A simple control scheme of single phase universal active filter for power quality improvement

In this paper, a simple control scheme for a single phase universal active filter with integrated series and shunt active filters is a solution for power quality problem is proposed. The series active filter is applied to maintain the load terminal voltage at the required level with a sinusoidal waveform, while the shunt active filter is used for eliminate all harmonic currents and the fundamental reactive current for the unity power factor operation. The output of the dc bus voltage controller with unit-sinusoidal voltage signal is used as the current command signal of the shunt active filter without the low pass and high pass filters. The resolution of the harmonics currents detection and the fast response of the harmonic currents regulation has been improved. The effectiveness of this concept is verified by simulation results.