An a-b-c reference frame-based control strategy for the three-phase four-wire shunt active power filter

The active power filter has been proved to be an effective method to mitigate harmonic currents generated by nonlinear loads as well as to compensate reactive power. In the past most three-phase four-wire active power filters were designed based on the conventional instantaneous power theory (i.e. p-q theory) with the 0-a-β reference frame. However, when designing and implementing the control strategy based on the p-q theory, it requires the reference-frame transformation. This process introduces additional efforts in realizing the control circuit. In the paper an a-b-c reference frame based strategy is proposed for simplifying the design of the control circuit of the active power filter. Simulation and experimental results show that the proposed control strategy gives the active power filter a good performance