Reduced switch number single-phase shunt active power filter using an indirect current control technique

This paper proposes a new indirect current control technique for single phase shunt active power filter (SPSAPF), based on current-controlled PWM converters, which allows precise compensation of harmonic current and reactive power produced by nonlinear loads. This method may reduce greatly the switch SPSAPF and eliminate the ripples in the supply current shapes. To evaluate its performance, we have compared it with the direct current control technique based on the classic demodulation method. The classic demodulation method of the single-phase circuits is used to obtain reference current. Usually, this later method uses a residual signal build from the comparison between the reference desired current and the actual reference current of the SPSAPF. Whereas, the new indirect method uses a residual signal constructed from the comparison between the supply current and the desired value. This implies a great reduction in the number of the SPSAPF switches and an elimination of the ripples in the supply current shape. Simulation results using power system blockset toolbox PSB of Matlab show the performance of the new control algorithm with a reduced switch SPSAPF circuit and its capability to compensate for harmonics and reactive power.