Active power filter design for improving power quality

The paper design a current control based active power filter (APF) for improving power quality by reactive power compensation and harmonic filtering. The designed APF is based on a voltage source inverter (VSI), where the VSI is controlled by two loops, the voltage control loop and the current control loop. The voltage control loop is used to regulate the DC link capacitor voltage of the VSI. Via triangular wave control, the current control loop is used to produce a tracking PWM signal to shape the harmonic current such that it is in-phase with the same shape as the input voltage. The major advantage of the proposed APF is to search the reference current for improving power quality by using dq0 detecting method. Simulation results are given to validate the proposed scheme. From the results, it shows that the reduction of %THD is better in power system networks.