PI controlled three-phase shunt active power filter for power quality improvement

The simulation and experimental study of proportional integrator ( PI) controlled DC bus voltage of three phase shunt active power filter ( APF) to improve power quality by compensating harmonics and reactive power required by nonlinear load is proposed. The compensation process is based on sensing mains currents only, an approach different from conventional methods, which usually require harmonics or reactive volt- ampere values of the load. The non- sinusoidal mains voltage problem is resolved by using phase locked loop ( PLL) system. Pulse width modulation ( PWM) signal generation is based on hysteresis control comparators to obtain the switching signals. u Various simulation and experimental results are presented under steady state and transient conditions.