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Sample records for active power filter

  1. Active Power Filter Using Predicted Current Control

    Xiaojie, Y.; Pivoňka, P.; Valouch, Viktor

    2001-01-01

    Roč. 46, č. 1 (2001), s. 41-50. ISSN 0001-7043 Institutional research plan: CEZ:AV0Z2057903 Keywords : active power filter * control strategy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  2. Prediction control of active power filters

    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

    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

    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

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

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

    2010-01-01

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

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

    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. Active Power Filter: Review of Converter Topologies and Control Strategies

    SARIBULUT, Lütfü; Ahmet TEKE; MERAL, M. EMIN; Tumay, Mehmet

    2011-01-01

    Decrease in the cost of power electronic devices and improvement in the efficiency of both power converters and energy storage components have increased the applicability of new technological solutions such as Custom Power (CP) and Flexible AC Transmission Systems (FACTS) Devices. Active Power Filter (APF) is one of the CP devices and can mitigate harmonics, reactive power and unbalanced load currents originating from load side. In this study, a comprehensive review of APF studies, the advant...

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

    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...

  10. Design and control of hybrid active power filters

    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...

  11. Voltage Harmonics Mitigation through Hybrid Active Power Filter

    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

    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 of...

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

    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

    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. Improvement of active filter for HIMAC power sources

    For the power sources of the synchrotron electromagnets for the heavy particle beam cancer therapy apparatus HIMAC in National Institute of Radiological Science, in order to stabilize the taken-out beam, the ripple property as low as below 1 x 10-6 is required. As for this electromagnet power sources, various devices were applied to lower ripples, and the required specifications have been satisfied. Also the beam spill is stable, but slight variation has been observed, therefore, by improving the performance of the active filter, the ripples were improved. The specifications of the electromagnet power sources and the whole constitution of the power source system are shown. In the HIMAC power sources, the means for having realized the low ripple performance so far are explained. Those are the absorption of the ineffective power generated from the power sources, the control of the ripples of common made due to the transducer thyristor, and the sure compensation of ripples by the control circuit for the power sources. By adding the band pass filters to the active filter, its characteristics were improved. As the result, 1200 Hz ripple component was reduced by 41 db, thus the sufficient effect was obtained. Hereafter, by the high sensitivity measurement of the current of electromagnets and the evaluation of magnetic fields, the validity will be evaluated. (K.I.)

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

    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

    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. Selective Harmonic Current Mitigation with Shunt Active Power Filter

    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...

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

    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.

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

    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. (authors)

  1. Harmonic Analysis and Active Filtering in Offshore Wind Power Plants

    Chaudhary, Sanjay Kumar; Freijedo Fernandez, Francisco Daniel; Guerrero, Josep M.; Teodorescu, Remus; Bak, Claus Leth; Kocewiak, Ł. H.; Jensen, C. F.

    the point of common coupling (PCC). The resonance conditions should be avoided in all cases. This paper describes the harmonic analysis techniques applied on an OWPP network model. A method is proposed to estimate the harmonic current compensation from a shunt-connected active power filter to mitigate......Due to presence of long high voltage cable networks, and power transformers for the grid connection, the offshore wind power plants (OWPPs) are susceptible to harmonic distortion and resonances. The grid connection of OWPP should not cause the harmonic distortion beyond the permissible limits at...... the harmonic voltage distortion at the PCC. Finally the harmonic distortions in the compensated and the uncompensated systems are compared to demonstrate the efficacy of the compensation....

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

    P. Jeno Paul

    2011-01-01

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

  3. Optimum PI Controllers of Active Power Filters for Harmonic Voltage Mitigation in Multibus Industrial Power Systems

    Tlustý, J.; Valouch, Viktor

    Palma de Mallorca: EA4EPQ, 2006, s. 1-5. ISBN 84-609-6604-6. [nternational Conference on Renewable Energies and Power Quality (ICREPQ'06). Palma de Mallorca (ES), 05.04.2006-07.04.2006] Institutional research plan: CEZ:AV0Z20570509 Keywords : active power filter * industrial power system * harmonic voltage mitigation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

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

    2015-01-01

    Unintentional series and/or parallel resonances, due to the tuned passive filter and the line inductance, may result in severe harmonic distortion in the industrial power system. This paper presents a hybrid active filter to suppress harmonic resonance and reduce harmonic distortion as well....... The proposed hybrid filter is operated as variable harmonic conductance according to the voltage total harmonic distortion, so harmonic distortion can be reduced to an acceptable level in response to load change or parameter variation of power system. Since the hybrid filter is composed of a seventh......-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...

  5. Advanced Techniques in Harmonic Suppression via Active Power Filter (APF): A Review

    Ekhlas Mhawi; Hamdan Daniyal; Mohd Herwan Sulaiman

    2015-01-01

    This paper intends to present the recent development of artificial intelligence (AI) applications in active power filter (APF). As a result of the development in power electronic technology, (APF) continues to attract ample attention. Compared with the traditional reactive LC filter, active power filter is considered to be more effective in compensating harmonic current generated by nonlinear loads.APF, can correct the power quality and improve the reliability and stability on power utility. ...

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

    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.

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

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

    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...

  8. Connection of Shunt Active Power Filters in Multibus Industrial Power Systems for Harmonic Voltage Mitigation

    Tlustý, J.; Valouch, Viktor

    Zaragoza: EA4EPQ, 2005, s. 1-5. ISBN 84-609-3234-6. [International Conference on Renewable Energies and Power Quality (ICREPQ 05). Zaragoza (ES), 16.03.2005-18.03.2005] R&D Projects: GA ČR(CZ) GA102/03/1551; GA AV ČR(CZ) IAA2057301 Institutional research plan: CEZ:AV0Z20570509 Keywords : active power filter * industrial power system * harmonic voltage mitigation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

    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.

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

    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.

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

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

    2005-01-01

    Active Power Filters have been intensively explored in the past decade. Various topologies and control schemes have been documented aiming at reducing the cost and improving the performance of the compensation system. Hybrid active filters inherit the efficiency of passive filters and the improved...

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

    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.

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

    Tlustý, J.; Škramlík, Jiří; Švec, J.; Valouch, Viktor

    2010-01-01

    Roč. 2010, č. 517184 (2010), s. 1-13. ISSN 1024-123X R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : active power filter * power system * wireless cooperation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.689, year: 2010 http://www.hindawi.com/journals/mpe/2010/517184.html

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

    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...

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

    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.  

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

    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...

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

    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.

  18. Passive Power Filters

    Künzi, R

    2015-01-01

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

  19. Advanced Techniques in Harmonic Suppression via Active Power Filter (APF: A Review

    Ekhlas Mhawi

    2015-06-01

    Full Text Available This paper intends to present the recent development of artificial intelligence (AI applications in active power filter (APF. As a result of the development in power electronic technology, (APF continues to attract ample attention. Compared with the traditional reactive LC filter, active power filter is considered to be more effective in compensating harmonic current generated by nonlinear loads.APF, can correct the power quality and improve the reliability and stability on power utility. A brief explanation of some important areas in AI and a comprehensive survey of the literature along the main categories of AI is presented to introduce the readers into the wide-ranging topics that AI encompasses. Plenty of relevant literatures have been selected in the review, mostly emphasized on better accuracy, robustness, efficiency, stability and tracking ability of the system.

  20. A New Soft-Switched Three-Phase Four-Wire Shunt Active Power Filter

    Mohammad Reza Moradian

    2010-07-01

    Full Text Available This paper presents a new soft switched topology for losses reduction in a three-phase four-wire shunt active power filter (SAPF. The soft-switching technique not only offers a reduction in switching loss and thermal requirement, but also allows the possibility of high frequency and snubberless operation. Improved circuit performance and efficiency as well as reduction of EMI emission can be achieved. The resonant dc link inverter with low voltage stress is used for power converter of a three-phase four-wire shunt active power filter. It is assumed that the active power filter is connected to a load that can be unbalanced and may also draw harmonic currents. The p-q theory is used for controlling the SAPF. The proposed topology and operation principle of the control method is discussed in detail, finally the feasibility of such a scheme is demonstrated through simulation studies.

  1. A Review of Parallel Operation of Active Power Filters in the Distributed Generation System

    Khadem, Shafiuzzaman Khan; Basu, Malabika; Conlon, Michael

    2011-01-01

    In this paper a technical review of parallel operation of Active Power Filter (APF) for harmonic power compensation in distributed generation (DG) network has been presented. Controlling methods and connection topologies with their pros and cons are described. Recent improvements in controlling and future trends for the application of APFs in distributed mode are also identified.

  2. Compensation of Disturbed Load Currents Using Active Power Filter and Generalized Non-active Power Theory

    Lettl, J.; Šimek, Petr; Valouch, Viktor

    Prague: Electromagnetics Academy, 2015, s. 2500-2505. ISSN 1559-9450. [Progress In Electromagnetics Research Symposium Proceedings. Prague (CZ), 06.07.2015-09.07.2015] Institutional support: RVO:61388998 Keywords : disturbed load * GNP (Generalized Non-active Power) * parallel compensation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering www.piers.org

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

    Asiminoaei, Lucian; Rodriguez, Pedro; Blaabjerg, Frede

    2007-01-01

    Classical discontinuous pulse width modulations (DPWM's) may not be efficiently applied in active power filters, 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 switching...... 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...... is described, analyzed and validated on a three-phase voltage source inverter, rated at 7 kVA, 400 V, controlled as an active power filter....

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

    Xiaoling, Guo; Jian, Cheng; 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 s...

  5. Adaptive RBF Neural Network Control for Three-Phase Active Power Filter

    Juntao Fei; Zhe Wang

    2013-01-01

    An adaptive radial basis function (RBF) neural network control system for three‐phase active power filter (APF) is proposed to eliminate harmonics. Compensation current is generated to track command current so as to eliminate the harmonic current of non‐linear load and improve the quality of the power system. The asymptotical stability of the APF system can be guaranteed with the proposed adaptive neural network strategy. The parameters of the neural network can be adaptively updated to achie...

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

    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.

  7. A New Soft-Switched Three-Phase Four-Wire Shunt Active Power Filter

    Mohammad Reza Moradian; Khalil Rahimi; Majid Pakdel

    2010-01-01

    This paper presents a new soft switched topology for losses reduction in a three-phase four-wire shunt active power filter (SAPF). The soft-switching technique not only offers a reduction in switching loss and thermal requirement, but also allows the possibility of high frequency and snubberless operation. Improved circuit performance and efficiency as well as reduction of EMI emission can be achieved. The resonant dc link inverter with low voltage stress is used for power converter of a thre...

  8. Performance Comparison of Three-Phase Shunt Active Power Filter Algorithms

    Moleykutty George

    2008-01-01

    Full Text Available The usage of parallel converters is ever increasing. However, the voltage and current harmonics, zero-sequence and negative- sequence components of voltage and current and reactive power present in parallel converters give an alarming signal to power system and power electronic engineers. This research discusses performance of three-phase shunt active power filter (APF system using three different control techniques namely synchronous detection algorithm (SDM, instantaneous active and reactive (p-q theory and instantaneous direct and quadrature (d-q current method for the control of zero and negative sequence components, reactive power and harmonics. The novelty of this research lies in the successful application of SDM based APF and (d-q current method APF for the control of reactive power, harmonics and negative and zero sequence currents resulted by the use of parallel three-phase converters. MATLAB 6.1 toolbox is used to model the systems.

  9. Digital Simulation of a Hybrid Active Filter - An Active Filter in Series with a Shunt Passive Filter

    Sitaram, Mahesh I; Padiyar, KR; Ramanarayanan, V

    1998-01-01

    Active filters have long been in use for the filtering of power system load harmonics. In this paper, the digital simulation results of a hybrid active power filter system for a rectifier load are presented. The active filter is used for filtering higher order harmonics as the dominant harmonics are filtered by the passive filter. This reduces the rating of the active filter significantly. The DC capacitor voltage of the active filter is controlled using a PI controller.

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

    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.

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

    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.

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

    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.

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

    FERDI Brahim; DIB Samira; BERBAOUI Brahim

    2014-01-01

    This paper proposes a novel application of the instantaneous P-Q theory in a wind energy conversion system (WECS). The proposed WECS is formed by permanent magnet synchronous generator (PMSG) wind turbine system connected to the grid through parallel active power filter (PAPF). PAPF uses the generated wind energy to feed loads connected at the point of common coupling (PPC), compensates current harmonics and injects the excess of this energy into the grid using P-Q theory as control method. T...

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

    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...

  15. DSP Control of Line Hybrid Active Filter

    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...... active filter. Simulation and experimental results obtained in laboratory confirmed the validity and effectiveness of the control....

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

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

  17. Mirrors as power filters

    Multilayer mirrors offer advantages in power filtering compared to total reflection mirrors in both wiggler and undulator beams at third generation synchrotron radiation sources currently under construction. These advantages come at the expense of increased absorbed power in the mirror itself, and of added complexity of beamline optical design. This paper discusses these aspects

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

    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.

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

    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.

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

    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....

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

    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.

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

    Zhuo, Fang; Wu, Longhui; Chen, Zhe;

    2009-01-01

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

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

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

    2008-01-01

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

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

    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.

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

    FERDI Brahim

    2014-05-01

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

  6. Parameters of Active Power Filter Controllers in an Industrial Power System

    Sýkora, T.; Tlustý, J.; Valouch, Viktor

    Setúbal : Escola Superior de Tecnologia - IEEE, 2007, s. 48-53. ISBN 1-4244-0895-4. [International Conference on Power Engineering, Energy and Electrical Drives. Setúbal (PT), 12.04.2007-14.04.2007] R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : multiple APF * multiple harmonic problem * industrial power system Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

    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.

  8. Sliding mode controller for four leg shunt active power filter to eliminating zero sequence current, compensating harmonics and reactive power with fixed switching frequency

    Chebabhi Ali

    2015-01-01

    Full Text Available In this paper, the four leg inverter controlled by the three dimensional space vector modulation (3D SVM is used as the shunt active power filter (SAPF for compensating the three phase four wire electrical network, by using the four leg inverter with 3D SVM advantages to eliminated zero sequence current, fixed switching frequency of inverter switches, and reduced switching losses. This four leg inverter is employed as shunt active power filter to minimizing harmonic currents, reducing magnitude of neutral wire current, eliminating zero sequence current caused by nonlinear single phase loads and compensating reactive power, and a nonlinear sliding mode control technique (SMC is proposed for harmonic currents and DC bus voltage control to improve the performances of the three phase four wire four leg shunt active power filter based on Synchronous Reference Frame (SRF theory in the dq0 axes, and to decoupling the four leg SAPF mathematical model.

  9. Comparative Study of two PWM techniques for Three Phase Shunt Hybrid Active Power Filter to Suppress Line Current Harmonics

    SELVAMUTHUKUMARAN Rajasekar; NATARAJAN Muraly; PERIANAYAGAM Ajay-D-VimalRaj; MAHALINGAM Sudhakaran

    2010-01-01

    This paper investigates the performanceand comparison of two pulse-width-modulation (PWM)techniques by employing direct current control strategyapplied to three phase shunt hybrid active power filter(SHAPF). The objective of SHAPF is to eliminate linecurrent harmonics and to incur reactive powercompensation. The direct current control strategy isimplemented using Standard PWM (S-PWM) and aModified PWM (M-WM), in order to compensatecurrent harmonic and reactive power generated bydifferent load...

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

    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.

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

    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.

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

    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

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

    Chih-Lung Shen; Jye-Chau Su

    2012-01-01

    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 cos...

  14. Adaptive control of active filter using DSP

    In order to reduce output-voltage ripple of power supply, an active filter is necessary. In this paper, the active filter with DSP is proposed. The waveform from active filter can be flexibly improved by DSP programming. The output-voltage ripple can be enough reduced by mixing frequency components of the input-voltage ripple. The result of adaptive control using LMS algorism is presented. The improvement by using filtered-X method is discussed. (author)

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

    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.

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

    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.

  17. Discussions and Comparisons between Comprehensive Harmonic Detection and Specific Harmonic Detection in a Shunt Active Filter for Installation on a Power Distribution System

    Yamashita, Hiroshi; Pichai, Jintakosonwit; Fujita, Hideaki; Akagi, Hirofumi; Shinohara, Junya

    This paper deals with harmonic voltage detection methods for a shunt active filter intended for installation on a power distribution system. The active filter acts as a resistor to damp out harmonic propagation throughout the power distribution system. However, the active filter may fall into an unstable condition, because the control system forms a complex feedback loop including harmonic detection, current control, and system impedance. Stability and harmonic-damping performance of two different harmonic detection methods, that are comprehensive harmonic detection and specific harmonic detection, are compared with each other. Moreover, a new compensation scheme for the comprehensive harmonic detection method is proposed to improve system stability.

  18. A Three Phase Four Wire Shunt Active Power Filter Control Algorithm under Unbalanced and Distorted Supply Voltage

    K.Srinivas

    2014-03-01

    Full Text Available In this paper a control algorithm is validated with simulation studies in MAT environment and experimental studies are performed in to validate the proposed control algorithm. The projected algorithm to compensate the nonlinear and loads in three phase four wire distribution system using shunt active power filter. In this algorithm a positive sequence extraction of the supply voltage and the theory of instantaneous symmetrical component. To exemplify the concept, a three phase four wire with unbalance and non linear load is considered for compensation and detailed simulation and experimental studies are presented.

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

    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...

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

    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.

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

    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.

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

    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...

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

    Blaabjerg, Frede; Teodorescu, Remus; Rodriguez, Pedro; Luna, A.; Liserre, Marco

    This paper presents a nonconventional three-phase four-wire shunt active power filter (APF) topology controlled by using an energy approach. A general study of power terms involved in the operation of the four-wire APF is conducted in order to evidence the relationship between instantaneous energ...... 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....... 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...

  5. New Control Strategy of Hybrid Power Filter

    Škramlík, Jiří; Valouch, Viktor

    Madeira : APDEE, 2007, s. 1-6. ISBN 978-972-8822-08-8. [ Portuguese -Spanish Conference in Electrical Engineering - XCLEEE /10./. Madeira (PT), 05.07.2007-07.07.2007] R&D Projects: GA ČR GA102/06/0112 Institutional research plan: CEZ:AV0Z20570509 Keywords : active power filters * feedback and feedforward control strategy * unsymetrical and non-sinusoidal voltage system Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  6. Reducting Power Dissipation in Fir Filter: an Analysis

    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.

  7. An Artificial Neural Network Controller for Three-level Shunt Active Filter to Eliminate the Current Harmonics and Compensate Reactive Power

    Chennai Salim

    2011-09-01

    Full Text Available The increased use of nonlinear devices in the industry has resulted in the direct increase of harmonic distortion in power systems during these last years. Active filter systems are proposed to mitigate current harmonics generated by nonlinear loads. The conventional scheme based on a two-level voltage source inverter controlled by a hysteresis controller has several disadvantages and cannot be used for medium or high-power applications. To overcome these drawbacks and improve the APF performance, there’s a great tendency to use multilevel inverters controlled by intelligent controllers. Three level (NPC inverter is one of the most widely used topologies in various industrial applications such as machine drives and power factor compensators. On the other hand, artificial neural networks are under study and investigation in other power electronics applications. In order to gain the advantages of the three-level inverter and artificial neural networks and to reduce the complexity of classical control schemes, a new active power filter configuration controlled by two MLPNN (Multi-Layer Perceptron Neural Network is proposed in this paper. The first ANN is used to replace the PWM current controller, and the second one to maintain a constant dc link voltage across the capacitors and compensate the inverter power losses. The performance of the global system, including power and control circuits is evaluated by Matlab-Simulink and SimPowerSystem Toolbox simulation. The obtained results confirm the effectiveness of the proposed control scheme.

  8. Low Power Adder Based Auditory Filter Architecture

    2014-01-01

    Cochlea devices are powered up with the help of batteries and they should possess long working life to avoid replacing of devices at regular interval of years. Hence the devices with low power consumptions are required. In cochlea devices there are numerous filters, each responsible for frequency variant signals, which helps in identifying speech signals of different audible range. In this paper, multiplierless lookup table (LUT) based auditory filter is implemented. Power aware adder archite...

  9. On Power Idealization Filter Topologies of Lattice Implication Algebras

    2014-01-01

    The aim of this paper is to introduce power idealization filter topologies with respect to filter topologies and power ideals of lattice implication algebras, and to investigate some properties of power idealization filter topological spaces and their quotient spaces.

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

    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 with...

  11. Active Harmonic Filtering Using Current-Controlled, Grid-Connected DG Units With Closed-Loop Power Control

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

    2014-01-01

    The increasing application of nonlinear loads may cause distribution system power quality issues. In order to utilize distributed generation (DG) unit interfacing converters to actively compensate harmonics, this paper proposes an enhanced current control approach, which seamlessly integrates system harmonic mitigation capabilities with the primary DG power generation function. As the proposed current controller has two well-decoupled control branches to independently control fundamental and ...

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

    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.

  13. Improvement of radioiodine filters installed in nuclear power plants

    A method had to be developed allowing to extend the authorized service life of iodine sorption filters. After the qualitative and quantitative assessment of filter pollutants in the exhaust air of a PWR safety containment the investigations concentrated on the adsorption of the poltutants through additional activated carbon, if applicable provided as a guard bed, and on the possibility of pollutant desorption with hot air as the sweeping gas. Only pollutant absorption proved to be a method to be applied with success in nuclear power stations. Due to the difficulties arising in the storage or disposal of contaminated activated carbon, the consumption of activated carbon is of decisive importance for the safe adherence to a given minimum removal efficiency. A special filter type was developed with a view to reduce the consumption af activated carbon and the removal efficiency obtained was compared with that of a conventional deep bed filter on the basis of similar carbon consumption (tests with model filters). (orig.)

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

    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...

  15. SRF Based Cascaded Multilevel Active Filter

    Narisetti Sai Lakshmi#1, B.N. Kartheek

    2013-04-01

    Full Text Available In this paper a power line conditioner using a cascaded multilevel inverter based shunt active filter using synchronous reference frame (SRF controller is developed to improve the power quality in the distribution system . The cascaded multilevel inverter consists of two H-bridges in which each bridge has separate dc source. Gating signals to the cascaded multilevel voltage source inverter are generated from proposed triangular-carrier current controller. Here control strategy is different from conventional methods and provides superior performance. Using Reference Frame Transformation, the current is transformed from a − b − c stationery frame to rotating 0 − d − q frame. Using the PI controller, the current in the 0 − d − q frame is controlled to get the desired reference signal. This proposed cascaded five level active power filter system is validated through MATLAB/SIMULINK Platform. From simulation results observed that the cascaded multilevel inverter based shunt active filter effectively compensates the current harmonics.

  16. EMI filter techniques in power electronic converters

    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.

  17. 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

    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.

  18. HEPA filters in nuclear power plants

    HEPA filters have been in use in the nuclear power industry as long as the industry has existed. This paper traces a short history of their development and use as it relates to the engineering of systems that contain HEPA filters. The all too common misuses of HEPA filters could be, in part, due to this historical development. Examples of common problems of basic design and operation are provided. All examples are from operating U.S. Light Water Reactors. Suggestions for possible solutions to some of the basic reasons for poor design are offered. While no single answer exists, understanding of the reasons the problems do exist can greatly aid in developing effective solutions

  19. Modeling,Analysis and Simulation ofThree Phase Hybrid Power Filter forPower Quality Improvement

    Prashanta Kumar Das

    2012-01-01

    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...

  20. Active resistance capacitance filter design

    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.

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

    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 ...

  2. Digital notch filter based active damping for LCL filters

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

    2015-01-01

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

  3. Application of Kalman filter in the accelerator power control

    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)

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

    Gholam Reza Arab

    2014-10-01

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

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

    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.

  6. Hybrid power filter for advanced power quality in industrial systems

    Švec, J.; Müller, Z.; Kasembe, A. G.; Tlustý, J.; Valouch, Viktor

    2013-01-01

    Roč. 103, october 2013 (2013), s. 157-167. ISSN 0378-7796 R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Institutional support: RVO:61388998 Keywords : hybrid power filter * power quality * industrial system Subject RIV: JA - Electronic s ; Optoelectronics, Electrical Engineering Impact factor: 1.595, year: 2013 http://www.sciencedirect.com/science/article/pii/S0378779613001417

  7. Modeling,Analysis and Simulation ofThree Phase Hybrid Power Filter forPower Quality Improvement

    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.

  8. 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

    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.

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

    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.

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

    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.

  11. Power filtering of nth order in the fractional Fourier domain

    Alieva, Tatiana; Calvo, Maria Luisa [Departamento de Optica, Facultad de Fisicas, Universidad Complutense de Madrid, Madrid (Spain); Bastiaans, Martin J. [Faculteit Elektrotechniek, Technische Universiteit Eindhoven, Eindhoven (Netherlands)

    2002-09-13

    The main properties of the power filtering operation in the fractional Fourier domain and its relationship to the differentiation operation are considered. The application of linear power filtering for solving the phase retrieval problem from intensity distributions only is proposed. The optical configuration for the experimental realization of the method is discussed. (author)

  12. Power filtering of nth order in the fractional Fourier domain

    The main properties of the power filtering operation in the fractional Fourier domain and its relationship to the differentiation operation are considered. The application of linear power filtering for solving the phase retrieval problem from intensity distributions only is proposed. The optical configuration for the experimental realization of the method is discussed. (author)

  13. 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

    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.

  14. Improving Industrial Energy Quality by an Active Current Filter

    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.

  15. Low-power adaptive filter based on RNS components

    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...

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

    A. Lumani

    2015-08-01

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

  17. High Power Combline Filter for Deep Space Applications

    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.

  18. Application of PQR Theory for control of a 3-phase 4-wire 4-legs shunt active power filter in the aß?-axes using 3D-SVM technique

    Ali CHEBABHI

    2015-05-01

    Full Text Available This article discusses and compares two control strategies applied to a 3-phase 4-wire 4-leg shunt active power filter. These two control strategies, including the cross-vector theory called CV theory and the direct method called PQR theory, are based on the instantaneous control of active and reactive power. On one hand, it is shown that, in some cases, cross-vector theory requires elimination of the zero sequence currents in a 3-phase 4-wire 4-leg shunt active power filter, which needs a power storage element, and on the other hand pretreatment system voltage is necessary to obtain compensated sinusoidal current and a degree of freedom. By relying on the cross-vector theory, the PQR theory is used to extract and remove harmonic currents components. In this control technique, there are two internal current control loops and an external voltage control loop, these control loops have been realized by PI controllers when applied 3D-SVM of switching technique. We choose as criteria for comparison the transient and the Total Harmonic Distortion in the line current. A series of simulations in MATLAB/ Simulink environment have been presented and discussed to show the performance of the two control strategies.

  19. Robust Light Filters Support Powerful Imaging Devices

    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.

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

    B.Vaikundaselvan; Ranithottungal

    2014-01-01

    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 t...

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

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

    2009-01-01

    quarter as much carbon (100 g/m(2)). Each filter was weighed at the beginning of the soiling period and after 3 and 6 months of service. Additionally, up- and down-stream ozone concentrations and filter pressure drops were measured monthly. Following 6 months of service, the air downstream of each of the...... 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...... combination filters was judged to be significantly better than the air downstream of the 6-month-old F7 filter, and was comparable to that from an unused F7 filter. Additionally, the combination filters removed more ozone from the air than the F7 filter, with their respective fractional removal efficiencies...

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

    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.

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

    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. .

  4. 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

    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。

  5. Harmonic Reduction System Using Active Filter

    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.

  6. Power and Aging Characterization of Digital FIR Filters Architectures

    Calimera, Andrea; Liu, Wei; Macii, Enrico; Nannarelli, Alberto; Poncino, Massimo

    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......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...

  7. Condition monitoring of power plants using extended Kalman filtering

    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.

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

    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.

  9. Power system harmonics and passive filter designs

    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.

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

    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. Design of Low Power Column Bypass Multiplier using FPGA and Implementation Using FIR Filter

    Vemula Prakash

    2013-09-01

    Full Text Available Design of area, high speed and power efficient data path logic systems in the low power VLSI circuits has been identified as vital technology in the in the DSP computations and signal processing applications like FIR,IIR filters. Since multipliers consume most of the power in DSP computations it is very important to develop new low-power multipliers for DSP computations. The switching activity of the multiplier depends on the input bit-coefficient, if the coefficient bits are zero the corresponding rows or columns need not to be activated. By inserting more number of zeros in the multiplicand using booth recoding unit we can reduce the switching activity by shutting down the idle part of the circuit and thereby reducing the power dissipation, based on this concept we presents low power column bypass multiplier and verifies the result using FIR filter

  12. Trends in active power line conditioners

    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.

  13. Improved Spatial Filter for high power Lasers

    Estabrook, Kent G.; Celliers, Peter M.; Murray, James E.; DaSilva, Luiz; MacGowan, Brian J.; Rubenchik, Alexander M.; Manes, Kenneth R.; Drake, Robert P.; Afeyan, Bedros

    1998-06-01

    A new pinhole architecture incorporates features intended to reduce the rate of plasma generation in a spatial filter for high-energy laser pulse beams. An elongated pinhole aperture is provided in an apertured body for rejecting off-axis rays of the laser pulse beam. The internal surface of the elongated aperture has a diameter which progressively tapers from a larger entrance cross-sectional area at an inlet to a smaller output cross-sectional area at an outlet. The tapered internal surface causes off-axis rays to be refracted in a low density plasma layer that forms on the internal surface or specularly reflected at grazing incidence from the internal surface. Off-axis rays of the high-energy pulse beam are rejected by this design. The external surface of the apertured body adjacent to the larger entrance cross-sectional area at the inlet to the elongated aperture is angled obliquely with respect to the to direction of the path of the high-energy laser pulse beam to backscatter off-axis rays away from the high-energy pulse beam. The aperture is formed as a truncated cone or alternatively with a tapered square cross-section. The internal surface of the aperture is coated with an ablative material, preferably high-density material which can be deposited with an exploding wire.

  14. 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

    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.

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

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

    2016-01-01

    resonance, where the notch frequency should be aligned exactly to the resonant frequency of the LCL filter. However, parameter variations of the LCL filter as well as the time delay appearing in digital control systems will induce resonance drifting, and thus break this alignment, possibly deteriorating the......Resonant poles of LCL filters may challenge the entire system stability especially in digital-controlled Pulse Width Modulation (PWM) inverters. In order to tackle the resonance issues, many active damping solutions have been reported. For instance, a notch filter can be employed to damp the......-connected PWM inverter verify the effectiveness of the proposed design for robust active damping using digital notch filters....

  16. Harmonics and Reactive Power Compensation Using Shunt Hybrid Filter

    R. Sriranjani; M. Geetha; S. Jayalalitha

    2013-01-01

    The supply current is distorted by the nonlinear load such UPS, DC drives, AC drives and arc furnace. This current harmonics derates the electrical equipments. Thus the current harmonics are reduced from the supply line using Shunt Hybrid filter. The Hysteresis controller controls the active filter thus the supply current tracks the reference fundamental current extracted by the synchronous reference frame unit. So supply current is free from harmonics and also it provides harmonic compensati...

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

    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)

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

    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

  19. Active pixel sensors with substantially planarized color filtering elements

    Fossum, Eric R. (Inventor); Kemeny, Sabrina E. (Inventor)

    1999-01-01

    A semiconductor imaging system preferably having an active pixel sensor array compatible with a CMOS fabrication process. Color-filtering elements such as polymer filters and wavelength-converting phosphors can be integrated with the image sensor.

  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

    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. Improving Industrial Energy Quality by an Active Current Filter

    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 ...

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

    Mr.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 ...

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

    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 in the...... 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...

  4. Techniques for Improving Filters in Power Grid Contingency Analysis

    Adolf, Robert D.; Haglin, David J.; Halappanavar, Mahantesh; Chen, Yousu; Huang, Zhenyu

    2011-12-31

    In large-scale power transmission systems, predicting faults and preemptively taking corrective action to avoid them is essential to preventing rolling blackouts. The computational study of the constantly-shifting state of the power grid and its weaknesses is called contingency analysis. Multiple-contingency planning in the electrical grid is one example of a complex monitoring system where a full computational solution is operationally infeasible. We present a general framework for building and evaluating resource-aware models of filtering techniques for this type of monitoring.

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

    Kouchaki, Alireza; Nymand, Morten

    2016-01-01

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

  6. 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.

    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

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

    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

  8. Estimating Power System Dynamic States Using Extended Kalman Filter

    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. Use of an iodine active quantum filter for image intensification

    Intensification of the image brightness using an iodine active quantum filter is studied experimentally. The image brightness was intensified by a factor of 3000 while preserving the diffraction-limited resolution. The obtained results suggest the possibility of using an iodine active quantum filter in laser ranging and laser probing. (lasers and amplifiers)

  10. Active Harmonics Filtering of Distributed AC System

    Shahbaz, Muhammad

    2012-01-01

    The tendency of connecting the Power Electronic loads and distributed power plants through Power Electronic converters is increasing day by day. These Power Electronic converters and loads are the sources of harmonics and reactive power which greatly affect the performance of the power system network. In a weak power grid, the voltage unbalance and non-sinusoidal regimes are very common. Under such circumstances not only the controllability of the power grid itself but also the controllabilit...

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

    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

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

    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...

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

    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...... 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....

  14. Orthonormal filters for identification in active control systems

    Mayer, Dirk

    2015-12-01

    Many active noise and vibration control systems require models of the control paths. When the controlled system changes slightly over time, adaptive digital filters for the identification of the models are useful. This paper aims at the investigation of a special class of adaptive digital filters: orthonormal filter banks possess the robust and simple adaptation of the widely applied finite impulse response (FIR) filters, but at a lower model order, which is important when considering implementation on embedded systems. However, the filter banks require prior knowledge about the resonance frequencies and damping of the structure. This knowledge can be supposed to be of limited precision, since in many practical systems, uncertainties in the structural parameters exist. In this work, a procedure using a number of training systems to find the fixed parameters for the filter banks is applied. The effect of uncertainties in the prior knowledge on the model error is examined both with a basic example and in an experiment. Furthermore, the possibilities to compensate for the imprecise prior knowledge by a higher filter order are investigated. Also comparisons with FIR filters are implemented in order to assess the possible advantages of the orthonormal filter banks. Numerical and experimental investigations show that significantly lower computational effort can be reached by the filter banks under certain conditions.

  15. Higher-order chaotic oscillator using active bessel filter

    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...

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

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

    2008-01-01

    derives fundamental concepts about the control of the resulting hybrid power filter. From this analysis, a specifc implementation of a three-phase four-wire hybrid power filter is presented as an illustrative application of the filtering topology. An extensive evaluation using simulation and experimental......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 can work either as a passive filter or as a hybrid filter. The paper analyzes the proposed topology and...

  17. Design Of EMI Filter For Flash Lamp Power Supply

    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.

  18. Real-Time Implementation of Type-2 FLC-Based Shunt Active Filter Control Strategies (p-q and Id-Iq) with Different Fuzzy MFs for Power Quality Improvement

    Mikkili, Suresh; Panda, Anup Kumar

    2014-06-01

    This research article proposes the shunt active filter (SHAF) control strategies (p-q and Id-Iq), which are used to improve the power quality of the electrical network by mitigating the harmonics with the help of Type-2 fuzzy logic controller (Type-2 FLC) different membership functions (MFs). Three-phase reference current waveforms generated by proposed scheme are tracked by the three-phase voltage source converter in a hysteresis band control scheme. The performance of the proposed control strategies has been evaluated in terms of harmonic mitigation and DC link voltage regulation under various source conditions. In order to maintain DC link voltage constant and to generate the compensating reference currents, we have developed Type-2 FLC with different fuzzy MFs (trapezoidal, triangular and Gaussian). The SHAF with proposed Type-2 FLC using Gaussian MF is able to eliminate the uncertainty in the system and SHAF gains outstanding compensation abilities. The detailed real-time results using real-time digital simulator are presented to support the feasibility of proposed control strategies.

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

    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. [Restoration filtering based on projection power spectrum for single-photon emission computed tomography].

    Kubo, N

    1995-04-01

    To improve the quality of single-photon emission computed tomographic (SPECT) images, a restoration filter has been developed. This filter was designed according to practical "least squares filter" theory. It is necessary to know the object power spectrum and the noise power spectrum. The power spectrum is estimated from the power spectrum of a projection, when the high-frequency power spectrum of a projection is adequately approximated as a polynomial exponential expression. A study of the restoration with the filter based on a projection power spectrum was conducted, and compared with that of the "Butterworth" filtering method (cut-off frequency of 0.15 cycles/pixel), and "Wiener" filtering (signal-to-noise power spectrum ratio was a constant). Normalized mean-squared errors (NMSE) of the phantom, two line sources located in a 99mTc filled cylinder, were used. NMSE of the "Butterworth" filter, "Wiener" filter, and filtering based on a power spectrum were 0.77, 0.83, and 0.76 respectively. Clinically, brain SPECT images utilizing this new restoration filter improved the contrast. Thus, this filter may be useful in diagnosis of SPECT images. PMID:7776546

  1. Restoration filtering based on projection power spectrum for single-photon emission computed tomography

    To improve the quality of single-photon emission computed tomographic (SPECT) images, a restoration filter has been developed. This filter was designed according to practical 'least squares filter' theory. It is necessary to know the object power spectrum and the noise power spectrum. The power spectrum is estimated from the power spectrum of a projection, when the high-frequency power spectrum of a projection is adequately approximated as a polynomial exponential expression. A study of the restoration with the filter based on a projection power spectrum was conducted, and compared with that of the 'Butterworth' filtering method (cut-off frequency of 0.15 cycles/pixel), and 'Wiener' filtering (signal-to-noise power spectrum ratio was a constant). Normalized mean-squared errors (NMSE) of the phantom, two line sources located in a 99mTc filled cylinder, were used. NMSE of the 'Butterworth' filter, 'Wiener' filter, and filtering based on a power spectrum were 0.77, 0.83, and 0.76 respectively. Clinically, brain SPECT images utilizing this new restoration filter improved the contrast. Thus, this filter may be useful in diagnosis of SPECT images. (author)

  2. New Hybrid Power Filter for Power Quality Improvement in Industrial Network

    Pecha, I.; Tlustý, J.; Müller, Z.; Valouch, Viktor

    Las Palmas de Gran Canaria: EA4EPQ, 2011, s. 1-5. ISBN 978-84-614-7527-8. [International Conference on Renewable Energies and Power Quality - ICREPQ 2011. Las Palmas de Gran Canaria (ES), 13.04.2011-15.04.2011] R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : hybrid power filter * topology * control strategy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

    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. Active filter solutions in energy systems

    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...

  5. Purification of power plant waters with high gradient magnetic filters

    This is a report of a literature survey. Magnetic high gradient filtration is suitable for separations in difficult surroundings because it can be used in high pressure and temperature, the filtration can be automated and the filter does not contain components which have to be replaced. Magnetic separators for purification of power plant waters have been manufactured commercially for a long time, but they have not always worked satisfactorily especially when separating small particles. The corrosion products in power plant waters are usually ferrimagnetic or paramagnetic and are well suited for magnetic separation. The particle sizes varies considerable but at least in nuclear power plants they are mostly in the range 0.1-30 μ, some even smaller. According to different publications most 60Co is in particles, while other publications indicate that more than 70 % is in solution. Similarly the data on the purification efficiency of 60Co varies significantly. Even small magnetic fields are sufficient to separate large ferrimagnetic particles, but the separation of small and paramagnetic particles requires a field more than 20 kT and the high gradient. Presently available commercial separators are so efficient that its seems not to be economically worthwhile to develop them further to improve the filtration efficiency for small particles. Instead it might be worthwhile to investigate methods to increase the particle size by water chemistry methods. (Au). (25 refs., 2 figs.)

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

    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 ...

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

    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...

  8. 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

    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。

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

    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. Kalman Filter Application to Symmetrical Fault Detection during Power Swing

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

    2016-01-01

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

  11. Using Passive and Active Filters for Effective Flicker Suppression in Distribution Systems

    Tlustý, J.; Doležal, J.; Valouch, Viktor

    Buenos Aires : Technical University of Buenos Aires, 2002, s. 30-35. [International Power Distribution Congress CIDEL Argentina 2002. Buenos Aires (AR), 01.12.2002] R&D Projects: GA ČR GA102/00/0483 Keywords : electrical arc furnace * flicker * passive and active filters Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

    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...

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

    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

  14. Low-power implementation of polyphase filters in Quadratic Residue Number System

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

    The aim of this work is the reduction of the power dissipated in digital filters, while maintaining the timing unchanged. A polyphase filter bank in the Quadratic Residue Number System (QRNS) has been implemented and then compared, in terms of performance, area, and power dissipation to the...... implementation of a polyphase filter bank in the traditional two's complement system (TCS). The resulting implementations, designed to have the same clock rates, show that the QRNS filter is smaller and consumes less power than the TCS one....

  15. Effect of common mode static filter in high-performance synchrotron power supply

    The power supply for synchrotron magnets was produced to test its performance. It has a common mode static filter of reactor type, and this filter can be bypassed. In this paper, an equivalent circuit model of the power supply can explain those measurement results. (author)

  16. 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

    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.

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

    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...... around the switching frequency and its multiples. Although the LCL-filters have several advantages compared to single inductance filter, its resonance problem should be noticed. Conventionally, the resonance analysis is mainly focused on the single inverter system, whereas in a renewable energy system...... 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-filtered...

  18. Active beamforming with interpolated FIR filtering

    Vaidyanathan, P.P.; Weng, Ching-Chih

    2010-01-01

    The interpolated FIR (IFIR) radar was recently introduced in the context of MIMO radar theory. It was shown that this system has a signal to clutter ratio intermediate between those of the SIMO and MIMO radars. This paper considers the optimal design of the active IFIR beamformer in presence of jammers. It is shown that this beamformer can achieve beamwidths as sharp as those of colocated MIMO radars with full-length virtual arrays. At the same time, the extra complexity ...

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

    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.

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

    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 μm 47 GHz SiGe BiCMOS technology; the receiver and transmitter filter occupy 0.21 mm2 and 0.11 mm2 (calibration circuit excluded), respectively.

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

    Taubman, Matthew S

    2013-07-02

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

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

    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.

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

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

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

    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).

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

    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).

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

    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...

  7. Assessment of Metal Media Filters for Advanced Coal-Based Power Generation Applications

    Alvin, M.A.

    2002-09-19

    Advanced coal and biomass-based gas turbine power generation technologies (IGCC, PFBC, PCFBC, and Hipps) are currently under development and demonstration. Efforts at Siemens Westinghouse Power Corporation (SWPC) have been focused on the development and demonstration of hot gas filter systems as an enabling technology for power generation. This paper reviews SWPC's material and component assessment efforts, identifying the performance, stability, and life of porous metal, advanced alloy, and intermetallic filters under simulated, pressurized fluidized-bed combustion conditions.

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

    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...

  9. Voltage harmonics mitigation through hybrid active power filer

    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)

  10. A review of DOE HEPA filter component test activities

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

    1997-08-01

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

  11. A review of DOE HEPA filter component test activities

    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. Harmonic Filtering Performance of a Hybrid Active Filter for a Three-Phase 12-Pulse Diode Rectifier

    Isozaki, Kohei; Akagi, Hirofumi

    This paper describes a hybrid active filter for harmonic-current compensation of a three-phase 12-pulse diode rectifier used as the front end of a medium-voltage motor drive system. This hybrid filter is characterized by the direct series connection of a simple LC filter and a small-rated active filter. This circuit configuration brings low cost, small size, and light weight to the hybrid filter. The authors design, construct, and test a three-phase experimental system rated at 400V and 15kW, which is a downscaled model of the medium-voltage motor drive system. In this experiment, the LC filter is tuned to the 11th harmonic frequency, and the active filter is based on a three-level diode-clamped PWM converter with a dc capacitor voltage as low as 28V. This hybrid filter is connected on either the first or fourth winding of a line-frequency transformer with a first Δ-winding voltage of 400V in the primary, and a second Δ-winding voltage of 220V, a third Y-winding voltage of 220V, and a fourth Δ-winding voltage of 400V in the secondary. Experimental results show that the hybrid filter performs satisfactory filtering in a range from the no-load to full-load conditions.

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

    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.

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

    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

  15. Filter - an interactive signal filtering program for power station log data

    'Noisy' plant data are often used as boundary conditions in reactor modelling. The effect of pre-processing the data using the FILTER package was studied. It was found that there were no significant differences in the simulation output from the various runs of the model, but that the simulation time could be reduced by a factor of four. (author)

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

    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.

  17. Robust high-order repetitive control of an active filter using an odd-harmonic internal model

    Ramos Fuentes, Germán Andrés; Costa Castelló, Ramon; Olm Miras, Josep Maria; Cardoner Parpal, Rafel

    2010-01-01

    Shunt active power filters have proven to be an efficient means to compensate for the negative effects of nonlinear and reactive loads on the power quality of the electrical distribution network. In this context, the control objective is to achieve a power factor close to 1, as well as load current harmonics and reactive power compensation. A useful control strategy for this purpose is repetitive control. However, the performance of repetitive controllers is strongly affe...

  18. Performance analysis of a low power low noise tunable band pass filter for multiband RF front end

    This paper presents a low power tunable active inductor and RF band pass filter suitable for multiband RF front end circuits. The active inductor circuit uses the PMOS cascode structure as the negative transconductor of a gyrator to reduce the noise voltage. Also, this structure provides possible negative resistance to reduce the inductor loss with wide inductive bandwidth and high resonance frequency. The RF band pass filter is realized using the proposed active inductor with suitable input and output buffer stages. The tuning of the center frequency for multiband operation is achieved through the controllable current source. The designed active inductor and RF band pass filter are simulated in 180 nm and 45 nm CMOS process using the Synopsys HSPICE simulation tool and their performances are compared. The parameters, such as resonance frequency, tuning capability, noise and power dissipation, are analyzed for these CMOS technologies and discussed. The design of a third order band pass filter using an active inductor is also presented. (semiconductor integrated circuits)

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

    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)

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

    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

  1. A New Extended Kalman Filtering for Shadow/Fading Power Estimation in Mobile Communications

    George P. Pappas

    2014-01-01

    Full Text Available This paper proposes a New Extended Kalman filter (NEKF approach to improve local mean power estimation. The method is being validated using a GUI system model and then compared to existing methods, Kalman Filter (KF with Gaussian and Non-Gaussian noise environments. Our analysis is showing that NEKF is a more accurate method in most situations. NEKF can accurately estimate the parameters and predict states in discrete nonlinear state-space for modeling shadow power.

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

    Tan, Yi-zhou; Yang, Yi-sheng; 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 traditio...

  3. Passively Track WiFi Users with an Enhanced Particle Filter using Power-based Ranging

    Li, Zan; Braun, Torsten

    2015-01-01

    Passive positioning systems produce user location information for third-party providers of positioning services. Since the tracked wireless devices do not participate in the positioning process, passive positioning can only rely on simple, measurable radio signal parameters, such as timing or power information. In this work, we provide a passive tracking system for WiFi signals with an enhanced particle filter using fine-grained power-based ranging. Our proposed particle filter provides an im...

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

    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....

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

    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...

  6. Shunt active filter algorithms for a three phase system fed to adjustable speed drive

    Sujatha.CH; Sravanthi.Kusam; Dr. K.Chandra shek

    2011-01-01

    This paper presents the simulation of Shunt Active Power filter by using two different control schemes, Indirect current control technique and Synchronous detection technique by using ANN. These two control techniques are working under both balanced and unbalanced three phase voltage source conditions and it is feeding to aadjustable speed drive the torque speed characteristics of a motor is presented. Indirect current control technique is implemented under dynamic load condition and load bal...

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

    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...

  8. 78 FR 44957 - Agency Information Collection Activities: BioWatch Filter Holder Log, Filter Holder Log DHS Form...

    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...

  9. Cadmium filtered neutron flux determination. Comparison of activation methods

    Neutron fluxes under cadmium filters are determined by the cadmium ratio and sandwich activation methods. The thermal neutron flux levels obtained with 7 detectors of different kinds: In, Au, Ag, W, Co, Mn, Zn are compared. The cadmium ratio method was used in locations for which the epithermal and thermal neutron flux ratio are quite different. By irradiating materials under different thicknesses of cadmium it was possible to establish experimental curves from which the flux depression factors for intermediate neutrons may be determined whatever the thickness of the filter used. Whereas the cadmium ratio method can only measure the mean flux above the cadmium cut-off energy the sandwich method enables the flux value to be determined in a narrow band around the resonance energy of each detector used

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

    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)

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

    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.

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

    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.

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

    Milad Askari Hashemabadi,; Dr. Farshid Keynia

    2014-01-01

    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.

  14. Calibration of filters for detection of airborne I-131 in the environment of nuclear power plant

    A simple and clean method for efficiency calibration of filters for collection of airborne I and corresponding Ge(Li) spectrometer is described. As the calibrated source of gaseous I-131 the radiopharmaceutical water solution of NaI is used. As calibration example the absolute activity distribution of I-131 measured in a charcoal filter is shown. (author)

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

    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.

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

    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.

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

    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 ...

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

    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.

  19. Placement Optimization of the Active Filters in the Industrial Networks

    Tlustý, J.; Švec, J.; Sýkora, T.; Doležal, J.; Škramlík, Jiří; Valouch, Viktor

    Košice : Technická univerzita v Košiciach, 2005, s. 1-10. ISBN 80-8073-305-8. [International Scientific Symposium ELEKTROENERGETIKA 2005 /3./. Stará Lesná - High Tatras (SK), 21.09.2005-23.09.2005] R&D Projects: GA ČR(CZ) GA102/03/1551; GA ČR(CZ) GA102/03/0241 Institutional research plan: CEZ:AV0Z20570509 Keywords : active filters * industrial networks Subject RIV: JA - Electronics ; Optoelectronics, Electric al Engineering

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

    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.

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

    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

  2. Analytical Modelling and Implementation of a New Four-Switch Hybrid Power Filter Topology

    Klíma, J.; Škramlík, Jiří; Valouch, Viktor

    Santander: Universidad de Cantabria, 2008, s. 1-5. ISBN 978-84-611-9290-8. [International Conference on Renewable Energies and Power Quality - ICREPQ´08. Santander (ES), 12.03.2008-14.03.2008] R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : hybrid power filter * harmonic and reactive power compensation * reduced circuit topology Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

    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.

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

    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

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

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

  6. From irradiance to output power fluctuations: the pv plant as a low pass filter

    de Marcos, Javier; Marroyo, Luis; Lorenzo Pigueiras, Eduardo; Alvira, David; Izco, Eloisa

    2011-01-01

    The power generated by large grid-connected photovoltaic (PV) plants depends greatly on the solar irradiance. This paper studies the effects of the solar irradiance variability analyzing experimental 1-s data collected throughout a year at six PV plants, totaling 18 MWp. Each PV plant was modeled as a first order filter function based on an analysis in the frequency domain of the irradiance data and the output power signals. An empiric expression which relates the filter parameters and the PV...

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

    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...

  8. Noise power spectrum studies of CT systems with off-centered image object and bowtie filter

    Gomez-Cardona, Daniel; Cruz-Bastida, Juan P.; Li, Ke; Budde, Adam; Hsieh, Jiang; Chen, Guang-Hong

    2016-03-01

    In previous studies of the noise power spectrum (NPS) of multi-detector CT (MDCT) systems, the image object was usually placed at the iso-center of the CT system; therefore, the bowtie filter had negligible impact on the shape of the two-dimensional (2D) NPS of MDCT. This work characterized the NPS of off-centered objects when a bowtie filter is present. It was found that the interplay between the bowtie filter and object position has significant impact on the rotational symmetry of the 2D NPS. Depending on the size of the bowtie filter, the degree of object off-centering, and the location of the region of interest (ROI) used for the NPS measurements, the symmetry of the 2D NPS can be classified as circular, dumbbell, and a peculiar cloverleaf symmetry. An anisotropic NPS corresponds to structured noise texture, which may directly influence the detection performance of certain low contrast detection tasks.

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

    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.

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

    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)

  11. 76 FR 24504 - Agency Information Collection Activities: BioWatch Filter Holder Log

    2011-05-02

    ... SECURITY Agency Information Collection Activities: BioWatch Filter Holder Log AGENCY: Department of... installing and removing filters from aerosol collection devices and transportation to local laboratories for sample analysis. A standard filter log form is completed for each sample and is archived by the...

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

    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

  13. 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

    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 ...

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

    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...

  15. Four-switch hybrid power filter working with six-fold switching symmetry

    Klíma, J.; Tlustý, J.; Škramlík, Jiří; Valouch, Viktor

    2011-01-01

    Roč. 56, č. 4 (2011), s. 433-446. ISSN 0001-7043 Institutional research plan: CEZ:AV0Z20570509 Keywords : component minimized hybrid power filter * control strategy * analytical model Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  16. Power handling capability improvement of HTS filter with sliced microstrip line resonators

    We investigated the third-order intermodulation distortion (IMD3) properties of high- temperature superconducting (HTS) filters with sliced microstrip line resonators. Electromagnetic simulations indicated that the current concentration along the outer edges of a sliced microstrip line was lower than that of a conventional microstrip line. We fabricated a 3-pole filter with a sliced microstrip line resonator using HTS YBCO thin films and measured the IMD3. Until the input power increase to 7 W, the filter has proper operation from 50 to 77.3 K. The third-order intercept point value of 64 dBm was observed at 70 K. The ΔIMD3 was less than -55 dBc at 1 W input power when the temperature was 50-77.3 K. The sliced microstrip line indicated low ΔIMD3 to the fundamental two-tone sinusoidal waves, which had a difference of 1 MHz, when the input power was 1 W. The results showed that HTS filters with sliced microstrip line resonators have better power handling capability and can feasibly be used in transmitters

  17. Analytical Modeling and Simulation of Four-Switch Hybrid Power Filter Working with Sixfold Switching Symmetry

    Tlustý, J.; Škramlík, Jiří; Švec, J.; Valouch, Viktor

    2012-01-01

    Roč. 2012, č. 292178 (2012), s. 1-17. ISSN 1024-123X Institutional support: RVO:61388998 Keywords : analytical modeling * four-switch hybrid power filter * sixfold switching symmetry Subject RIV: JA - Electronic s ; Optoelectronics, Electrical Engineering Impact factor: 1.383, year: 2012 http://www.hindawi.com/journals/mpe/2012/292178/

  18. New Hybrid Power Filter Topology and Control for Application in Industrial Networks

    Pecha, I.; Šimek, Petr; Škramlík, Jiří; Valouch, Viktor

    Brno : University of Technology Brno, 2011, s. 1-5. ISBN 9788021443624. [International Conference on Low Voltage Electrical Machines - LVEM 2011 /11./. Šlapanice (CZ), 07.11.2011-08.11.2011] Institutional research plan: CEZ:AV0Z20570509 Keywords : hybrid power filter * control strategy * industrial system Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  19. Hybrid Active-Passive Microwave Photonic Filter with High Quality Factor

    A hybrid high quality factor (Q-factor) microwave photonic filter with a cascaded active filter and a passive filter is presented and experimentally demonstrated. The active infinite impulse response filter is realized by a recirculating delay line loop with a semiconductor optical amplifier, and a much narrower 3 dB bandwidth of response peaks can be achieved. A passive finite impulse response filter is realized by an unbalance Mach–Zehnder interferometer, and it is cascaded to select the desired filter frequencies and to suppress the intermediate peaks. Compared with the purely active filter scheme, the free spectrum range and the Q-factor of the hybrid structure can be doubled. Stable operation and a high Q-factor of 362 are experimentally demonstrated

  20. Programmable Power-of-two RNS Scaler and its Application to a QRNS Polyphase Filter

    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 is applied to a polyphase filter bank. A comparison of the filter bank scaled with RNS to binary and binary to RNS conversions, and the RNS scaled implementation is presented. A reduction of area and power consumption of about 30% for the scaling block is obtained....

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

    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.

  2. 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

    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。

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

    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

  4. A new Methodology for achieving MMIC Bandpass Active Filters at High Frequencies

    Darcel, L.; Duême, P.; Funck, R.; Alquié, G.

    2004-01-01

    This paper presents a new methodology based on actively coupled resonators, for achieving microwave active filters. In this method, which lends itself to narrowband and wideband filtering applications, we associate core cells with different resonance frequencies, adjusted separately, to synthesise a Butterworth, Chebyshev or other all-pole approximation. Two 1-pole bandpass filters centred at 9GHz, with 3dB bandwidth of 500 MHz, high gain of 17 dB and 21 dB, including ...

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

    Alzola, Rafael Pena; Liserre, Marco; Blaabjerg, Frede; Sebastián, Rafael; Dannehl, Jörg; Wilhelm Fuchs, Friedrich

    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...... without using dissipative elements but, sometimes, needing additional sensors. This solution has been addressed in many publications. The lead-lag network method is one of the first reported procedures and continues being in use. However, neither there is a direct tuning procedure (without trial and error...

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

    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

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

    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.

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

    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

  9. High-power active devices

    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.

  10. LOW ACTIVITY WASTE FEED SOLIDS CARACTERIZATION AND FILTERABILITY TESTS

    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

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

    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. Control Strategy of Hybrid Power Filter under Disturbed Voltage System Conditions

    Škramlík, Jiří; Tlustý, J.; Valouch, Viktor

    Tel Aviv : IEEE, 2008, s. 115-119. ISBN 978-1-4244-2482-5. [2008 IEEE Convention of Electrical and Electronics Engineers in Israe /25./. Eilat (IL), 03.12.2008-05.12.2008] R&D Projects: GA MPO FT-TA5/123; GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : hybrid power filter * feedback * feedforward Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  13. Sliding mode Control using 3D-SVM for Three-phase Four-Leg Shunt Active Filter

    Bouzidi Mansour

    2013-02-01

    Full Text Available This paper proposes a sliding mode control strategy for a three-phase shunt active power filter. The SAPF consists of four-leg voltage source inverter bridge. The SAPF ensures full compensation for harmonic phase currents, harmonic neutral current, reactive power compensation and unbalanced nonlinear load currents. The modulation task can be carried out with three dimensional space vector modulation, which operate under a constant switching frequency. The simulation results show that the performance of the four-leg SAPF with the proposed control algorithm – compared with PI controller - is found considerably effective and adequate to compensate harmonics, reactive power, neutral current and balance load currents.

  14. The use of active power factor corrector for efficiency improvement of computer power supplies

    Al-Mawsawi, S.A. [Bahrain Univ., Isa Town (Bahrain). Dept. of Electrical and Electronics Engineering

    2008-07-01

    A study was conducted in which an active Power Factor Corrector (PFC) was used to improve the efficiency of electronic circuits. The effect of using the active PFC was illustrated in a simple circuit simulated by CIRCUITMAKER. The study revealed that using this technology together with architectural-level and components-level improvements will result in greater efficiency in electronic equipment, including computers. The active PFC improved the efficiency of the computer hard desk power supply by using a harmonic reduction circuit. This study simulated and tested the active PFC circuit. The technology can increase the efficiency in traditional power supplies from 65 per cent to an efficiency ratio that exceeds 90 per cent. Additionally, the active PFC will improve the power factor to a value close to unity, thereby eliminating the reactive power drawn by the power supply. The DC power supply can be considered as the buffer between the equipment and the primary electric power source. Switching-mode DC power supplies basically convert AC voltage to DC voltage using low loss components such as capacitors, inductors, transformers, and electronic switches. Computers and other electronic equipment need well filtered and regulated DC voltage to operate. 12 refs., 1 tab., 10 figs.

  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.

    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

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

    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.

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

    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.

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

    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...

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

    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...

  20. 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

    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

  1. Low power consumption silicon photonics tuning filters based on compound microring resonators

    Vázquez, C.; Contreras, P.; Vargas, S.

    2013-02-01

    Scalable integrated optics platforms based on silicon-on-insulator allow to develop optics and electronics functions on the same chip. Developments in this area are fostered by its potential as an I/O technology that can meet the throughputs demand of future many-core processors. Most of the optical interconnect designs rely on small footprint and high power efficiency microring resonators. They are used to filter out individual channels from a shared bus guide. Second-order microring filters enable denser channel packing by having sharper pass-band to stop-band slopes. Taking advantage of using a single physical ring with clockwise and counter-clockwise propagation, we implement second order filters with lower tuning energy consumption as being more resilient to some fabrication errors. Cascade ability, remote stabilization potential, energy efficiency along with simple design equations on coupling coefficients are described. We design second-order filters with FWHM from 45 GHz to 20 GHz, crosstalk between channels from -40 dB to -20 dB for different channel spacing at a specific FSR, with energy efficiencies of single ring configurations and compatible with silicon-on-insulator (SOI) state of the art platforms.

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

    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 lo...

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

    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...

  4. Prominence and Filament Activity Recorded with a New, Tunable, One-Angstrom Filter

    Martin, S. F.; Martin, D. C.

    2003-05-01

    New observations using a one-Angstrom Hα tunable multi-layer interference filter demonstrate the efficacy of this filter in detecting key Doppler shifts in filaments and prominences both before and during their eruption. The new filter is superior as a prefilter. However, here we emphasize its merits as a stand-alone filter. The new filter was constructed from 2 single-period interference filters. Used in tandem, the two filters allow us to achieve an effective one Angstrom passband that is tunable by mechanical tilting over a useful range of at least 6 Angstroms. Employed in a solar telescope and starting at Hα line center, an observer can detect all filaments on the solar disk, a goal not achievable with most other one-Angstrom filters. The observer can then initiate manual or automated tuning of the filter to determine whether a filament has normal, low Doppler shifts or increased Doppler shifts signaling that it is either activated or in the early stage of eruption. Our few initial observations reveal activations as readily as through much more expensive, ultra-narrow passband filters of the Fabry-Perot or birefringent type. Less visibility of chromospheric fine structure might be considered either an asset or disadvantage depending upon the observational goals. Minor changes in the filter passband with wavelength are a possible downside to be weighed against its relative low cost, minimal mass, and ruggedness which make it practical for monitoring major solar activity in space experiments as well as from the ground. The development and use of this filter was possible through NASA grant NAG5-9517.

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

    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...

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

    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

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

    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)

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

    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.

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

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

    2014-01-01

    A mineral coating develops on the filter grain surface when groundwater is treated via rapid sand filtration in drinking water production. The coating changes the physical and chemical properties of the filter material, but little is known about its effect on the activity, colonization, diversity...

  10. 76 FR 42130 - Agency Information Collection Activities: BioWatch Filter Holder Log

    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... installing and removing filters from aerosol collection devices and transportation to local laboratories...

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

    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.

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

    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

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

    Huang, Min; Wang, Xiongfei; Loh, Poh Chiang; Blaabjerg, Frede; Wu, Weimin

    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....

  14. Design of Low Power and Area Efficient New Reconfigurable FIR Filter using PSM and Shift and Add Method

    G.O. Jijina

    2014-12-01

    Full Text Available This study presents an architectural approach to the design of Low power and area efficient reconfigurable Finite Impulse Response (FIR filter. FIR digital filters are used in DSP by the virtue of its, linear phase, fewer finite precision error, stability and efficient implementation. The proposed architectures implemented by using carry save adder, it offer Low power and area reductions and compared to the best existing reconfigurable FIR filter implementations in the literature and the proposed architectures have been implemented and tested on Spartan-3 xc3s200-5pq208 Field-Programmable Gate Array (FPGA and synthesized.

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

    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.

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

    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.

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

    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

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

    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.)

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

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

    2004-01-01

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

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

    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...

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

    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.

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

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

    2013-01-01

    layers. A water sampler was installed in the full scale filter of plant 1 to observe the ammonium profile with depth. Ammonium was removed within the upper 15 cm with a removal rate ranging of 3.6- 7.7 g NH4+-N/ m3 sand/h. Full scale observations fit with the lab scale activity measurements showing that......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...

  3. Alpha activity estimation in used HEPA filters of glove box ventilation system

    At Radiochemistry facility, various radio-chemical operations are carried out on isotopes of Plutonium and trans-plutonics under containment and safe operational conditions. The ventilation system is designed with separate headers for laboratory and glove box exhausts. The ventilation provided to the labs act as dynamic containment is a Once - through system with the ventilation inlet as processed air and exhausted through stack after filtration through HEPA filter banks. These activity saturated/used HEPA filters are changed periodically. This paper describes the assessment of buildup α activity in the used filter. (author)

  4. Analog filters in nanometer CMOS

    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 ...

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

    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...... impedance variations due to its ability to tune the grid-tie inverter on-site. Finally, the analysis is validated with both simulation and experiments....

  6. In-situ tests on absolute filters at the Fessenheim nuclear power station

    The Fessenheim nuclear power station is of the PWR type and is situated on the Alsace Grand Canal near the village of Fessenheim (Upper Rhine). It comprises two blocks, each with a capacity of 900 MWe, the first of which should be commissioned before the end of 1976. The absolute filters installed in the power station ventilation systems (individual systems for the auxiliary equipment block, the fuel store, the containment penetration zone, and the control room will be in-situ tested before start-up using the sodium fluoresceinate method as developed by the Commissariat a l'Energie Atomique. Following a brief review of the principles of this method, a description is given of the circuits and equipment installed at Fessenheim (injection and sampling points) which permit checks to be carried out

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

    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

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

    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...

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

    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.

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

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke; Tonnes, Michael; Lau, Mogens

    The modern grid requirement has caused that the wind power system behaves more like conventional rotating generators and it is able to support certain amount of the reactive power. For a typical doubly-fed induction generator wind turbine system, the reactive power can be supported either through...... for the generator and the wind power converter in terms of the reactive power done by the rotor-side converter or the grid-side converter with various grid filters. Afterwards, the annual energy loss is also estimated based on yearly wind profile. Finally, experimental results of the loss distribution...... 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...

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

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke; Tonnes, Michael; Lau, Mogens

    2015-01-01

    The modern grid requirement has caused that the wind power system behaves more like conventional rotating generators, and it is able to support certain amount of the reactive power. For a typical doubly fed induction generator (DFIG) wind turbine system, the reactive power can be supported either...... for the generator and the wind power converter in terms of the reactive power done by the rotor-side converter or the grid-side converter with various grid filters. Afterward, the annual energy loss is also estimated based on yearly wind profile. Finally, experimental results of the loss distribution...... 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...

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

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

    2015-01-01

    This paper presents a technology for high-power lowlosscontinuously tunable RF filters demonstrated by the exampleof a two-pole coupled-resonator filter. The resonators are shortenedcoaxial cavities loaded with ferrite inserts, where an externallyapplied transverse dc magnetic bias controls...... the center frequency.The filter is analyzed by simulations that take into accountthe inhomogeneity of the bias field. A prototype is manufacturedand tested, exhibiting a tuning span of 41% in which theunloaded factor varies in the range from 1223 to 2425. Goodcorrespondance is observed between simulation...... 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...

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

    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.

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

    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.

  15. The influence of an additional filter in epithermal neutron activation analysis

    Additional filters of tungsten and sodium in different thicknesses have been used in the epithermal neutron activation analysis of geological samples to reduce the interferences caused by resonance neutron capture in these two elements. The results show that a selective reduction of the interfering activities in favor of the activities sought can be obtained. Improvements in terms of detection sensitivity and precision in the γ-spectrometric determinations of Sc, Fe, Co, La, Sm, Eu, Gd, Tb, Yb, Lu, Th and W have been calculated. The possible applications of the filtered epithermal neutron activation analysis (FENA) method to different kinds of samples are also briefly discussed. (author)

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

    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...

  17. Speech enhancement via Mel-scale Wiener filtering with a frequency-wise voice activity detector

    This paper presents a speech enhancement system that enables a comfortable communication inside an automobile. A couple of novel concepts are proposed in an effort to improve two major building blocks in the existing speech enhancement systems: a voice activity detector (VAD) and a noise filtering algorithm. The proposed VAD classifies a given data frame as speech or noise at each frequency, enabling the frequency-wise updates of noise statistics and thereby improving the effectiveness of the noise filtering algorithms by providing more up-to-date noise statistics. The celebrated Wiener filter is adopted in this paper as the accompanying noise filtering algorithm, which results in significant noise suppression. Yet, the musical noise present in most Wiener filter-based systems prompts the idea of applying the Wiener filter in the Mel-scale in which the human auditory system responds to the external stimulation. It turns out that the Mel-scale Wiener filter creates some masking effects and thereby reduces musical noise significantly, leading to smooth transition between data frames

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

    Lorzadeh, Iman; Firoozabadi, Mehdi Savaghebi; Askarian Abyaneh, Hossein; Guerrero, Josep M.

    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...... 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 the...

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

    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.

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

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

    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.

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

    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

    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. Modification of spent filter treat method at Uljin nuclear power plant

    Spent resin drying system(SRDS) and concentrated waste drying system (CWDS) have been introduced into Uljin NPP designed to treat spent resin, concentrated waste and spent filter at the waste cementation facility. Spent filter has been the only waste to treat at the cementation facility so that it is to become difficult to be provided the C-type containers needed to treat spent filter. To solve this problem, two programs including to change the spent filter container have been considered. One os to treat spent filter at the cementation facility using DOT - 17H drum, and another is to contain several spent filters in a High Integrated Container(HIC). (author)

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

    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.

  6. 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

    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.)

  7. A Transformerless Hybrid Active Filter Capable of Complying with Harmonic Guidelines for Medium-Voltage Motor Drives

    Kondo, Ryota; Akagi, Hirofumi

    This paper presents a transformerless hybrid active filter that is integrated into medium-voltage adjustable-speed motor drives for fans, pumps, and compressors without regenerative braking. The authors have designed and constructed a three-phase experimental system rated at 400V and 15kW, which is a downscaled model from a feasible 6.6-kV 1-MW motor drive system. This system consists of the hybrid filter connecting a passive filter tuned to the 7th harmonic filter in series with an active filter that is based on a three-level diode-clamped PWM converter, as well as an adjustable-speed motor drive in which a diode rectifier is used as the front end. The hybrid filter is installed on the ac side of the diode rectifier with no line-frequency transformer. The downscaled system has been exclusively tested so as to confirm the overall compensating performance of the hybrid filter and the filtering performance of a switching-ripple filter for mitigating switching-ripple voltages produced by the active filter. Experimental results verify that the hybrid filter achieves harmonic compensation of the source current in all the operating regions from no-load to the rated-load conditions, and that the switching-ripple filter reduces the switching-ripple voltages as expected.

  8. Purification of Sardine Oil Using Adsorbent (Active Filter) of Scallop Shells, Carp Scales and Attapulgite

    Sugeng Heri Suseno; Yosephina M.J. Batafor; Nurjanah; Ayu Fitri Izaki

    2014-01-01

    Fish oil especially from sardine has contain great omega 3, but it needs purification because has poor quality. Fish oil purification can be done by using various types of adsorbents. One of them are scallop shells and carp scales. The purpose of this study is to choose the best type of active filter (adsorbent) to improve the quality of fish oil. Sardine oil is purified using an active filter (adsorbent) of carp scales, scallop shells and attapulgite. The result this study show that the best...

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

    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...

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

    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

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

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus; Kerekes, Tamas; Blaabjerg, Frede

    2015-01-01

    for the two parallel interleaved VSCs is derived in order to obtain the worst case voltage magnitude of the individual harmonic components. The required value of the filter admittance for the specific harmonic component is obtained by using the worst case voltage magnitude and the allowable harmonic...... injection limit. In order to achieve the desired filter performance with optimal values of the filter parameters, the use of a LC trap branch with the conventional LCL filter is proposed. The expressions for the resonant frequencies of the proposed line filter are derived and used in the design to...

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

    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

  13. Determination of plutonium from air filters for the detection of undeclared nuclear activities

    In Finland analytical development in being carried out to support the IAEA Action Team which has the UN's mission to detect undeclared nuclear activities in Iraq. A research consortium Finnish Nuclear Verification (FINUVE), which combines the analytical surveys of the Laboratory of Radiochemistry, Technical Research Centre of Finland and the Finnish Radiation and Nuclear Safety Authority, has carried out air filter testing in Kazakhstan in the years 2000-2001. In the Laboratory of Radiochemistry weekly filters have been first wet-ashed and then Pu separated by extraction chromatography using Eichrom's UTEVA and TRU resins. Finally the plutonium activity and isotopic composition have been determined by alpha spectrometry. Development of the analytical procedures, especially the features concerning air filters, are described in this paper. (author)

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

    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.

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

    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...

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

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

    2015-01-01

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

  17. Active control of radiated sound power from a baffled, rectangular panel

    Mørkholt, Jakob

    Active control of radiated sound power from a rectangular baffled panel by minimisation of an accurate power estimate, using piezoceramic actuators, has been investigated. Computer simulations have shown that minimising a power estimate obtained by discretised integration of the far field intensity...... with an array of eleven microphones in front of the panel, is very close to minimising the actual radiated sound power. Practical experiments where such an array estimate has been minimised using the filtered X LMS algorithm have shown that substantial reductions of radiated sound power can be obtained...

  18. Active control of radiated sound power from a baffled, rectangular panel

    Mørkholt, Jakob

    1996-01-01

    Active control of radiated sound power from a rectangular baffled panel by minimisation of an accurate power estimate, using piezoceramic actuators, has been investigated. Computer simulations have shown that minimising a power estimate obtained by discretised integration of the far field intensity...... with an array of eleven microphones in front of the panel, is very close to minimising the actual radiated sound power. Practical experiments where such an array estimate has been minimised using the filtered X LMS algorithm have shown that substantial reductions of radiated sound power can be obtained over...

  19. Design and construction of electronic filters

    The design and construction of very low frequencies electronic filters which will be used for carrying out analysis of pile noise at Mexico's Nuclear Center Triga Mark III Reactor, in order to realize measurements of its parameters is presented. NIM norms and active filters with lineal integrated circuits were used: a. Band pass filter from 10 to 500 hertz, band width 50. b. Low pass filter from 0.001 to 10 hertz in 3 steps. c. Kalman Bucy filter, an analogical simulation of this filter was undertaken, obtained from a mathematical model of a Zero power experimental reactor, with the purpose to establish a control searching. (author)

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

    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

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

    Lu, Minghui; Wang, Xiongfei; Blaabjerg, Frede; Muyeen, S.M.; Al-Durra, Ahmed; Leng, Siyu

    2016-01-01

    damping resistor and a reactance paralleled with filter capacitor. The damping performance in different frequency regions are discussed through Bode diagrams. Compared to other widely used active damping strategies, no extra sensor is needed because the Point of Common Coupling (PCC) voltage is sampled...

  2. Note: Thermally stable thin-film filters for high-power extreme-ultraviolet applications.

    Tarrio, C; Berg, R F; Lucatorto, T B; Lairson, B; Lopez, H; Ayers, T

    2015-11-01

    We investigated several types of thin-film filters for high intensity work in the extreme-ultraviolet (EUV) spectral range. In our application, with a peak EUV intensity of 2.7 W cm(-2), Ni-mesh-backed Zr filters have a typical lifetime of 20 h, at which point they suffer from pinholes and a 50% loss of transmission. Initial trials with Si filters on Ni meshes resulted in rupture of the filters in less than an hour. A simple thermal calculation showed that the temperature rise in those filters to be about 634 K. A similar calculation indicated that using a finer mesh with thicker wires and made of Cu reduces the temperature increase to about 60 K. We have exposed a Si filter backed by such a mesh for more than 60 h with little loss of transmission and no leaks. PMID:26628184

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

    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...

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

    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.

  5. Instrumentation amplifier implements second-order active low-pass filter with high gain factor

    A single-ended second-order active low-pass filter can simultaneously provide high gain factor and dc voltage subtraction. This makes it possible to reduce the number of components and signal processing stages needed in an application where small voltage changes are measured on the top of large dc voltage masked by a large amplitude oscillating carrier. The filter described in this paper is constructed from a conventional 3-op-amp instrumentation amplifier and five passive circuit elements. (technical design note)

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

    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.

  7. High-efficiency particulate air filter test activities at the Department of Energy

    For the past 2 years, test activities at the three Department of Energy HEPA Filter Test Facilities (FTFs) have been conducted under a unified set of operating standards intended to help achieve consistency in test methods and test results. Reviews of test operations are conducted at each FTF annually, and technical support and guidance are provided on request. Round Robin tests are conducted twice a year to compare penetration and resistance test results among the three FTFs. The FTFs prepare summary test data twice a year, and the data is analyzed for trends with respect to ongoing quality of HEPA filters in nuclear facilities. Data and conclusions from both the Round Robin tests and semiannual reports are discussed, the latter without reference to specific manufacturers. The new DOE standards include provisions for consideration and approval of new test aerosols or test methods, under closely controlled change procedures. Progress in obtaining DOE approval for DOS as a new aerosol, and for the Alternative Test System (ATS) developed by, and reported on by the LANL, as an approved new test method are discussed, as are 2 significant changes in standard NE-F-3-43, related to (a) toxicology test alternatives, and (b) the test aerosol definition. Finally, the emergence of new, higher flow rated HEPA filters and Ultra Low Particulate Air (ULPA) filters will impact DOE's design, procurement, testing and use of HEPA filters in the near future

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

    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.

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

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

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

    2014-01-01

    . Therefore, large filter components are often required in order to meet the stringent grid code requirements imposed by the utility. As a result, the size, weight and cost of the overall system increase. The use of interleaved carriers of the parallel connected VSCs, along with the high order line filter, is...

  11. Evolution of the passive harmonic filters optimization problem in industrial power systems

    Cabral-Leite, Jandecy; Pérez-Abril, Ignacio; Santos-Azevedo, Manoel Socorro; de Lima-Tostes, Maria Emilia; Holanda-Bezerra, Ubiratan

    2014-01-01

    Several authors have treated the optimization of passive filters in electric distribution systems. Optimization methods like: sequential quadratic programming (SQP), simulated annealing (SA), differential evolution (DE), artificial neural networks (ANN), particle swarm optimization (PSO), genetic algorithm (GA), etc., have been employed for optimizing certain configurations of passive filters. These optimization methods have been employed to solve several formulations of the problem of the pr...

  12. Method of regenerating desalination type filters in condensate clean-up systems of nuclear power plants

    Purpose: To significantly decrease the amounts of solid wastes, particularly those of wasted powder resins produced in a desalination type filters in a condensate clean-up system. Constitution: The desalination type filters provided in a condensate clean-up system are subjected to back-washing and then precoated with fresh powder resins for the regeneration of the filters. In this case, the contaminated powder resins obtained in the back-washing are removed with contaminates through magnetic filters and then they are precoated at least as a part of the fresh powder resins on the desalination filters. This can significantly decrease the amount of wasted powder resins, as well as reduce the amount of the fresh resins to be used. (Furukawa, Y.)

  13. Test results with a high performance-electromagnetic filter and their general importance for filtration of corrosion products in power plants

    The high capacity electromagnetic filter is distinguishable from the well-known electromagnetic filter mainly because part of the sphere filling is replaced by a matrix of wire meshes stacked on top of each other and of different or uniform wire strength. Tests in the feedwater tank of a nuclear power station (Grafenrheinfeld nuclear power station) and in the condensate-/feedwater system of a fossil fuel-fired peak load power station (Staudinger power station, Unit No. III) prove that the new filter exhibits an improved capacity and good backwash performance, in addition to increased collection efficiency, even with widely ranging oxide compounds. (orig.)

  14. Power Quality Improvement and LVRT Capability Enhancement of Wind Farms by Means of an Inductive Filtering Method

    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.

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

    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.

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

    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. Preventive maintenance activities for nuclear power station

    The supply of stable electric power by getting rid of the failures of nuclear power plants is an important factor for obtaining reliance and social acceptance for nuclear power plants as power sources. Electric power companies have improved their installations as well as carried out maintenance during operation, regular inspection and arrangement. Nuclear plant manufacturers not only implement maintenance and facility-improving works at the request of electric power companies, but also have charge of cooperation in maintenance planning, maintenance engineering services such as operation and repair data analysis and the development of working robots for maintenance. This paper introduces the maintenance activities presently performed by Hitachi Ltd., that is (1) servicing activities for supporting maintenance centering around the Nuclear Plant Service Center; (2) maintenance works in regular inspection; (3) maintenance engineering services to offer preventive maintenance data; and (4) the automation of maintenance works and the development of working robots for reducing exposure to radiation. The robots for nuclear plants are roughly divided into the following four types, and the results of using robots are described. They are exchange machines for replacing reactor or auxiliary components; inspection machines for monitoring plant conditions during reactor operation and for inspection works during shutdown; decontamination machines for reducing radiation dose of reactor equipment; and machining robots for reactor equipment reconstruction or repairing works. (Wakatsuki, Y.)

  18. 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)

    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)

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

    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.

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

    Shan, Chi-En

    2016-01-01

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

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

    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.

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

    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.

  3. DETECTING ACTIVE GALACTIC NUCLEI USING MULTI-FILTER IMAGING DATA. II. INCORPORATING ARTIFICIAL NEURAL NETWORKS

    Dong, X. Y.; De Robertis, M. M., E-mail: xydong@yorku.ca [Physics and Astronomy Department, York University, Toronto, ON M3J 1P3 (Canada)

    2013-10-01

    This is the second paper of the series Detecting Active Galactic Nuclei Using Multi-filter Imaging Data. In this paper we review shapelets, an image manipulation algorithm, which we employ to adjust the point-spread function (PSF) of galaxy images. This technique is used to ensure the image in each filter has the same and sharpest PSF, which is the preferred condition for detecting AGNs using multi-filter imaging data as we demonstrated in Paper I of this series. We apply shapelets on Canada-France-Hawaii Telescope Legacy Survey Wide Survey ugriz images. Photometric parameters such as effective radii, integrated fluxes within certain radii, and color gradients are measured on the shapelets-reconstructed images. These parameters are used by artificial neural networks (ANNs) which yield: photometric redshift with an rms of 0.026 and a regression R-value of 0.92; galaxy morphological types with an uncertainty less than 2 T types for z ≤ 0.1; and identification of galaxies as AGNs with 70% confidence, star-forming/starburst (SF/SB) galaxies with 90% confidence, and passive galaxies with 70% confidence for z ≤ 0.1. The incorporation of ANNs provides a more reliable technique for identifying AGN or SF/SB candidates, which could be very useful for large-scale multi-filter optical surveys that also include a modest set of spectroscopic data sufficient to train neural networks.

  4. DETECTING ACTIVE GALACTIC NUCLEI USING MULTI-FILTER IMAGING DATA. II. INCORPORATING ARTIFICIAL NEURAL NETWORKS

    This is the second paper of the series Detecting Active Galactic Nuclei Using Multi-filter Imaging Data. In this paper we review shapelets, an image manipulation algorithm, which we employ to adjust the point-spread function (PSF) of galaxy images. This technique is used to ensure the image in each filter has the same and sharpest PSF, which is the preferred condition for detecting AGNs using multi-filter imaging data as we demonstrated in Paper I of this series. We apply shapelets on Canada-France-Hawaii Telescope Legacy Survey Wide Survey ugriz images. Photometric parameters such as effective radii, integrated fluxes within certain radii, and color gradients are measured on the shapelets-reconstructed images. These parameters are used by artificial neural networks (ANNs) which yield: photometric redshift with an rms of 0.026 and a regression R-value of 0.92; galaxy morphological types with an uncertainty less than 2 T types for z ≤ 0.1; and identification of galaxies as AGNs with 70% confidence, star-forming/starburst (SF/SB) galaxies with 90% confidence, and passive galaxies with 70% confidence for z ≤ 0.1. The incorporation of ANNs provides a more reliable technique for identifying AGN or SF/SB candidates, which could be very useful for large-scale multi-filter optical surveys that also include a modest set of spectroscopic data sufficient to train neural networks

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

    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...

  6. Influence of geometry calibration in the determination of gamma emitters in active carbon filters

    Testing laboratories participate in external quality controls. For these controls are useful it is necessary to eliminate factors that can introduce sources of variability in the results. A factor to consider in this paper as a source of variability is the calibration geometry chosen for the correct quantification of the activity concentrations. This work contains the results of the intercomparison exercise and from them analysed the effect of the geometry of calibration used in the quantification of activity concentrations present in the activated carbon filter. (Author)

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

    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...

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

    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...

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

    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. ...

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

    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...

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

    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.

    2016-02-01

    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 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.

  12. Demonstration of a Realtime Active-Tag RFID, Java Based Indoor Localization System using Particle Filtering

    Wendlandt, Kai; Robertson, Patrick; Khider, Mohammed; Angermann, Michael; Sukchaya, Kosawat

    2007-01-01

    To develop and demonstrate accurate indoor pedestrian navigation, we implemented a flexible location framework which is able to use various sensors as positioning sources. In the current setup, the main positioning data is derived from an active long range RFID system which collects RSS values from various RFID tags in the environment. The position is calculated using particle filtering algorithms. The demonstration shows the real time tracking of a person on a remote visualization screen.

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

    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.)

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

    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.

  15. Diesel oxidation catalyst and particulate filter modeling in active - Flow configurations

    A one-dimensional transient model is developed in order to carry out theoretical investigations on the active flow diesel aftertreatment configurations. Simulations are carried out to predict the thermal response of particulate filters during active flow regeneration operations. Results indicate that the active flow-control strategies can achieve higher energy efficiency in aftertreatment operations. The energy efficiency analysis is carried out using various active-flow configurations. The theoretical model is validated using the experimental results. Further empirical investigation is carried out in order to study energy efficiency of supplemental fuel in the active-flow configurations. Different engine operating modes are also investigated with the active-flow configurations. It is observed that diesel aftertreatment with active flow can significantly improve in the supplemental energy efficiency.

  16. Active micromachines: Microfluidics powered by mesoscale turbulence.

    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

  17. Active micromachines: Microfluidics powered by mesoscale turbulence

    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.

  18. Active micromachines: Microfluidics powered by mesoscale turbulence

    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

  19. Investigation of a broadband TiO2/SiO2 optical thin-film filter for hybrid solar power systems

    Highlights: ► We present a new optical filter to get optimal performance of PV power system. ► The experimental results of the filter fabrication match well with numerical design. ► The measured results of a typical Si cell show efficiency increase using the filter. ► A proposed model for hybrid PV–TEG system demonstrates the benefits of the filter. -- Abstract: Using the technology of spectral selectivity to integrate different solar power generators in a hybrid system is a feasible way to improve the optical-electric efficiency. This paper presents an 82-layer broadband optical interference thin-film filter matching with crystalline silicon photovoltaic cells, which using TiO2 and SiO2 as fabrication materials and can be used in hybrid solar power systems like photovoltaic–thermoelectric generator (PV–TEG) systems. The design, optimization and fabrication process of the filter is described, high reflectance from 400 nm to 1100 nm as well as high transmittance from 1100 nm to 2500 nm over the broadband of solar spectrum are obtained. The classical electron beam evaporation plant is used to fabricate the filter. Four different incidence angles’ optical performances of the sample filter are measured which agree well with the numerical simulation results. The electrical characteristics of a typical Silicon photovoltaic cell using the fabricated sample filter are measured. An average efficiency increase of 3.24% for the solar cell with respect to the solar energy it receives can be obtained due to the filter. A calculation model for a hybrid PV–TEG system using this thin-film filter is proposed and the benefits of the filter for hybrid solar power systems are demonstrated.

  20. Hydrogen countermeasures and activity retention by filtered venting for WWER-440/V230 NPP confinement

    In order to prevent loss of confinement integrity caused by steam and hydrogen generation nuclear power plants in the Federal Republic of Germany as well as in most other European countries have been or will be back-fitted with a system for filtering the confinement atmosphere prior to release to the environment and a system for reducing and measuring the H2 concentration inside the confinement. For these tasks systems for confinement atmosphere control are presented, capable of: handling high H2 production rates and cleaning of high contaminated confinement atmosphere. (author)

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

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

    2015-01-01

    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 of...

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

    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

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

    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

  4. Design and application of finite impulse response digital filters

    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.)

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

    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

  6. A Two-Stage Kalman Filter Approach for Robust and Real-Time Power System State Estimation

    Zhang, Jinghe; Welch, Greg; Bishop, Gary; Huang, Zhenyu

    2014-04-01

    As electricity demand continues to grow and renewable energy increases its penetration in the power grid, realtime state estimation becomes essential for system monitoring and control. Recent development in phasor technology makes it possible with high-speed time-synchronized data provided by Phasor Measurement Units (PMU). In this paper we present a two-stage Kalman filter approach to estimate the static state of voltage magnitudes and phase angles, as well as the dynamic state of generator rotor angles and speeds. Kalman filters achieve optimal performance only when the system noise characteristics have known statistical properties (zero-mean, Gaussian, and spectrally white). However in practice the process and measurement noise models are usually difficult to obtain. Thus we have developed the Adaptive Kalman Filter with Inflatable Noise Variances (AKF with InNoVa), an algorithm that can efficiently identify and reduce the impact of incorrect system modeling and/or erroneous measurements. In stage one, we estimate the static state from raw PMU measurements using the AKF with InNoVa; then in stage two, the estimated static state is fed into an extended Kalman filter to estimate the dynamic state. Simulations demonstrate its robustness to sudden changes of system dynamics and erroneous measurements.

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

    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...

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

    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...

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

    Bester, Kai; Banzhaf, Stefan; Burkhardt, Michael;

    2011-01-01

    . A technical scale activated vertical soil filter (biofilter) with different layers (peat, sand and gravel), was planted with reed (Phragmites australis) and used to study the removal rates and fate of hydrophilic to moderate hydrophobic (log Kow 1.8–4.4) biocides and biocide metabolites such as...... first one (36 d) under low flow conditions (61 L m2 d1) 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 m2 within 5 min (retention time <1 h......). During this experiment the removal rates of the compounds decreased drastically. For five compounds (Cybutryn, Descyclopropyl–Cybutryn, Diuron, Isoproturon, and Iodocarb) the removal dropped temporarily below 60%, while it was always above 70% for the others (Terbutryn, Benzo-isothiazolinone, n...

  10. Monitoring Biological Activity at Geothermal Power Plants

    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.

  11. Active filtering applied to radiographic images unfolded by the Richardson-Lucy algorithm

    Degradation of images caused by systematic uncertainties can be reduced when one knows the features of the spoiling agent. Typical uncertainties of this kind arise in radiographic images due to the non - zero resolution of the detector used to acquire them, and from the non-punctual character of the source employed in the acquisition, or from the beam divergence when extended sources are used. Both features blur the image, which, instead of a single point exhibits a spot with a vanishing edge, reproducing hence the point spread function - PSF of the system. Once this spoiling function is known, an inverse problem approach, involving inversion of matrices, can then be used to retrieve the original image. As these matrices are generally ill-conditioned, due to statistical fluctuation and truncation errors, iterative procedures should be applied, such as the Richardson-Lucy algorithm. This algorithm has been applied in this work to unfold radiographic images acquired by transmission of thermal neutrons and gamma-rays. After this procedure, the resulting images undergo an active filtering which fairly improves their final quality at a negligible cost in terms of processing time. The filter ruling the process is based on the matrix of the correction factors for the last iteration of the deconvolution procedure. Synthetic images degraded with a known PSF, and undergone to the same treatment, have been used as benchmark to evaluate the soundness of the developed active filtering procedure. The deconvolution and filtering algorithms have been incorporated to a Fortran program, written to deal with real images, generate the synthetic ones and display both. (author)

  12. Adaptive unscented Kalman filter based state of energy and power capability estimation approach for lithium-ion battery

    Zhang, Weige; Shi, Wei; Ma, Zeyu

    2015-09-01

    Accurate estimations of battery energy and available power capability are of great of importance for realizing an efficient and reliable operation of electric vehicles. To improve the estimation accuracy and reliability for battery state of energy and power capability, a novel model-based joint estimation approach has been proposed against uncertain external operating conditions and internal degradation status of battery cells. Firstly, it proposes a three-dimensional response surface open circuit voltage model to calibrate the estimation inaccuracies of battery state of energy. Secondly, the adaptive unscented Kalman filter (AUKF) is employed to develop a novel model-based joint state estimator for battery state of energy and power capability. The AUKF algorithm utilizes the well-known features of the Kalman filter but employs the method of unscented transform (UT) and adaptive error covariance matching technology to improve the state estimation accuracy. Thirdly, the proposed joint estimator has been verified by a LiFePO4 lithium-ion battery cell under different operating temperatures and aging levels. The result indicates that the estimation errors of battery voltage and state-of-energy are less than 2% even if given a large erroneous initial value, which makes the state of available power capability predict more accurate and reliable for the electric vehicles application.

  13. Statistical Performances of Resistive Active Power Splitter

    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.

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

    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 is...... 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....

  15. Prediction of stopping-power ratios in flattening-filter free beams.

    Ceberg, Crister; Johnsson, Stefan; Lind, Mårten; Knöös, Tommy

    2010-01-01

    PURPOSE: In recent years, there has been an increasing interest in flattening-filter free (FFF) beams. However, since the removal of the flattening filter will affect both the mean and the variance of the energy spectrum, current beam-quality specifiers may not be adequate for reference dosimetry in such beams. The purpose of this work was to investigate an alternative, more general beam-quality specifier. METHODS: The beam-quality specifier used in this work was a combination of the kerma-we...

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

    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.)

  17. Managing Siting Activities for Nuclear Power Plants

    One of the IAEA's statutory objectives is to ''seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world''. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. The introduction of nuclear power brings new challenges to States - one of them being the selection of appropriates sites. It is a project that needs to begin early, be well managed, and deploy good communications with all stakeholders; including regulators. This is important, not just for those States introducing nuclear power for the first time, but for any State looking to build a new nuclear power plant. The purpose of the siting activities goes beyond choosing a suitable site and acquiring a licence. A large part of the project is about producing and maintaining a validated

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

    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....

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

    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...

  20. 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

    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.

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

    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.

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

    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.

  3. Adaptive intelligent power systems: Active distribution networks

    Electricity networks are extensive and well established. They form a key part of the infrastructure that supports industrialised society. These networks are moving from a period of stability to a time of potentially major transition, driven by a need for old equipment to be replaced, by government policy commitments to cleaner and renewable sources of electricity generation, and by change in the power industry. This paper looks at moves towards active distribution networks. The novel transmission and distribution systems of the future will challenge today's system designs. They will cope with variable voltages and frequencies, and will offer more flexible, sustainable options. Intelligent power networks will need innovation in several key areas of information technology. Active control of flexible, large-scale electrical power systems is required. Protection and control systems will have to react to faults and unusual transient behaviour and ensure recovery after such events. Real-time network simulation and performance analysis will be needed to provide decision support for system operators, and the inputs to energy and distribution management systems. Advanced sensors and measurement will be used to achieve higher degrees of network automation and better system control, while pervasive communications will allow networks to be reconfigured by intelligent systems

  4. A study on the purification of primary coolant in a nuclear power plant using a magnetic filter - electrodeionization hybrid separation system

    A study on the purification of primary coolant system in a nuclear power plant is carried out using magnetic filter - electrodeionization hybrid separation process. Magnetic filter system with 3000 Gauss permanent manget is used for the removal of CRUD (Chalk River Unidentified Deposit) and electrodeionization for ionic nuclide species. The removal and transport mechanism of nickel ion in an electrodeionization system is explained. The developed magnetic filter - electrodeionization hybrid separation process showed high removal rate over 98 %. The results suggested the applicable possibility for the purification of primary coolant system in a nuclear power plant

  5. Removal of heavy metals using a microbial active, continuously operated sand filter

    Heavy metals play an important role within the spectrum of the various pollutants, emitted into the environment via human activities. In contrast to most organic pollutants, heavy metal can not be degraded. Many soils, lakes and rivers show a high contamination with heavy metals due to the enrichment of these pollutants. In addition to existing chemical-physical and biological technologies for the treatment of heavy metal containing waste waters a demand for new, efficient and low-cost cleaning technologies exists, particularly for high volumes of weakly contaminated waters. Such a technology was developed within the framework of a scientific project of the European Union. The approach makes use of a continuously operated, moving-bed Astrasand filter, which has been operated as a continuous biofilm reactor. By inoculation of the reactor with bacteria providing different, defined mechanisms of metal immobilization, and by continuous supply of suitable nutrients, a metal-immobilizing biofilm is built up and regenerated continuously. Metal-enriched biomass is removed continuously from the system, and the contained metals can be recycled by pyrometallurgical treatment of the biomass. The subjects of the present work were the optimization of the nutrient supply for the process of metal removal, the investigation of the toxicity of different waste waters, the optimization of inoculation and biofilm formation, set-up and operation of a lab scale sand filter and the operation of a pilot scale sand filter treating rinsing water of a chemical nickel plating plant. First, basic parameters like toxicity of heavy metal-containing waste waters and the influence of the nutrition of bacteria on biosorption and total metal removal were examined, using freely suspended bacteria in batch culture. Concerning toxicity great differences could be found within the spectrum of heavy metal-containing waste waters tested. Some waters completely inhibited growth, while others did not

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

    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

  7. Power spectra of active galactic nuclei

    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.

  8. Power spectra of active galactic nuclei

    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.

  9. Enhanced Stability of Capacitor-Current Feedback Active Damping for LCL-Filtered Grid Converters

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

    2015-01-01

    The proportional capacitor-current feedback active damping method has been widely used to suppress the LCL-filter resonance. However, the time delay in the damping control loop may lead to non-minimum phase or even unstable responses when the resonance frequency varies in a wide range. To improve...... the robustness of damping, this paper proposes an improved damping controller with the capacitor current feedback loop, which is based on the second-order generalized integrator, instead of a proportional gain, which can effectively mitigate the detrimental effect of the time delay. Robustness of the...

  10. Tunable add-drop filter using an active whispering gallery mode microcavity

    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%.

  11. Component handling for replacement of filter cartridge in integrated purification units at Creys-Malville power plant

    At Creys-Malville power plant, the primary sodium is purified by two submerged integrated purification units in the reactor vessel. Each unit consists of a main structure entering the vessel sodium header and an interchangeable structure comprising a plug and filter cartridge. When a spent cartridge is replaced, special equipment is required to ensure containment of the reactor cover gas and radiological protection of the personnel. This equipment includes a handling flask and a lock-and-valve system. This operation to replace a spent cartridge by a new one was performed for the first time in industrial conditions in August 1987

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

    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.)

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

    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.

  14. A pre-estimation filtering process of bad data for linear power systems state estimators using PMUs

    Fosso, Olav; Bell, Keith; Pignati, Marco; Zanni, Lorenzo; Sarri, Stela; Cherkaoui, Rachid; Le Boudec, Jean-Yves; Paolone, Mario

    2014-01-01

    The paper proposes a specific algorithm for the pre-estimation filtering of bad data (BD) in PMU-based power systems linear State Estimators (SEs). The approach is framed in the context of the so-called real-time SEs that take advantage of the high measurement frame rate made available by PMUs (i.e., 50–60 frames per second). In particular, the proposed algorithm examines PMU measurement innovations for each new received set of data in order to locate anomalies and apply countermeasures. The ...

  15. Variable power distribution for zoned regeneration of an electrically heated particulate filter

    Bhatia, Garima [Bangalore, IN; Gonze, Eugene V [Pinckney, MI

    2012-04-03

    A system includes a particulate matter (PM) filter with multiple zones, an electric heater and a control module. The electrical heater includes heater segments, which each correspond with a respective one of the zones. The electrical heater is arranged upstream from and is proximate with the PM filter. The control module selectively applies a first energy level to a first one of the zones via a first one of the heater segments to initiate regeneration in the first zone. The control module also selectively applies a second energy level that is less than the first energy level to a second one of the zones via a second one of the heater segments to initiate regeneration in the second zone.

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

    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

  17. Endocrine activity and developmental toxicity of cosmetic UV filters--an update

    UV filters represent a new class of endocrine active chemicals. In vitro, 8/9 chemicals showed estrogenic (MCF-7 cells), and 2/9 antiandrogenic activity (MDA-kb2 cells). Six/nine filters (benzophenone (Bp)-1, Bp-2, Bp-3, 3-benzylidene camphor (3-BC), 4-methylbenzylidene camphor (4-MBC), octyl-methoxycinnamate (OMC)) increased uterine weight in immature rats. 3-Benzylidene camphor and 4-MBC displaced 16α125I-estradiol from human estrogen receptor (ER)β , not ERα. Developmental toxicity of 4-MBC (0.7-47 mg/kg body weight/day) and 3-BC (0.24-7 mg/kg), administered in chow was investigated in Long Evans (LE) rats. Weight gain of pregnant rats was reduced only by 3-BC, early postnatal survival rate and thymus weight by both compounds at higher doses. 4-Methylbenzylidene camphor and 3-BC delayed male puberty, and dose-dependently affected reproductive organ weights of adult male and female F1 offspring, with partly different effect patterns. Thyroid weight was increased by higher 4-MBC doses. Tissue-specific changes in mRNA levels of estrogen-regulated genes in prostate, uterus and brain regions, determined by real-time PCR, and in their response to acute estradiol challenge in adult gonadectomized offspring were observed. Lowest effective doses were 0.24 mg/kg/day for 3-BC and 7 mg/kg/day for 4-MBC. Fat tissue levels at 7 mg/kg 4-MBC (GC-MS) approached the range of UV filters in fish (Nagtegaal et al., 1997; Balmer et al., 2004)

  18. Reviewing surveillance activities in nuclear power plants

    This document provides guidance to Operational Safety Review Teams (OSARTs) for reviewing surveillance activities at a nuclear power plant. In addition, the document contains reference material to support the review of surveillance activities, to assist within the Technical Support area and to ensure consistency between individual reviews. Drafts of the document have already been used on several OSART missions and found to be useful. The document first considers the objectives of an excellent surveillance programme. Investigations to determine the quality of the surveillance programme are then discussed. The attributes of an excellent surveillance programme are listed. Advice follows on how to phrase questions so as to obtain an informative response on surveillance features. Finally, specific equipment is mentioned that should be considered when reviewing functional tests. Four annexes provide examples drawn from operating nuclear power plants. They were selected to supplement the main text of the document with the best international practices as found in OSART reviews. They should in no way limit the acceptance and development of alternative approaches that lead to equivalent or better results. Refs, figs and tabs

  19. 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

    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

  20. FILTER COMPONENT ASSESSMENT--CERAMIC CANDLES--

    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.

  1. Analog Electronic Filters Theory, Design and Synthesis

    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...

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

    Ayan Mitra; Abhisek Roy

    2012-01-01

    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 valu...

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

    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 ...

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

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

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

    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

  6. Collaborative filtering for brain-computer interaction using transfer learning and active class selection.

    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.

  7. Wind Powering America FY07 Activities Summary

    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.

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

    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.

  9. Autonomous navigation for autonomous underwater vehicles based on information filters and active sensing.

    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

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

    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

  11. Wind Powering America FY06 Activities Summary

    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.

  12. Benefit-cost analysis of commercially available activated carbon filters for indoor ozone removal in single-family homes.

    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. PMID:25952610

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

    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...

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

    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%.

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

    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.

  16. Optically powered active sensing system for Internet Of Things

    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.

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

    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

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

    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.

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

    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

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

    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...

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

    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...

  2. Co-generation system with integrated functions of active filter; Sistema de cogeneracion con funciones de filtro activo integradas

    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

  3. Novel Algorithm for Active Noise Control Systems Based on Frequency Selective Filters

    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.

  4. Voltage Quality Enhancement and Fault Current Limiting with Z-Source based Series Active Filter

    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.

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

    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.

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

    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

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

    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

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

    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.

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

    Pavlík Haddad, S.A.

    2006-01-01

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

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

    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 harmonic...

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

    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

  12. Controlling of crustacean zooplankton reproduction in biological activated carbon (BAC) filters by strengthen operation and management of conventional process

    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.

  13. Wavelet Enveloped Power Spectrum and Optimal Filtering For Fault Diagnosis in Gear

    M. Lokesha; Manik Chandra Majumder; K. P. Ramachandran; Khalid Fathi Abdul Raheem

    2013-01-01

    The methodology of vibration based condition monitoring technology has been developing at a rapid stage in the recent years suiting to the maintenance of sophisticated and complicated machines. The ability of wavelet analysis to efficiently detect non-stationary, non-periodic, transient features of the vibration signal makes it a demanding tool for condition monitoring. In this paper, the vibration condition monitoring based on Laplace and Morlet wavelet enveloped power spectrum analysis to d...

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

    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...

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

    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

  16. Digital filtering techniques applied to electric power systems protection; Tecnicas de filtragem digital aplicadas a protecao de sistemas eletricos de potencia

    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.

  17. Filter material charging apparatus for filter assembly for radioactive contaminants

    A filter charging apparatus for a filter assembly is described. The filter assembly includes a housing with at least one filter bed therein and the filter charging apparatus for adding filter material to the filter assembly includes a tank with an opening therein, the tank opening being disposed in flow communication with opposed first and second conduit means, the first conduit means being in flow communication with the filter assembly housing and the second conduit means being in flow communication with a blower means. Upon activation of the blower means, the blower means pneumatically conveys the filter material from the tank to the filter housing

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

    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.

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

    Wu, Dan; Tang, Fen; Guerrero, Josep M.;

    2014-01-01

    This paper proposes an autonomous active and reactive power distribution strategy that can be applied directly on current control mode (CCM) inverters, being compatible as well with conventional droop-controlled voltage control mode (VCM) converters. In a microgrid, since renewable energy sources...... (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 in a...... distributed way. Real-time hardware-in-the-loop results are presented to verify the proposed control strategy....

  20. A Robust Pre-Filter and Power Loading Design for Time Reversal UWB Systems over Time-Correlated MIMO Channels

    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.

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

    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...

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

    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.

  3. Active Power Flow Optimization of Industrial Power Supply with Regard to the Transmission Line Conductor Heating

    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.

  4. Assessment of multiple hormone activities of a UV-filter (octocrylene) in zebrafish (Danio rerio).

    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

  5. Analytical Model and Investigation of a Four-Switch Space-Vector Modulated Hybrid Power Filter with Six-Fold Switching Symmetry

    Klíma, J.; Tlustý, J.; Škramlík, Jiří; Valouch, Viktor

    Valencia: Universidad Politecnica, 2009, s. 1-6. ISBN 978-84-612-8014-8. [International Conference on Renewable Energies and Power Quality (ICREPQ 09). Valencia (ES), 15.04.2009-17.04.2009] R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : hybrid power filter * six-fold switching symmetry * four-switch inverter Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  6. Nitrogen Removal in a Full-Scale Domestic Wastewater Treatment Plant with Activated Sludge and Trickling Filter

    Davood Nourmohammadi

    2013-01-01

    Full Text Available During the last decade, more stringent effluent requirements concerning the nutrients effluent values have been imposed by legislation and social concern. In this study, efficiency of total nitrogen removal in activated sludge and trickling filter processes (AS/TF was investigated in Tehran North wastewater treatment plant. Biological system in this site was included, anoxic selector tank, aeration tank, final sedimentation, and trickling filter. A part of treated wastewater before chlorination was mixed with supernatant of dewatered sludge and fed to the trickling filter. Supernatant of dewatered sludge with high concentration of NH4-N was diluted by treated wastewater to provide complete nitrification in trickling filter Produced nitrate in trickling filter was arrived to the anoxic tank and converted to nitrogen gas by denitrification. According to the study result, low concentration of organic carbone and high concentration of NH4-N led to nitrification in TF, then nitrate denitrification to nitrogen gas occurred in selector area. NH4-N concentration decreased from 26.8 mg/L to 0.29 mg/L in TF, and NO3-N concentration increased from 8.8 mg/L to 27 mg/L in TF. Consequently, the total nitrogen decreased approximately to 50% in biological process. This efficiency has been observed in returned flow around 24% from final sedimentation into TF. It was concluded that, in comparison with biological nutrient removal processes, this process is very efficient and simple.

  7. Retention of titanium dioxide nanoparticles in biological activated carbon filters for drinking water and the impact on ammonia reduction.

    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

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

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

    2015-01-01

    Stability in the nowadays distribution power system is endangered by interaction problems that may arise from newly added power-electronics based power devices. Recently, a new concept to deal with this higher frequency instability, the active damper, has been proposed. The active damper is a power...... electronics based power device, which provides an adjustable damping capability to the power system where the voltage harmonic instability is measured. It can stabilize by adjusting the equivalent node impedance with its plug and play feature. This feature gives many degrees of freedom of its installation...... is important for stabilizing the overall network and the active damper should be placed near to the problematic power devices. Finally, the unstable network with five inverters is able to obtain stability by adopting an active damper to the place where its ability becomes the most effective....

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

    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.

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

    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...

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

    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.

  12. Digital Filters for Low Frequency Equalization

    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...

  13. Weighted Robust Adaptive Filtering in Krein Space and Its Application in Active Noise Control

    Jayawardhana, Bayu; Yuan, Shuqing; Xie, Lihua

    2002-01-01

    Robust adaptive filtering ensures the minimization of the transfer function from the disturbance to the estimation error and thus, guarantees the robustness against the worst-case disturbance in the system. However, a more general approach will be given in this paper hy employing frequency weighting, which offers flexibility in determining robustness sensitivity in certain frequency of interest. Using the projection in Krein space, we developed a weighted recursive H∞ filtering that computes ...

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

    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...

  15. Ceramic fiber filter technology

    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.

  16. Spherical auto-flushing pipe filter used in the sea water cooling system of nuclear power plant

    Taking TNPS Unit 1 and 2 as an example, this paper briefly introduces the constitutes and functions of the sea water cooling system, especially the issues when the heat exchanger was jam-packed with sea sundries. The necessity to erect the auto-flushing pipe filter is discussed. The scheme design and equipment selection of auto-flushing filter and the effect of using the auto-flushing filter in TNPS are introduced. (authors)

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

    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.

  18. CNEN activities and brazilian nuclear power policy

    The goal of the brazilian policy in nuclear power is to provide its use in a pacific way to promote the well being of our people. It is intended, as well, to finish the construction of Angra II and III and proceed with the implementation of the nuclear fuel cycle, progressively fomenting its nationalization. (A.C.A.S.)

  19. Facile and Sensitive Fluorescence Sensing of Alkaline Phosphatase Activity with Photoluminescent Carbon Dots Based on Inner Filter Effect.

    Li, Guoliang; Fu, Huili; Chen, Xuejie; Gong, Peiwei; Chen, Guang; Xia, Lian; Wang, Hua; You, Jinmao; Wu, Yongning

    2016-03-01

    A simple and sensitive fluorescent assay for detecting alkaline phosphatase (ALP) based on the inner filter effect (IFE) has been proven, which is conceptually different from the previously reported ALP fluorescent assays. In this sensing platform, N-doped carbon dots (CDs) with a high quantum yield of 49% were prepared by one-pot synthesis and were directly used as a fluorophore in IFE. p-Nitrophenylphosphate (PNPP) was employed to act as an ALP substrate, and its enzyme catalytic product (p-nitrophenol (PNP)) was capable of functioning as a powerful absorber in IFE to influence the excitation of fluorophore (CDs). When in the presence of ALP, PNPP was transformed into PNP and induced the absorption band transition from 310 to 405 nm, which resulted in the complementary overlap between the absorption of PNP and the excitation of CDs. Because of the competitive absorption, the excitation of CDs was significantly weakened, resulting in the quenching of CDs. The present IFE-based sensing strategy showed a good linear relationship from 0.01 to 25 U/L (R(2) = 0.996) and provided an exciting detection limit of 0.001 U/L (signal-to-noise ratio of 3). The proposed sensing approach was successfully applied to ALP sensing in serum samples, ALP inhibitor investigation and phosphatase cell imaging. The presented IFE-based CDs fluorescence sensing strategy gives new insight on the development of the facile and sensitive optical probe for enzyme activity assay because the surface modification or the linking between the receptor and the fluorophore is no longer required. PMID:26820049

  20. Nuclear power plant construction activity, 1986

    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

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

    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.

  2. Sustainable Buildings. Using Active Solar Power

    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.

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

    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)

  4. 基于级联有源滤波器与静止无功补偿器的综合补偿控制方案%A Universal Compensation Control Scheme Based on Cascade Active Power Filter and Static Var Compensator

    高聪哲; 姜新建; 李永东

    2012-01-01

    How to keep system stability and optimize var compensation capability is the key issue in the combined system based on cascade multilevel active power filter(CS-APF) and static var compensator(SVC).A universal control strategy is proposed for the combined system.For the SVC,a feed forward control for the compensation of positive sequence reactive component and negative sequence component of the load is adopted.The network susceptance(with no components of CS-APF) feedback control is applied to decrease the compensation error.For the CS-APF control,a feed forward control of harmonic compensation for thyristor control reactor(TCR) and the load is applied.The network harmonic current feedback control is applied to decrease the compensation error.The fixed capacitor(in SVC) current component is removed from the network current feedback control loop of CS-APF to improve the stability of the combined system.The var compensation capability of CS-APF is enabled to optimize the performance of SVC.Moreover,a novel pre-calculation method for the TCR harmonic current detection is proposed.According to the triggering angle of the thyristor in TCR and the network voltage phase,the harmonic current is constructed with no time delay.Finally,the simulation and experimental results show that: 1)the system stability is high without closed loop between the control of CS-APF and SVC;2)the real-time harmonic compensation of TCR is realized;3)the system responsibility is quick;and 4)the capability of var compensation of SVC is improved.%级联多电平有源滤波器(CS-APF)与静止无功补偿器(SVC)同时运行存在稳定性及无功补偿控制优化等问题。文中提出一种统一控制策略,结合SVC和CS-APF的功能特点,使SVC对负载正序无功分量及负序分量的补偿进行前馈控制和电网电纳(不包含CS-APF分量)反馈控制;CS-APF对晶闸管相控电抗器(TCR)与电网负载谐波的补偿进行前馈

  5. KfK Laboratory for Aerosol Physics and Filter Technology. Progress report and development activities in 1990

    The activities undertaken by the laboratory for aerosol physics and filter technology (LAF) in 1990 under the following projects are described: (1) nuclear safety research (safety and material problems of fast breeders, IWR-oriented safety research); (2) pollutant control in the environment (communal waste management, emission-reducing processes, climate research - pollutants' behaviour in the atmosphere), and (3) radioactive waste management (basic work on reprocessing technologies). The annex lists the publications by the LAF staff. (BBR)

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

    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...

  7. Nuclear power company activity based costing management analysis

    With Nuclear Energy Industry development, Nuclear Power Company has the continual promoting stress of inner management to the sustainable marketing operation development. In view of this, it is very imminence that Nuclear Power Company should promote the cost management levels and built the nuclear safety based lower cost competitive advantage. Activity based costing management (ABCM) transfer the cost management emphases from the 'product' to the 'activity' using the value chain analysis methods, cost driver analysis methods and so on. According to the analysis of the detail activities and the value chains, cancel the unnecessary activity, low down the resource consuming of the necessary activity, and manage the cost from the source, achieve the purpose of reducing cost, boosting efficiency and realizing the management value. It gets the conclusion from the detail analysis with the nuclear power company procedure and activity, and also with the selection to 'pieces analysis' of the important cost related project in the nuclear power company. The conclusion is that the activities of the nuclear power company has the obviously performance. It can use the management of ABC method. And with the management of the procedure and activity, it is helpful to realize the nuclear safety based low cost competitive advantage in the nuclear power company. (author)

  8. Water Filter

    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.

  9. Optimal placement of an active power line conditioner by using of Fuzzy logic

    After recognition of the sources of harmonic producing and their destructive effects on power system equipment, the necessity of the reduction of harmonic voltage and current distortion till resting to harmonic standards permissible restricted area is revealed. There is different methods for encountering with harmonics. One of the newest exciting methods is the use of active power line conditioner. Active power line conditioner is a kind of active filters that by means of injecting harmonic currents to network busses is able to reduce harmonic distortion in all network busses. In this thesis after network components modeling at harmonic areas, harmonic power flow is done by current injecting method. Then the amount of active power line conditioner injected currents for minimizing the voltage. T.H.Ds and M.L.L s in all busses in two cases constrained and non constrained is computed by using of nonlinear optimal theorem and considering of T.H.D and M.L.L as two objective functions. For selecting the optimal place of active power line conditioner installing a fuzzy system has designed that is able to determine the best bus intelligently by simulating of experiences of a expert person and considering of the harmonic standards permissible restricted area. Different particles of this fuzzy system are: Fuzzifier, Fuzzy rule base, Fuzzy inference engine and Defuzzifier that these components is contemplate by detailed. At the end of thesis the upper simulation has done on three networks (3 busses, 5 busses and 18 busses) and the obtained results has presented

  10. Instantaneous Active and Reactive Power Measuring Method in Three Phase Power System

    A. TAHRI

    2005-01-01

    Full Text Available This paper describes an electronic means of measuring the instantaneous active and reactive power absorbed by any electrical equipment. The measurements are based on the Clark (a-b and Park (d-q transformations. The system is useful to teach electrical machines in Park’s coordinates and it allows also the study and control of some power electronics converters that are connected to three phase power network, such as static VAR compensator. The principle of the measuring method of the active and reactive power is described, and analyzed for different tests. The effectiveness of the proposed measuring method is confirmed by experimental investigation employing a test system.

  11. Control Strategies for Trap Filter Interfaced Three-Phase Grid Connected Converters

    Min, Huang

    spectrum analysis. A basic parameters design for high order filters is proposed and also the stability issued of LLCL filter-based grid-connected inverter with grid current control is analyzed. Chapter 3 investigates the impedance-based active damping methods investigation for voltage source converter with...... damping in order to stabilize the whole system with resonance issue. LC trap filter application for current source converters to reduce the size of the filter and get a higher power factor....

  12. Model based active power control of a wind turbine

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

    2014-01-01

    In recent decades there has been increasing interest in green energies, of which wind energy is one of the most important. Wind turbines are the most common wind energy conversion systems and are hoped to be able to compete with traditional power plants in near future. This demands better...... 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...

  13. Time-domain filtered-x-Newton narrowband algorithms for active isolation of frequency-fluctuating vibration

    Li, Yan; He, Lin; Shuai, Chang-geng; Wang, Fei

    2016-04-01

    A time-domain filtered-x Newton narrowband algorithm (the Fx-Newton algorithm) is proposed to address three major problems in active isolation of machinery vibration: multiple narrowband components, MIMO coupling, and amplitude and frequency fluctuations. In this algorithm, narrowband components are extracted by narrowband-pass filters (NBPF) and independently controlled by multi-controllers, and fast convergence of the control algorithm is achieved by inverse secondary-path filtering of the extracted sinusoidal reference signal and its orthogonal component using L×L numbers of 2nd-order filters in the time domain. Controller adapting and control signal generation are also implemented in the time domain, to ensure good real-time performance. The phase shift caused by narrowband filter is compensated online to improve the robustness of control system to frequency fluctuations. A double-reference Fx-Newton algorithm is also proposed to control double sinusoids in the same frequency band, under the precondition of acquiring two independent reference signals. Experiments are conducted with an MIMO single-deck vibration isolation system on which a 200 kW ship diesel generator is mounted, and the algorithms are tested under the vibration alternately excited by the diesel generator and inertial shakers. The results of control over sinusoidal vibration excited by inertial shakers suggest that the Fx-Newton algorithm with NBPF have much faster convergence rate and better attenuation effect than the Fx-LMS algorithm. For swept, frequency-jumping, double, double frequency-swept and double frequency-jumping sinusoidal vibration, and multiple high-level harmonics in broadband vibration excited by the diesel generator, the proposed algorithms also demonstrate large vibration suppression at fast convergence rate, and good robustness to vibration with frequency fluctuations.

  14. State of charge estimation for LiMn2O4 power battery based on strong tracking sigma point Kalman filter

    Li, Di; Ouyang, Jian; Li, Huiqi; Wan, Jiafu

    2015-04-01

    The State of Charge (SOC) estimation is important since it has a crucial role in the operation of Electrical Vehicle (EV) power battery. This paper built an Equivalent Circuit Model (ECM) of the LiMn2O4 power battery, and vast characteristics experiments were undertaken to make the model identification and thus the battery SOC estimation was realized. The SOC estimation was based on the Strong Tracking Sigma Point Kalman Filter (STSPKF) algorithm. The comparison of experimental and simulated results indicates that the STSPKF algorithm performs well in estimating the battery SOC, which has the advantages of tracking the variables in real-time and adjusting the error covariance by taking the Strong Tracking Factor (STF) into account. The results also show that the STSPKF algorithm estimated the SOC more accurately than the Extended Kalman Filter (EKF) algorithm.

  15. Design and feasibility of high temperature nanoparticle fluid filter in hybrid thermal/photovoltaic concentrating solar power

    DeJarnette, Drew; Brekke, Nick; Tunkara, Ebrima; Hari, Parameswar; Roberts, Kenneth; Otanicar, Todd

    2015-09-01

    A nanoparticle fluid filter used with concentrating hybrid solar/thermal collector design is presented. Nanoparticle fluid filters could be situated on any given concentrating system with appropriate customized engineering. This work shows the design in the context of a trough concentration system. Geometric design and physical placement in the optical path was modeled using SolTrace. It was found that a design can be made that blocks 0% of the traced rays. The nanoparticle fluid filter is tunable for different concentrating systems using various PV cells or operating at varying temperatures.

  16. Requirements Specication for Ampliers and Power Supplies in Active Loudspeakers

    Schneider, Henrik; Jensen, Lasse Crone; Petersen, Lars Press; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This work aims to provide designers with a method to develop a requirements specication for power supplies and ampliers in active loudspeakers. The motivation is to avoid over-sizing and unnecessary cost. A realistic estimation of the power supplied during playback of audio in a given loudspeaker...

  17. Junction temperature estimation for an advanced active power cycling test

    Choi, Uimin; Blaabjerg, Frede; Jørgensen, S.

    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 of the...

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

    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...

  19. Measurement of gamma activity from the PUREX stack, Number 296-A-10, HEPA filters

    In response to the Environmental Protection Agency's requirements for evaluating radioactive emissions from stacks, this test plan was developed. The test plan employs the use of low resolution (NaI) portable gamma spectrometry to identify and measure gamma emitting radionuclides from HEPA filters. The test description, expected results, and test set-up and steps are discussed

  20. Facilities of management magnetoresistive transformer of active power

    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.

  1. Analysis and design of a parallel-connected single active bridge DC-DC converter for high-power wind farm applications

    Park, Kiwoo; Chen, Zhe

    2013-01-01

    This paper presents a parallel-connected Single Active Bridge (SAB) dc-dc converter for high-power applications. Paralleling lower-power converters can lower the current rating of each modular converter and interleaving the outputs can significantly reduce the magnitudes of input and output current...... ripples without increasing switching losses or device stresses. Analysis of both the input and output current characteristics and design aspects of the transformer, the filter inductor, and the input and output filter capacitors will be presented. Considering the high maintenance cost and fault tolerant...... requirements, this modular converter concept is expected to be highly beneficial especially for the offshore wind farm application....

  2. Photon harvesting, coloring and polarizing in photovoltaic cell integrated color filters: efficient energy routing strategies for power-saving displays

    Wen, Long; Chen, Qin; Song, Shichao; Yu, Yan; Jin, Lin; Hu, Xin

    2015-07-01

    We describe the integral electro-optical strategies that combine the functionalities of photovoltaic (PV) electricity generation and color filtering as well as polarizing to realize more efficient energy routing in display technology. Unlike the conventional pigment-based filters and polarizers, which absorb substantial amounts of unwanted spectral components and dissipate them in the form of heat, we propose converting the energy of those photons into electricity by constructing PV cell-integrated color filters based on a selectively transmitting aluminum (Al) rear electrode perforated with nanoholes (NHs). Combining with a dielectric-metal-dielectric (DMD) front electrode, the devices were optimized to enable efficient cavity-enhanced photon recycling in the PV functional layers. We perform a comprehensive theoretical and numerical analysis to explore the extraordinary optical transmission (EOT) through the Al NHs and identify basic design rules for achieving structural coloring or polarizing in our PV color filters. We show that the addition of thin photoactive polymer layers on the symmetrically configured Al NH electrode narrows the bandwidth of the EOT-assisted high-pass light filtering due to the strongly damped anti-symmetric coupling of the surface modes excited on the front and rear surface of the Al NHs, which facilitates the whole visible coloring with relatively high purity for the devices. By engineering the cut-off characteristics of the plasmonic waveguide mode supported by the circular or ellipsoidal Al NHs, beyond the photon recycling capacity, PV color filters and PV polarizing color filters that allow polarization-insensitive and strong polarization-anisotropic color filtering were demonstrated. The findings presented here may shed some light on expanding the utilization of PV electricity generation across new-generation energy-saving electrical display devices.

  3. Sensitivity analysis of an LCL-filter-based three-phase active rectifier via a virtual circuit approach

    Blaabjerg, Frede; Chiarantoni, Ernesto; Aquila, Antonio Dell’; Liserre, Marco; Vergura, Silvano

    2004-01-01

    Three-phase active rectifiers based on the voltage source converter topology can successfully replace traditional thyristor based rectifiers or diode bridge plus chopper in interfacing dc-systems to the grid. However, if the application in which they are employed has a high safety issue or if there......, 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...

  4. Analysis of Signal Transition Activity in FIR Filters Implemented by Parallel Multiplier Accumulator Based on Modified Booth Algorithm

    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.

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

    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. Smoke and pollutant filtering device

    A smoke and pollutant filtering device comprising a mask having a filter composed of a series of contiguous, serial layers of filtering material. The filter consists of front and rear gas permeable covers, a first filter layer of pressed vegetable matter, a second filter layer comprising a layer of activated charcoal adjacent a layer of aqua filter floss, a third filter comprising a gas permeable cloth situated between layers of pressed vegetable matter, and a fourth filter layer comprising an aqua filter floss. The first through fourth filter layers are sandwiched between the front and rear gas permeable covers. The filtering device is stitched together and mounted within a fireretardant hood shaped to fit over a human head. Elastic bands are included in the hood to maintain the hood snugly about the head when worn

  7. METAL FILTERS FOR PRESSURIZED FLUID BED COMBUSTION (PFBC) APPLICATIONS

    M.A. Alvin

    2004-01-02

    Advanced coal and biomass-based gas turbine power generation technologies (IGCC, PFBC, PCFBC, and Hipps) are currently under development and demonstration. Efforts at the Siemens Westinghouse Power Corporation (SWPC) have been focused on the development and demonstration of hot gas filter systems as an enabling technology for power generation. As part of the demonstration effort, 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 reviews SWPC's material and component assessment efforts, identifying the performance, stability, and life of porous commercial metal, advanced alloy, and intermetallic filters under simulated, pressurized fluidized-bed combustion (PFBC) conditions.

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

    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...... component, e.g. inductors or film capacitors for ripple energy storage because this task can be accomplished by the dc-link capacitors, and therefore its implementation cost can be minimized. Another unique feature of the proposed topology is that the current stress of power semiconductors can be reduced...

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

    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. Internal active power reserve management in Large scale PV Power Plants

    Craciun, Bogdan-Ionut; Spataru, Sergiu; Kerekes, Tamas;

    Active Power Reserves (APRs) provided through curtailment (iAPRs) or through auxiliary storage systems (aAPR) with Large scale PV Power Plants (LPVPPs) becomes a reality in the near future with high penetration levels of Photovoltaic (PV) power into the grid. Therefore, this paper analyses the...... solutions for iAPR fulfilment in central inverter based - LPVPPs in terms of their layout, configuration and control architecture. During iAPR supply, the LPVPP has to operate under its Maximum Power Point (MPP), which means that the MPP algorithm has to undergo several changes. For this purpose, the paper...

  11. Power Management Strategy for Active Power Sharing in Hydro/PV/Battery Hybrid Energy System

    Sweeka Meshram; Ganga Agnihotri; Sushma Gupta

    2013-01-01

    Simulation and modeling of standalone DC linked hydro/PV/battery hybrid energy system (HES) and power management strategy (PMS) for identifying the active power sharing have been done. The performance analysis of the proposed HES and its power management strategy has been done using the simulink toolboxes of MATLAB software. The proposed system consists of 10 kW PV system, 7.5 kW hydro system, battery, and power condition unit. In some remote/rural areas, it is very difficult to satisfy the d...

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

    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.

  13. Nuclear power development and nuclear data activities in Malaysia

    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)

  14. On Variable Reverse Power Flow-Part I: Active-Reactive Optimal Power Flow with Reactive Power of Wind Stations

    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.

  15. Communication Systems and Study Method for Active Distribution Power systems

    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...

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

    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 ...

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

    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....

  18. Effects of statistical quality, sampling rate and temporal filtering techniques on the extraction of functional parameters from the left ventricular time-activity curves

    Several techniques for the processing of a series of curves derived from two left ventricular time-activity curves acquired at rest and during exercise with a nuclear stethoscope were evaluated. They were three and five point time smoothing. Fourier filtering preserving one to four harmonics (H), truncated curve Fourier filtering, and third degree polynomial curve fitting. Each filter's ability to recover, with fidelity, systolic and diastolic function parameters was evaluated under increasingly 'noisy' conditions and at several sampling rates. Third degree polynomial curve fittings and truncated Fourier filters exhibited very high sensitivity to noise. Three and five point time smoothing had moderate sensitivity to noise, but were highly affected by sampling rate. Fourier filtering preserving 2H or 3H produced the best compromise with high resilience to noise and independence of sampling rate as far as the recovery of these functional parameters is concerned. (author)

  19. Effects of statistical quality, sampling rate and temporal filtering techniques on the extraction of functional parameters from the left ventricular time-activity curves

    Guignard, P.A.; Chan, W. (Royal Melbourne Hospital, Parkville (Australia). Dept. of Nuclear Medicine)

    1984-09-01

    Several techniques for the processing of a series of curves derived from two left ventricular time-activity curves acquired at rest and during exercise with a nuclear stethoscope were evaluated. They were three and five point time smoothing. Fourier filtering preserving one to four harmonics (H), truncated curve Fourier filtering, and third degree polynomial curve fitting. Each filter's ability to recover, with fidelity, systolic and diastolic function parameters was evaluated under increasingly 'noisy' conditions and at several sampling rates. Third degree polynomial curve fittings and truncated Fourier filters exhibited very high sensitivity to noise. Three and five point time smoothing had moderate sensitivity to noise, but were highly affected by sampling rate. Fourier filtering preserving 2H or 3H produced the best compromise with high resilience to noise and independence of sampling rate as far as the recovery of these functional parameters is concerned.

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

    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.