United States)

    Tuaprakone, T.; Wongphaet, N.; Wasanapiarnpong, T.

    2011-04-01

    Activated charcoal has been widely used as an odor absorbent in household and water purification industry. Filtration equipment for drinking water generally consists of four parts, which are microporous membrane (porous alumina ceramic or diatomite, or porous polymer), odor absorbent (activated carbon), hard water treatment (ion exchange resin), and UV irradiation. Ceramic filter aid is usually prepared by slip casting of alumina or diatomite. The membrane offers high flux, high porosity and maximum pore size does not exceed 0.3 μm. This study investigated the fabrication of hybrid activated charcoal tube for water filtration and odor absorption by slip casting. The suitable rice husk charcoal and water ratio was 48 to 52 wt% by weight with 1.5wt% (by dry basis) of CMC binder. The green rice husk charcoal bodies were dried and fired between 700-900 °C in reduction atmosphere. The resulting prepared slip in high speed porcelain pot for 60 min and sintered at 700 °C for 1 h showed the highest specific surface area as 174.95 m2/g. The characterizations of microstructure and pore size distribution as a function of particle size were investigated.

  16. 燃煤电厂用新型高分子复合滤料性能的测试%Test on performance of new macromolecule compound filter media used in coal-fired power plants

    Institute of Scientific and Technical Information of China (English)

    王振华; 沈恒根; 薛婷婷

    2013-01-01

    耐高温滤料的使用寿命和稳定性是影响袋式除尘器运行寿命的因素之一。对新型高分子复合滤料进行了基本性能的测试,并与目前燃煤电厂常用的玻纤滤料性能进行了对比试验。结果表明,新型复合滤料在耐高温、耐酸腐蚀和抗氧化性能方面均优于常用的玻纤滤料,适合在电厂烟气处理系统中应用。%Lifetime and stability of the high temperature resistance filter media is one of the factors that affect the operation lifetime of bag house duster .The basic performance test and analysis of the newly developed compound filter media were carried out , and the comparing test of the performances between the material and general glass fiber filter media used in coal-fired power plants was discussed.The test result demon-strates that high temperature resistance and acid corrosion resistance as well as oxidation resistance of new compound filter media were better than that of glass fiber filter media .The fiter media is feasible on used in flue gas treatment system in power plant .

  17. Application of Kalman Filter in the Accelerator Power Control%卡尔曼滤波在加速器电源控制中的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘太联; 乔卫民; 钱湘萍; 林飞宇

    2011-01-01

    提出了将基于卡尔曼滤波的最佳滤波方法应用于兰州重离子加速器电源控制的方案.给出了加速器控制系统中加速器电源控制的通用模型,用matlab对卡尔曼滤波算法在该模型上的应用进行了建模仿真,给出了叠加噪声和滤波之后的效果比较图,经对比可知卡尔曼滤波能有效减小各种随机噪声的干扰,使电源控制的均方误差减小为原来的23%,尤其能减小尖峰噪声的影响,能有效提高控制精度,从而提高束流品质.%In order to boost accelerator controlling accuracy and improve beam quality, a best filtering method that is Kalman filter was proposed. In the article gived general model of the accelerator power and used Matlab to modeling the kaerman filter on the accelerator power model and simulate. Compared the chart of fitering effect, showed that Kalman filter can effectively filter out the effect of random noise. After kalman filtering , Mean square error of the control system was reduced to 23% of the original, Kalman filter especially can reduce the impact of the peak pulse to make the control accuracy improve.

  18. Low powdered activated carbon concentrations to improve MBR sludge filterability at high salinity and low temperature

    NARCIS (Netherlands)

    Remy, M.J.J.; Temmink, B.G.; Brink, van den P.; Rulkens, W.H.

    2011-01-01

    Previous research has demonstrated that powdered activated carbon (PAC), when applied at very low dosages and long SRTs, reduces membrane fouling in membrane bioreactor (MBRs). This effect was related to stronger flocs which are less sensitive to shear. Low temperature and high salt concentration ar

  19. Bioavailable and biodegradable dissolved organic nitrogen in activated sludge and trickling filter wastewater treatment plants

    Science.gov (United States)

    A study was carried out to understand the fate of biodegradable dissolved organic nitrogen (BDON) and bioavailable dissolved organic nitrogen (ABDON) along the treatment trains of a wastewater treatment facility (WWTF) equipped with an activated sludge (AS) system and a WWTF equipped with a two-stag...

  20. Impact of thermostatically controlled loads' demand response activation on aggregated power: A field experiment

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam; Marinelli, Mattia; Kosek, Anna Magdalena;

    2015-01-01

    This paper describes the impacts of different types of DR (demand response) activation on TCLs' (thermostatically controlled loads) aggregated power. The different parties: power system operators, DR service providers (or aggregators) and consumers, have different objectives in relation to DR...