Power Quality Improvement by Employing PWM Techniques and FLC based Shunt Active Power Filter

Abstract

Power quality issues are created in the power system mainly due to the nonlinear characteristics of power electronic based equipments. The large scale utilization of these nonlinear and time varying load lead to the distortion of current and voltage waveforms and simultaneously demands more reactive power from the supply. Harmonic distortion is identified as the cause of several power quality problems like extra power loss, heating in rotating machines, flicker and the communication circuit interference. To solve these problems active power filters have been developed, which is used to eliminate the harmonics and simultaneously compensate for the reactive power requirement. In this work, pulse width modulation techniques and fuzzy logic control based three phase shunt active power filter is implemented for three phase three wire system in order to eliminate the harmonics and reactive power compensation and hence improving the power quality. Compensation is based on sensing the line currents only. The system has been simulated using the Matlab/Simulink platform. Various simulation results are presented and performance of the different control techniques is compared and it is found that the performance of fuzzy controller is better than the other control techniques.