SHUNT HYBRID ACTIVE POWER FILTER USING PI AND HYSTERESIS CURRENT CONTROLLERS FOR POWER QUALITY IMPROVEMENT

This paper presents the performance of Shunt Hybrid Active Power Filter (SHAPF) for power quality improvement in terms of harmonics and reactive power compensation, and power factor improvement in the distribution network caused by nonlinear load. In the proposed control method, the compensation process is based on sensing of source currents only. A Proportional Integral (PI) controller 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 Hybrid APF is designed with shunt APF and shunt connected single tuned passive filters. Shunt APF is implemented with PWM-current controlled Voltage Source Inverter (VSI). The switching pattern is generated through hysteresis current controller. The performance of the filter is investigated under steady-state as well as transient state conditions.