Power Quality Improvement by Optimum Gain controlled SAPF

Now-a-days active power filters (APFs) became popular for harmonics mitigation and compensation of reactive power generated by non-linear power electronics load devices. This paper illustrates modeling and simulation of three-phase and three-wire shunt active power filters (SAPF). The active power filters (APF) model consist a three-leg voltage source inverter (VSI) having a common DC-link capacitor. For switching pulse generation of VSI hysteresis band pulse width modulation (PWM) based current controller is used. Reference current generation is important part of controlling of APFs, since any inaccuracy in current references generation results incorrect compensation. Instantaneous reactive power (IRPT) theory is used for current references estimation for various manually selected gains of PI-controller and their results are analyzed to get the optimum gains for minimum harmonics & Total Harmonics Distortion (THD). This technique is implemented in MATLAB/Simulink environment & harmonics determining parameter, Total Harmonics Distortion (THD) is calculated and compared for different manually selected values of gains of PI-controller.