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L Moran - One of the best experts on this subject based on the ideXlab platform.

  • a clean four quadrant sinusoidal power rectifier using multistage converters for subway applications
    IEEE Transactions on Industrial Electronics, 2005
    Co-Authors: J Dixon, L Moran
    Abstract:

    A special 27-level four-quadrant rectifier for subway applications is analyzed. The arrangement uses only three H-bridges per phase, common dc bus, and independent input transformers for each H-bridge. The transformers allow galvanic isolation and power escalation to obtain high-quality Voltage waveforms, with total harmonic distortion of less than 1%. Some advantages of this 27-level rectifier are: 1) only one of the three H-bridges, called the main converter, manages more than 80% of the total active power in each phase and 2) it switches at fundamental frequency, reducing the switching losses at a minimum value. The rectifier analyzed in this paper is a current-Controlled Voltage-Source type, with a conventional feedback control loop. Some simulations in a rectifier substation, including power reversal at full load are displayed (750 Vdc, 1200 A). The rectifier shows the ability to produce clean ac and dc waveforms without any ripple, and fast reversal of power. Some experimental results with a small prototype, showing Voltage and current waveforms, are finally displayed.

  • a series active power filter based on a sinusoidal current Controlled Voltage Source inverter
    IEEE Transactions on Industrial Electronics, 1997
    Co-Authors: J Dixon, G Venegas, L Moran
    Abstract:

    A series active power filter working as a sinusoidal current Source, in-phase with the mains Voltage, has been developed and tested. The amplitude of the fundamental current in the series filter is Controlled through the error signal generated between the load Voltage and a pre-established reference. The control allows an effective correction of power factor, harmonic distortion and load Voltage regulation. Compared with previous methods of control developed for series active filters, this method is simpler to implement because it is only required to generate a sinusoidal current, in-phase with the mains Voltage, the amplitude of which is Controlled through the error in the load Voltage. The proposed system has been studied analytically and tested using computer simulations and experiments. In the experiments, it has been verified that the filter keeps the line current almost sinusoidal and in-phase with the line Voltage supply. It also responds very quickly under sudden changes in load conditions, reaching its steady-state in about two cycles of the fundamental.

  • practical evaluation of different modulation techniques for current Controlled Voltage Source inverters
    IEE Proceedings - Electric Power Applications, 1996
    Co-Authors: J Dixon, S Tepper, L Moran
    Abstract:

    The quality of the current waveform generated by a current-Controlled, Voltage Source inverter, depends basically on three factors: (a) the switching frequency of the PWM modulator; (b) the type of current waveform being generated; and (c) the modulation method used. In the paper, three modulation methods, whose characteristics are their simplicity, are analysed: periodical sampling control, hysteresis band control, and triangular carrier control. These three methods have been tested with three different waveform templates: sinusoidal, quasisquare and rectifier compensation current. They are compared in terms of the harmonic content and distortion at the same switching frequency. The paper shows that for sinusoidal current generation, the best method is the triangular carrier, followed by the hysteresis band and the periodical sampling. However, for the other two types of reference templates, the analysis showed that, depending on external factors such as inverter inductance, type of load, or delays in the PWM switching signals, one strategy may be better than the others. The paper shows that each control method is affected in a different way by the switching time delays present in the driving circuitry and in the power semiconductors. The results are analysed and compared, with the help of computer simulations and experimental results.

  • a series active power filter based on a sinusoidal current Controlled Voltage Source inverter
    Conference of the Industrial Electronics Society, 1995
    Co-Authors: J Dixon, G Venegas, L Moran
    Abstract:

    A series active power filter, working as a sinusoidal current Source, in phase with the mains Voltage, has been developed and tested. The amplitude of the fundamental current in the series filter is Controlled through the error signal generated between the load Voltage and a pre-established reference. The control allows an effective correction of power factor, harmonic distortion, and load Voltage regulation.

C V Nayar - One of the best experts on this subject based on the ideXlab platform.

  • dc bus compensation for a sinusoidal Voltage Source inverter with wave shaping control
    IEEE Transactions on Industrial Electronics, 2008
    Co-Authors: M C Trigg, C V Nayar
    Abstract:

    This paper presents a study on the effects of different parameters on the dc bus Voltage of a single-phase Voltage-Controlled Voltage-Source inverter (VCVSI) with conventional load-Voltage root-mean-square (rms) feedback control and a wave-shaping controller (WSC). It is shown that the load-Voltage rms feedback control and the WSC require compensation for the fluctuations in the dc bus Voltage caused by the battery and lead-wire resistance and the lead-wire inductance. The dc-bus-Voltage compensation is shown to provide performance improvements, including better load-Voltage regulation and less load-Voltage distortion. The mathematical modeling, computer simulations, and experimental results based on a 2-kVA single-phase full-bridge VCVSI are presented.

  • application of Voltage and current Controlled Voltage Source inverters for distributed generation systems
    IEEE Transactions on Energy Conversion, 2006
    Co-Authors: Seongryong Lee, H Dehbonei, C V Nayar
    Abstract:

    Voltage Source inverters (VSI) have been widely used in uninterruptible power supplies, unified power flow controllers or unified power quality conditioners, and distributed generation systems (DGS). VSIs are inherently efficient, compact, and economical devices used to control power flow and provide quality supply. VSIs can be classified as Voltage-Controlled VSIs (VCVSIs) and current-Controlled VSIs (CCVSIs), depending on their control mechanism. In this paper, a detailed comparison of VCVSIs and CCVSIs for DGS applications is presented. This paper examines the advantages and limitations of each control technique in a single-phase DGS, without incorporating additional hardware and/or extra complex control techniques. Discussions on the concepts, hypotheses, and computer simulations of different VSIs in the presence of different loads and conditions are presented. The experimental results confirm the validity of the analysis and simulations outlined. The paper provides design recommendations for the use of VCVSIs and CCVSIs in various applications

  • analysis of a series inductance implementation on a three phase shunt active power filter for various types of non linear loads
    Australian journal of electrical and electronics engineering, 2005
    Co-Authors: Hanny Hosiana Tumbelaka, L Borle, C V Nayar
    Abstract:

    In this paper, the implementation of a shunt active power filter with a small series inductor for a three-phase system is presented. The filter consists of a three-phase current-Controlled Voltage Source inverter (CC-VSI) with a filter inductance at the ac output and a dc-bus capacitor. The series inductor is primarily used to handle the harmonic Voltage Source. The main concern is the size of the series inductance so that it is as small as possible but effective in compensating the harmonics. In order to select the proper value of the series inductance, the simulation is conducted to evaluate the value for different types of load.

  • a combined Voltage Controlled and current Controlled dual converter for a weak grid connected photovoltaic system with battery energy storage
    Power Electronics Specialists Conference, 2002
    Co-Authors: H Dehbonei, C V Nayar, L J Borle
    Abstract:

    In this paper, a novel power converter capable of extracting maximum power from solar photovoltaic panels is described. It employs a combination of a Voltage Controlled Voltage Source inverter and a current Controlled Voltage Source inverter, connected in series on the DC side and in parallel on the AC side. This dual converter is able to provide uninterruptible power supply feature, load Voltage stabilisation, unity power factor operation, maximum power point tracking as well as reactive power support. The overall efficiency of the proposed converter is higher than the conventional system with a DC-DC converter between the PV panels and the battery.

Kamalakanta Mahapatra - One of the best experts on this subject based on the ideXlab platform.

  • pi and fuzzy logic controllers for shunt active power filter a report
    Isa Transactions, 2012
    Co-Authors: P Karuppanan, Kamalakanta Mahapatra
    Abstract:

    Abstract This paper presents a shunt Active Power Filter (APF) for power quality improvements in terms of harmonics and reactive power compensation in the distribution network. The compensation process is based only on Source current extraction that reduces the number of sensors as well as its complexity. A Proportional Integral (PI) or Fuzzy Logic Controller (FLC) is used to extract the required reference current from the distorted line-current, and this controls the DC-side capacitor Voltage of the inverter. The shunt APF is implemented with PWM-current Controlled Voltage Source Inverter (VSI) and the switching patterns are generated through a novel Adaptive-Fuzzy Hysteresis Current Controller (A-F-HCC). The proposed adaptive-fuzzy-HCC is compared with fixed-HCC and adaptive-HCC techniques and the superior features of this novel approach are established. The FLC based shunt APF system is validated through extensive simulation for diode-rectifier/R–L loads.

  • Adaptive-Fuzzy Controller Based Shunt Active Filter for Power Line Conditioners
    TELKOMNIKA (Telecommunication Computing Electronics and Control), 2011
    Co-Authors: Karuppanan Pitchaivijaya, Kamalakanta Mahapatra
    Abstract:

    This paper presents a novel Fuzzy Logic Controller (FLC) in conjunction with Phase Locked Loop (PLL) based shunt active filter for Power Line Conditioners (PLCs) to improve the power quality in the distribution system. The active filter is implemented with current Controlled Voltage Source Inverter (VSI) for compensating current harmonics and reactive power at the point of common coupling. The VSI gate control switching pulses are derived from proposed Adaptive-Fuzzy-Hysteresis Current Controller (HCC) and this method calculates the hysteresis bandwidth effectively using fuzzy logic.  The bandwidth can be adjusted based on compensation current variation, which is used to optimize the required switching frequency and improves active filter substantially. These shunt active power filter system is investigated and verified under steady and transient-state with non-linear load conditions. This shunt active filter is in compliance with IEEE 519 and IEC 61000-3 recommended harmonic standards.

  • pll with fuzzy logic controller based shunt active power filter for harmonic and reactive power compensation
    India International Conference on Power Electronics 2010 (IICPE2010), 2011
    Co-Authors: P Karuppanan, Kamalakanta Mahapatra
    Abstract:

    This paper presents a novel fuzzy logic controller in conjunction with phase locked loop synchronization based shunt Active Power Filter (APF) for harmonics and reactive power compensation in the distribution grid due to the non-linear loads. The Mamdani-type fuzzy logic is adpted and this controller is linguistic description, so it does not require a mathematical calculations. The active power filter is implemented with current Controlled Voltage Source inverter (VSI) and is connected at the point of common coupling for compensating current harmonics by injecting equal but opposite harmonic components. The desired reference current(s) are extracted using FLC with PLL-algorithm and this method maintains the dc-side capacitor Voltage of the inverter nearly constant. The VSI gate switching signals are derived from adaptive-hysteresis current controller. The adaptive-hysteresis controller changes the bandwidth based on instantaneous compensation current variation; it is used to optimize the required switching frequency. The shunt APF system is investigated and the performances parameters are verified under different non-linear load conditions.

Bhim Singh - One of the best experts on this subject based on the ideXlab platform.

  • Modelling and Analysis of STATCOM Based Voltage Regulator for Self-Excited Induction Generator with Unbalanced Loads
    2016
    Co-Authors: Bhim Singh, S S Murthy, Sushma Gupta
    Abstract:

    Abstract ' This paper presents an analysis of the three-phase self-excited induction generator (SEIG) with static-compensator {STATCOM) as a Voltage regulator. Current Controlled Voltage Source inverter (CC-VSI) is used as STATCOM, which provides fast dynamic response to maintain constant Voltage at SEIG terminals during severe load perturbations and acts as a Source and sink of reactive power. The performance equations are derived using d-q variable in stationary reference frame to develop a mathematical model of SEIG-STATCOM system feeding unbalanced loads. Transient analysis of the SEIG-STATCOM system is carried out for Voltage build-up; switching in STATCOM, application and removal of balanced/unbalanced resistive/reactive loads. The STATCOM compensates the unbalanced load and keeps the generating system balanced while maintaining constant AC terminal Voltage. 1

  • instantaneous symmetrical component theory based Voltage and frequency controller for isolated small hydropower generation
    Electric Power Components and Systems, 2011
    Co-Authors: V. Rajagopal, Bhim Singh
    Abstract:

    Abstract This article deals with the design and implementation of an instantaneous sequence component theory based integrated Voltage and frequency controller for an isolated asynchronous generator, which is used in constant power small hydropower generation for feeding three-phase four-wire consumer loads. The proposed integrated Voltage and frequency controller is used to control the Voltage and frequency of an isolated asynchronous generator in the integrated manner. This integrated Voltage and frequency controller is realized using a zigzag/star transformer and a three-leg insulated-gate bipolar transistor based current-Controlled Voltage Source converter, a capacitor, a chopper switch, and an auxiliary load on its DC bus. The proposed integrated Voltage and frequency controller with an isolated generating system is modeled and simulated in MATLAB along with Simulink and simpower system (SPS) toolboxes (The MathWorks, Natick, Massachusetts, USA). The simulated results are validated with test results o...

  • Neural-Network-Based Integrated Electronic Load Controller for Isolated Asynchronous Generators in Small Hydro Generation
    IEEE Transactions on Industrial Electronics, 2011
    Co-Authors: Bhim Singh, V. Rajagopal
    Abstract:

    This paper deals with a neural-network (NN)-based integrated electronic load controller (IELC) for an isolated asynchronous generator (IAG) driven by a constant-power small hydro unControlled turbine feeding three-phase four-wire loads. The proposed IELC utilizes an NN based on the least mean-square algorithm known as adaptive linear element to extract the fundamental component of load currents to control the Voltage and the frequency of an IAG with load balancing in an integrated manner. The IELC is realized using zigzag/three single-phase transformers and a six-leg insulated-gate bipolar-transistor-based current-Controlled Voltage-Source converter, a chopper switch, and an auxiliary load on its dc bus. The proposed IELC, with the generating system, is modeled and simulated in MATLAB environment using Simulink and Simpower System toolboxes. The simulated results are validated with test results on a developed prototype to demonstrate the effectiveness of IELC for the control of an IAG feeding three-phase four-wire linear/nonlinear balanced/unbalanced loads with neutral-current compensation.

  • statcom based Voltage regulator for self excited induction generator feeding nonlinear loads
    IEEE Transactions on Industrial Electronics, 2006
    Co-Authors: Bhim Singh, S S Murthy, Sushma Gupta
    Abstract:

    This paper deals with the performance analysis of a static compensator (STATCOM)-based Voltage regulator for self-excited induction generators (SEIGs) supplying nonlinear loads. In practice, a number of loads are nonlinear in nature, and therefore, they inject harmonics in the generating systems. The SEIG's performance, being a weak isolated system, is very much affected by these harmonics. The additional drawbacks of the SEIG are poor Voltage regulation and that it requires an adjustable reactive power Source with varying loads to maintain a constant terminal Voltage. A three-phase insulated-gate-bipolar-transistor-based current-Controlled Voltage Source inverter working as STATCOM is used for harmonic elimination, and it provides the required reactive power for the SEIG, with varying loads to maintain a constant terminal Voltage. A dynamic model of the SEIG-STATCOM feeding nonlinear loads using stationary d-q axes reference frame is developed for predicting the behavior of the system under transient conditions. The simulated results show that SEIG terminal Voltage is maintained constant, even with nonlinear balanced and unbalanced loads, and free from harmonics using STATCOM-based Voltage regulator

  • design and digital implementation of active filter with power balance theory
    IEE Proceedings - Electric Power Applications, 2005
    Co-Authors: Baldeo Singh, Bhim Singh, Ambrish Chandra, Kamal Alhaddad
    Abstract:

    The design, development and experimental investigations of an active filter (AF) are considered. A current-Controlled Voltage Source inverter is used as an AF system. The AF system employs power balance theory, which in this investigation is implemented using a TMS320C31 DSP. The design details, including necessary equations of a prototype model of the AF system, are given. The AF system is tested with nonlinear balanced and unbalanced loads to demonstrate its effectiveness and capabilities for harmonic elimination, reactive power compensation, power-factor correction and load balancing. The developed prototype model of the AF system is tested for different operating conditions of nonlinear load. Experimental results are given and discussed in detail.

Hamdy M Mharous - One of the best experts on this subject based on the ideXlab platform.

  • three phase active power filter based on current Controlled Voltage Source inverter
    International Journal of Electrical Power & Energy Systems, 2006
    Co-Authors: E E Elkholy, A Elsabbe, A Elhefnawy, Hamdy M Mharous
    Abstract:

    This paper presents a shunt active power filter to compensate reactive power and reduce the unwanted harmonics. A shunt active filter is realized employing three-phase Voltage Source inverter (VSI) bridge with common DC bus capacitor. The shunt active filter acts as a current Source, which is connected in parallel with a nonlinear load and Controlled to generate the required compensation currents. Two different proposed control methods for determining the reference compensating currents of the three-phase shunt active power filters based on proportional-integral (PI) controller and artificial neural network (ANN) are presented. Current controller based on modified hysteresis current controller is used to generate the firing pulses. The proposed system is implemented using a high speed Digital Signal Processor (DSP). Experimental and simulation results with different nonlinear loads are presented to confirm the validity of the proposed technique.