A new strategy to control three-phase shunt active filters under balanced and unbalanced conditions by controlling one phase current

In this paper, a new control method based on positive sinusoidal signal regulator (PSSR) is proposed to control the shunt active filters under power system balanced and unbalanced operation conditions. This is accomplished in a way that the harmonical components in all phases´ positive and negative sequences are correctly detected independent from the network voltage just by controlling one phase current under network voltage unbalanced condition. Therefore, the voltage unbalancing has no considerable affect on the detection process. The proposed approach does not utilize the rotating reference frame theory in its control system despite the other techniques and consequently does not face with the problems such as error existence in the phase and the amplitude of the generated compensation signal conventional techniques face under network voltage unbalancing condition. The balanced and unbalanced loads compensation, independency from the network voltage profile, and simple hardware implementation could be mentioned as the distinctive advantageous of the proposed method. The proposed method along with the mathematical analysis is initially investigated in this paper and finally, the efficiency of the proposed method is proved by simulating the proposed technique and other vastly applied techniques such as p - q and i_p - i_q methods in PSCAD/EMTDC.