Rating Of Voltage Source Inverter Research Articles

고조파 보상을 위한 하이브리드 능동전력필터(HAPF)에서 APF의 정현파 전압 주입에 따른 무효전력 상관 관계 분석 및 보상방안

Active power filter (APF) is the preeminent solution against nonlinear loads, current harmonics, and power quality problems. Hybrid APF topologies combining low-power rating APF with LC-based passive power filters(PPF) are used to reduce the power rating of voltage source inverter. If the parameter of the PPF part of the HAPF for decreasing the THD is not properly designed to match the system, efficiency degradation due to control error and overcompensation of reactive power may occur, leading power factor. In order to properly design the capacity of the passive filter of the HAPF, this paper proposes a capacity selection method that considers harmonics and reactive power at the same time.BRAlso, in this paper, reactive power analysis and compensation method in HAPF is presented, operating with the injected sinusoidal waveform voltage of APF. The compensated reactive power performance when considering the variable injection voltage as the proposed method was compared through simulation. As a result, THD was minimized and the controlled reactive power could be reached.

Three-Phase Transformerless Shunt Active Power Filter With Reduced Switch Count for Harmonic Compensation in Grid-Connected Applications

Shunt active power filter (SAPF) is the preeminent solution against nonlinear loads, current harmonics, and power quality problems. APF topologies for harmonic compensation use numerous high-power rating components and are therefore disadvantageous. Hybrid topologies combining low-power rating APF with passive filters are used to reduce the power rating of voltage source inverter (VSI). Hybrid APF topologies for high-power rating systems use a transformer with large numbers of passive components. In this paper, a novel four-switch two-leg VSI topology for a three-phase SAPF is proposed for reducing the system cost and size. The proposed topology comprises a two-arm bridge structure, four switches, coupling inductors, and sets of LC PFs. The third leg of the three-phase VSI is removed by eliminating the set of power switching devices, thereby directly connecting the phase with the negative terminals of the dc-link capacitor. The proposed topology enhances the harmonic compensation capability and provides complete reactive power compensation compared with conventional APF topologies. The new experimental prototype is tested in the laboratory to verify the results in terms of total harmonic distortion, balanced supply current, and harmonic compensation, following the IEEE-519 standard.

WECS Based Self - Excited Squirrel - Cage Induction Generator with Reduced Voltage Source Inverter Rating

WECS Based Self - Excited Squirrel - Cage Induction Generator with Reduced Voltage Source Inverter Rating

Neural Network-Based Selective Compensation of Current Quality Problems in Distribution System

Active power filters (APFs) have been used to compensate harmonics, reactive current, and negative sequence fundamental frequency current drawn by nonlinear loads. The control of APF is the core issue for their proper operation. The flexibility of selective compensation embedded in the control scheme makes APF versatile for compensation of reactive power, harmonic currents, and unbalance in source currents and their combinations, depending upon the limited rating of voltage source inverter employed as APF. The proposed scheme utilizes neural network-based decomposition of the load current into positive and negative sequence fundamental frequency component, reactive component and harmonic components. The adaline-based current decomposer estimates the reference currents through tracking of unit vectors together with tuning of the weights. The implementation of the control scheme facilitates selective compensation which respects the limited rating of the APF. The simulated results using developed MATLAB model are presented and are validated by experimental results to depict the effectiveness of the proposed control method of APF