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Sample records for active power filter

  1. LCL Interface Filter Design for Shunt Active Power Filters

    Directory of Open Access Journals (Sweden)

    DOBRICEANU, M.

    2010-08-01

    Full Text Available This paper is focused on finding the parameters of a second order interface filter connected between the power system and the shunt active filter based on switching frequency of the active filter. Many publications on power active filters include various design methods for the interface inductive filter which take into account the injected current and its dynamic. Compared to these ones, the approach presented in this paper is oriented toward the design of the interface filter starting from filter transfer functions by imposing the performances of the filter.

  2. 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.

  3. 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...

  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. 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.

  6. 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.

  7. A New Multilevel Active Power Filter Using Switches Meticulously Controlled

    Directory of Open Access Journals (Sweden)

    Zoubir Zahzouh

    2015-03-01

    Full Text Available Shunt active power filter based on multilevel inverter is used to compensate the power factor and to delete the harmonics. This one permits to reduce the inverse voltages applied to the filter switches and their switching frequencies. Nevertheless, the high number of used switches requires a complicated controller and increases the switching losses; where the necessity of finding another resolution system. In this work a new topology of multilevel inverter is proposed as a shunt active power filter using two IGBT transistors in series of opposite sense meticulously controlled by a parallel control algorithm, with the concept of reduced number of six switches which are able to create five levels of the output voltage. This system substute the classical system of eight switches. The harmonic currents identification is carried out using the instantaneous active and reactive power method. The simulation is performed using Matlab/Simulink. The obtained results show that the filtering performances are well enhanced.

  8. 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...... or similar inductances, the filter designing become more simple and effective, meanwhile the capacitance requirement is minimized. A pole-zero automatic cancellation phenomenon is discussed in this paper, which can be applied to simplify the current regulator designing. The tuning method is presented, based...... on pole-zero mapping. Some simulation results of APF with LCL-filter are presented to verify the feasibility and stability of the proposed designing method and control strategy....

  9. 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...

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

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Blaabjerg, Frede; Hansen, Steffan

    2005-01-01

    In the attempt to minimize the harmonic disturbances created by the non-linear loads the choice of the active power filters comes out to improve the filtering efficiency and to solve many issues existing with classical passive filters. One of the key points for a proper implementation of an active...... 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...

  11. Voltage Harmonics Mitigation through Hybrid Active Power Filter

    Directory of Open Access Journals (Sweden)

    Anwer Ali Sahito

    2016-01-01

    Full Text Available Fast dynamic response, high efficiency, low cost and small size of power electronic converters have exponentially increased their use in modern power system which resulted in harmonically distorted voltage and currents. Voltage harmonics mainly caused by current harmonics are more dangerous as performance and expected operating life of other power system equipment are affected by harmonically distorted supply voltage. Electronic filter circuits are used to improve system power quality by mitigating adverse effects of harmonics. Hybrid filters having advantages of both passive and active filters are preferred to resolve the problem of harmonics efficiently and avoiding any chance of resonance. In this paper, a three phase three wire network is considered to supply an adjustable speed drive represented by a resistive load connected across a three phase bridge rectifier. Simulation of the considered system shows THD (Total Harmonic Distortion of 18.91 and 7.61% in supply current and voltage respectively. A HAPF (Hybrid Active Power Filter is proposed to reduce these THD values below 5% as recommended by IEEE Standard-519. P-Q theorem is used to calculate required parameters for proposed filter, which is implemented through hysteresis control. Simulation results confirm the effectiveness of the designed filter as THD for both current and voltage have reduced below allowable limit of 5%.

  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. 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.

  14. 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...

  15. A predictive control algorithm for an active three-phase power filter

    Directory of Open Access Journals (Sweden)

    R.V. Vlasenko

    2014-09-01

    Full Text Available The paper deals with grid connection circuits for active filters, structures of active power filter control systems, and methods based on full capacity components determination. The existing structures of active power filter control and control algorithm adjustment for valve commutation loss reduction are analyzed. A predictive control algorithm for an active three-phase power filter is introduced.

  16. A predictive control algorithm for an active three-phase power filter

    OpenAIRE

    R.V. Vlasenko; Bialobrzeski, O. V.

    2014-01-01

    The paper deals with grid connection circuits for active filters, structures of active power filter control systems, and methods based on full capacity components determination. The existing structures of active power filter control and control algorithm adjustment for valve commutation loss reduction are analyzed. A predictive control algorithm for an active three-phase power filter is introduced.

  17. Design of LCL-Filter Based Three-level Active Power Filter

    Directory of Open Access Journals (Sweden)

    Shilan Chen

    2013-07-01

    Full Text Available This paper proposes an improved design of LCL-Filters for Three-Level Shunt Active power filters (APF. Available design principles are presented to achieve high compensation bandwidth and low switching frequency current. Then, affecitons of different parameters are taken into consideration of constraints on LCL-Filter design with detail analysis of ripple current. A simple and practical design procedure of LCL-Filter for Three-Level APF is subsequently proposed. The first step is to choose the resonant frequency of LCL-Filter according to the highest order harmonic needed to be compensated. Then it is aim to optimize the parameters of the LCL-Filter based on the design principles and constraints. The simulation results verify the effectiveness of the proposed method.

  18. 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.

  19. Selective Harmonic Current Mitigation with Shunt Active Power Filter

    DEFF Research Database (Denmark)

    Hansen, Steffan; Lascu, Cristian; Asiminoaei, Lucian;

    2007-01-01

    drawbacks, the paper shows that the last two methods have a more compact mathematical representation which may extend to straightforward DSP implementation. However, the first method, i.e. selective compensation in harmonic dq-frame, is more flexible and allows a better tuning and adjustment, which is of a......The paper presents three methods of selective harmonic compensation with shunt Active Power Filters in different reference frames: harmonic dq-frame, stationary frame and fundamental dq-frame; and shows that the last two methods are derived from the first one. By analyzing their advantages and...... great importance in practice. For experimental tests only the selective harmonic control in fundamental dq-frame is presented, to demonstrate the selectiveness harmonic current compensation. The experimental results are performed in laboratory conditions on a 7 kVA Active Filter prototype, indicating a...

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

    CERN Document Server

    Xiaoling, Guo

    2013-01-01

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

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  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. 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.

  7. High Performances of an Active Filter Compared to a Passive Filter: Improvement of the Electric Power Quality

    Directory of Open Access Journals (Sweden)

    M.S.Djebbar

    2015-10-01

    Full Text Available The work presented in this paper focuses on the harmonic pollution of electrical networks, linked to disturbances generated by static converters. The solutions to eliminate these disturbances were presented; they are based on passive and active filtering methods. Some elements of definition and sizing of passive filters are mentioned. The active filter is then treated, with an approach based on the use the Instantaneous Active and Reactive Power (p-q Method, in the purpose of controlling a Shunt Active Power Filter (Shunt APF. This latter offers to the filtering operation a great stability and robustness against various possible disturbances. However, the passive filter is less stable and loses its performance as soon as the network frequency varies, or once the pollutant load evolves. The temporal and frequency analysis of the obtained simulation results confirms the value of our considered approach.

  8. THREE-PHASE ACTIVE POWER FILTER CONTROLLER FOR BALANCED AND UNBALANCED NON-LINEAR LOAD

    Directory of Open Access Journals (Sweden)

    G.NAGESWARA RAO

    2010-09-01

    Full Text Available The active power filter produces equal but opposite harmonic currents to the point of connection with the nonlinear load. This results in a reduction of the original distortion and correction of the power factor. A threephase insulated gate bipolar transistor based current controlled voltage source inverter with a dc bus capacitor is used as an active filter. The firing pulses to the shunt active filter will be generated by using sine PWM method. The models for three-phase active power filter controller for balanced and unbalanced non-linear load is made and is simulated using Matlab/simulink software.

  9. 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 ...... of the discrete-time implementation of such filter due to the proximity to Nyquist-Shannon limit. A detailed analysis of the filter and the control system is also included. The experimental results validate the effectiveness of the proposed technique....

  10. Hierarchical Coordinated Control of Distributed Generators and Active Power Filters to Enhance Power Quality of Microgrids

    DEFF Research Database (Denmark)

    Savaghebi, Mehdi; Hashempour, Mohammad M.; Guerrero, Josep M.

    2014-01-01

    includes two control levels: primary control and secondary control. Primary control consists of power controllers, selective virtual impedance loops and proportional-resonant (PR) voltage/current controllers. Secondary control manages the compensation of voltage harmonic distortion of sensitive load bus......This paper addresses the coordinated control of distributed generators (DGs) inverters and active power filters (APFs) to compensate voltage harmonics in microgrids. For this, a hierarchical control system is proposed to mitigate voltage harmonic distortion. The hierarchical control structure...... (SLB). Compensation of SLB harmonics by control of DGs may cause excessive voltage harmonics at the terminal of one or more of DGs interface inverters and/or overloading of the inverters. After occurrence of each of these cases, active power filter (APF) participates in harmonic compensation...

  11. Performance Improvement of Shunt Active Power Filter With Dual Parallel Topology

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Lascu, Cristian; Blaabjerg, Frede;

    2007-01-01

    loop and the other is in a feedforward loop for harmonic compensation. Thus, both active power filters bring their own characteristic advantages, i.e., the feedback filter improves the steady-state performance of the harmonic mitigation and the feedforward filter improves the dynamic response. Another...

  12. 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 improve...... as a harmonic filter but also as a switching-ripple filter around 10kHz. Simulation results and experimental results obtained in laboratory confirmed the validity and effectiveness of the control.......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......, which are directly connected in series without any matching transformer. The required rating of the active filter is much smaller than a conventional standalone active filter would be. No additional switching-ripple filter is required for the hybrid filter because the LC filter functions not only...

  13. Power Quality Improvement in Distribution System using ANN Based Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Somlal Jarupula

    2015-02-01

    Full Text Available This paper focuses on an Artificial Neural Network (ANN controller based Shunt Active Power Filter (SAPF for mitigating the harmonics of the distribution system. To increase the performance of the conventional controller and take advantage of smart controllers, a feed forward-type (trained by a back propagation algorithm ANN-based technique is implemented in shunt active power filters for producing the controlled pulses required for IGBT inverter. The proposed approach mainly work on the principle of capacitor energy to maintain the DC link voltage of a shunt connected filter and thus reduces the transient response time when there is abrupt variation in the load. The entire power system block set model of the proposed scheme has been developed in MATLAB environment. Simulations are carried out by using MATLAB, it is noticed that the %THD is reduced to 2.27% from 29.71% by ANN controlled filter. The simulated experimental results also show that the novel control method is not only easy to be computed and implemented, but also very successful in reducing harmonics.  

  14. 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

    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...

  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. 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.

  18. 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.

  19. 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.

  20. 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)

  1. PI, FUZZY and ANFIS Control of 3-Phase Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Brahmaiah.routhu

    2013-06-01

    Full Text Available this paper describes control of 3-phase shunt active filter by using PI, fuzzy and ANFIS controls to improve the power quality and reactive power compensation and harmonic current compensation due to nonlinear loads. The controller is capable of controlling the DC capacitor voltage capable of reference source current. Hysteresis control is used to control the current in PWM inverter. The simulation results reveals that comparative study of all this results shows the advantage anddisadvantages of 3 control strategies.

  2. Single-phase shunt active filter interfacing renewable energy sources with the power grid

    OpenAIRE

    Neves, Pedro; Gonçalves, Domingos; Pinto, J. G.; Alves, Renato; Afonso, João L.

    2009-01-01

    This paper presents a single-phase Shunt Active Filter combined with a Maximum Power Point Tracker (MPPT) connected to a solar panel array. The Shunt Active Filter’s power stage consists of a two-leg IGBT inverter commanded by a Digital Signal Processor (DSP) with control based on the Theory of Instantaneous Reactive Power (p-q Theory). The MPPT is based on a step-up circuit commanded by a DSP with MPPT Algorithm implemented. The output of the MPPT circuit is connected...

  3. Feedback Linearization Control of a Shunt Active Power Filter Using a Fuzzy Controller

    Directory of Open Access Journals (Sweden)

    Tianhua Li

    2013-09-01

    Full Text Available In this paper, a novel feedback linearization based sliding mode controlled parallel active power filter using a fuzzy controller is presented in a three-phase three-wire grid. A feedback linearization control with fuzzy parameter self-tuning is used to implement the DC side voltage regulation while a novel integral sliding mode controller is applied to reduce the total harmonic distortion of the supply current. Since traditional unit synchronous sinusoidal signal calculation methods are not applicable when the supply voltage contains harmonics, a novel unit synchronous sinusoidal signal computing method based on synchronous frame transforming theory is presented to overcome this disadvantage. The simulation results verify that the DC side voltage is very stable for the given value and responds quickly to the external disturbance. A comparison is also made to show the advantages of the novel unit sinusoidal signal calculating method and the super harmonic treatment property of the designed active power filter.

  4. 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.

  5. 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.

  6. 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.

  7. 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...

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

    OpenAIRE

    Biricik, Samet; Redif, Soydan; Ozerdem, Ozgur; Shafiuzzaman K. Khadem; Basu, Malabika

    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...

  9. 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.

  10. 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.

  11. 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.

  12. 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

    A new current control scheme for selective harmonic compensation is proposed for shunt active power filters. The method employs an array of resonant current controllers, one for the fundamental, and one for each harmonic, implemented in fundamental reference frame in order to reduce the overall...... 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...... is supported by experimental results on a 7.6-kVA laboratory filter, indicating a reduction in current THD factor from 34% to 2%, while the highest harmonic compensated is the 37th harmonic current....

  13. 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.

  14. 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...

  15. 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...

  16. 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...... is studied for current harmonic compensation. The hybrid filter is formed by a single tuned Le filter and a small-rated power active filter, which are directly connected in series without any matching transformer. Thus the required rating of the active filter is much smaller than a conventional standalone...

  17. 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.

  18. Active Optical Lattice Filters

    OpenAIRE

    Gary Evans; MacFarlane, Duncan L.; Govind Kannan; Jian Tong; Issa Panahi; Vishnupriya Govindan; L. Roberts Hunt

    2005-01-01

    Optical lattice filter structures including gains are introduced and analyzed. The photonic realization of the active, adaptive lattice filter is described. The algorithms which map between gains space and filter coefficients space are presented and studied. The sensitivities of filter parameters with respect to gains are derived and calculated. An example which is relevant to adaptive signal processing is also provided.

  19. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

    Three-phase three-wire shunt active power filters (APFs) usually employ very large electrolytic capacitors in the dc-link to mitigate utility side harmonics. These capacitors are however known to be bulky and of short operating lifetime, particularly for systems where high ripple currents exist....... 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...

  5. An advanced static var compensator based on a three level IGBT inverter modelling analysis and active power filtering

    Science.gov (United States)

    Draou, Azeddine

    2012-12-01

    This paper presents the dynamic performance analysis of an Advanced Static Var Compensator (ASVC) using three-level neutral point-clamped voltage source inverter. The paper presents the principles of operating and the method of reference currents generation. The dynamic behaviour of the system is further analysed using Matlab/Simulink with SimPower Systems toolbox through a set of simulation tests. The results obtained have been applied to an active power filter which might lead to the design of a robust controller for current harmonics and reactive power applications

  6. 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.)

  7. 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.

  8. 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.

  9. 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.

  10. Grid-Connection Half-Bridge PV Inverter System for Power Flow Controlling and Active Power Filtering

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-01-01

    Full Text Available A half-bridge photovoltaic (PV system is proposed, which can not only deal with bidirectional power flowing but also improve power quality. According to varying insolation, the system conditions real power for dc and ac loads to accommodate different amounts of PV power. Furthermore, the system eliminates current harmonics and improves power factor simultaneously. As compared with conventional PV inverter, the total number of active switches and current sensors can be reduced so that its cost is lower significantly. For current command determination, a linear-approximation method (LAM is applied to avoid the complicated calculation and achieve the maximum power point tracking (MPPT feature. For current controlling, a direct-source-current-shaping (DSCS algorithm is presented to shape the waveform of line current. Simulation results and practical measurements also demonstrate the feasibility of the proposed half-bridge PV system.

  11. 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.

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

    OpenAIRE

    Sergio Salas-Duarte; Ismael Araujo-Vargas; Jazmin Ramirez-Hernandez; Marco Rivera

    2016-01-01

    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-qu...

  13. Magnetic Bearing Amplifier Output Power Filters for Flywheel Systems

    Science.gov (United States)

    Lebron-Velilla, Ramon C.; Jansen, Ralph H.; Palazzolo, Alan; Thomas, Erwin; Kascak, Peter E.; Birchenough, Arthur G.; Dever, Timothy P.

    2003-01-01

    Five power filters and two types of power amplifiers were tested for use with active magnetic bearings for flywheel applications. Filter topologies included low pass filters and low pass filters combined with trap filters at the PWM switching frequency. Two state and three state PWM amplifiers were compared. Each system was evaluated based on current magnitude at the switching frequency, voltage magnitude at 500 kHz, and power consumption. The base line system was a two state amplifier without a power filter. The recommended system is a three state power amplifier with a 50 kHz low pass filter and a 27 kHz trap filter. This system uses 5.57 W. It reduces the switching current by an order of magnitude and the 500 kHz voltage by two orders of magnitude. The relative power consumption varied depending on the test condition between 60 to 130 percent of the baseline.

  14. 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.

  15. 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.

  16. A Study of Parallel Operation of an active Filter and passive Filters

    DEFF Research Database (Denmark)

    Chen, Zhe; Blaabjerg, Frede; Pedersen, John Kim

    2002-01-01

    arrangements of the active and passive filters can operate relatively independently, also the compensation flexibility of the active filter can be fully exploited, such as one active filter for several harmonic sources.The simulation studies on various systems have been performed to evaluate the effectiveness......This paper reports investigations of the parallel operations of a current controlled active filter and passive filters in a system with current harmonic sources. The task of reactive power and harmonic compensation is shared by the active filter and passive filters. The passive filters are used for...

  17. 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 switching losses in any operating point. This paper proposes a new DPWM strategy for shunt APFs. The proposed modulation strategy detects the current vector position relative to the inverter voltage reference and determines the optimum clamped duration for each phase, in terms of switching power losses....... It achieves a clamped voltage pattern, with variable lengths depending on the magnitude of the inverter current. This property reduces the current stress and minimizes the inverter switching losses. The proposed modulation strategy is described, analyzed, and validated on a three-phase voltage source inverter...

  18. Reducting Power Dissipation in Fir Filter: an Analysis

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Bansal

    2010-03-01

    Full Text Available In this paper, three existing techniques, Signed Power-of-Two (SPT, Steepest decent and Coefficient segmentation, for power reduction of FIR filters are analyzed. These techniques reduce switching activity which is directly related to the power consumption of a circuit. In an FIR filter, the multiplier consumes maximum power. Therefore, power consumption can be reduced either by by making the filter multiplier-less or by minimizing hamming distance between the coefficients of this multiplier as it directly translates into reduction in power dissipation [8]. The results obtained on four filters (LP show that hamming distance can be reduced upto 26% and 47% in steepest decent and coefficient segmentation algorithm respectively. Multiplier-less filter can be realized by realizing coefficients in signed power-of-two terms, i.e. by shifting and adding the coefficients, though at the cost of shift operation overhead.

  19. 并联型有源电力滤波器的控制原理分析%Domination Principle Analysis of Parallel Active Power Filter

    Institute of Scientific and Technical Information of China (English)

    王忠利; 张久辉

    2016-01-01

    This paper takes the three-phase parallel active power filter as the research object,and introduces the operation principle of active power filter and instantaneous reactive power theory,then gives the current detecting method of p-q and ip-iq based on instantaneous reactive power theory.%以三相并联型有源电力滤波器为研究对象,介绍了三相并联型有源电力滤波器工作原理和瞬时无功理论,并给出了基于瞬时无功理论的p-q和ip-iq谐波电流检测方法。

  20. 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.

  1. 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....

  2. 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.

  3. 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...... 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...... of steady-state fundamental current tracking errors in the DG units. Thus, an accurate power control is realized even when the harmonic compensation functions are activated. In addition, this paper also briefly discusses the performance of the proposed method when DG unit is connected to a grid...

  4. 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.

  5. 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

    , the influence of the synchronizing signal error on current detection of APF is analyzed in this paper. Voltage distortion, voltage unbalance and frequency fluctuation are frequent and severe in small rating stand-alone power grids, so traditional synchronizing signal obtaining method--phase locking based...... on zero-cross detection can't work effectively in small rating stand-alone power grid. Then a soft phase locked loop with additional filter is proposed. It can lock the phase angle on to the positive sequence of fundamental voltage accurately and rapidly. It ensures the performance of APF applied...... in the small rating stand-alone power grid. Moreover, the soft phase locked loop is easy to be implemented in a Digital Signal Processor (DSP). Simulation and experimental results validate that the soft phase locked loop has satisfactory performance....

  6. 有源滤波在谐波治理中的应用%Application of Active Power Filter in Harmonic Suppressing

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      介绍了常州中天钢铁第三轧钢厂辅传动系统产生谐波的主要情况,根据测试该变压器的各次谐波结果,设计选用ABB PQFM型有源滤波器,通过测试滤波前后的相电流和三相电流电压波形,并进行比较分析,得出结论:滤波器的滤波效率明显,超过95%。%The main harmonics situation of the auxiliary transmission system of No.3 rolling mill of Zenith Iron & Steel Group Co., Ltd. is introduced. On the basis of harmonics test results of the transformer, ABB PQFM active power filter is selected in design. The phase current and the three phase current and voltage waveform before and after filtering are tested and compared. It is concluded that filtering efficiency of the filter is obvious and more than 95%.

  7. 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.

  8. 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.

  9. Active filter to improve the energetic efficiency in electric installations.

    OpenAIRE

    Amarís Duarte, Hortensia; Robles Muñoz, Guillermo

    2009-01-01

    The Department of Electrical Engineering of the University Carlos III of Madrid has developed a prototype of active filter to compensate the disturbances that a nonlinear load produces. The active filters appears like the dynamic solution that best fits to the needs of compensation of electrical disturbances in industrial facilities. This active filter allows correcting the power factor of the installation. With this improvement, electrical consumes are reduced, which results in significa...

  10. 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.

  11. 基于小波分析的有源滤波器技术研究%Research on Technology of Wavelet-based Active Power Filter

    Institute of Scientific and Technical Information of China (English)

    郭晓玲; 程建

    2014-01-01

    High power accelerators demand excellent stability to magnet power supplies .Wavelet-based active power filter can improve the quality of current passing magnets .The information about harmonics can be got by wavelet analysis ,and then the active power filter circuit works according to the result of wavelet transform ,out-putting current and counteracting the harmonics from PS .The simulation program of this type of active power fil-ter using Matlab approves its effect ,and the experiment agrees with the simulation program .%现代先进的高能加速器对束流的稳定性提出了越来越高的要求,而磁铁电源输出电流的稳定性是直接影响束流品质的主要因素之一。基于小波分析的有源滤波器针对北京正负电子对撞机( BEPC II)中部分直流磁铁电源输出电流纹波过大的问题,利用小波分析对电源输出电流数据进行谐波分析,得出电源输出电流纹波中各个频段内谐波的信息,并根据该信息输出幅值相等、方向相反的纹波电流,用于抵消磁铁电源输出电流中的纹波,达到降低纹波含量、提高电源输出质量的目的。利用Mat-lab对该有源滤波器的工作进行仿真,并在小电源样机上对仿真结果进行实验验证。

  12. AN ACTIVE POWER FILTER BASED ON SUPERCONDUCTING MAGNETIC ENERGY STORAGE SYSTEM%基于超导储能系统的有源电力滤波器

    Institute of Scientific and Technical Information of China (English)

    王屹; 高鹏; 赵勇

    2012-01-01

    The widely application of electronics and electric devices in the power system have an effect upon the stable operation of electric network, because of its injection harmonic and idle current in the system. In this paper, an Active Power Filter(APF) based on Superconducting Magnetic Energy Storage(SMES) system which adopt direct power control strategy has been shown. Compared with the traditional APF, SMES system can filter not only the harmonic but also the fluctuate of the active power. By use of Matlab/Simulink software, this thesis proved the feasibility of the system.%电力系统中电力电子装置的广泛应用,为电网中注入了一定的谐波及无功电流,从而影响电网的稳定运行.本文提出了一种基于超导储能系统并采用直接功率控制的有源电力滤波器.与传统的有源电力滤波器相比,超导储能系统不但可以滤除谐波,还可以滤除有功功率波动.通过Matlab/Simulink对基于超导储能系统的有源电力滤波器进行仿真验证.

  13. 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.

  14. Application of Kalman filter in the accelerator power control

    International Nuclear Information System (INIS)

    In order to boost accelerator controlling accuracy and improve beam quality, a best filtering method that is Kalman filter was proposed. In the article given general model of the accelerator power and used Matlab to modeling the Kalman filter on the accelerator power model and simulate. Compared the chart of filtering 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. (authors)

  15. Using active power filter to compensate the current component of asymmetrical non-linear load in the four wire network

    OpenAIRE

    Власенко, Руслан Володимирович; Бялобржеський, Олексій Володимирович

    2016-01-01

    Electricity quality improving is extremely relevant nowadays. With such industrial loads as induction motors, induction furnaces, welding machines, controlled or uncontrolled rectifiers, frequency converters and others reactive power, harmonics and unbalance are generated in power grid. Reactive power, higher harmonic currents and asymmetry loads influence the functioning of electric devices and electrical mains. An effective technical solution is the use of new compensating devices, that is ...

  16. Integrated electric alternators/active filters

    Science.gov (United States)

    Towliat Abolhassani, Mehdi

    In response to energy crisis and power quality concerns, three different methodologies to integrate the concept of active filtering into the alternators are proposed. Wind energy, due to its free availability and its clean and renewable character, ranks as the most promising renewable energy resource that could play a key role in solving the worldwide energy crisis. An Integrated Doubly-fed Electric Alternator/Active filter (IDEA) for wind energy conversion systems is proposed. The proposed IDEA is capable of simultaneously capturing maximum power of wind energy and improving power quality, which are achieved by canceling the most significant and troublesome harmonics of the utility grid and power factor correction and reactive power compensation in the grid. The back-to-back current regulated power converters are employed to excite the rotor of IDEA. The control strategy of rotor-side power converter is based on position sensorless field oriented control method with higher power density. Analysis and experimental results are presented to demonstrate the effectiveness of the proposed IDEA. In the next step, an integrated synchronous machine/active filter is discussed. The proposed technology is essentially a rotating synchronous machine with suitable modification to its field excitation circuit to allow dc and ac excitations. It is shown that by controlling the ac excitation, the 5 th and 7th harmonics currents of the utility are compensated. The proposed method is cost effective because it can be applied to existing standby generators in commercial and industrial plants with minimal modification to the excitation circuits. To boost the gain of harmonic compensatory, an advanced electric machine is proposed. An Asymmetric Airgap Concentrated Winding Synchronous Machine (AACWSM) with ac and dc excitation was designed and employed. It is shown that the AACWSM with its unique design, in addition to power generation capability, could be used to compensate the most

  17. 基于DSP三相有源电力滤波器研制%Research of Three-phase Active Power Filter Based on DSP

    Institute of Scientific and Technical Information of China (English)

    桂存兵; 谢运祥; 公伟勇; 陈江辉

    2011-01-01

    为消除电网中越来越多的谐波,运用瞬时无功功率理论的ip-iq法,采用DSP芯片作为控制核心实现系统数字控制,提高了补偿精度和运算能力,介绍了有源电力滤波器的硬件电路设计过程和软件设计流程图,并制作了实验装置.实验结果表明:谐波源负载的进线电源电流实现正弦化,验证了谐波检测算法的正确性和控制策略的有效性.%In order to eliminate more and more harmonic pollution in power system, using ip-iq instantaneous reactive power theory and DSP digital control system as control core, the compensation precision and the operational capability were increased. At the same time, the active power filter's hardware circuit design process and the software design were introduced, and the test sample was constructed. The experimental results indicated that the harmonic source load's current realized the sine, which had indicated that the harmonic examination algorithm and the control strategy were accuracy and validity.

  18. Active resistance capacitance filter design

    Science.gov (United States)

    Kerwin, W. J.

    1970-01-01

    Filters, formed by combinations of distributed RC elements with positive-feedback voltage amplifiers, provide transfer functions similar to those the heavier LC filters ordinarily employ. They also provide signal amplification.

  19. 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.

  20. 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.

  1. 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.

  2. 基于DSP的有源电力滤波器研究%Research on Active Power Filter based on DSP

    Institute of Scientific and Technical Information of China (English)

    党常亮

    2013-01-01

    The system structure and working principle of APF were analyzed,harmonic order current was obtained based on the instantaneous reactive power theory of ip-iq detecting algorithm,then hysteresis comparator method was applied to follow tracks of harmonic current.Modeling and simulating were carried out under the environment of PSCAD/EMTDC.Finally,control system was designed based on DSP.The experimental results proved the effectiveness of control strategy.%分析了有源电力滤波器(active power filter,简称APF)的系统结构和工作原理,采用基于瞬时无功功率理论的ip-iq检测算法,计算出APF的谐波指令电流,并选择电流跟踪控制方式之一的滞环比较方式.采用PSCAD/EMTDC软件为工具,对APF进行了建模及仿真分析;并在此基础上,设计了基于DSP的控制系统,仿真和试验结果证明了控制策略的有效性.

  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. 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.

  5. 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.

  6. 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

  7. Power Consumption Models for Decimation FIR Filters in Multistandard Receivers

    Directory of Open Access Journals (Sweden)

    Khaled Grati

    2012-01-01

    Full Text Available Decimation filters are widely used in communication-embedded systems. In fact, decimation filters are useful for implementing channel filtering or selection with low-computation complexity requirements. Many multistandard receiver designs that are required in ubiquitous embedded systems are based on a cascade of decimation filter processing. Filter number and implementation architectures have a significant impact on system performances, such as computation complexity, area, throughput, and power consumption. In this work, we present filter power consumption estimation models for FIR filters. Power consumption models were obtained from a large number of FIR filter syntheses using a direct form. Several curves that estimate power consumption were extracted from these synthesis results. Then, we have evaluated the impact of polyphase decomposition on power consumption of FIR filter and compared it with the direct form results. Some tips regarding power consumption were deduced for the polyphase implementation form. The aim of this work is to help a system designer to select an efficient implementation for FIR in terms of power consumption without having to implement and synthesize the different possible solutions. The proposed method is applied for STMicroelectronics libraries 90 nm and 65 nm low power then validated with a use case of multistandard receiver designing.

  8. 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.

  9. Active Power

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    ActivePower,Inc.(NASDAQ股票代号:ACPW)成立于1992年,是一家久负盛誉的不间断电源解决方案供应商。Active Power凭借其卓越的飞轮储能技术,Cleansouce UPS系统和全系列的电源解决方案,为客户提供高效,可靠且环保的电源系统,以确保在发生电源波动时实现业务连续。

  10. 混合有源滤波在直流磁铁电源整流装置中的应用%Application of Hybrid Active Filter in DC Magnet Power Supply Rectifying Devices

    Institute of Scientific and Technical Information of China (English)

    庞科旺; 瞿盛; 耿璜; 马华峰

    2012-01-01

    针对直流磁铁电源的并联12脉波整流电路进行分析,而12脉波整流装置产生的主要特征谐波由无源滤波器滤除,有源部分使用注入式电路,以抑制无源支路和电网等效电感产生的谐振现象并可以显著降低有源装置的容量。而针对瞬时无功功率理论的不足,谐波电流检测采取了实时性更好的单位功率因数法(UPF)。最后对整个整流装置和串联谐振注入式混合有源滤波装置进行了simulink仿真,仿真结果表明了该磁铁电源的综合补偿系统的可行性和有效性。%The parallel 12-pulse rectifying circuit of DC magnet power supply was analyzed. The passive filter can filter main characteristic harmonic generated from 12-pulse rectifying devices, the active filter part adopts the injection type topology to suppress the resonance between the passive branch and the equivalent inductance power grid and reduce the capacity of the active devices significantly. Aiming at the deficiency of instantaneous reactive power theory, a better real-time characteristic unity power factor approach CUPF) for harmonic current detection technique was adopted. At last, rectifying devices and series resonance hybrid active filter devices with injection circuit were simulated by Simulink, the simulation results indicate feasibility and validity of the magnet power supply integrated compensation system.

  11. Low-power adaptive filter based on RNS components

    DEFF Research Database (Denmark)

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

    2007-01-01

    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......In this paper a low-power implementation of an adaptive FIR filter is presented. The filter is designed to meet the constraints of channel equalization for fixed wireless communications that typically requires a large number of taps, but a serial updating of the filter coefficients, based on the...

  12. 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.

  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. 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......, cannot be neglected any longer. In this work, we take advantage of the properties of the Residue Number System (RNS) to implement FIR filters with reduced static and dynamic power consumption. The results show that the RNS filters offer a reduction of 50% in static power dissipation and a total power...

  16. Robust Light Filters Support Powerful Imaging Devices

    Science.gov (United States)

    2009-01-01

    Infrared (IR) light filters developed by Lake Shore Cryotronics Inc. of Westerville, Ohio -- using SBIR funding from NASA s Jet Propulsion Laboratory and Langley Research Center -- employ porous silicon and metal mesh technology to provide optical filtration even at the ultra-low temperatures required by many IR sensors. With applications in the astronomy community, Lake Shore s SBIR-developed filters are also promising tools for use in terahertz imaging, the next wave of technology for applications like medical imaging, the study of fragile artworks, and airport security.

  17. 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。

  18. 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

    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...... filter and three modifications of a bag-type fiberglass combination filter: the "Heavy" corresponded to a commercially available filter containing 400 g of carbon per square meter of filter area, the "Medium" contained half as much carbon (200 g/m(2)), and the "Light" contained a quarter as much carbon...

  19. 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. .

  20. 有源补偿同相供电系统牵引变压器接线方式选择%Optimal Selection of Traction Transformer in Cophase Power Supply System Based on Active Power Filter

    Institute of Scientific and Technical Information of China (English)

    吕晓琴; 张秀峰; 章春军; 方华

    2013-01-01

    The minimum capacity of compensation device in cophase power supply system based on active power filter has no relation with transformer connection, so using normal connection is significant. Under cophase power supply systems with YN, d11, V, v, and Scott transformer, this paper analyzes based on balance compensation principle that the capacity demands have relations with negative and reactive compensation degree, power factor angle, connection angle of load, and phase shift angel. Choosing right transformer connection from the curves between capacity efficiency and negative compensation degree under assigned reactive compensation degree can get the best economic indicator. Finally, with the simulations, it is shown that no matter which transformer is chosen, theoptimal selection can get right compensation characteristics with better control methods.%  有源补偿同相牵引供电系统,所需补偿装置最小容量与变压器接线方式无关,采用常规接线变压器具有一定的工程意义。利用平衡补偿原理,分析出YN,d11、V, v和Scott常规接线构成的同相供电系统变压器容量需求与负序和无功补偿度、负荷功率因数角、负荷接线角以及变压器移相角有关。通过在指定无功补偿度下,变压器容量利用率与负序补偿度关系曲线,选择合适的接线方式,使其具备最佳经济指标;通过系统仿真波形,验证在正确的控制方法下,无论采用何种常规接线变压器,均能得到较好的补偿特性。

  1. 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.

  2. 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

  3. Condition monitoring of power plants using extended Kalman filtering

    OpenAIRE

    Øyvin Skarstein

    1988-01-01

    Extended Kalman Filtering (EKF) is applied to the condition monitoring of hydro-power production plants. This method is well suited to real-time failure detection and identification. This paper presents one important application: monitoring of hydraulic performance of hydro-power plants.

  4. 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.

  5. 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.

  6. Harmonic Reduction System Using Active Filter

    Directory of Open Access Journals (Sweden)

    Pallavi B.Endait

    2016-06-01

    Full Text Available This paper presents the harmonics analysis and compensation which occurred in the electrical system. We use the electrical signal analysis based on FFT technique in order to calculate harmonics that occurred in the electrical system. The harmonics are compensated by using active harmonic filters. This system consists of a computer which works as controller, processor, analysis, monitor and database unit together with a microcontroller which has A/D converter is used for sampling the electrical signals via a parallel port of the computer. The active harmonic filters (IGBT Module are controlled by PWM (Pulse Width Modulation signal from the microcontroller. The PWM data (Switching angle is programmed by computer. The data such as voltages, currents, the total harmonic distortion etc., can be saved as database for analysis. The harmonics compensation increase high efficiency of the electrical system and decrease the damage and incorrect operation that may happen with electrical devices.

  7. Trends in active power line conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Akagi, Hirofumi (Okayama Univ. (Japan). Dept. of Electrical Engineering)

    1994-05-01

    Active power line conditioners, which are classified into shunt and series ones, have been studied with the focus on their practical installation in industrial power systems. In 1986, a combined system of a shunt active conditioner of rating 900 kVA and a shunt passive filter of rating 6,600 kVA was practically installed to suppress the harmonics produced by a large capacity cycloconverter for steel mill drives. More than one hundred shunt active conditioners have been operating properly in Japan. The largest one is 10 mVA, which was developed for flicker compensation for an arc furnace with the help of a shunt passive filter of 20 mVA. In this paper, the term of ''active power line conditioners'' would be used instead of that of ''active power filters'' because active power line conditioners would cover a wider sense than active power filters. The primary intent of this paper is to present trends in active power line conditioners using PWM inverters, paying attention to practical applications.

  8. Power and Aging Characterization of Digital FIR Filters Architectures

    DEFF Research Database (Denmark)

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

    2012-01-01

    -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......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...... with respect to throughput, area, power dissipation and aging. The exploration is intended to provide new design guidelines when considering aging of components in power/performance tradeoffs....

  9. Application of neural-fuzzy control-based active power filters in electric propulsion ships%神经模糊控制APF在电力推进船舶中的应用

    Institute of Scientific and Technical Information of China (English)

    刘培哲; 赵红; 郭晨

    2013-01-01

    采用有源电力滤波器(APF)进行谐波抑制与无功补偿,提出一种基于混合神经模糊控制策略的APF,并将之应用到电力推进船舶中.仿真实验结果表明,本文提出的APF较常规APF具有更好的谐波抑制效果,直流侧电压等动态性能更佳.%Active power filter (APF) is introduced to suppress harmonics and compensate reactive power. And a hybrid neural-fuzzy based on APF is proposed and applied in an electric propulsion ship. Simulation results show that the proposed APF has better performance in harmonics suppression and dynamic DC voltage comparing with conventional APFs.

  10. 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.

  11. Digital notch filter based active damping for LCL filters

    DEFF Research Database (Denmark)

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

    2015-01-01

    LCL filters are widely used in Pulse Width Modulation (PWM) inverters. However, it also introduces a pair of unstable resonant poles that may challenge the controller stability. The passive damping is a convenient possibility to tackle the resonance problem at the cost of system overall efficienc...

  12. Aggregated wind power generation probabilistic forecasting based on particle filter

    International Nuclear Information System (INIS)

    Highlights: • A new method for probabilistic forecasting of aggregated wind power generation. • A dynamic system is established based on a numerical weather prediction model. • The new method handles the non-Gaussian and time-varying wind power uncertainties. • Particle filter is applied to forecast predictive densities of wind generation. - Abstract: Probability distribution of aggregated wind power generation in a region is one of important issues for power system daily operation. This paper presents a novel method to forecast the predictive densities of the aggregated wind power generation from several geographically distributed wind farms, considering the non-Gaussian and non-stationary characteristics in wind power uncertainties. Based on a mesoscale numerical weather prediction model, a dynamic system is established to formulate the relationship between the atmospheric and near-surface wind fields of geographically distributed wind farms. A recursively backtracking framework based on the particle filter is applied to estimate the atmospheric state with the near-surface wind power generation measurements, and to forecast the possible samples of the aggregated wind power generation. The predictive densities of the aggregated wind power generation are then estimated based on these predicted samples by a kernel density estimator. In case studies, the new method presented is tested on a 9 wind farms system in Midwestern United States. The testing results that the new method can provide competitive interval forecasts for the aggregated wind power generation with conventional statistical based models, which validates the effectiveness of the new method

  13. Methods for in-place testing of HEPA and iodine filters used in nuclear power plants

    International Nuclear Information System (INIS)

    The purpose of this work was a general investigation of existing in-place test methods and to build an equipment for in-place testing of HEPA and iodine sorption filters. In this work the discussion is limited to methods used in in-place testing of HEPA and iodine sorption filters used in light-water-cooled reactor plants. Dealy systems, built for the separation of noble gases, and testing of them is not discussed in the work. Contaminants present in the air of a reactor containment can roughly be diveded into three groups: aerosols, reactive gases, and noble gases. The aerosols are filtered with HEPA (High Efficiency Particulate Air) filters. The most important reactive gases are molecular iodine and its two compounds: hydrogen iodide and methyl iodide. Of gases to be removed by the filters methyl iodide is the gas most difficult to remove especially at high relative humidities. Impregnated activated charcoal is generally used as sorption material in the iodine filters. Experience gained from the use of nuclear power plants proves that the function of high efficiency air filter systems can not be considered safe until this is proved by in-place tests. In-place tests in use are basically equal. A known test agent is injected upstream of the filter to be tested. The efficiency is calculated from air samples taken from both sides of the filter. (author)

  14. 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。

  15. 基于单周控制和ip-iq检测法的有源电力滤波器研究%Research of active power filter based on one-cycle control and ip-iq detection method

    Institute of Scientific and Technical Information of China (English)

    康增尚; 李岚

    2013-01-01

    针对基于单周控制的有源电力滤波器只能同时补偿谐波和无功分量的问题,提出了一种基于单周控制和ip-iq检测法的有源电力滤波器的设计方案.ip-iq检测法检测出的含有谐波或无功分量或两者皆有的基波分量作为单周控制器的参考信号,电源电流信号作为单周控制器的输入信号,这2个信号通过单周控制器生成补偿电流,从而实现单独补偿谐波或同时补偿谐波和无功分量的目的.仿真与实验结果验证了该方案的可行性.%In view of problem that active power filter based on one-cycle control can only compensate harmonic and reactive component simultaneously,a design scheme of active power filter based on one-cycle control and ip-iq detection method was proposed.Fundamental components including harmonic or reactive component or the both detected by ip-iq detection method are took as reference signal of one-cycle controller,signal of power current is took as input signal of one-cycle controller.The two signals generate compensation current through one-cycle controller,so as to realize the purpose of compensating harmonic individually or compensating harmonic and reactive component simultaneously.The simulation and experiment results validate feasibility of the scheme.

  16. 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

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

    DEFF Research Database (Denmark)

    Khodaparast, Jalal; Silva, Filipe Miguel Faria da; Bak, Claus Leth;

    2016-01-01

    capability of Kalman Filter. The proposed in- dex is calculated by assessing the dierence between predicted and actual samples of impedance. The predicted impedance samples are obtained using Kalman lter and Taylor expansion, which is used in this paper to track the phasor precisely. Second or- der of Taylor...... expansion is used to decrease corrugation eect of impedance estimation and increase the reliability of proposed method. The instantaneous estimation and pre- diction capability of Kalman lter are two reasons for proposing utilizing Kalman lter. Intensive studies have been performed and the merit...... of the method is demonstrated by test simulations. Keywords: Kalman Filter, Power Swing, Dynamic Phasor, Symmetrical Fault....

  18. 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.

  19. 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....

  20. Transformerless Inverter for Single-Phase Photovoltaic Systems with Active Power Filter%具有有源滤波功能的单相无变压器光伏并网系统

    Institute of Scientific and Technical Information of China (English)

    陈兆岭; 杨兆银; 刘国海; 廖志凌; 刘慧

    2012-01-01

    For low-power grid-connected applications; a single-phase active power filter based on a double-stage grid-connected photovoltaic system without transformer is proposed in this paper; which can not only inject photovoltaic (PV) power into utility but can always act as an active power filter to compensate the load harmonics and reactive power. In PV applications; it is possible to remove the transformer in the inverter to reduce losses; costs and size; however; which will bring in some safety issues caused by the stray capacitance between the PV panels and ground. Dangerous common-mode current (also called leakage current) generated by varying common-mode voltage will inject into ground through the parasitic capacitance. H5 topology inverter that generates no varying common-mode voltage has been used in this paper. The feasibility of control strategy and system topology is verified by the simulation and experimental results.%针对小功率光伏并网系统,提出了一种基于两级式无变压器光伏并网系统,具有单相有源滤波功能.该系统不仅能将有功功率注入到电网,而且能起到有源滤波器的作用消除非线性负载产生的谐波和无功.在光伏系统中去除变压器结构可以有效地减少损耗,降低成本,缩小体积.但是由于在太阳能电池阵列和地之间存在寄生电容,变化的共模电压产生的共模电流(也称漏电流)将会通过虚拟的寄生电容流入大地,给人身安全带来威胁.本系统采用不会产生变化的共模电压的H5拓扑结构.仿真和实验结果证明了本文控制方法和拓扑结构的可行性.

  1. 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

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

    DEFF Research Database (Denmark)

    Nielsen, Lars Skovby; Sparsø, Jens

    1999-01-01

    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...... 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...

  3. Improving Industrial Energy Quality by an Active Current Filter

    OpenAIRE

    Reyes–Trujillo E; Rodríguez–Rivas J.J; Robles–García J.

    2010-01-01

    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 ...

  4. Multilevel Inverter for Grid-Connected Photovoltaic Systems with Active Filtering Function

    OpenAIRE

    Oliveira, Kleber,; Afonso, João,; Cavalcanti, Marcelo,

    2013-01-01

    Part 11: Integration of Power Electronics Systems with ICT - I; International audience; This paper presents a single-phase inverter with multilevel topology adopted to interface photovoltaic systems with the electrical power grid, and at the same time, to eliminate harmonics currents and to compensate reactive power, operating as shunt active power filter. Multilevel inverters have been attracting increasing attention in the past few years as power converters of choice in high voltage and hig...

  5. 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....

  6. 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 ...

  7. 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

    with unknown grid impedance at high frequency, simplify the model of the filter, and provide repetitive measurements. In this paper, all the filter parameters are derived with analyzing the behavior of the converter at high frequency with presence of LISN impedance. The minimum required filter capacitor......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...... for filter. By introducing of fast power switches for PFC applications such as silicon-carbide, major current harmonics around the switching frequency drops in the region that LISN can actively provide well-defined impedance for measuring the harmonics (i.e. 9 kHz- 30MHz). Therefore, LISN can be replaced...

  8. Estimating Power System Dynamic States Using Extended Kalman Filter

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhenyu; Schneider, Kevin P.; Nieplocha, Jaroslaw; Zhou, Ning

    2014-10-31

    Abstract—The state estimation tools which are currently deployed in power system control rooms are based on a steady state assumption. As a result, the suite of operational tools that rely on state estimation results as inputs do not have dynamic information available and their accuracy is compromised. This paper investigates the application of Extended Kalman Filtering techniques for estimating dynamic states in the state estimation process. The new formulated “dynamic state estimation” includes true system dynamics reflected in differential equations, not like previously proposed “dynamic state estimation” which only considers the time-variant snapshots based on steady state modeling. This new dynamic state estimation using Extended Kalman Filter has been successfully tested on a multi-machine system. Sensitivity studies with respect to noise levels, sampling rates, model errors, and parameter errors are presented as well to illustrate the robust performance of the developed dynamic state estimation process.

  9. 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.

  10. 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. PMID:27018144

  11. Suppression of harmonics resonance using active filter in cycloconverter for Maglev

    Energy Technology Data Exchange (ETDEWEB)

    Kaga, Shigeo; Kawaguchi, Ikuo; Ikeda, Haruo [Railway Technical Research Inst., Tokyo (Japan); Ogihara, Yoshiya; Tokuda, Noriaki; Miyata, Toshio [Nissin Electric Co., Ltd, Kyoto (Japan)

    1995-12-31

    A cycloconverter is widely adopted as the VVVF (variable voltage variable frequency) power source because of its stable characteristics. In order to compensate the input reactive power and the input harmonics of the cycloconverter, LC (reactor-capacitor) type AC filter is provided. However, in this system, a harmonic resonance tends to appear. Therefore we have developed a harmonic suppressing system which combines a small capacity active filter and an AC filter. This paper describes the system configuration and the operational principle of the new harmonics suppression system, and the field test results. 3 refs, 8 figs, 1 tab

  12. The invariant of the stiffness filter function with the weight filter function of the power function form

    Institute of Scientific and Technical Information of China (English)

    Zhen Shang; Yun-Kang Sui

    2012-01-01

    Based on the independent,continuous and mapping (ICM) method and homogenization method,a research model is constructed to propose and deduce a theorem and corollary from the invariant between the weight filter function and the corresponding stiffness filter function of the form of power function.The efficiency in searching for optimum solution will be raised via the choice of rational filter functions,so the above mentioned results are very important to the further study of structural topology optimization.

  13. 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.

  14. Development of filters and housings for use on active plant

    International Nuclear Information System (INIS)

    New designs of housings for conventional HEPA filters have been developed and are now in use. A further design is planned for future use. The main features to be developed are the engineering of double door systems to replace bag posting and other methods of filter changing which expose personnel to hazardous environments and the addition of a secondary containment to reduce the role of the gasket seal in the filtration efficiency. Also under development are circular geometry filters of HEPA standard which offer significant advantages over rectangular filters for applications requiring remote shielded change facilities. Two types of filter construction are being evaluated, conventional radial flow cartridge filters and spiral-wound, axial-flow filters. The application of circular filters for primary filter systems on active plant is in hand. A push-through change system has been developed for a new cell facility under construction at Harwell. Existing rectangular filters on a high activity cell are being replaced with clusters of small cartridge filters to overcome changing and disposal problems. A similar system but using 1700 m3/h filters for large volume off-gas treatment is also being studied. A remote change shielded filter installation is being developed for use in high alpha, beta, gamma extract systems. The design incorporates large cartridge filters in sealed drums with remote transfer and connection to duct work in the facility. A novel application of the use of double-lid technology removes the need for separate shut off dampers and enables the drums to be sealed for all transfer operations

  15. Comparison of the Extended Kalman Filter and the Unscented Kalman Filter for Magnetocardiography activation time imaging

    OpenAIRE

    Ahrens, H.; F. Argin; L. Klinkenbusch

    2013-01-01

    The non-invasive and radiation-free imaging of the electrical activity of the heart with Electrocardiography (ECG) or Magnetocardiography (MCG) can be helpful for physicians for instance in the localization of the origin of cardiac arrhythmia. In this paper we compare two Kalman Filter algorithms for the solution of a nonlinear state-space model and for the subsequent imaging of the activation/depolarization times of the heart muscle: the Extended Kalman Filter (EKF) and the...

  16. 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.

  17. 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.

  18. 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....

  19. 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...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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......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...... make itself fail to damp the resonance. Specifically, the phase lag can make the current control stable despite of the resonant frequency drifting, when the grid current is fed back. In contrast, in the case of an inverter current feedback control, the influence of the phase lead or lag on the active...

  1. 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 ...

  2. 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

    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...... 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...

  3. 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.

  4. 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。

  5. Active filter solutions in energy systems

    OpenAIRE

    RÜSTEMLİ, SABİR; CENGİZ, MEHMET SAİT

    2015-01-01

    Recent developments in power electronics have increased the usage of nonlinear loads in energy systems. With increases in the usage of semiconductor-sourced nonlinear loads, the adverse effects of harmonics-sensitive loads (e.g., protection control circuits and circuit breakers) have also increased. Generally, the negative effects of harmonics in power systems include the following: increased power losses; motor, generator, and transformer overheating; faulty operation of measurement and prot...

  6. 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。

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

    OpenAIRE

    Blaabjerg, Frede; Teodorescu, Remus; RODRIGUEZ, Pedro; Candela, Ignacio; Luna, Alvaro

    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, with two different and simultaneous resonance frequencies and sequences, is achieved -one frequency for positive-/negative- sequence and another one for zero-sequence components. This filter topology...

  8. Miniaturisation of combline filters for switched-mode power amplifier systems

    Directory of Open Access Journals (Sweden)

    E. Serebryakova

    2008-05-01

    Full Text Available This paper presents a coaxial combline filter for a class-S power amplifier for an operating frequency of 450 MHz. According to the measurement results, the filter provides a bandwidth of 26 MHz, an insertion loss of 0.55 dB, and a second pass-band only at 2.8 GHz. As the filter dimensions are crucial for the envisaged application, different ways to miniaturise the filter are proposed and their features and disadvantages discussed.

  9. 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....

  10. Active power compensator of the current harmonics based on the instantaneous power theory

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2005-12-01

    Full Text Available The quality of the electrical current becomes a major concern. The proliferation of the power electronic converters, which are used extensively to control electrical apparatus in industrial and commercial applications (dc and ac variable speed motor drives, induction furnaces, power line conditioners, and industrial power supplies, is at the origin of the AC current distribution network pollution and the reactive power demand. These power electronic converters typically draw non-sinusoidal currents from the utility, causing interference with adjacent sensitive loads and limit the utilization of the available electrical supply. The quality of the electrical current thus becomes a significant concern for the distributors of energy and their customers. Recent progress as regards technology of the power electronics brings a capacity of compensation and correction of the harmonic distortion generated by the nonlinear loads. In this paper a parallel active filter prototype capable of reducing the total harmonic distortion in the supply for most current source or adjustable speed drive type loads is presented. A 33 kVA active power filter was developed for harmonic and reactive power compensation based on the instantaneous power theory. The active filter configuration requires the measurement of both the load and filter currents. Experimental results from a prototype active power filter confirm the suitability of the proposed approach. The actual 33kVA prototype converter has been built and tested in the SIEI S.p.A. (Italy laboratory under the Marie Curie Post Doctoral research. The active power compensator is controlled by a high performance DSP platform, resulting in the following active filter features: source current reduction up to the 25th harmonic, 10% THD achievable for current source type loads, efficiency above 97%, does not cause resonance with other loads, operation in the presence of unbalanced loads, reactive power and harmonics

  11. 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.

  12. Optimal Recursive Digital Filters for Active Bending Stabilization

    Science.gov (United States)

    Orr, Jeb S.

    2013-01-01

    In the design of flight control systems for large flexible boosters, it is common practice to utilize active feedback control of the first lateral structural bending mode so as to suppress transients and reduce gust loading. Typically, active stabilization or phase stabilization is achieved by carefully shaping the loop transfer function in the frequency domain via the use of compensating filters combined with the frequency response characteristics of the nozzle/actuator system. In this paper we present a new approach for parameterizing and determining optimal low-order recursive linear digital filters so as to satisfy phase shaping constraints for bending and sloshing dynamics while simultaneously maximizing attenuation in other frequency bands of interest, e.g. near higher frequency parasitic structural modes. By parameterizing the filter directly in the z-plane with certain restrictions, the search space of candidate filter designs that satisfy the constraints is restricted to stable, minimum phase recursive low-pass filters with well-conditioned coefficients. Combined with optimal output feedback blending from multiple rate gyros, the present approach enables rapid and robust parametrization of autopilot bending filters to attain flight control performance objectives. Numerical results are presented that illustrate the application of the present technique to the development of rate gyro filters for an exploration-class multi-engined space launch vehicle.

  13. 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......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 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....

  14. A new hysteresis band current control technique for a shunt active filter

    OpenAIRE

    KALE, MURAT; ÖZDEMİR, ENGİN

    2015-01-01

    This paper proposes a hysteresis band (HB) current control technique to reduce the power losses in a shunt active filter. During a switching period in the zero-crossing region, the inverter output current flows through a transistor. By changing the direction, it flows through the free-wheeling diode of the same switch in an inverter leg, or vice versa. The shunt active filter current typically has 6 zero-crossing regions during a fundamental frequency cycle. This paper presents a HB current c...

  15. 并联有源电力滤波器空间矢量电流控制新方法%Space vector current control of shunt active power filter

    Institute of Scientific and Technical Information of China (English)

    赵伟; 王文; 肖勇; 孟金岭; 李洲; 罗安

    2013-01-01

    基于电压空间矢量分析原理,提出一种适用于并联型有源电力滤波器的电流控制方法.揭示了参考电流优化跟踪策略,该策略能保证在单个开关周期内,使误差电流矢量的幅值以最快的速度逼近于零,从而实现参考电流的快速跟踪.基于参考电流优化跟踪策略,在充分考虑逆变器的实际电压输出能力的情况下,对逆变器输出电压矢量进行精确计算,并通过在单位开关周期内输出多个基本电压矢量的方法合成该矢量,以保证误差电流微分矢量同时具有最优方向和最大幅值,从而在快速跟踪指令电流的同时,不会造成逆变器不可控,提高控制系统的快速性和可靠性.实验结果验证了所提方法的有效性.%A current control method based on the theory of voltage space vector analysis is proposed for SAPF(Shunt Active Power Filter).The optimal tracking of reference current is introduced,which ensures the amplitude of error current vector swiftly approaching to zero within a switching period.With full consideration of the actual voltage output capability,the output voltage vector of inverter is accurately calculated and composed by outputting multiple basic voltage vectors within a switching period,which ensures the differential of error current vector has the best direction and the largest amplitude.Therefore,the reference current is thus quickly followed while the inverter is controllable and the rapidness and reliability of control system are enhanced.Experimental results show the validity of the proposed control method.

  16. 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.

  17. 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。

  18. A Novel Microwave Tunable Band-Pass Filter Integrated Power Divider Based on Liquid Crystal

    OpenAIRE

    Yupeng Liu; Di Jiang; Lei Xia; Ruimin Xu

    2015-01-01

    This paper proposes a novel microwave continuous adjustable band-pass filter integrated power divider based on nematic liquid crystals (LCs). The proposed power divider uses liquid crystal (LC) as the dielectric material. It can realize phase shift by changing the dielectric anisotropy, when biasing the high anisotropy nematic liquid crystal. It is mainly used in microwave frequencies. It has a large number of advantages compared to conventional filter integrated power divider, such as low lo...

  19. Spatial Filter with Volume Gratings for High-peak-power Multistage Laser Amplifiers

    CERN Document Server

    Tan, Yi-zhou; Zheng, Guang-wei; Shen, Ben-jian; Pan, Heng-yue; Li, Liu

    2012-01-01

    The regular spatial filters comprised of lens and pinhole are essential component in high power laser systems, such as lasers for inertial confinement fusion, nonlinear optical technology and directed-energy weapon. On the other hand the pinhole is treated as a bottleneck of high power laser due to harmful plasma created by the focusing beam. In this paper we present a spatial filter based on angular selectivity of Bragg diffraction grating to avoid the harmful focusing effect in the traditional pinhole filter. A spatial filter consisted of volume phase gratings in two-pass amplifier cavity were reported. Two-dimensional filter was proposed by using single Pi-phase-shifted Bragg grating, numerical simulation results shown that its angular spectrum bandwidth can be less than 160urad. The angular selectivity of photo-thermo-refractive glass and RUGATE film filters, construction stability, thermal stability and the effects of misalignments of gratings on the diffraction efficiencies under high-pulse-energy laser...

  20. A multi-standard active-RC filter with accurate tuning system

    Energy Technology Data Exchange (ETDEWEB)

    Ma Heping; Yuan Fang; Shi Yin [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Dai, F F, E-mail: hpma@semi.ac.c [Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849-5201 (United States)

    2009-09-15

    A low-power, highly linear, multi-standard, active-RC filter with an accurate and novel tuning architecture is presented. It exhibits IEEE 802.11 a/b/g (9.5 MHz) and DVB-H (3 MHz, 4 MHz) application. The filter exploits digitally-controlled polysilicon resistor banks and a phase lock loop type automatic tuning system. The novel and complex automatic frequency calibration scheme provides better than 4 corner frequency accuracy, and it can be powered down after calibration to save power and avoid digital signal interference. The filter achieves OIP3 of 26 dBm and the measured group delay variation of the receiver filter is 50 ns (WLAN mode). Its dissipation is 3.4 mA in RX mode and 2.3 mA (only for one path) in TX mode from a 2.85 V supply. The dissipation of calibration consumes 2 mA. The circuit has been fabricated in a 0.35 {mu}m 47 GHz SiGe BiCMOS technology; the receiver and transmitter filter occupy 0.21 mm{sup 2} and 0.11 mm{sup 2} (calibration circuit excluded), respectively.

  1. Grid Connected Wind Energy Conversions System Performance is Improved by Switching of Shunt Active Filter

    Directory of Open Access Journals (Sweden)

    B.Vaikundaselvan

    2014-05-01

    Full Text Available This study presents a Grid connected Wind Energy Conversions System (WECS where performance is improved by switching of Shunt Active Filter. Shunt active filter for non linear loads is designed to minimize the harmonics present in the wind power system. Due to large penetration of power electronic controllers in the wind power applications, switching of these power electronic circuits induces harmonics in the source which causes undesirable effects on the wind energy conversion systems and the electrical components which is in the power system network. Shunt active filter is a harmonic mitigating device comprising of voltage source inverter fed through a DC capacitor. The control strategy is based on extraction of harmonics using synchronous reference frame theory. The major contributions of this study is to extract harmonics from the grid connected Wind Energy Conversion Systems (WECS by generating the PWM signals using the Space Vector Pulse Width Modulation (SVPWM to control the Voltage Source Inverter (VSI which has reduced the losses. The proposed method has been simulated and validated using MATLAB/SIMULINK. The end result of the proposed system shows that the Total Harmonic Distortion (THD of the grid connected wind generator has been reduced at the Point of Common Coupling (PCC.

  2. Voltage harmonics mitigation through hybrid active power filer

    International Nuclear Information System (INIS)

    Fast dynamic response, high efficiency, low cost and small size of power electronic converters have exponentially increased their use in modern power system which resulted in harmonically distorted voltage and currents. Voltage harmonics mainly caused by current harmonics are more dangerous as performance and expected operating life of other power system equipment are affected by harmonically distorted supply voltage. Electronic filter circuits are used to improve system power quality by mitigating adverse effects of harmonics. Hybrid filters having advantages of both passive and active filters are preferred to resolve the problem of harmonics efficiently and avoiding any chance of resonance. In this paper, a three phase three wire network is considered to supply an adjustable speed drive represented by a resistive load connected across a three phase bridge rectifier. Simulation of the considered system shows THD (Total Harmonic Distortion) of 18.91 and 7.61 percentage in supply current and voltage respectively. A HAPF (Hybrid Active Power Filter) is proposed to reduce these THD values below 5 percentage as recommended by IEEE Standard-519. P-Q theorem is used to calculate required parameters for proposed filter, which is implemented through hysteresis control. Simulation results confirm the effectiveness of the designed filter as THD for both current and voltage have reduced below allowable limit of 5 percentage. (author)

  3. Proposal of Switching Power Amplifier Using Small Capacity Linear Amplifier and LC Filter

    Science.gov (United States)

    Kamada, Jo; Funato, Hirohito; Ogasawara, Satoshi

    The higher efficiency and the low noise in output voltage and current has been required in some applications, i.e. audio-video equipment, medical equipment and so on. This paper proposes a power amplifier in which a PWM inverter is used as a main circuit. In the proposed power amplifier, a hybrid filter composed of a simple and general LC filter and a small capacity linear amplifier is connected to the output of the inverter. The linear amplifier is inserted in series to the filter capacitor to improve the filtering effect of the LC filter. Switching ripples and LC resonances are considerably suppressed by controlling the amplifier using the proposed method and a low distortion switching power amplifier is realized. The effects of the proposal circuit are verified by simulations and experiments. As a result, the proposed circuit achieves low noise about THD=0.68% in simulation and THD=1.7% in experiment.

  4. Accuracy of telemetry signal power loss in a filter as an estimate for telemetry degradation

    Science.gov (United States)

    Koerner, M. A.

    1989-01-01

    When telemetry data is transmitted through a communication link, some degradation in telemetry performance occurs as a result of the imperfect frequency response of the channel. The term telemetry degradation as used here is the increase in received signal power required to offset this filtering. The usual approach to assessing this degradation is to assume that it is equal to the signal power loss in the filtering, which is easily calculated. However, this approach neglects the effects of the nonlinear phase response of the filter, the effect of any reduction of the receiving system noise due to the filter, and intersymbol interference. Here, an exact calculation of the telemetry degradation, which includes all of the above effects, is compared with the signal power loss calculation for RF filtering of NRZ data on a carrier. The signal power loss calculation is found to be a reasonable approximation when the filter follows the point at which the receiving system noise is introduced, especially if the signal power loss is less than 0.5 dB. The signal power loss approximation is less valid when the receiving system noise is not filtered.

  5. Activated sludge filterability and full-scale membrane bioreactor operation

    NARCIS (Netherlands)

    Krzeminski, P.

    2013-01-01

    Despite continuous developments in the field of MBR technology, membrane fouling together with the associated energy demand and related costs issues remain major challenges. The efficiency of the filtration process in an MBR is governed by the activated sludge filterability, which is still limitedly

  6. 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).

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

    International Nuclear Information System (INIS)

    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).

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

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Ivan A.; Saveliev, Alexei V.; Rasipuram, Srinivasan; Kuznetsov, Andrey V.; Brown, Alan; Jasper, Warren [Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Textile Engineering Chemistry and Science, North Carolina State University, Raleigh, NC 27695 (United States)

    2012-05-15

    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).

  9. Power enhancement with super-Gaussian sliding-frequency guiding filters

    International Nuclear Information System (INIS)

    I show with numerical simulations that higher-order sliding filters, especially super-Gaussian filters, can produce dramatic power enhancement of optical solitons, similar to that of dispersion-managed solitons. This approach should allow smaller timing jitter without sacrificing the signal-to-noise ratio. copyright 1998 Optical Society of America

  10. An active damping method based on biquad digital filter for parallel grid-interfacing inverters with LCL filters

    DEFF Research Database (Denmark)

    Lu, Xiaonan; Sun, Kai; Huang, Lipei;

    2014-01-01

    With the increasing penetration of renewable energy sources into modern power system, power electronic converters are commonly employed as the interface to the utility grid nowadays. During the operation of the interfacing converters, LCL-filters are usually used in order to reduce the harmonics...... with parallel interfacing inverters, the resonance analysis should be expanded due to the parallel configuration of the LCL-filters. In this paper, the resonance phenomenon of the renewable energy system with multiple LCL-filters is studied. The frequency domain characteristics of the parallel LCL...

  11. 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.

  12. 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.

  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. 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...... arise in the current control loop if the present resonance is not properly damped. Passive damping simply adds resistors in series with the LCL-filter capacitors. This simplicity is at the expense of increased losses and encumbrances. Active damping modifies the control algorithm to attain stability...

  15. 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

    The main purpose of power swing blocking is to distinguish faults from power swings. However, faults occurred during a power swing should still be detected and cleared promptly. This paper proposes an index based on detecting abrupt jump of impedance trajectory by utilization of predicting capabi...

  16. A numerical design approach for single amplifier, Active-RC Butterworth filter of order 5

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    2007-01-01

    A design method is presented for the design of all pole lowpass active-RC filters applying operational amplifiers. The operational amplifier model used is the integrator model: omegat/s where omegat is the unity gain frequency. The design method is used for the design of a fifth order Butterworth...... filter applying just one operational amplifier coupled as a unity gain amplifier. It is shown that the influence from the real operational amplifier may be reduced by trimming just one resistor in the circuit. The unity gain amplifiers have the advantage of providing low power consumption, yielding...... a large dynamic range, sometimes simplifying the amplifier design and being usable over a larger frequency range than conventional constant gain amplifiers. The Schoeffler sensitivity index is used as a basis for a sensitivity comparison with other similar filters reported in the literature. © 2007 IEEE....

  17. Hormonal activity, cytotoxicity and developmental toxicity of UV filters.

    Science.gov (United States)

    Balázs, Adrienn; Krifaton, Csilla; Orosz, Ivett; Szoboszlay, Sándor; Kovács, Róbert; Csenki, Zsolt; Urbányi, Béla; Kriszt, Balázs

    2016-09-01

    Ultraviolet (UV) filters are commonly used compounds in personal care products and polymer based materials, as they can absorb solar energy in the UVA and UVB spectrum. However, they are able to bind to hormone receptors and have several and different types of hormonal activities determined by in vitro assays. One of the aims of this work was to measure the hormonal and cytotoxic activities of four frequently used UV filters using bioluminescence based yeast test organisms. Using Saccharomyces cerevisiae BLYES and BLYAS strains allowed the rapid and reliable detection of agonist and antagonist hormonal activities, whereas BLYR strain served to measure cytotoxicity. Results confirmed that all tested UV filters show multiple hormonal activities. Cytotoxicity is detected only in the case of benzophenone-3. Research data on the toxic effects of benzophenone-3, especially on aquatic organisms are scarce, so further investigations were carried out regarding its cytotoxic and teratogenic effects on bacteria and zebrafish (Danio rerio) embryos, respectively. Results revealed the cytotoxicity of benzophenone-3 not only to yeasts but to bacteria, as well as its ability to influence zebrafish embryo hatching and development. PMID:27208882

  18. HARMONIC CURRENT COMPENSATION IN SELF EXCITED INDUCTION GENERATOR USING ACTIVE FILTER

    OpenAIRE

    K, Premalatha

    2015-01-01

    The Self-Excited Induction Generator (SEIG) is more suitable for wind energy conversion systems in remotely located areas. The system consists of squirrel cage induction machine coupled with wind turbine through a gear box, Voltage Source Converter (VSC) as active power filter, fixed capacitor bank and diode rectifier with RL load.  SEIG feeding nonlinear load causes current harmonics in the generator current. This paper focuses on minimizing the current harmonics to some extent using shunt A...

  19. A New Method of Filter Control Management for Power Reduce In a Stand-Alone WECS

    Directory of Open Access Journals (Sweden)

    Milad Askari Hashemabadi,

    2014-02-01

    Full Text Available In this paper, a novel sinusoidal PWM Switched Power Filter (SPF and Dynamic Voltage Compensation (DVC scheme using VSC/SMC/B-B controller for power mitigation and quality enhancements in medium power distribution networks are simulated and run. The system is based upon a standalone Wind Energy Conversion Scheme (WECS using an induction generator and the proposed system control mechanisms, which are digitally simulated by using the MATLAB/Simulink/SimPowerSystems software.

  20. A Performance Comparison Between Extended Kalman Filter and Unscented Kalman Filter in Power System 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. There have been several kinds of research in the state estimation approaches which have used different methods to capture dynamic states of the power system. The concept of DSE involves desi...

  1. Activated sludge filterability and full-scale membrane bioreactor operation

    OpenAIRE

    Krzeminski, P.

    2013-01-01

    Despite continuous developments in the field of MBR technology, membrane fouling together with the associated energy demand and related costs issues remain major challenges. The efficiency of the filtration process in an MBR is governed by the activated sludge filterability, which is still limitedly understood and is determined by the interactions between the biomass, the wastewater and the applied process conditions. The purpose of this thesis is to increase understanding of the factors impa...

  2. Design of a Low-Power Universal Gm-C Filter in Sub-Threshold Region

    Directory of Open Access Journals (Sweden)

    Mohammad Aghaei Jeshvaghani

    2013-10-01

    Full Text Available In this paper, a second order universal filter with the ability of electronically tuning central frequency (ω0 and quality factor (Q, based on the inverter as transconductance block which realizes multi-mode responses (voltage, current, transconductance, transresistance in sub-threshold region, is presented. Biasing transistors in sub-threshold region, reduces the power consumption of the proposed filter and the grounded capacitors are used to reduce the parasitic effects which is another advantage of the proposed filter circuit. Furthermore, low sensitivity of the performance of the proposed filter to the values of gmi , Ci is considered as another advantage of the proposed circuit. In addition, realizing the proposed filter based on the inverter circuit leads to a reduced value of layout area as well as power consumption. Finally, the proposed filter performance is simulated in HSPICE using 0.18 µm (LEVEL49 CMOS technology parameters. As it is shown in the paper, the proposed filter consumes only 64.69 nW power in a ±0.3V supply voltage.

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

    Science.gov (United States)

    2013-07-25

    ... Final Rule; FR citation: 67 FR 76908 and the CDC Interim Final Rule 42 CFR Part 73 Possession, Use, and Transfer of Select Agents and Toxins; Interim Final Rule; FR citation: 67 FR 76886, inter alia. Information... SECURITY Agency Information Collection Activities: BioWatch Filter Holder Log, Filter Holder Log DHS...

  4. A Novel Microwave Tunable Band-Pass Filter Integrated Power Divider Based on Liquid Crystal

    Directory of Open Access Journals (Sweden)

    Yupeng Liu

    2015-01-01

    Full Text Available This paper proposes a novel microwave continuous adjustable band-pass filter integrated power divider based on nematic liquid crystals (LCs. The proposed power divider uses liquid crystal (LC as the dielectric material. It can realize phase shift by changing the dielectric anisotropy, when biasing the high anisotropy nematic liquid crystal. It is mainly used in microwave frequencies. It has a large number of advantages compared to conventional filter integrated power divider, such as low loss, multifunction integration, continuous adjustable, miniaturization, low processing costs, low operating voltage, high phase shift, and convenient manufacture. Therefore, it has shown great potential for application.

  5. Peak to Average Power Ratio Reduction in OFDM System by Clipping and Filtering

    Directory of Open Access Journals (Sweden)

    Dr. O.P. Sahu

    2012-05-01

    Full Text Available This paper results clipping and filtering technique for peak to average power ratio (PAPR reduction in orthogonal frequency division multiplexing (OFDM. Our simulation results show that this technique removes inband and out of band distortion along with 1dB reduction in peak to average power ratio when crest ratio changes from 1.4 to 1.2.

  6. 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.

  7. A reconfigurable CBP/LP active RC filter with noise-shaping technique for wireless receivers

    International Nuclear Information System (INIS)

    A reconfigurable complex band-pass (CBP)/low-pass (LP) active-RC filter with a noise-shaping technique for wireless receivers is presented. Its bandwidth is reconfigurable among 500 kHz, 1 MHz and 4 MHz in LP mode and 1 MHz, 2 MHz and 8 MHz in CBP mode with 3 MHz center frequency. The Op-Amps used in the filter are realized in cell arrays in order to obtain scalable power consumption among the different operation modes. Furthermore, the filter can be configured into the 1st order, 2nd order or 3rd order mode, thus achieving a flexible filtering property. The noise-shaping technique is introduced to suppress the flicker noise contribution. The filter has been implemented in 180 nm CMOS and consumes less than 3 mA in the 3rd 8 MHz-bandwidth CBP mode. The spot noise at 100 Hz can be reduced by 14.4 dB at most with the introduced noise-shaping technique. (semiconductor integrated circuits)

  8. Design of a Low-Power Universal Gm-C Filter in Sub-Threshold Region

    OpenAIRE

    Mohammad Aghaei Jeshvaghani; Mehdi Dolatshahi

    2013-01-01

    In this paper, a second order universal filter with the ability of electronically tuning central frequency (ω0) and quality factor (Q), based on the inverter as transconductance block which realizes multi-mode responses (voltage, current, transconductance, transresistance) in sub-threshold region, is presented. Biasing transistors in sub-threshold region, reduces the power consumption of the proposed filter and the grounded capacitors are used to reduce the parasitic effects which is another ...

  9. 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.

  10. 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.

  11. Evaluation of a Kalman filter based power pressurizer instrument failure detection system implemented on a nuclear power plant training simulator

    International Nuclear Information System (INIS)

    The usefulness of a nuclear power plant training simulator for developing and testing modern estimation and control applications for nuclear power plants is demonstrated. A Kalman filter based instrument failure detection technique for a pressurized water reactor pressurizer is implemented on the Department of Energy N Reactor Training Simulator. This real-time failure detection method computes the first two moments (mean and variance) of each element of a normalized filter innovations vector. Failed pressurizer instrumentation can be detected by comparing these moments to the known statistical properties of the steady state, linear Kalman fitler innovations sequence. The capabilities of the detection system are evaluated using simulated plant transients and instrument failures

  12. 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

    by a three-phase active rectifier. However, stability problems can arise in the current control loop. In order to overcome them, a damping resistor can be inserted, at the price of a reduction of efficiency. The use of active damping by means of control may seem attractive, but it is often limited by the use......Active rectifiers/inverters are becoming used more and more often in regenerative systems and distributed power systems. Typically, the interface between the grid and rectifier is either an inductor or an LCL-filter. The use of an LCL-filter mitigates the switching ripple injected in the grid...... or complex calculations. Moreover, in the paper particular attention is devoted to the susceptibility of the systems in a high polluting environment....

  13. Low Power Architecture Design of De-Blocking Filter and Hardware Implementations in H.264/AVC

    Directory of Open Access Journals (Sweden)

    Mrs. T. Priyadarsini

    2014-11-01

    Full Text Available An adaptive in-loop de-blocking filter (DF is standardized in H.264/AVC to reduce blocking artifacts and improve compression efficiency. This paper proposes a low power DF architecture with hybrid and intelligent edge skip filtering order. We further adopt a four-stage pipeline to boost the speed of DF process and the proposed Horizontal Edge Skip Processing Architecture (HESPA offers an edge skip aware mechanism for filtering the horizontal edges that not only reduces power consumption but also reduces the filtering processes down to 100 clock cycles per macro block (MB. In addition, the architecture utilizes the buffers efficiently to store the temporary data without affecting the standard defined data dependency by a reasonable strategy of edge filtering order to enhance the reusability of the intermediate data. The system throughput can then be improved and the power consumption can also be reduced. Simulation results show that more than 34% of logic power measured in FPGA can be saved when the proposed HESPA is enabled. Furthermore, the proposed architecture is implemented on a 0.18μm standard cell library, which consumes 19.8K gates at a clock frequency of 200 MHz, which compares competitively with other state-of-the-art works in terms of hardware cost

  14. A nonlinear neural fir filter with an adaptive activation function

    Directory of Open Access Journals (Sweden)

    Lee Su Goh

    2003-01-01

    Full Text Available An adaptive amplitude normalized nonlinear gradient descent (AANNGD algorithm for the class of nonlinear finite impulse response (FIR adaptive filters (dynamical perception is introduced. This is achieved by making the amplitude of the nonlinear activation function gradient adaptive. The proposed learning algorithm is suitable for processing of nonlinear and nonstationary signals with a large dynamical range, and removes the unwanted effect of saturation nonlinearities. For rigor, sensitivity analysis is performed and the improved performance of the AANNGD algorithm over the standard LMS, NGD, NNGD, the fully adaptive NNGD (FANNGD and the sign algorithm is verified by simulations on nonlinear and nonstationary inputs with large dynamics.

  15. 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.

  16. 76 FR 24504 - Agency Information Collection Activities: BioWatch Filter Holder Log

    Science.gov (United States)

    2011-05-02

    ... SECURITY Agency Information Collection Activities: BioWatch Filter Holder Log AGENCY: Department of... sample analysis. A standard filter log form is completed for each sample and is archived by the BioWatch... of collection and laboratory analysis activities, including the preparation of the filter log...

  17. 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.

  18. Power mapping in a Canada deuterium uranium reactor using Kalman filtering technique

    International Nuclear Information System (INIS)

    For a Canada Deuterium Uranium 600 MWe (CANDU 6) reactor, a new power mapping method has been developed by using detector readings as boundary conditions. In this study, the measured detector readings are combined with the diffusion theory with the Kalman filtering (DIKAL) method. The measured detector readings are transformed into the measured mesh flux through appropriate approximation. And, the difference between calculated and measured mesh flux is filtered out by Kalman filtering technique. Then, the measured mesh fluxes are used as an internal boundary condition in the diffusion equation. The performance of the DIKAL method has been assessed for the various core states, and has been also applied to the calculation of power and flux distribution calculation in the CANDU 6 reactor. Sensitivity studies have shown that DIKAL is quite stable to the detector random noise and systematic errors. Also, it is shown that the DIKAL approach is more accurate than the currently used flux synthesis approach in CANDU 6 reactors. (author)

  19. NEUTRON ACTIVATION ANALYSIS FOR SIMULTANEOUS DETERMINATION OF TRACE ELEMENTS IN AMBIENT AIR COLLECTED ON GLASS-FIBER FILTERS

    Science.gov (United States)

    Arsenic with 25 other elements are simultaneously determined in ambient air samples collected on glass-fiber filter composites at 250 United States sites. The instrumental neutron activation analysis (NAA) technique combined with the power of a dedicated mini-computer resulted in...

  20. 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...

  1. Physical features of accumulation and distribution processes of small disperse coal dust precipitations and absorbed radioactive chemical elements in iodine air filter at nuclear power plant

    CERN Document Server

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

    2012-01-01

    The physical features of absorption process of radioactive chemical elements and their isotopes in the iodine air filters of the type of AU-1500 at the nuclear power plants are researched. It is shown that the non-homogenous spatial distribution of absorbed radioactive chemical elements and their isotopes in the iodine air filter, probed by the gamma-activation analysis method, is well correlated with the spatial distribution of small disperse coal dust precipitations in the iodine air filter. This circumstance points out to an important role by the small disperse coal dust fractions of absorber in the absorption process of radioactive chemical elements and their isotopes in the iodine air filter. The physical origins of characteristic interaction between the radioactive chemical elements and the accumulated small disperse coal dust precipitations in an iodine air filter are considered. The analysis of influence by the researched physical processes on the technical characteristics and functionality of iodine ...

  2. Adaptive RSOV filter using the FELMS algorithm for nonlinear active noise control systems

    Science.gov (United States)

    Zhao, Haiquan; Zeng, Xiangping; He, Zhengyou; Li, Tianrui

    2013-01-01

    This paper presents a recursive second-order Volterra (RSOV) filter to solve the problems of signal saturation and other nonlinear distortions that occur in nonlinear active noise control systems (NANC) used for actual applications. Since this nonlinear filter based on an infinite impulse response (IIR) filter structure can model higher than second-order and third-order nonlinearities for systems where the nonlinearities are harmonically related, the RSOV filter is more effective in NANC systems with either a linear secondary path (LSP) or a nonlinear secondary path (NSP). Simulation results clearly show that the RSOV adaptive filter using the multichannel structure filtered-error least mean square (FELMS) algorithm can further greatly reduce the computational burdens and is more suitable to eliminate nonlinear distortions in NANC systems than a SOV filter, a bilinear filter and a third-order Volterra (TOV) filter.

  3. 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.

  4. Simplified Solutions for Activity Deposited on Moving Filter Media.

    Science.gov (United States)

    Smith, David L; Chabot, George E

    2016-10-01

    Simplified numerical solutions for particulate activity viewed on moving filter continuous air monitors are developed. The monitor configurations include both rectangular window (RW) and circular window (CW) types. The solutions are demonstrated first for a set of basic airborne radioactivity cases, for a series of concentration pulses, and for indicating the effects of step changes in reactor coolant system (RCS) leakage for a pressurized water reactor. The method is also compared to cases from the prior art. These simplified solutions have additional benefits: They are easily adaptable to multiple radionuclides, they will accommodate collection and detection efficiencies that vary in known ways across the collection area, and they also ease the solution programming. PMID:27575345

  5. 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.

  6. Design of PWM Siginal Generator of the Active Power Filter Based on FPGA%基于FPGA的有源电力滤波器PWM信号发生器的设计

    Institute of Scientific and Technical Information of China (English)

    段月霞; 郭振华

    2011-01-01

    Focus on the high requirements of active power filter(APF) on the control of the IGBT trigger pulse signal,the PWM signal mechanism is analyzed.And a fully digital three-phase PWM signal generator is designed based on Quartus II,which can realize the comparing between the pulse width signal modulated and triangular wave signal.After processed by the dead-generator signal,the pulse width signal produces six-way PWM pulse signal.Signal modulated circuit can control the state of IGBT,if it should be on or off.It can get the aim of harmonic suppression,reactive current compensation.At last the program of dead zone generator is introduced.In the simulation experiments,the results are confirmed correctly and feasibly.%针对有源电力滤波器(APF)对IGBT触发脉冲信号控制的较高要求,分析了PWM信号产生机理,基于QuartusII软件设计了一种全数字三相PWM信号发生器,给定脉宽信号经过调理与数字三角波信号比较,经过宽度可调的死区发生器信号处理后,产生六路PWM脉冲信号,经驱动保护信号调理电路控制相关IGBT的导通,达到抑制谐波、补偿无功电流的目的。给出了死区发生器程序。通过仿真实验,结果证实了设计的正确性和可行性。

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. High-power active devices

    CERN Document Server

    Carroll, E

    2006-01-01

    Very high-power (HP) electronics represents a small part of the electronics market. In semiconductor terms, HP represents a world device market of 600 million euros out of a total 200 billion euros for all semiconductors—a mere 0.3 per cent. At the multi-megawatt spectral end, the numbers are even smaller, so that it is quite common for electronics engineers to be unaware of developments in Very High Power (VHP). In this presentation we discuss the categories of VHP active devices, the basic topologies in which they operate, and the trend towards higher voltage and current. New press-pack technologies are introduced and the salient differences between Insulated Gate Bipolar Transistors (IGBTs) and Integrated Gate Commutated Thyristors (IGCTs) are compared. Finally, recent developments in turn-off ratings for both these devices are presented.

  13. Microbial activity in granular activated carbon filters in drinking water treatment

    NARCIS (Netherlands)

    Knezev, A.

    2015-01-01

    The investigations described are carried out to analyse the microbiological processes in relation to the GAC characteristics and the removal of natural organic matter (NOM) in Granular Activated Carbon filters (GACFs) in water treatment. The main goal of the study was to obtain a qualitative descrip

  14. 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. PMID:27247483

  15. 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.

  16. Active Q-switching of a fiber laser using a modulated fiber Fabry-Perot filter and a fiber Bragg grating

    Science.gov (United States)

    Martínez Manuel, Rodolfo; Kaboko, J. J. M.; Shlyagin, M. G.

    2016-02-01

    We propose and demonstrate a simple and robust actively Q-switched erbium-doped fiber ring cavity laser. The Q-switching is based on dynamic spectral overlapping of two filters, namely a fiber Bragg grating-based filter and a fiber Fabry-Perot tunable filter. Using 3.5 m of erbium-doped fiber and a pump power of only 60 mW, Q-switched pulses with a peak power of 9.7 W and a pulse duration of 500 ns were obtained. A pulse repetition rate can be continuously varied from a single shot to a few KHz.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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

    In order to reduce size and cost, high-order passive filters are generally preferred in power converters to cancel out high frequency harmonics caused by pulse width modulation. However, the filter resonance peaks may require the use of passive dampers to stabilize the interactions between the load...... and source impedances. Furthermore, the stabilizing effect is more difficult to be guaranteed for cost-optimized filters, which are characterized by low inductance and high capacitance passive components. In this paper, several passive filter topologies used to interface voltage source converters...... 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...

  2. 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

  3. 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.

  4. 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.

  5. 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...

  6. 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...... of the filter is where nitrification mostly happens. Deeper layers that are less active, provide extra nitrifying capacity in case ammonium is not removed within the top 15 cm. qPCR counts for ammonium oxidizing bacteria showed a decrease from 5*107 cells /gr sand at the top of the filter to 2*105 cells /gr...

  7. 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

  8. Removal of inclusions from molten aluminum with actively coated ceramic filters

    Institute of Scientific and Technical Information of China (English)

    周鸣; 倪红军; 疏达; 张为玉; 李克; 孙宝德; 王俊

    2003-01-01

    Molten aluminum (A001) was filtered by using ceramic foam filters coated with active enamel. Tensile test shows that the elongation of filtered sample is increased by 15.5%, but the tensile strength of the sample is almost the same as that of unfiltered one. The fracture cracks and dimples of filtered sample are fine and homogeneous according to SEM examination. In addition, metallographic observation shows that the filtered sample has very few inclusions of approximately 8 μm in diameter, but the unfiltered sample has some inclusions of approximately 60 μm in length and 20 μm in width. However, it is suggested that the active enamel coat can effectively capture the inclusions and dissolve them during filtering molten aluminum.

  9. Impact of grounding and filtering on power insulation monitoring in insulated terrestrial power networks

    NARCIS (Netherlands)

    Vugt, Pieter; Bijman, Rob; Timens, Roelof Bernardus; Leferink, Frank

    2013-01-01

    Insulated terrestrial power networks are used for reliable systems such as large production plants, hospital operating rooms and naval ships. The system is isolated from ground and a first fault, such as a short circuit between a phase and ground, will not result in disconnection of the power via re

  10. A narrow band-pass filter type Wilkinson power divider for I-Q demodulator in microwave interferometer system

    Science.gov (United States)

    Wang, X.; Yoshikawa, M.; Kohagura, J.; Shima, Y.; Ikezoe, R.; Sakamoto, M.; Imai, T.; Nakashima, Y.; Ma, Z.; Sakagami, I.; Mase, A.

    2015-11-01

    I-Q (In-phase Quadrature) demodulator is one of key components in microwave interferometer system application. Normally, I-Q demodulator consists of amplifiers, mixers, 90 degree phase shifter, power divider and band-pass filters, and it is widely used in various microwave communication systems and measurement systems. In this paper, power divider and band-pass filters are newly designed as one single passive component, therefore, I-Q demodulator topology becomes simplified. The novel narrow band-pass filter type Wilkinson power divider not only provides extremely miniaturized circuit size, but also maintains the band-pass filter performance and power division function as well. One experimental circuit shows good agreement with the theoretical simulation.

  11. A narrow band-pass filter type Wilkinson power divider for I-Q demodulator in microwave interferometer system

    International Nuclear Information System (INIS)

    I-Q (In-phase Quadrature) demodulator is one of key components in microwave interferometer system application. Normally, I-Q demodulator consists of amplifiers, mixers, 90 degree phase shifter, power divider and band-pass filters, and it is widely used in various microwave communication systems and measurement systems. In this paper, power divider and band-pass filters are newly designed as one single passive component, therefore, I-Q demodulator topology becomes simplified. The novel narrow band-pass filter type Wilkinson power divider not only provides extremely miniaturized circuit size, but also maintains the band-pass filter performance and power division function as well. One experimental circuit shows good agreement with the theoretical simulation

  12. 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)

  13. 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)

  14. Implementation of high-speed–low-power adaptive finite impulse response filter with novel architecture

    Directory of Open Access Journals (Sweden)

    Manish Jaiswal

    2015-03-01

    Full Text Available An energy efficient high-speed adaptive finite impulse response filter with novel architecture is developed. Synthesis results along with novel architecture on different complementary metal–oxide semiconductor (CMOS families are presented. Analysis is performed using Artix-7, Spartan-6 and Virtex-4 for most popular adaptive least mean square filter for different orders such as N = 8, 16, 32. The presented work is done using MATLAB (2013b and Xilinx (14.2. From the synthesis results, it can be found that CMOS (28 nm achieves the lowest power and critical path delay compared to others, and thus proves its efficiency in terms of energy. Different parameters are considered such as look up tables and input–output blocks, along with their optimised results.

  15. Internal Model Control of Three-phase Four-leg Active Power Filter Based on LS-SVM Generalized Inverse System Method%基于LS-SVM广义逆的三相四桥臂有源滤波器的内模控制

    Institute of Scientific and Technical Information of China (English)

    齐虹; 邵振华; 陈冲; 黄宴委

    2011-01-01

    The dynamic model of the three-phase four-leg active power filter is a multi-variable>nonlinear and strong coupling system. The internal model control based on LS-SVM generalized inverse system method for this system is studied in this paper. The generalized inverse system can be approximated by LS-SVM due to the fast operational speed of LS-SVM. The internal model and decoupling controls are used to construct a generalized pseudo-linear system. In this way , the system control is changed into the Kalman filtering. At last,the simulation results show that a good steady-state performance and a rapid transient response can be obtained under the improved method.%考虑到有源滤波器数学模型的多变量、强耦合、非线性的特点,提出了基于最小二乘支持向量机(LS-SVM)广义逆系统的三相四桥臂有源滤波器的内模控制策略.利用LS-SVM运算速度快的特点,动态逼近原系统的广义逆模型,同时引入内模控制和解耦控制,构成了广义伪线性复合系统,将控制转化为最优滤波问题.仿真结果表明,该方法稳态精度高,动态响应速度快.

  16. Hybrid Particle and Kalman Filtering for Pupil Tracking in Active IR Illumination Gaze Tracking System

    OpenAIRE

    Jian-nan Chi; Li-hua Xie; Peng-yun Zhang; Yi-fang Lu; Guo-sheng Zhang

    2014-01-01

    A novel pupil tracking method is proposed by combining particle filtering and Kalman filtering for the fast and accurate detection of pupil target in an active infrared source gaze tracking system. Firstly, we utilize particle filtering to track pupil in synthesis triple-channel color map (STCCM) for the fast detection and develop a comprehensive pupil motion model to conduct and analyze the randomness of pupil motion. Moreover, we built a pupil observational model based on the similarity mea...

  17. Collaborative recommendations with content-based filters for cultural activities via a scalable event distribution platform

    OpenAIRE

    De Pessemier, Toon; Coppens, Sam; Geebelen, Kristof; Vleugels, Chris; Bannier, Stijn; Mannens, Erik; Vanhecke, Kris; Martens, Luc

    2012-01-01

    Nowadays, most people have limited leisure time and the offer of (cultural) activities to spend this time is enormous. Consequently, picking the most appropriate events becomes increasingly difficult for end-users. This complexity of choice reinforces the necessity of filtering systems that assist users in finding and selecting relevant events. Whereas traditional filtering tools enable e.g. the use of keyword-based or filtered searches, innovative recommender systems draw on user ratings, pr...

  18. Inverse class-f power amplifier using slot resonators as a harmonic filter

    Directory of Open Access Journals (Sweden)

    Rassokhina Yu. V.

    2014-06-01

    Full Text Available The authors proposed and experimentally verified the power amplifier circuit of inverse class F (F–1 based on GaN transistor NPTB00004, operating at 1,7 GHz. The novelty of this scheme is the application of a three-layer structure based on slot rectangular shaped resonators in the ground plane of the microstrip transmission line as a filter of higher harmonics. To control the levels of the second and third harmonics in the output signal spectrum and simultaneously to match the 50 ohm load at the operating frequency of the amplifier, a planar periodic structure is used, consisting of two slot resonators of different lengths. Power added efficiency for experimental model of the amplifier is 60% at an output power of 3.9 W and a gain factor of 13 dB.

  19. 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.

  20. A unified active damping control for single-phase differential buck inverter with LCL-filter

    DEFF Research Database (Denmark)

    Yao, Wenli; Wang, Xiongfei; Zhang, Xiaobin;

    2015-01-01

    control of a grid-connected differential mode buck inverter with an LCL filter. A generalized small-signal model of the inverter is built first with the averaged switching model. It is shown that the LCL filter resonance merely occurs in the differential mode, while an LC filter resonance exists in the...... common mode, provided that the filter parameters of the two bridges are kept the same. A unified active damping control approach is then proposed for stabilizing the inverter and improving the transient performance under a wide range of grid impedance. Lastly, experimental tests are carried out and the...

  1. The retention of iodine by iodine filters in nuclear power plants in the case of fire

    International Nuclear Information System (INIS)

    Due to the liberation of considerable amounts of gaseous combustion products, fires in nuclear power plants may lead to a deterioration in the retention of radioiodine by iodine filters. The combustion products of the burnable materials, i.e., insulations, lubricants and paints, vary considerably with the development of the fire. Combustion product analyses of these materials have been performed only to a limited extent. The reaction of iodine with combustion products as well as the retention of the resulting iodine reaction products by sorbents have not yet been investigated. The reduction in the removal efficiencies of iodine sorbents due to the presence of combustion products is unknown. (orig.)

  2. 76 FR 42130 - Agency Information Collection Activities: BioWatch Filter Holder Log

    Science.gov (United States)

    2011-07-18

    ... collection request (ICR) in the Federal Register on May 2, 2011 at 76 FR 24504, for a 60-day public comment... SECURITY Agency Information Collection Activities: BioWatch Filter Holder Log AGENCY: Department of... sample analysis. A standard filter log form is completed for each sample and is archived by the...

  3. Microbial Survey of a Full-Scale, Biologically Active Filter for Treatment of Drinking Water

    OpenAIRE

    White, Colin P.; DeBry, Ronald W.; Lytle, Darren A.

    2012-01-01

    The microbial community of a full-scale, biologically active drinking water filter was surveyed using molecular techniques. Nitrosomonas, Nitrospira, Sphingomonadales, and Rhizobiales dominated the clone libraries. The results elucidate the microbial ecology of biological filters and demonstrate that biological treatment of drinking water should be considered a viable alternative to physicochemical methods.

  4. 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

  5. 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.

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

    OpenAIRE

    Basit, Abdul; Anca Daniela HANSEN; Altin, Müfit; Sørensen, Poul Ejnar; Gamst, Mette

    2016-01-01

    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 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 thede...

  7. 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.

  8. Stability Analysis and Active Damping for LLCL-filter-Based Grid-Connected Inverters

    DEFF Research Database (Denmark)

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

    2015-01-01

    to use either passive or active damping methods. This paper analyzes the stability of the LLCL-filter based grid-connected inverter and identifies a critical resonant frequency for the LLCL-filter when sampling and transport delays are considered. In a high resonant frequency region the active damping...... is not required but in a low resonant frequency region the active damping is necessary. The basic LLCL resonance damping properties of different feedback states based on a notch filter concept are also studied. Then an active damping method which is using the capacitor current feedback for LLCL......-filter is introduced. Based on this active damping method, a design procedure for the controller is given. Last, both simulation and experimental results are provided to validate the theoretical analysis of this paper....

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

    Science.gov (United States)

    Ryou, Albert; Simon, Jonathan

    2016-05-01

    We demonstrate a novel approach to enhancing the closed-loop bandwidth of a feedback-controlled mechanical system by digitally cancelling its acoustical resonances and antiresonances with an FPGA FIR filter. By performing a real-time convolution of the feedback error signal with an arbitrary filter, we can suppress arbitrarily many poles and zeros below 100 kHz, each with a linewidth as small as 10 Hz. We demonstrate the efficacy of this technique by cancelling the six largest resonances and antiresonances of a high-finesse optical resonator piezomechanical transfer function, thereby enhancing the unity gain frequency by more than an order of magnitude. More broadly, this approach is applicable to stabilization of optical resonators, external cavity diode lasers, and scanning tunneling microscopes.

  10. 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.

  11. 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 ...

  12. Integrating powdered activated carbon into wastewater tertiary filter for micro-pollutant removal.

    Science.gov (United States)

    Hu, Jingyi; Aarts, Annelies; Shang, Ran; Heijman, Bas; Rietveld, Luuk

    2016-07-15

    Integrating powdered activated carbon (PAC) into wastewater tertiary treatment is a promising technology to reduce organic micro-pollutant (OMP) discharge into the receiving waters. To take advantage of the existing tertiary filter, PAC was pre-embedded inside the filter bed acting as a fixed-bed adsorber. The pre-embedding (i.e. immobilization) of PAC was realized by direct dosing a PAC solution on the filter top, which was then promoted to penetrate into the filter media by a down-flow of tap water. In order to examine the effectiveness of this PAC pre-embedded filter towards OMP removal, batch adsorption tests, representing PAC contact reactor (with the same PAC mass-to-treated water volume ratio as in the PAC pre-embedded filter) were performed as references. Moreover, as a conventional dosing option, PAC was dosed continuously with the filter influent (i.e. the wastewater secondary effluent with the investigated OMPs). Comparative results confirmed a higher OMP removal efficiency associated with the PAC pre-embedded filter, as compared to the batch system with a practical PAC residence time. Furthermore, over a filtration period of 10 h (approximating a realistic filtration cycle for tertiary filters), the continuous dosing approach resulted in less OMP removal. Therefore, it was concluded that the pre-embedding approach can be preferentially considered when integrating PAC into the wastewater tertiary treatment for OMP elimination. PMID:27082256

  13. 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...

  14. 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...

  15. 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 currents...... may increase due to changes in the commutation behavior of diode rectifier converters. The change of natural commutation determines higher harmonics currents of the diode rectifiers and therefore higher harmonic loading of the Active Filter in the installation. This paper presents a method to estimate...... 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...

  16. 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.

  17. Case study of a unique power quality problem and solution. Application of a damped harmonic filter to a cycloconverter

    Energy Technology Data Exchange (ETDEWEB)

    Baier, M.; Sheppard, J. [Westinghouse Power System Services, Oakdale, PA (United States)

    1995-12-31

    As detailed in numerous references, variable speed drives cause degradation of power quality by distorting current and voltage waveforms in the distribution systems. Commonly applied solutions incorporate devices of a passive shunt filter design connected at the nearest power distribution bus. Apart from improving harmonic distortion at the point of their connection, such filters, consisting of capacitors, also provide necessary power factor correction to the application. Cycloconverters represent a special type of variable speed AC drive. Most commonly applied variable speed drives, such as variable frequency and variable speed DC drives, produce harmonics at their characteristic frequencies. These frequencies are essentially constant in time. In addition to the characteristic frequencies, cycloconverter spectra also contain frequencies that vary with the output converter frequency. Therefore, when passive harmonic filtering is considered for a cycloconverter application, special precautions have to be observed. It is the intent of this paper to discuss such an approach based on an example of an actual filter design. The motivation for the filter application was similar to most situations; to reduce the electrical costs by improving the power factor and to prevent equipment misoperation due to poor power quality. While the goal was common, the solution was not.

  18. New type adsorbent material of impregnated activated carbon fibers for iodine filter

    International Nuclear Information System (INIS)

    Impregnated granular activated carbon bed filters have been used worldwide to treat nuclear power plant exhaust gases of containing iodine and extensive experimental studies have been conducted. It has been discovered that the impregnated granular activated carbon has some inherent defect such as the ignition temperature is lower, the adsorption efficiency and capacity were lower and affected strongly by relative humidity and the adsorption velocity is lower. A new type impregnated activated carbon fibers (IACF) material was developed. The IACF is a felt material which has a wealth of micropores, low apparent density, high chemical stability, significantly higher ignition temperature, low affinity for water, high adsorption velocity, and the shape of IACF can be tailored to achieve the best adsorption results. Therefore, the IACF is possessed of a high adsorption capacity and efficiency in high relative humidity (> 95% R.H.). According to the ASTM D 3803 method A test, the result showed that the adsorption efficiency of >99% in bed depth of 2.5 cm. In this work, the various surface structural parameters, surface chemical characteristics and adsorption dynamics were studied by the x-ray diffraction, infrared absorption, and x-ray photoelectron spectrometry method. The results show that the various characteristics of the IACF are better than existing nuclear grade granular activated carbon

  19. 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.

  20. 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.

  1. INCREASING THE FISHER INFORMATION CONTENT IN THE MATTER POWER SPECTRUM BY NONLINEAR WAVELET WIENER FILTERING

    International Nuclear Information System (INIS)

    We develop a purely mathematical tool to recover some of the information lost in the nonlinear collapse of large-scale structure. From a set of 141 simulations of dark matter density fields, we construct a nonlinear Wiener filter in order to separate Gaussian and non-Gaussian structure in wavelet space. We find that the non-Gaussian power is dominant at smaller scales, as expected from the theory of structure formation, while the Gaussian counterpart is damped by an order of magnitude on small scales. We find that it is possible to increase the Fisher information by a factor of three before reaching the translinear plateau, an effect comparable to other techniques like the linear reconstruction of the density field.

  2. On the structurization of coal dust precipitations and their influence on aerodynamic resistance by granulated mediums in air filters at nuclear power plants

    CERN Document Server

    Neklyudov, I M; Fedorova, L I; Poltinin, P Ya

    2012-01-01

    The processes of structurization of dust precipitations in granulated filtering mediums, formed by the monolithic glass spherical granules with the diameters of 2mm and 3mm, are re-searched. The distinctions between the distributions of filtered coal dust masses in the air filters with cylindrical granules and the air filters with spherical granules, are found. The influences by the filtered dust masses on the air resistance of both the air filters with the cylindrical granules and the air filters with the spherical granules are described. The conclusions on a possibility of the use of various chemical adsorbents with different geometric forms and volumetric dimensions to improve the filtering properties of granulated filtering mediums in air filters at nuclear power plants are formulated.

  3. 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

  4. 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.

  5. 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.

  6. Design of CDBA-based active polyphase filter for low-IF receiver applications

    OpenAIRE

    Sağbaş, Mehmet

    2011-01-01

    A novel first-order active-RC polyphase filter section, using current differencing buffered amplifiers (CDBAs), is presented. The section uses 6 resistors, 2 capacitors, and 2 CDBAs. The transfer function of the proposed section has a single pole and optionally a single zero. Increasing the number of cascading sections, any higher order polyphase filter can be realized. This paper also introduces the leakage caused by element deviation and the effects of the amplifier in nonideal ca...

  7. Design of LCL filters for converters with low switching frequency used in decentralised power generating plants; Auslegung eines LCL Filters fuer Umrichter mit niedriger Schaltfrequenz in dezentralen Erzeugungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Robert; Mertens, Axel [Hannover Univ. (DE). Inst. fuer Antriebssysteme und Leistungselektronik (IAL)

    2011-07-01

    This paper describes a method for designing LCL filters to be used in decentralized power generating plants. It is especially suitable for converters with low switching frequency and/or converters with modulation methods generating harmonics in the entire frequency range. As an example, the flat-top modulation is examined more detailed. The method is based on the fact that the converter's spectrum is known, for which a calculation approach is presented. The method discussed enables a filter design meeting all requirements of the utility companies concerning voltage quality for all relevant operating ranges. In general, it is suitable for all converter topologies and modulation methods generating periodical output voltages. (orig.)

  8. Active Damping Techniques for LCL-Filtered Inverters-Based Microgrids

    DEFF Research Database (Denmark)

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

    2015-01-01

    LCL-type filters are widely used in gridconnected voltage source inverters, since it provides switching ripples reduction with lower cost and weight than the L-type counterpart. However, the inclusion of LCL-filters in voltage source inverters complicates the current control design regarding syst...... the different active damping approaches for grid-connected inverters with LCL filters, which are based on high-order filters and additional feedbacks methods. These techniques are analyzed and discussed in detail.......LCL-type filters are widely used in gridconnected voltage source inverters, since it provides switching ripples reduction with lower cost and weight than the L-type counterpart. However, the inclusion of LCL-filters in voltage source inverters complicates the current control design regarding system...... stability issues; because an inherent resonance peak appears due to zero impedance at that resonance frequency. Moreover, in grid-interactive low-voltage microgrids, the interactions among the LCL-filtered-based parallel inverters may result in a more complex multiresonance issue which may compromise...

  9. 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...

  10. 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.

  11. Dual-tunable multiferroic active ring filter for microwave photonic oscillators

    Science.gov (United States)

    Vitko, V. V.; Nikitin, A. A.; Ustinov, A. B.; Kalinikos, B. A.

    2015-12-01

    A theoretical model of a microwave active ring filter based on a ferrite-ferroelectric layered structure serving as a waveguide for spin-electromagnetic waves is developed. An experimental prototype of the device is fabricated and characterized. The device is implemented as an active-ring resonator with a microwave amplifier and a ferrite-ferroelectric delay line. The resonance properties of this system are studied theoretically and experimentally. The results show dual control of central frequency of the filter with magnetic and electric fields. An effective Q-factor of 50 000 and tuning by 5 MHz with an electric field are achieved at 8 GHz.

  12. 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

  13. 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...

  14. 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.

  15. A repetitive control scheme aiming to compensate the 6k+1 harmonics for three-phase hybrid active filter

    DEFF Research Database (Denmark)

    Luo, Zhaoxu; Su, Mei; Yang, Jian;

    2016-01-01

    in stationary reference frame, which only compensates the 6k+1 harmonics (e.g. -5, +7, -11, +13) in three-phase systems and reduces the time delay to T0/6 . So compared with the earlier reduced delay time repetitive controllers, the robustness and transient performance is further improved, the waste of control...... effort is reduced, and the possibility of amplifying and even injecting any harmonic noises into system is avoided to the greatest extent. Moreover, the proposed repetitive scheme is used in the control of a three-phase hybrid active power filter. The experimental results validate the effectiveness...

  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...

  17. Operator tracking system using particle filter for skill evaluation in nuclear power plant control room

    International Nuclear Information System (INIS)

    This article proposes an automated operator tracking system by the use of particle filter and image processing technology to help operator skill evaluation in nuclear power plant operator training facilities. In each of the control room of the training facilities, a full-scope plant simulator with mock-up control panels are used for real-time operator training. At this point, the operators' behaviors and plant's events are recorded as video-log and event-log, by a multi-media recording system to evaluate operators' skills at training review meetings in which the instructors and trainees discuss each of their action during the training process. Multiple cameras that are placed on the control room ceiling are used in the recording system. However, the views from these cameras are limited and therefore it is not possible to thoroughly check how each of the operator approaches the target panel within an appropriate timing that corresponds to the plant's event. For example, the instructors have to estimate operators' real-world position from the views; and in some cases other operators might conceal the target operators from the cameras. The purpose of the proposed system is to help checking whether the position and timing of each operator is appropriate during each event or alarm occurrence, by tracking the operators from the recorded video. To achieve this objective, the real-time image processing technology is newly introduced in this study, where particle filter is one of convenient algorithms for operator tracking. In this algorithm, the main issue is how to recognize multiple operators from the background and to get their positions within the coordinates of the control room. For this purpose, one 3-D particle filter is used for each operator wearing colored vests and the similarity calculation algorithm is based on color histogram. The particles are directly placed inside the control room. By converting the particle coordinates into camera coordinates and taking

  18. Highly efficient high power single-mode fiber amplifier utilizing the distributed mode filtering bandgap rod fiber

    DEFF Research Database (Denmark)

    Laurila, Marko; Alkeskjold, Thomas T.; Jørgensen, Mette Marie;

    2012-01-01

    high average output power levels and demonstrate a 44% power improvement before the threshold-like onset of mode instabilities by operating the rod fiber in a leaky waveguide regime. We investigate the guiding dynamics of the rod fiber and explain the improved performance by thermally induced......We report on an ytterbium doped single mode distributed mode filtering rod fiber in an amplifier configuration delivering high average output power, up to 292 watts, using a mode-locked 30ps source at 1032nm with good power conversion efficiency. We study the modal stability of the output beam at...

  19. 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.

  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. 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.

  2. 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. PMID:26405842

  3. 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.

  4. Effect of activated carbon layer at sand-carbon filters vertical flow in domestic wastewater treatment

    Directory of Open Access Journals (Sweden)

    Ewa Wąsik

    2014-12-01

    Full Text Available The paper presents the results of the research concerning treatment of domestic sewage in sand filters of vertical flow with granular activated carbon layer. Removal of organic compounds and nitrogen from wastewater pre-treated in a septic tank, as well as total suspended solids at different hydraulic load of sand-carbon filters were specified. It was shown that favourable conditions for the development of both heterotrophic and nitrifying bacteria were created in the double layer of sand and carbon filter with the upper layer of the activated carbon. For three-month cycle in the load range of 13-131 mm·d-1, mean effectiveness of BOD5, CODCr, N-NH4+ and total suspension were respectively 98%, 94%, 98% and 82%.

  5. 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

  6. 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...

  7. Linear filters as a method of real-time prediction of geomagnetic activity

    International Nuclear Information System (INIS)

    Important factors controlling geomagnetic activity include the solar wind velocity, the strength of the interplanetary magnetic field (IMF), and the field orientation. Because these quantities change so much in transit through the solar wind, real-time monitoring immediately upstream of the earth provides the best input for any technique of real-time prediction. One such technique is linear prediction filtering which utilizes past histories of the input and output of a linear system to create a time-invariant filter characterizing the system. Problems of nonlinearity or temporal changes of the system can be handled by appropriate choice of input parameters and piecewise approximation in various ranges of the input. We have created prediction filters for all the standard magnetic indices and tested their efficiency. The filters show that the initial response of the magnetosphere to a southward turning of the IMF peaks in 20 minutes and then again in 55 minutes. After a northward turning, auroral zone indices and the midlatitude ASYM index return to background within 2 hours, while Dst decays exponentially with a time constant of about 8 hours. This paper describes a simple, real-time system utilizing these filters which could predict a substantial fraction of the variation in magnetic activity indices 20 to 50 minutes in advance

  8. Reduction in Power Consumption for Full-Color Active Matrix Organic Light-Emitting Devices

    Science.gov (United States)

    Kanno, Hiroshi; Hamada, Yuji; Nishimura, Kazuki; Okumoto, Kenji; Saito, Nobuo; Mameno, Kazunobu; Shibata, Kenichi

    2006-09-01

    The active matrix organic light-emitting diode (AMOLED) is expected to serve as next generation flat panels display with the outstanding features of wide viewing angle, vivid images, and quick response. For practical use of full-color AMOLEDs in mobile devices, it is essential to reduce the power consumption, which is generally higher than that of liquid crystal displays (LCDs). For this aim, a red, green, blue, and white (RGBW) pixel format combined with an RGB color filter array (RGBW format) with a common white emission layer (EML) has been developed. We find that the RGBW format can successfully reduce the power consumption of a full-color AMOLED by nearly half that of a conventionally filtered RGB pixel format. This improved power consumption is almost equal to the power consumption of a same-sized LCD. The RGBW format is a promising technique for the further reduction of the power consumption of a full-color AMOLED.

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. Impact of Cylinder Deactivation on Active Diesel Particulate Filter Regeneration at Highway Cruise Conditions

    OpenAIRE

    Lu, Xueting; Ding, Chuan; Ramesh, Aswin K.; Shaver, Gregory M.; Holloway, Eric; McCarthy, James; Ruth, Michael; Koeberlein, Edward; Nielsen, Douglas

    2015-01-01

    Heavy-duty over-the-road trucks require periodic active diesel particulate filter regeneration to clean the filter of stored particulate matter. These events require sustained temperatures between 500 and 600°C to complete the regeneration process. Engine operation during typical 65 mile/h highway cruise conditions (1200 rpm/7.6 bar) results in temperatures of approximately 350°C, and can reach approximately 420°C with late fuel injection. This necessitates hydrocarbon fueling of a diesel oxi...

  14. 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 thermal shields. X-ray transparent filters need to be mounted on these open windows to attenuate the IR radiation from warm surfaces, to attenuate 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.

  15. Enhancement of the power system efficiency using the hybrid-type harmonic filters for a KSTAR nuclear fusion experimental system

    International Nuclear Information System (INIS)

    Highlights: → The low power factor and power quality problems are occurred by the operation of the PF facility in KSTAR system. We model the power system of KSTAR system including the PF facility. We show a method of the filter insertion to improve the problem and conduct the simulations to verify our method. - Abstract: The KSTAR system, which includes a large amount of nonlinear load, is a relatively high reactive power consumption load which injects harmonic currents into the power system which could result in the possibility for a power system perturbation to occur in the transmission lines, affecting nearby customers. In order to maintain the power quality and power factor in the inner system of the KSTAR system and the adjacent distribution lines, the assessment of the effect of the DC power supply in the KSTAR system is required for appropriate countermeasures to be put in place. In this paper, on the basis of a preliminary inspection of the power system near a KSTAR system, the simulation of a compensating device is performed for the prevention of abnormal voltage variations caused by a large amount of reactive and nonlinear load. In addition, through the comparison of the pre- and post-application of compensation devices in the actual power system, it is verified that a stable operation of the KSTAR nuclear fusion experimental system can be achieved.

  16. 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...

  17. 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

    and measurementresults. Furthermore, the power-handling capability of the filter isdiscussed and the ionization breakdown limit under normal conditionsis estimated to be 800 W. The filter’s linearity is characterizedby a standard two-tone test, where the level of the third-order passiveintermodulation product...... is observed to be 53.1 dBm at aninput fundamental tone level of 2 43 dBm....

  18. Filter for retaining radioactive iodine in water from nuclear power stations

    International Nuclear Information System (INIS)

    The purpose of the invention is a selective filter material absorbing the element iodine. Starch is used as the material absorbing the iodine. The element iodine is incorporated in the spiral hollow spaces of the starch. The mechanism of incorporating is due to Van der Waal forces. The filter effect is not affected by salt loading or by extreme pH values of the water to be cleaned. (orig.)

  19. 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.

  20. 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.

  1. 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)

  2. 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.

  3. Active micromachines: Microfluidics powered by mesoscale turbulence

    Science.gov (United States)

    Thampi, Sumesh P.; Doostmohammadi, Amin; 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 characterized by mesoscale turbulence, which is 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-organizes into a spin state where neighboring 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. PMID:27419229

  4. Active micromachines: Microfluidics powered by mesoscale turbulence.

    Science.gov (United States)

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

    2016-07-01

    Dense active matter, from bacterial suspensions and microtubule bundles driven by motor proteins to cellular monolayers and synthetic Janus particles, is characterized by mesoscale turbulence, which is 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-organizes into a spin state where neighboring 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. PMID:27419229

  5. 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.

  6. 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...

  7. Impact of Cylinder Deactivation on Active Diesel Particulate Filter Regeneration at Highway Cruise Conditions

    Directory of Open Access Journals (Sweden)

    Xueting eLu

    2015-08-01

    Full Text Available Abstract—Heavy-duty over-the-road trucks require periodic active diesel particulate filter regeneration to clean the filter of stored particulate matter. These events require sustained temperatures between 500 and 600□C to complete the regeneration process. Engine operation during typical 65 mile/hour highway cruise conditions (1200 rpm/7.6 bar results in temperatures of approximately 350□C, and can reach approximately 420□C with late fuel injection. This necessitates hydrocarbon fueling of a diesel oxidation catalyst or burner located upstream of the diesel particulate filter to reach the required regeneration temperatures. These strategies require increased fuel consumption, and the presence of a fuel-dosed oxidation catalyst (or burner between the engine and particulate filter. This paper experimentally demonstrates that, at the highway cruise condition, deactivation of valve motions and fuel injection for two or three (of six cylinders can instead be used to reach engine outlet temperatures of 520-570□C, a 170-220□C increase compared to normal operation. This is primarily a result of a reduction in the air-to-fuel ratio realized by reducing the displaced cylinder volume through cylinder deactivation.

  8. Influence factors of photocatalytic activity of the filter media modified by TiO2

    Directory of Open Access Journals (Sweden)

    Shen Rongyan

    2014-01-01

    Full Text Available The gangue filter media was modified by the titanium dioxide (TiO2 through the liquid phase deposition method. Some influence factors of photocatalytic activity were investigated, including the mole ratio of initial solution, the water bath temperature, the deposition time, the calcination temperature, and the heat preservation time of calcination. The morphology of the film was examined by SEM, EDS, and crystallite structure by X-Ray Diffraction (XRD. The SEM, EDS, and XRD data showed that new TiO2 crystal was found in the modified filter media. And the specific surface area of the modified filter media greatly increased. By the orthogonal experiment, the optimum parameters of modification were (NH42TiF6:H3BO3=1:2, water bath temperature of 80ºC, deposition time of 5h, calcination temperature of 500ºC, and 1h heat preservation time of calcination. Under above conditions, the heavy nitrogen wastewater of 1589.94 mg/L COD and 18750 times chroma was treated by the modified filter media. After 1h catalytic reaction, the decolorization rate and COD removal rate reached 65.89% and 47.87%, respectively.

  9. 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...... damping control. However, in digital systems, the discrete implementation of the derivative suffers from noise amplification and accuracy issues. To overcome these drawbacks, this paper proposes a new derivative method based on Second-Order Generalized Integrator. Theoretical study shows that the proposed...... derivative is more suited for capacitor voltage feedback active damping control. Experimental results validate the effectiveness of the proposed method....

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

    OpenAIRE

    N.V.K.Mahalakshmi; Sindhu, D; B. Ranjith Kumar; N.Santhisri; G. Sowjanya Rao

    2014-01-01

    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 p...

  11. 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...... 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, as...

  12. Design and application of finite impulse response digital filters

    International Nuclear Information System (INIS)

    The finite impulse response (FIR) digital filter is a spatial domain filter with a frequency domain representation. The theory of the FIR filter is presented and techniques are described for designing FIR filters with known frequency response characteristics. Rational design principles are emphasized based on characterization of the imaging system using the modulation transfer function and physical properties of the imaged objects. Bandpass, Wiener, and low-pass filters were designed and applied to 201Tl myocardial images. The bandpass filter eliminates low-frequency image components that represent background activity and high-frequency components due to noise. The Wiener, or minimum mean square error filter 'sharpens' the image while also reducing noise. The Wiener filter illustrates the power of the FIR technique to design filters with any desired frequency reponse. The low-pass filter, while of relative limited use, is presented to compare it with a popular elementary 'smoothing' filter. (orig.)

  13. Energy Efficient Indoor VOC Air Cleaning with Activated Carbon Fiber (ACF) Filters

    OpenAIRE

    Sidheswaran, Meera

    2012-01-01

    This study explores the potential environmental and energy benefits of using activated carbon fiber (ACF) filters for air cleaning in HVAC systems. The parallel aims for the air cleaning system were to enable reduced indoor exposures to volatile organic compounds (VOCs) and to simultaneously allow reduced rates and energy consumption for outdoor-air ventilation. We evaluated the use of ACF media to adsorb VOCs from indoor air during repeated simulated 12-hour to 24-hour periods of occupancy. ...

  14. Object Structure from Manipulation via Particle Filter and Robot-based Active Learning

    OpenAIRE

    LI, Kun; Meng, Max Q.-H.

    2014-01-01

    To learn object models for robotic manipulation, unsupervised methods cannot provide accurate object structural information and supervised methods require a large amount of manually labeled training samples, thus interactive object segmentation is developed to automate object modeling. In this article, we formulate a novel dynamic process for interactive object segmentation, and develop a solution based on particle filter and active learning so that a robot can manipulate and learn object str...

  15. Influence factors of photocatalytic activity of the filter media modified by TiO2

    OpenAIRE

    Shen Rongyan; Feng Guoyong; Liang Yuting; Zhao Xingqing; Zhang Wenyi

    2014-01-01

    The gangue filter media was modified by the titanium dioxide (TiO2) through the liquid phase deposition method. Some influence factors of photocatalytic activity were investigated, including the mole ratio of initial solution, the water bath temperature, the deposition time, the calcination temperature, and the heat preservation time of calcination. The morphology of the film was examined by SEM, EDS, and crystallite structure by X-Ray Diffraction (XRD). Th...

  16. 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.

  17. 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

    Gain-saturation-induced self-phase modulation (SPM) leading to pulse distortion in a semiconductor optical amplifier (SOA) is overcome by shifting a tunable optical filter (TOF). A recovered or broadened pulse can be obtained after filtering the amplified pulse in the SOA even if the short pulse...... to a longer wavelength for RZ signals and to a shorter for NRZ signals. 80-Gb/s optical time division multiplexing (OTDM) signal amplification in the SOA is demonstrated for the first time. We also demonstrate that a large IPDR for the 80-Gb/s OTDM signal can be obtained by shifting the TOF....

  18. 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.

  19. Effects of ozonation and temperature on the biodegradation of natural organic matter in biological granular activated carbon filters

    NARCIS (Netherlands)

    Van der Aa, L.T.J.; Rietveld, L.C.; Van Dijk, J.C.

    2011-01-01

    Four pilot (biological) granular activated carbon ((B)GAC) filters were operated to quantify the effects of ozonation and water temperature on the biodegradation of natural organic matter (NOM) in (B)GAC filters. The removal of dissolved organic carbon (DOC), assimilable organic carbon (AOC) and oxy

  20. Effects of ozonation and temperature on biodegradation of natural organic matter in biological granular activated carbon filters

    NARCIS (Netherlands)

    Van der Aa, L.T.J.; Rietveld, L.C.; Van Dijk, J.C.

    2010-01-01

    Four pilot (biological) granular activated carbon ((B)GAC) filters were operated to quantify the effects of ozonation and water temperature on the biodegradation of natural organic matter (NOM) in (B)GAC filters. Removal of dissolved organic carbon (DOC), assimilable organic carbon (AOC) and oxygen

  1. 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

  2. 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. PMID:27045540

  3. Statistical Performances of Resistive Active Power Splitter

    Science.gov (United States)

    Lalléchère, Sébastien; Ravelo, Blaise; Thakur, Atul

    2016-03-01

    In this paper, the synthesis and sensitivity analysis of an active power splitter (PWS) is proposed. It is based on the active cell composed of a Field Effect Transistor in cascade with shunted resistor at the input and the output (resistive amplifier topology). The PWS uncertainty versus resistance tolerances is suggested by using stochastic method. Furthermore, with the proposed topology, we can control easily the device gain while varying a resistance. This provides useful tool to analyse the statistical sensitivity of the system in uncertain environment.

  4. Sensory Pollution from Bag Filters, Carbon Filters and Combinations

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Clausen, Geo; Weschler, Charles J.

    2008-01-01

    by an upstream pre-filter (changed monthly), an EU7 filter protected by an upstream activated carbon (AC) filter, and EU7 filters with an AC filter either downstream or both upstream and downstream. In addition, two types of stand-alone combination filters were evaluated: a bag-type fiberglass filter...

  5. COMPARING BINARY, CSD AND CSD4 APPROACHES ON THE ASPECT OF POWER CONSUMPTION IN FIR FILTERS USING MULTIPLIERLESS ARCHITECTURES ON FPGAS

    OpenAIRE

    Birkeland, Guri Kristine

    2005-01-01

    The aim of this thesis is to compare several different algorithms of FIR-filter design on the aspect of the amount of power they consume. Three different approaches are presented: One based on binary, two's complement representation of the coefficients in the filter. The second approach is based on CSD representation, and the third approach is based on CSD4 representation of the coefficients. The three approaches are compared due to their overall power consumption when implemented on an FPGA....

  6. A Repetitive Control Scheme Aimed at Compensating the 6k + 1 Harmonics for a Three-Phase Hybrid Active Filter

    DEFF Research Database (Denmark)

    Luo, Zhaoxu; Su, Mei; Yang, Jian;

    2016-01-01

    is reduced, and the possibility of amplifying and even injecting any harmonic noises into the system is avoided to a great extent. Moreover, the proposed repetitive scheme is used in the control of a three-phase hybrid active power filter. The experimental results validate the effectiveness of the proposed......The traditional repetitive controller has relatively worse stability and poor transient performance because it generates infinite gain at all the integer multiples of the fundamental frequency, and its control action is postponed by one fundamental period (T0). To improve these disadvantages, many...... repetitive controllers with reduced delay time have been proposed, which can selectively compensate the odd harmonics or 6k ± 1 harmonics with delay time reduced to T0/2 and T0/3, respectively. To further study in this area, this paper proposes an improved repetitive scheme implemented in a stationary...

  7. 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....

  8. Influence by small dispersive coal dust particles of different fractional consistence on characteristics of iodine air filter at nuclear power plant

    CERN Document Server

    Neklyudov, I M; Fedorova, L I; Poltinin, P Ya

    2013-01-01

    The main purpose of research is to determine the influence by the small dispersive coal dust particles of the different fractional consistence on the technical characteristics of the vertical iodine air filter at nuclear power plant. The research on the transport properties of the small dispersive coal dust particles in the granular filtering medium of absorber in the vertical iodine air filter is completed in the case, when the modeled aerodynamic conditions are similar to the real aerodynamic conditions. It is shown that the appearance of the different fractional consistence of small dispersive coal dust particles with the decreasing dimensions down to the micro and nano sizes at the action of the air dust aerosol stream normally results in a significant change of distribution of the small dispersive coal dust particles masses in the granular filtering medium of an absorber in the vertical iodine air filter, changing the vertical iodine air filter aerodynamic characteristics. The precise characterization of...

  9. 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.

  10. 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...

  11. Cryptosporidium Removal from Runoff by Active Carbon Filter with Coal Gangue

    Directory of Open Access Journals (Sweden)

    Ping Lu

    2016-01-01

    Full Text Available Transport of Cryptosporidium in runoff will contaminate the surrounding water body. Cryptosporidium-sized microspheres and inactive Cryptosporidium parvum oocysts removal using an active carbon (AC filter with/without coal gangue from the runoff was evaluated. Chemical composition of coal gangue was determined, and its performance as a water treatment material was tested. Results showed SiO2 was the dominant chemical component of coal gangue. Removal was only 20% for microspheres and 24% for oocysts by AC filtration alone. The removal for both was increased to more than 98% by addition of coal gangue powder to the filter. Furthermore, gangue reuse turned commercially worthless material to a water treatment material as well helping prevent gangue from occupying agriculture/industry land.

  12. 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

    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.......6 μm) of the mineral coating, which had a thickness of up to 600 ± 51 μm. Environmental scanning electron microscopic (E-SEM) observations suggested an extracellular polymeric substance-rich matrix and submicron-sized bacterial cells. Nitrifier diversity profiles were similar irrespective of the degree...... of mineral coating, as indicated by pyrosequencing analysis. Overall, our results demonstrate that mineral coating positively affects microbial colonization and activity in rapid sand filters, most likely due to increased volumetric cell abundances facilitated by the large surface area of internal mineral...

  13. Feasibility of Tunable Amplifier and Bandpass Filter for Mobile Handsets Using Active Inductor Circuits

    OpenAIRE

    Majeed, B.; N. T. Ali; J. Rodriguez Tellez

    2002-01-01

    In this paper active inductor circuits are employed to assess their suitability for providing a tuning function in GaAs MMIC circuits. The specifications for a mobile handset amplifier and a bandpass filter operating from a 3 V supply rail are used as test vehicles. The design and simulation of the circuits employs a low-cost commercially available low pinch-off GaAs MESFET process. The suitability of active inductors for tuning in such applications considers issues such as frequency tuning r...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...... in the literature. Its effect with parasitic capacitance present in the grid has also usually been ignored, even though it may bring new challenges to the active damper. To address these issues, passivity is applied to study the grid converter stability before the understanding gained is used for formulating...

  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...... 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...

  16. 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....

  17. 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.)

  18. 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.

  19. 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.

  20. 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

  1. The retention of iodine by iodine filters in nuclear power plants in the case of fire (a literature review)

    International Nuclear Information System (INIS)

    Due to the liberation of considerable amounts of gaseous combustion products, fires in nuclear power plants may lead to a deterioration in the retention of radioiodine by iodine filters. The combustion products of the burnable materials, i.e., insulations, lubricants and paints, vary considerably with the development of the fire. Combustion product analyses of these materials have been performed only to a limited extent. The reaction of iodine with combustion products as well as the retention of the resulting iodine reaction products by sorbents have not yet been investigated. The reduction in the removal efficiencies of iodine sorbents due to the presence of combustion products is unknown. (orig.)

  2. Tunable microwave bandpass filter integrated power divider based on the high anisotropy electro-optic nematic liquid crystal

    Science.gov (United States)

    Liu, Yupeng; Liu, Yang; Li, Haiyan; Jiang, Di; Cao, Weiping; Chen, Hui; Xia, Lei; Xu, Ruimin

    2016-07-01

    A novel, compact microwave tunable bandpass filter integrated power divider, based on the high anisotropy electro-optic nematic liquid crystal, is proposed in this letter. Liquid crystal, as the electro-optic material, is placed between top inverted microstrip line and the metal plate. The proposed structure can realize continuous tunable bandpass response and miniaturization. The proposed design concept is validated by the good performance of simulation results and experimental results. The electro-optic material has shown great potential for microwave application.

  3. 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.

  4. 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...

  5. 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.

  6. Nitrification and denitrification in biological activated carbon filter for treating high ammonia source water

    Institute of Scientific and Technical Information of China (English)

    Jianguang LIU; Xiaojian ZHANG; Zhansheng WANG

    2008-01-01

    Since the ammonia in the effluent of the tradi-tional water purification process could not meet the supply demand, the advanced treatment of a high concentration of NH4+-N micro-polluted source water by biological activated carbon filter (BACF) was tested. The filter was operated in the downflow manner and the results showed that the remov-ing rate of NH4+-N was related to the influent concentration of NH4+-N. Its removing rate could be higher than 95% when influent concentration was under 1.0 mg/L. It could also decrease with the increasing influent concentration when the NH4+-N concentration was in the range from 1.5-to 4.9 mg/L and the dissolved oxygen (DO) in the infuent was under 10 mg/L, and the minimum removing rate could be 30%. The key factor of restricting nitrifcation in BACF was the influent DO. When the influent NH4+-N concentration was high, the DO in water was almost depleted entirely by the nitrifying and hetetrophic bacteria in the depth of 0.4 m filter and the filter layer was divided into aerobic and anoxic zones. The nitrification and degradation of organic matters existed in the aerobic zone, while the denitrification occurred in the anoxic zone. Due to the limited carbon source, the denitrification could not be carried out properly, which led to the accu-mulation of the denitrification intermediates such as NO2-. In addition to the denitrification bacteria, the nitrification and the heterotrophic bacteria existed in the anoxic zone.

  7. 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.

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

    Science.gov (United States)

    Bester, Kai; Banzhaf, Stefan; Burkhardt, Michael; Janzen, Niklas; Niederstrasser, Bernd; Scheytt, Traugott

    2011-11-01

    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 K(ow) 1.8-4.4) biocides and biocide metabolites such as: Terbutryn, Cybutryn (Irgarol® 1051), Descyclopropyl-Cybutryn (Cybutryn and Terbutryn metabolite), Isoproturon, Diuron, and its metabolite Diuron-desmonomethyl, Benzo-isothiazolinone, n-Octyl-isothiazolinone, Dichloro-n-octylisothiazolinone and Iodocarbamate (Iodocarb). Three experiments were performed: the first one (36 d) under low flow conditions (61 L m(-2) d(-1)) reached removal rates between 82% and 100%. The second one was performed to study high flow conditions: During this experiment, water was added as a pulse to the filter system with a hydraulic load of 255 L m(-2) within 5 min (retention time octylisothiazolinone). However, this removal is a considerable improvement compared to direct discharge into surface waters or infiltration into soil without appropriate removal. In the last experiment the removal efficiencies of the different layers were studied. Though the peat layer was responsible for most of the removal, the sand and gravel layers also contributed significantly for some compounds. All compounds are rather removed by degradation than by sorption. PMID:21855108

  9. 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

  10. 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 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......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...

  11. 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%.

  12. 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...

  13. 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...

  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

    (RES) units regulate different active power, the proposed reactive power distribution is adaptively controlled according to the active power distribution among energy storage systems (ESS) and RES units. The virtual impedance is implemented in order to improve the reactive power sharing...

  15. First filter test of market power in Finnish food retailing sector

    OpenAIRE

    Niemi, Jyrki S.; Xing, Liu

    2010-01-01

    Buyer power and competition policy in food supply chains has emerged as an important economic issue and a highly sensitive item on the policy agenda all around the world. Claims that large retailers and food companies are depressing farm prices because of their market power have been made in many countries around the world (Swinnen and Vandeplas, 2009). Arising concentration of retailer sector increases the concern of existence and gradual growth of buyer power in this sector. The key reason ...

  16. 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.

  17. 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...

  18. Ammonium removal of drinking water at low temperature by activated carbon filter biologically enhanced with heterotrophic nitrifying bacteria.

    Science.gov (United States)

    Qin, Wen; Li, Wei-Guang; Zhang, Duo-Ying; Huang, Xiao-Fei; Song, Yang

    2016-03-01

    We sought to confirm whether use of Acinetobacter strains Y7 and Y16, both strains of heterotrophic nitrifying bacteria, was practical for removing ammonium (NH4 (+)-N) from drinking water at low temperatures. To test this, ammonium-containing drinking water was treated with strains Y7 and Y16 at 8 and 2 °C. Continuous ammonium treatment was conducted in order to evaluate the performance of three biologically enhanced activated carbon (BEAC) filters in removing ammonium. The three BEAC filters were inoculated with strain Y7, strain Y16, and a mixture of strains Y7 and Y16, respectively. A granular activated carbon (GAC) filter, without inoculation by any strains, was tested in parallel with the BEAC filters as control. The results indicated that NH4 (+)-N removal was significant when a BEAC filter was inoculated with the mixture of strains Y7 and Y16 (BEAC-III filter). Amounts of 0.44 ± 0.05 and 0.25 ± 0.05 mg L(-1) NH4 (+)-N were removed using the BEAC-III filter at 8 and 2 °C, respectively. These values were 2.8-4.0-fold higher than the values of ammonium removal acquired using the GAC filter. The synergistic effect of using strains Y7 and Y16 in concert was the cause of the high-ammonium removal efficiency achieved by using the BEAC-III filter at low temperatures. In addition, a high C/N ratio may promote NH4 (+)-N removal efficiency by improving biomass and microbial activity. This study provides new insight into the use of biofilters to achieve biological removal of ammonium at low temperature. PMID:26527340

  19. 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 in...

  20. A high regulated low ripple DC power supply based on LC filter & IGBT

    Directory of Open Access Journals (Sweden)

    Ayan Mitra

    2012-12-01

    Full Text Available Filaments operating at a high temperature region would require ripple free current constant power source for their heating purposes. Introduction of ripple in the power supply would result in high power loss, aberrant, unpredictable temperature rise etc. High current ripple can also extenuate the life of electrolytic capacitors used in the circuit. In this paper we propose a scheme in which we would not only use simple, low cost, easily available electronic components but also reduce the value of ripple factor to <0.1% and load regulation to 0.1%.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. The Real-Time Research of Optimal Power Flow Calculation in Reduce Active Power Loss Aspects of Power Grid

    OpenAIRE

    Yuting Pan; Yuchen Chen; Zhiqiang Yuan; Bo Liu

    2015-01-01

    In order to research how to availably reduce the active power loss value in power grid system when the power system is operating, it offers a quantitative research in theory through conceiving the unbalanced losses of power grid system under the overloading bus as the investigative object, and establishing an active power loss mathematical model. It carries out online real-time optimal flow calculation within the condition that meets the control variables and state variables of the equality a...

  8. Analysis of Parallel Topology for Active Power Factor Correction Using Single and Dual Mode Boost Converters

    Directory of Open Access Journals (Sweden)

    Md. Mosfiqur Rahaman

    2014-11-01

    Full Text Available The ratio between real or average power and apparent power known as power factor has a high impact on power system industries. Efficient usage of the real power is very indicative in developing a power system. With the profusely development of technology in power semiconductor devices, the rate of using power electronic systems has expanded to new and wide application range that include residential, commercial, aerospace and other systems. In the nonlinear system, loads are the main source of harmonics. So that nonlinear behavior puts a question mark on their high efficiency. The current drawn by power electronic interfaces from the line is distorted resulting in a high total Harmonic Distortion and low p.f. this creates adverse effects on the power system include increased magnitudes of neutral currents in three phase systems, overheating in transformers and induction motors. This paper aims to develop a circuit for PFC by using active filtering approach by implementing two (single & dual boost converters arranged in parallel, for improving circuit quality and switching loss. This work actually involves simulation of basic power electronic circuit and it starts with simple circuit with a gradual increase in complexity by inclusion of new components and their subsequent effect on current and voltage wave forms. We focused to improve the condition of input current waveforms for making it sinusoidal by tuning the circuits.

  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. Interactions between microbial activity and distribution and mineral coatings on sand grains from rapid sand filters treating groundwater

    DEFF Research Database (Denmark)

    Gülay, Arda; Tatari, Karolina; Musovic, Sanin;

    Rapid sand filtration is a traditional and widespread technology for drinking water purification which combines biological, chemical and physical processes together. Granular media, especially sand, is a common filter material that allows several oxidized compounds to accumulate on its surface......, physico-chemical and biokinetic techniques to determine the interaction between attached bacteria and attached minerals in rapid sand filters as well as the causality of the relation. Strong pairwise correlations revealed the strong relation between mineral physical properties and bacterial activity...

  11. 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.

  12. 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....... Then the stability of the different methods and the design of the feedback coefficient are analyzed and compared using root loci. Finally, experimental results are presented to validate the theoretical analysis....

  13. In situ activity recovery of aging biofilm in biological aerated filter: Surfactants treatment and mechanisms study.

    Science.gov (United States)

    Yu, Qisheng; Huang, Hui; Ren, Hongqiang; Ding, Lili; Geng, Jinju

    2016-11-01

    In situ activity recovery of aging biofilm in the biological aerated filter (BAF) is an important but underappreciated problem. Lab-scaled BAFs were established in this study and three kinds of surfactants containing sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS) and rhamnolipid were employed. Multiple indicators including effluent qualities, dissolved organic matters, biofilm physiology and morphology characteristics were investigated to explore the mechanisms. Results showed that removal rates of effluent COD in test groups significantly recovered to the level before aging. Compared with the control, effluent in SDBS and rhamnolipid-treated groups obtained more protein-like and humic-like substances, respectively. Furthermore, great live cell ratio, smooth surface and low adhesion force of biofilm were observed after rhamnolipid treatment, which was in consistent with good effluent qualities in the same group. This is the first report of applying rhamnolipid for in situ activity recovery of aging biofilm in bioreactors. PMID:27513646

  14. 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.

  15. Autonomous Active and Reactive Power Distribution Strategy in Islanded Microgrids

    OpenAIRE

    Wu, Dan; Tang, Fen; Guerrero, Josep M.; Vasquez, Juan Carlos; Chen, Guoliang; Sun, Libing

    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 (RES) units regulate different active power, the proposed reactive power distribution is adaptively controlled according to the active power distribution among energy storage systems (ESS) and RES un...

  16. 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.

  17. Prognostics of lumen maintenance for High power white light emitting diodes using a nonlinear filter-based approach

    International Nuclear Information System (INIS)

    High power white light emitting diodes (HPWLEDs), with advantages in terms of luminous efficacy, energy saving, and reliability, have become a popular alternative to conventional luminaires as white light sources. Like other new electronic products, HPWLEDs must also undergo qualification testing before being released to the market. However, most traditional qualification tests, which require all devices under testing to fail, are time-consuming and expensive. Nowadays, as recommended by the Illuminating Engineering Society (IES, IES-TM-21-11), many LED manufacturers use a projecting approach based on short-term collected light output data to predict the future lumen maintenance (or lumen lifetime) of LEDs. However, this projecting approach, which depends on the least-square regression method, generates large prediction errors and uncertainties in real applications. To improve the prediction accuracy, we present in this paper a nonlinear filter-based prognostic approach (the recursive Unscented Kalman Filter) to predict the lumen maintenance of HPWLEDs based on the short-term observed data. The prognostic performance of the proposed approach and the IES-TM-21-11 projecting approach are compared and evaluated with both accuracy- and precision-based metrics

  18. Filter and window assemblies for high power insertion device synchrotron radiation sources

    International Nuclear Information System (INIS)

    The powerful beams of x-ray radiation generated by insertion devices at high power synchrotron facilities deposit substantial amounts of localized heat in the front end and optical components that they intercept. X-ray beams from undulator sources, in particular, are confined to very narrow solid angles and therefore impose very high absorbed heat fluxes. This paper is devoted to a detailed study of the design of windows for the Advanced Photon Source undulators and wigglers, emphasizing alternative design concepts, material considerations, and cooling techniques necessary for handling the high heat load of the insertion devices. Various designs are thermally and structurally analyzed by numerically simulating full-power operating conditions. This analysis also has relevance to the design and development of other beam line components which are subjected to the high heat loads of insertion devices

  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. 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. PMID:22346682

  1. 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. PMID:22346682

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Iman Lorzadeh

    2016-08-01

    Full Text Available 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 attracted considerable attention due to its effective damping performance and simple implementation. This paper thus presents a state-of-the-art review of resonance and stability characteristics of CCF-based AD approaches for a digitally-controlled LCL filter-based grid-connected inverter taking into account the effect of computation and pulse width modulation (PWM delays along with a detailed analysis on proper design and implementation.

  4. MODIFIED CLIPPING AND FILTERING TECHNIQUE FOR PEAK-TO-AVERAGE POWER RATIO REDUCTION OF OFDM SIGNALS USED IN WLAN.

    Directory of Open Access Journals (Sweden)

    P.K.Sharma

    2010-10-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM has several attributes which make it a preferred modulation scheme for high speed wireless communication. However, the increased Peak-to-Average Power Ratio (PAPR of the signal is a significant drawback for OFDM systems since it restricts the efficiency of the transmitter. This paper is focused in the domain of PAPR reduction of OFDM signals. The main idea is to use a combination of data interleaving with clipping and filtering and use of optimum clipping ratio (Υ in order to increase the overall performance of the system and the PAPR and BER is valuated in AWGN channel. The main advantage of the proposed combination lies in reducing PAPR and significantly reduction in BER in the presence of AWGN channel.

  5. 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.

  6. Resonant-inductor-voltage feedback active damping based control for grid-connected inverters with LLCL-filters

    DEFF Research Database (Denmark)

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

    2014-01-01

    LLCL-filter is recently emerging into grid-connected inverters due to its high attenuation of high-frequency harmonics with a smaller size. Active damping methods have been proposed to reduce the resonance peak caused by the LLCL-filter to stabilize the whole system without extra losses. The active......-phase grid-connected voltage source inverter (VSI). The design method is described through the analysis in the s-domain and the z-domain. Then the robustness and harmonic rejection of the grid voltage with the active damping method is analyzed considering the processing delay. Finally, the performance of the...

  7. 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. I...

  8. 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

  9. Using an in-line uninterruptable power supply as TEMPEST 'filter' for naval vessels

    NARCIS (Netherlands)

    Bergsma, Hans; Leferink, Frank

    2015-01-01

    A major objective of TEMPEST engineering is to separate equipment carrying classified (=RED) data from equipment carrying unclassified (=BLACK) data, to prevent unintentional radio or electrical signals, containing classified data, emission. RED/BLACK separation in the power supply system is in gene

  10. Active and reactive power in stochastic resonance for energy harvesting

    OpenAIRE

    Kubota, Madoka; Takahashi, Ryo(Graduate School of Science and Engineering, Shimane University, Matsue, 690-8504, Japan); Hikihara, Takashi

    2015-01-01

    A power allocation to active and reactive power in stochastic resonance is discussed for energy harvesting from mechanical noise. It is confirmed that active power can be increased at stochastic resonance, in the same way of the relationship between energy and phase at an appropriate setting in resonance.

  11. 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

  12. 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.

  13. 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.

  14. Synthesis and evaluation of octocrylene-inspired compounds for UV-filter activity

    Directory of Open Access Journals (Sweden)

    Hudson C. Polonini

    2014-07-01

    Full Text Available Octocrylene (2-ethylhexyl 2-cyano-3,3-diphenyl-2-propenoate is present in several sunscreens and is known to work synergistically with UV filters. We prepared eight octocrylene-related compounds to test their photoprotective activities by measuring diffuse transmittance. The compounds had varied photoprotection profiles, with Sun Protection Factors (SPF ranging from 1 to 5 and UVA Protection Factors (UVAPF ranging from 1 to 8. Compounds 4, 5, and 7 showed the best protection against UVB sunrays, while compounds 5, 6, and 7 presented the best results for protection from UVA, so compound 7 had the most balanced protection overall. Results for compounds 4, 8, and 9 are reported for the first time in the literature.

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

    OpenAIRE

    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. The main difficulty in dealing with biomedical signal processing is that the information of interest is often a combination of features that are well localized temporally (e.g., spikes) and other...

  16. 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 pow...

  17. 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.

  18. 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.

  19. 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.

  20. Lightweight MAC-Spoof Detection Exploiting Received Signal Power and Median Filtering

    OpenAIRE

    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 s...

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. Model based active power control of a wind turbine

    DEFF Research Database (Denmark)

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

    2014-01-01

    technology to increase competitiveness of the wind power plants. One way to increase competitiveness of wind power plants is to offer grid services (also called ancillary services) that are normally offered by traditional power plants. One of the ancillary services is called reserve power. There are instants...... 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...

  6. 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.

  7. 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.

  8. Removal of microcystin-LR from spiked water using either activated carbon or anthracite as filter material.

    Science.gov (United States)

    Drogui, Patrick; Daghrir, Rimeh; Simard, Marie-Christine; Sauvageau, Christine; Blais, Jean François

    2012-01-01

    The occurrence of cyanobacterial toxins (blue-green algae) in drinking water sources is a big concern for human health. Removal of microcystin-LR (MC-LR) from drinking water was evaluated at the laboratory pilot scale using either granular activated carbon (GAC) or powdered activated carbon (PAC) and compared with the treatment using anthracite as filter material. Virgin GAC was more effective at removing MC-LR (initial concentration ranging from 9 to 47 microg L(-1)) to reach the World Health Organization recommended level (1.0 microg L(-1)). When the GAC filter was colonized by bacteria, the filter became less effective at removing MC-LR owing to competitive reactions occurring between protein adsorption (released by bacteria) and MC-LR adsorption. Using PAC, the concentration of MC-LR decreased from 22 to 3 microg L(-1) (removal of 86% of MC-LR) by the addition of 100 mg PAC L(-1). PMID:22629609

  9. 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

    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 to a...

  10. MMIC Tunable Transversal Bandpass Active Filter at 9–12 GHz

    OpenAIRE

    Gomez–Garcıa, Roberto; Briso–Rodrıguez, Cesar; Mahfoudi, Mustapha; Jose I. Alonso

    2003-01-01

    In this paper a novel microwave tunable filtering structure based on a transversal configuration is proposed. A specific MMIC prototype is designed, fabricated and measured at 9–12 GHz range. The main constraints of the monolithic technology in tunable transversal filter design and construction are also discussed.

  11. 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

  12. 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

  13. 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 ...

  14. 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.

  15. Active screening of magnetic field near power stations generator buses

    Directory of Open Access Journals (Sweden)

    B.I. Kuznetsov

    2013-12-01

    Full Text Available An experimental study technique for a prototyping system of active screening of power-frequency magnetic field distortions near power station generator buses via controllable magnetic field sources is presented. Results of experimental research on a proto-typing active screening system with different control algorithms are given.

  16. 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

  17. 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. PMID:27337435

  18. A Kalman filtering based control scheme for the improvement of dynamic performance of an AC/DC power system

    Science.gov (United States)

    Pecen, Recayi

    In this dissertation, two major accomplishments are achieved. First, the feasibility of a proposed Wyoming to California HVDC system having the ratings of 1000 MW, ±500 kV, 2 kA, 860 miles and 12-pulse bipolar lines is shown for exporting Wyoming's electrical power resources to the heavy loaded western states. The second and the main objective of this dissertation is the development of a Kalman filtering (KF) based control scheme applied to an ac/dc power system. It is shown that the use KF algorithm to estimate some of the system states and utilizing them in a proportional Integral (PI) controller which has a better performance for this specific control scheme have resulted in a better dynamic performance of the proposed system. A set of case studies has shown that the system dynamic performance is improved for most of the contingencies. Ac and dc noisy voltage and current measurements received from the simulated ac/dc power system are sent to the KF estimation algorithm. The noise-separated best estimates of measurable states are computed and sent to a PI controller-based current and firing angle control subsections in order to provide a set of optimum thyristor firing angles for both converter stations during and after contingencies until the normal operation is reached. To evaluate the dynamic performance of the system with the KF algorithm, the model is simulated by a well-known digital simulation package, Electromagnetic Transients DC Program (PSCAD/EMTDC) of Manitoba HVDC Research Center. To apply the KF algorithm, a general, linearized, state-space model of the proposed ac/dc system, appropriate for analyzing both the KF and the electromagnetics transients, is derived first. The derived model enables the representation of an ac power system with two ac sources and one HVDC line with a parallel ac line connecting the two systems. It is shown that system eigenvalues of the discretized system model for a normal operating point are inside the unit circle that

  19. 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.

  20. 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. PMID:26931341

  1. Implementation of a Novel Control Strategy Using Fuzzy Logic Controller to Shunt Active Filter for Line Harmonic Reduction

    OpenAIRE

    T Manigandan; N. Senthilnathan

    2012-01-01

    Problem statement: Now days, power quality has been given attention due to the intensive use of power electronic equipments in all types of industries such as steel, paper, textile industries and so on. These power electronic devices induce harmonic distortion into the supply lines which gives rise to many undesirable effects. Approach: This study presents a new method for harmonic and reactive power compensation with a Fuzzy logic controller and a new control algorithm for active power filte...

  2. 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...

  3. DESIGN OF RENEWABLE ENERGY BASED SHUNT ACTIVE FILTER WITH MULTILEVEL INVERTER USING GENETIC ALGORITHM

    Directory of Open Access Journals (Sweden)

    P.Saravanan

    2013-05-01

    Full Text Available The total harmonic distortion is the major problem in cascaded multilevel inverters. Compared to the three level voltage source inverters, the step-wise output voltage is a major advantage of multilevel inverters. In phase I, the minimization of THD with reduced number of switches using genetic algorithm(GA in a cascaded multilevel inverter with common H-bridge is used. The selective harmonic elimination pulse width modulation technique(SHEPWM has been applied to cascaded multilevel inverter to eliminate lower order harmonics.THD value is minimized by using minimization of total harmonic distortion (MTHD technique in an eleven level cascaded multilevel inverter with common H-bridge and also the harmonics upto 13th order will be reduced. In phase II, a cascaded multilevel inverter with common H-bridge is implemented in the shunt active filter for further reduction of THD and also for load current compensation. A photovoltaic cell is used as a continuous source of energy. Simulation and performance is verified by using MATLAB/Simulink.

  4. Particle Filter with Integrated Voice Activity Detection for Acoustic Source Tracking

    Directory of Open Access Journals (Sweden)

    Anders M. Johansson

    2007-01-01

    Full Text Available In noisy and reverberant environments, the problem of acoustic source localisation and tracking (ASLT using an array of microphones presents a number of challenging difficulties. One of the main issues when considering real-world situations involving human speakers is the temporally discontinuous nature of speech signals: the presence of silence gaps in the speech can easily misguide the tracking algorithm, even in practical environments with low to moderate noise and reverberation levels. A natural extension of currently available sound source tracking algorithms is the integration of a voice activity detection (VAD scheme. We describe a new ASLT algorithm based on a particle filtering (PF approach, where VAD measurements are fused within the statistical framework of the PF implementation. Tracking accuracy results for the proposed method is presented on the basis of synthetic audio samples generated with the image method, whereas performance results obtained with a real-time implementation of the algorithm, and using real audio data recorded in a reverberant room, are published elsewhere. Compared to a previously proposed PF algorithm, the experimental results demonstrate the improved robustness of the method described in this work when tracking sources emitting real-world speech signals, which typically involve significant silence gaps between utterances.

  5. 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.

  6. Nuclear power plant construction activity, 1986

    International Nuclear Information System (INIS)

    Cost estimates, chronological data on construction progress, and the physical characteristics of nuclear units in commercial operation and units in the construction pipeline as of December 31, 1986, are presented. This report, which is updated annually, was prepared to provide an overview of the nuclear power plant construction industry. The report contains information on the status of nuclear generating units, average construction costs and lead-times, and construction milestones for individual reactors

  7. Autonomous Navigation for Autonomous Underwater Vehicles Based on Information Filters and Active Sensing

    OpenAIRE

    Tianhong Yan; Yan Liang; Shujing Zhang; Chao Li; Bo He; Hongjin Zhang

    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 irrespec...

  8. 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...

  9. Continuous monitoring α-activity on aerosol filters by the pseudo-coincidence-technique. Explicitly taking into account the short lived Po-218 activity

    International Nuclear Information System (INIS)

    Pseudo-coincidence-technique is applied to continuous monitoring of α-activity on aerosolfilters by proportional counters. Filter activity can markedly increase or decrease by changing air conditions especially by the amount of short lived Po-218 activity. Conditions of constant proportions of activity concentrations for the short lived species for operating this technique are seldom fulfilled. The dynamic behavior of artificial (long lived) and natural (short lived) activity is mathematically modelled and the measured moving count rates are analyzed under this model by a multivariate regression analysis for activity concentrations of artificial resp. short lived activity. Results are compared to standard recommendations of DIN ISO 11929.

  10. 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.

  11. 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

  12. Exploring the Role of Mechanotransduction Activation and Adaptation Kinetics in Hair Cell Filtering Using a Hodgkin-Huxley Approach

    Science.gov (United States)

    Wells, Gregg B.; Ricci, Anthony J.

    2011-11-01

    In the auditory system, mechanotransduction occurs in the hair cell sensory hair bundle and is the first major step in the translation of mechanical energy into electrical. Tonotopic variations in the activation kinetics of this process are posited to provide a low pass filter to the input. An adaptation process, also associated with mechanotransduction, is postulated to provide a high pass filter to the input in a tonotopic manner. Together a bandpass filter is created at the hair cell input. Corresponding mechanical components to both activation and adaptation are also suggested to be involved in generating cochlear amplification. A paradox to this story is that hair cells where the mechanotransduction properties are most robust possess an intrinsic electrical resonance mechanism proposed to account for all required tuning and amplification. A simple Hodgkin-Huxley type model is presented to attempt to determine the role of the activation and adaptation kinetics in further tuning hair cells that exhibit electrical resonance. Results further support that steady state mechanotransduction properties are critical for setting the resting potential of the hair cell while the kinetics of activation and adaptation are important for sharpening tuning around the characteristic frequency of the hair cell.

  13. 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.

  14. 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

    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......Silent PowerFactory software demonstrates the accuracy of the proposed method....

  15. Water Filter

    Science.gov (United States)

    1982-01-01

    A compact, lightweight electrolytic water sterilizer available through Ambassador Marketing, generates silver ions in concentrations of 50 to 100 parts per billion in water flow system. The silver ions serve as an effective bactericide/deodorizer. Tap water passes through filtering element of silver that has been chemically plated onto activated carbon. The silver inhibits bacterial growth and the activated carbon removes objectionable tastes and odors caused by addition of chlorine and other chemicals in municipal water supply. The three models available are a kitchen unit, a "Tourister" unit for portable use while traveling and a refrigerator unit that attaches to the ice cube water line. A filter will treat 5,000 to 10,000 gallons of water.

  16. Comparison of active-set method deconvolution and matched-filtering for derivation of an ultrasound transit time spectrum

    International Nuclear Information System (INIS)

    The quality of ultrasound computed tomography imaging is primarily determined by the accuracy of ultrasound transit time measurement. A major problem in analysis is the overlap of signals making it difficult to detect the correct transit time. The current standard is to apply a matched-filtering approach to the input and output signals. This study compares the matched-filtering technique with active set deconvolution to derive a transit time spectrum from a coded excitation chirp signal and the measured output signal. The ultrasound wave travels in a direct and a reflected path to the receiver, resulting in an overlap in the recorded output signal. The matched-filtering and deconvolution techniques were applied to determine the transit times associated with the two signal paths. Both techniques were able to detect the two different transit times; while matched-filtering has a better accuracy (0.13 μs versus 0.18 μs standard deviations), deconvolution has a 3.5 times improved side-lobe to main-lobe ratio. A higher side-lobe suppression is important to further improve image fidelity. These results suggest that a future combination of both techniques would provide improved signal detection and hence improved image fidelity. (note)

  17. 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.

  18. Effect of point-of-use, activated carbon filters on the bacteriological quality of rural groundwater supplies.

    OpenAIRE

    Synder, J W; Mains, C N; Anderson, R. E.; Bissonnette, G K

    1995-01-01

    The water quality of 24 rural, domestic groundwater supplies treated with point-of-use, powdered activated carbon (PAC) filters was monitored to determine how such treatment might impact the bacteriological quality of private, residential drinking water supplies. Heterotrophic-plate-count (HPC) and total coliform analyses were performed on raw, PAC-treated, and overnight or stagnant (first-draw) PAC-treated water samples. Densities of HPC bacteria were elevated by 0.86 and 0.20 orders of magn...

  19. Space Power Amplification with Active Linearly Tapered Slot Antenna Array

    Science.gov (United States)

    Simons, Rainee N.; Lee, Richard Q.

    1993-01-01

    A space power amplifier composed of active linearly tapered slot antennas (LTSA's) has been demonstrated and shown to have a gain of 30 dB at 20 GHz. In each of the antenna elements, a GaAs monolithic microwave integrated circuit (MMIC) three-stage power amplifier is integrated with two LTSA's. The LTSA and the MMIC power amplifier has a gain of 11 dB and power added efficiency of 14 percent respectively. The design is suitable for constructing a large array using monolithic integration techniques.

  20. Enhanced static ground power unit based on flying capacitor based h-bridge hybrid active-neutral-point-clamped converter

    DEFF Research Database (Denmark)

    Abarzadeh, Mostafa; Madadi Kojabadi, Hossein; Deng, Fujin;

    2016-01-01

    Static power converters have various applications, such as static ground power units (GPUs) for airplanes. This study proposes a new configuration of a static GPU based on a novel nine-level flying capacitor h-bridge active-neutral-point-clamped (FCHB_ANPC) converter. The main advantages of the p......Static power converters have various applications, such as static ground power units (GPUs) for airplanes. This study proposes a new configuration of a static GPU based on a novel nine-level flying capacitor h-bridge active-neutral-point-clamped (FCHB_ANPC) converter. The main advantages...... of the proposed converter in comparison with conventional nine-level ANPC converter are decreasing the number of switches and flying capacitors (FCs) in the proposed converter, doubling the output voltage level of a traditional ANPC converter and reduction of output L-C filter sizes which results in significant...

  1. The Bacterial Communities of Full-Scale Biologically Active, Granular Activated Carbon Filters Are Stable and Diverse and Potentially Contain Novel Ammonia-Oxidizing Microorganisms

    OpenAIRE

    LaPara, Timothy M.; Hope Wilkinson, Katheryn; Strait, Jacqueline M.; Hozalski, Raymond M.; Sadowksy, Michael J.; Hamilton, Matthew J

    2015-01-01

    The bacterial community composition of the full-scale biologically active, granular activated carbon (BAC) filters operated at the St. Paul Regional Water Services (SPRWS) was investigated using Illumina MiSeq analysis of PCR-amplified 16S rRNA gene fragments. These bacterial communities were consistently diverse (Shannon index, >4.4; richness estimates, >1,500 unique operational taxonomic units [OTUs]) throughout the duration of the 12-month study period. In addition, only modest shifts in t...

  2. 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.

  3. 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.

  4. Photovoltaic solar system connected to the electric power grid operating as active power generator and reactive power compensator

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Fabio L.; Moraes, Adelio J.; Guimaraes, Geraldo C.; Sanhueza, Sergio M.R.; Vaz, Alexandre R. [Universidade Federal de Uberlandia, Uberlandia-MG, CEP 38400-902 (Brazil)

    2010-07-15

    In the case of photovoltaic (PV) systems acting as distributed generation (DG) systems, the DC energy that is produced is fed to the grid through the power-conditioning unit (inverter). The majority of contemporary inverters used in DG systems are current source inverters (CSI) operating at unity power factor. If, however, we assume that voltage source inverters (VSI) can replace CSIs, we can generate reactive power proportionally to the remaining unused capacity at any given time. According to the theory of instantaneous power, the inverter reactive power can be regulated by changing the amplitude of its output voltage. In addition, the inverter active power can be adjusted by modifying the phase angle of its output voltage. Based on such theory, both the active power supply and the reactive power compensation (RPC) can be carried out simultaneously. When the insolation is weak or the PV modules are inoperative at night, the RPC feature of a PV system can still be used to improve the inverter utilisation factor. Some MATLAB simulation results are included here to show the feasibility of the method. (author)

  5. The Bacterial Communities of Full-Scale Biologically Active, Granular Activated Carbon Filters Are Stable and Diverse and Potentially Contain Novel Ammonia-Oxidizing Microorganisms.

    Science.gov (United States)

    LaPara, Timothy M; Hope Wilkinson, Katheryn; Strait, Jacqueline M; Hozalski, Raymond M; Sadowksy, Michael J; Hamilton, Matthew J

    2015-10-01

    The bacterial community composition of the full-scale biologically active, granular activated carbon (BAC) filters operated at the St. Paul Regional Water Services (SPRWS) was investigated using Illumina MiSeq analysis of PCR-amplified 16S rRNA gene fragments. These bacterial communities were consistently diverse (Shannon index, >4.4; richness estimates, >1,500 unique operational taxonomic units [OTUs]) throughout the duration of the 12-month study period. In addition, only modest shifts in the quantities of individual bacterial populations were observed; of the 15 most prominent OTUs, the most highly variable population (a Variovorax sp.) modulated less than 13-fold over time and less than 8-fold from filter to filter. The most prominent population in the profiles was a Nitrospira sp., representing 13 to 21% of the community. Interestingly, very few of the known ammonia-oxidizing bacteria (AOB; amoA genes, however, suggested that AOB were prominent in the bacterial communities (amoA/16S rRNA gene ratio, 1 to 10%). We conclude, therefore, that the BAC filters at the SPRWS potentially contained significant numbers of unidentified and novel ammonia-oxidizing microorganisms that possess amoA genes similar to those of previously described AOB. PMID:26209671

  6. 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.

  7. Nuclear power development and nuclear data activities in Malaysia

    International Nuclear Information System (INIS)

    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)

  8. 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)

  9. Filtres à activité catalytique pour moteur Diesel Catalytic Activity Filters for Diesel Engines

    Directory of Open Access Journals (Sweden)

    Goldenberg E.

    2006-11-01

    Full Text Available A partir de l'examen des normes actuelles et envisagées dans le futur pour limiter les émissions de particules Diesel, et en considérant les propriétés physico-chimiques de ces particules, cet article expose les problèmes posés par la filtration des suies Diesel et leur élimination par combustion sur les différents types de filtres actuellement retenus. La régénération des filtres par combustion catalytique du dépôt est plus particulièrement discutée. From an examination of present regulations and ones being considered for the future to limit particle emissions by diesel engines, and considering the physicochemical properties of such particles, this article describes the problems raised by filtering soot from diesel engines and eliminating it by various types of filters now used. Filter regeneration by catalytic combustion of the deposit is considered in particular.

  10. 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......) reference seven-layer model of communication systems, and the main communication technologies and protocols on each corresponding layer are introduced. Some newly developed communication techniques, like Ethernet, are discussed with reference to the possible applications in distributed power system....... 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...

  11. Design and analysis of an active power factor correction circuit

    OpenAIRE

    Zhou, Zhen

    1989-01-01

    The design of an active-unity power factor correction circuit with variable-hysteresis control for off-line dc-to-dc switching power supplies is described. Design equations relating the boost inductor current ripple to the circuit components selection and circuit performance arc discussed. A computer-aided design program (CADO) is developed to give the optimal circuit components selection. A 500 watt, 300 volt experimental circuit is built to verify the simulation and analysis ...

  12. 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...

  13. Gamma power is phase-locked to posterior alpha activity.

    Directory of Open Access Journals (Sweden)

    Daria Osipova

    Full Text Available Neuronal oscillations in various frequency bands have been reported in numerous studies in both humans and animals. While it is obvious that these oscillations play an important role in cognitive processing, it remains unclear how oscillations in various frequency bands interact. In this study we have investigated phase to power locking in MEG activity of healthy human subjects at rest with their eyes closed. To examine cross-frequency coupling, we have computed coherence between the time course of the power in a given frequency band and the signal itself within every channel. The time-course of the power was calculated using a sliding tapered time window followed by a Fourier transform. Our findings show that high-frequency gamma power (30-70 Hz is phase-locked to alpha oscillations (8-13 Hz in the ongoing MEG signals. The topography of the coupling was similar to the topography of the alpha power and was strongest over occipital areas. Interestingly, gamma activity per se was not evident in the power spectra and only became detectable when studied in relation to the alpha phase. Intracranial data from an epileptic subject confirmed these findings albeit there was slowing in both the alpha and gamma band. A tentative explanation for this phenomenon is that the visual system is inhibited during most of the alpha cycle whereas a burst of gamma activity at a specific alpha phase (e.g. at troughs reflects a window of excitability.

  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. Effects of ozonation and temperature on biodegradation of natural organic matter in biological granular activated carbon filters

    Directory of Open Access Journals (Sweden)

    L. T. J. van der Aa

    2010-02-01

    Full Text Available Four pilot (biological granular activated carbon ((BGAC filters were operated to quantify the effects of ozonation and water temperature on the biodegradation of natural organic matter (NOM in (BGAC filters. Removal of dissolved organic carbon (DOC, assimilable organic carbon (AOC and oxygen and the production of carbon dioxide were taken as indicators for NOM biodegradation. Ozonation stimulated DOC and AOC removal in the BGAC filters, but had no significant effect on oxygen removal and carbon dioxide production. The temperature had no significant effect on DOC and AOC removal, while oxygen removal and carbon dioxide production increased with increasing temperature. Multivariate linear regression was used to quantify these relations. In summer the ratio between oxygen consumption and DOC removal exceeded the theoretical maximum of 2.5 g O2·g C−1 and the ratio between carbon dioxide production and DOC removal exceeded the theoretical maximum of 3.7 g CO2·g C−1. Bioregeneration of large NOM molecules could explain this excesses and the non-correlation between DOC and AOC removal and oxygen removal and carbon dioxide production. However bioregeneration of large NOM molecules was considered not likely to happen, due to sequestration.

  16. 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.

  17. 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

    more practical control strategy appears to be to minimise the weighted sum of squared forces and velocities below the mounts, which gives near-optimal performance in simulations. These theoretical results are supported by experiments with a real-time control system. The actuator and sensor requirements...... 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...

  18. 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.

  19. Geostatistical Characteristics of the Structure of Spatial Variation of Electrical Power in the National 110 KV Network Including Results of Variogram Model Components Filtering

    Directory of Open Access Journals (Sweden)

    Barbara Namysłowska-Wilczyńska

    2015-03-01

    Full Text Available The paper provides results of analysing the superficial variability of electrical power using two geostatistical methods – lognormal kriging and ordinary kriging. The research work was to provide detailed characterization and identification of the electrical load variability structure at nodes of a 110 kV network over the whole territory of Poland having been analyzed on the basis of results from kriging techniques applied. The paper proposes the methodology using two techniques of modelling and estimating average values Z* of electrical powers, i.e. lognormal kriging and ordinary kriging. The input data for calculations were electrical powers at nodes of 110 kV network related to the same time moment, i.e. 11:00 a.m. in summer and winter seasons. Kriging calculations were made for various variants of examinations. Filtering was carried out for assumed complex theoretical models of semivariograms of electrical powers, which means their dividing into several models components of the covariance (nugget effect, 1 spherical model, 2 spherical model, which were filtered out successively. Then, estimations were made for average values Z* of powers while particular components are passed over. The results of analyses made with considering particular components of semivariograms models were shown in raster maps providing distributions of estimated average values Z* of electrical powers. This allowed the orientation of variations in values of this parameter, both over the territory of the whole country and in time domain, for two seasons – summer and winter, and also when various models components were assumed of semivariograms of the loads. Detailed analysis of spatial-time variability of average values Z* of electrical loads over the country allowed to identify their range and nature of variability.

  20. 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...

  1. High Performance Harmonic Isolation By Means of The Single-phase Series Active Filter Employing The Waveform Reconstruction Method

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk; Hava, Ahmet M.

    2009-01-01

    This paper proposes the Waveform Reconstruction Method (WRM), which is utilized in the single-phase Series Active Filter's (SAF's) control algorithm, in order to extract the load harmonic voltage component of voltage harmonic type single-phase diode rectifier loads. Employing WRM and the line...... current sampling delay reduction method (SDRM), a single-phase SAF compensated system provides higher harmonic isolation performance and higher stability margins compared to the system using conventional synchronous reference frame based methods. The analytical, simulation, and experimental studies of a 2.......5 kW single-phase SAF compensated system prove the theory....

  2. 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.

  3. Microwave Filters

    OpenAIRE

    Zhou, Jiafeng

    2010-01-01

    The general theory of microwave filter design based on lumped-element circuit is described in this chapter. The lowpass prototype filters with Butterworth, Chebyshev and quasielliptic characteristics are synthesized, and the prototype filters are then transformed to bandpass filters by lowpass to bandpass frequency mapping. By using immitance inverters ( J - or K -inverters), the bandpass filters can be realized by the same type of resonators. One design example is given to verify the theory ...

  4. Comparing cost and process performance of activated sludge (AS) and biological aerated filters (BAF) over ten years of full sale operation.

    Science.gov (United States)

    Hansen, R; Thogersen, T; Rogalla, F

    2007-01-01

    In the early 1990s, the Wastewater Treatment Plant (WWTP) of Frederikshavn, Denmark, was extended to meet new requirements for nutrient removal (8 mg/L TN, 1.5 mg TP/L) as well as to increase its average daily flow to 16,500 m(3)/d (4.5 MGD). As the most economical upgrade of the existing activated sludge (AS) plant, a parallel biological aerated filter (BAF) was selected, and started up in 1995. Running two full scale processes in parallel for over ten years on the same wastewater and treatment objectives enabled a direct comparison in relation to operating performance, costs and experience. Common pretreatment consists of screening, an aerated grit and grease removal and three primary settlers with chemical addition. The effluent is then pumped to the two parallel biological treatment stages, AS with recirculation and an upflow BAF with floating media. The wastewater is a mixture of industrial and domestic wastewater, with a dominant discharge of fish processing effluent which can amount to 50% of the flow. The maximum hydraulic load on the pretreatment section as a whole is 1,530 m(3)/h. Approximately 60% of the sewer system is combined with a total of 32 overflow structures. To avoid the direct discharge of combined sewer overflows into the receiving waters, the total hydraulic wet weather capacity of the plant is increased to 4,330 m(3)/h, or 6 times average flow. During rain, some of the raw sewage can be directed through a stormwater bypass to the BAF, which can be modified in its operation to accommodate various treatment needs: either using simultaneous nitrification/denitrification in all filters with recirculation introducing bottom aeration with full nitrification in some filters for storm treatment and/or post-denitrification in one filter. After treatment, the wastewater is discharged to the Baltic Sea through a 500 m outfall. The BAF backwash sludge, approximately 1,900 m(3) per 24 h in dry weather, is redirected to the AS plant. Primary settler

  5. Active power reserves evaluation in large scale PVPPs

    DEFF Research Database (Denmark)

    Crăciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso;

    2013-01-01

    The present trend on investing in renewable ways of producing electricity in the detriment of conventional fossil fuel-based plants will lead to a certain point where these plants have to provide ancillary services and contribute to overall grid stability. Photovoltaic (PV) power has the fastest...... growth among all renewable energies and managed to reach high penetration levels creating instabilities which at the moment are corrected by the conventional generation. This paradigm will change in the future scenarios where most of the power is supplied by large scale renewable plants and parts...... 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...

  6. 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.

  7. 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.

  8. A low power Gm-C filter with on-chip automatic tuning for a WLAN transceiver

    International Nuclear Information System (INIS)

    A sixth-order Butterworth Gm-C low-pass filter (LPF) with a continuous tuning architecture has been implemented for a wireless LAN (WLAN) transceiver in 0.35 μm CMOS technology. An interior node scaling technique has been applied directly to the LPF to improve the dynamic range and the structure of the LPF has been optimized to reduce both the die size and the current consumption. Measurement results show that the filter has 77.5 dB dynamic range, 16.3 ns group delay variation, better than 3% cutoff frequency accuracy, and 0 dBm passband IIP3. The whole LPF with the tuning circuit dissipates only 1.42 mA (5 MHz cutoff frequency) or 2.81 mA (10 MHz cutoff frequency) from 2.85 V supply voltage, and only occupies 0.175 mm2 die size. (semiconductor integrated circuits)

  9. A low power Gm-C filter with on-chip automatic tuning for a WLAN transceiver

    Energy Technology Data Exchange (ETDEWEB)

    Liu Silin; Ma Heping; Shi Yin, E-mail: slliu@semi.ac.c [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2010-06-15

    A sixth-order Butterworth Gm-C low-pass filter (LPF) with a continuous tuning architecture has been implemented for a wireless LAN (WLAN) transceiver in 0.35 {mu}m CMOS technology. An interior node scaling technique has been applied directly to the LPF to improve the dynamic range and the structure of the LPF has been optimized to reduce both the die size and the current consumption. Measurement results show that the filter has 77.5 dB dynamic range, 16.3 ns group delay variation, better than 3% cutoff frequency accuracy, and 0 dBm passband IIP3. The whole LPF with the tuning circuit dissipates only 1.42 mA (5 MHz cutoff frequency) or 2.81 mA (10 MHz cutoff frequency) from 2.85 V supply voltage, and only occupies 0.175 mm{sup 2} die size. (semiconductor integrated circuits)

  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. 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.

  12. Conversion rates in power plant plumes based on filter pack data. Part I. Coal-fired Cumberland plume

    Energy Technology Data Exchange (ETDEWEB)

    Forrest, J; Garber, R W; Newman, L

    1980-01-01

    The TVA Cumberland Steam Plant plume was monitored during the August 1978 Tennessee Plume Study of Project STATE. Samples were obtained by employing a triple screen high-volume assembly which contained: (1) a quartz filter for collecting particulate SO/sub 4//sup 2 -/, NO/sub 3//sup -/ and NH/sub 4//sup +/, (2) two NaCl-impregnated cellulose filters for collecting gaseous nitrate, and (3) two K/sub 2/CO/sub 3/-impregnated cellulose filters for collecting SO/sub 2/. Formation rates of sulfate and nitrate in the atmosphere were calculated by using total sulfur as a conservative tracer. Conversion of SO/sub 2/ to SO/sub 4//sup 2 -/ varied from approx. 0.1 to 0.8% h/sup -1/ during night and early morning hours; late morning and afternoon rates ranged from approx. 1 to 4% h/sup -1/. Rate of formation of NO/sub 3//sup -/ from NO was approx. 0.1 to 3% h/sup -1/ and approx. 3 to 12% h/sup -1/ for similar time periods. Particulate NH/sub 4//sup +/ concentrations generally increased with plume age, but rates of formation varied widely. Mole ratios of NH/sub 4//sup +//SO/sub 4//sup 2 -/ fell within 1 to 3.

  13. Onversion rates in power plant plumes based on filter pack data: The coal-fired cumberland plume

    Science.gov (United States)

    Forrest, Joseph; Garber, Robert W.; Newman, Leonard

    The TVA Cumberland Steam Plant plume was monitored during the August 1978 Tennessee Plume Study of Project STATE. Samples were obtained by employing a triple screen high-volume assembly which contained (1) a quartz filter for collecting particulate SO 42-, NO 3- and NH 4+, (2) two NaCl-impregnated cellulose filters for collecting gaseous nitrate and (3) two K 2CO 3-impregnated cellulose filters for collecting SO 2. Formation rates of sulfate and nitrate in the atmosphere were calculated by using total sulfur as a conservative tracer. Conversion of SO 2 to SO 42- varied from ~0.-0.8%h -1 during night and early morning hours; late morning and afternoon rates ranged from ~1-4% h -1'. Plumes were tracked to distances of 200 km and 9 h duration. Rate of formation of NO 3-from NO was ~0.1-3%h -1 and ~3-12%h -1 for similar time periods. Particulate NH 4+ concentrations generally increased with plume age, but rates of formation varied widely. Mole ratios of NH 4+/SO 42- fell within 1-3.

  14. Public acceptance (PA) activities of nuclear power in Japan

    International Nuclear Information System (INIS)

    At the first part of presentation present status of nuclear power development in Japan is described. Then results of poll on nuclear energy acceptance by population are analyzed. Further, current activities and future efforts directed to broad understanding by people benefits of nuclear energy are described. 6 figs

  15. The management plan preparation activities nuclear power plant in Indonesia

    International Nuclear Information System (INIS)

    A feasibility Study that has been updated show that two nuclear power units with each unit of power up to 1000 MWe can represent decently an economical alternative energy supply. It added that the available time schedule was quite tight so that the preparation for the development must be starting first. This paper will discuss the preparation of plans of the first nuclear power plant which includes program activities, the structure of contracts, schedules of activities and funding. From the information obtained to date that in addition to a candidate site that is ready to be built in Muria peninsula is still required another potential alternative site besides to search other complete data information. This site investigation activities completed within the time schedule was passed ''critical path'', so that these activities should be carried out intensively and obey the time. This paper describes the steps that need to be prepared to welcome the first nuclear power plant, after reviewing the various input above and apply the reality in Indonesia as the initial conditions. (author)

  16. 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

    different. It emerges that the fourth one has superior behavior and robustness and can stably work at higher frequencies than the others. Theoretical findings and analysis are supported by comparative experimental results on a 7-kVA laboratory setup. The highest harmonic frequency that can be stably...

  17. Water Filters

    Science.gov (United States)

    1993-01-01

    The Aquaspace H2OME Guardian Water Filter, available through Western Water International, Inc., reduces lead in water supplies. The filter is mounted on the faucet and the filter cartridge is placed in the "dead space" between sink and wall. This filter is one of several new filtration devices using the Aquaspace compound filter media, which combines company developed and NASA technology. Aquaspace filters are used in industrial, commercial, residential, and recreational environments as well as by developing nations where water is highly contaminated.

  18. 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

  19. Teollisuuden Voima Oy - Industrial Power Company Ltd. Local information activity

    International Nuclear Information System (INIS)

    There are two nuclear power producers in Finland - the state-owned power company Imatran Voima Oy which operates two 440 MW Soviet-made PWR units in southern Finland, east of Helsinki and the Teollisuuden Voima Oy - Industrial Power Company Ltd, or TVO, owned by Finnish industrial companies. TVO operates two 710 MW ABB ATOM BWR units producing about one fifth of the country's electricity consumption. Operating experiences are extremely good from all Finnish nuclear power plants. The Finns' attitude towards nuclear power has changed into a positive direction in recent times. This can probably be noted as an international trend now that the Chernobyl accident is becoming an incident of the past. The Finnish citizens and politicians are facing two questions; first, what is their attitude towards nuclear power as a source of energy, in other words, do they approve of the plants currently in operation. The second question is how they stand on the building of new plants. It is probably another universal phenomenon that the attitudes of people living in the vicinity of nuclear power plants are less critical than the attitudes of those living farther away. This does not, by any means, result in local information activity being easier or less important than nationwide information activity. On the contrary, local decision-makers, local media and inhabitants are those who can, and through whom we can, influence also wider circles. The Nuclear Energy Act, which became effective in Finland last year, defines that the final decision on whether nuclear power plants can be built inside a municipality, is made at local level. As far as TVO is concerned one factor making local information activity easier is the small size of the locality. The difficulty TVO has to face is the people's suspicion of information activity. All information is considered propaganda, regardless of its form, and only negative news are considered information. Also, a large proportion of people are passive

  20. Active Snubber Circuit for High Power Inverter Leg

    DEFF Research Database (Denmark)

    Rasmussen, Tonny Wederberg; Johansen, Morten Holst

    2009-01-01

    Abstract— High power converters in the conventional 6 pulse configuration with 6 switching elements IGBTs (Insulated Gate Bipolar Transistor) are pushed to the limit of power. Especially the switching loss is high. This reduces the switching frequency due to cooling problems. Passive snubber...... circuits have been introduced to reduce the loss even though some of the loss is removed from the IGBT to the snubber resistance. This paper takes also the next step to introduce the active Undeland snubber which in principle is lossless. The paper describes this solution together with some simulations...