Control strategy of a hybrid active filter based on output voltage correction

A control strategy of a hybrid active filter based on output voltage correction is proposed. The active power filter (APF) is controlled as a voltage source. To improve the filtering performance, a sinusoidal signal is calculated as the APF output voltage correction signal on the basis of proportional control. The amplitude and phase of the correction signal are calculated based on those of system residual harmonic current. The sliding window discrete-fourier-transform (DFT) method is used to detect the amplitude and phase of the system residual harmonic current. A simple method is given to determine the parameters of the control strategy. The simulation results show that selection of the parameter is simple and effective, the APF responds fast to load harmonic current changes and performs well under background harmonic with the proposed method. © Springer International Publishing Switzerland 2015.