A comparative study on the control schemes of series power quality controller

Series power quality controller (SPQC) has been the load, usually consists of a voltage-source inverter drawing more and more attentions recently for compensation of the power quality interferences coining from the electric power network side. The control of the series power quality controller has been a very critical issue. Three control schemes are discussed in comparison in this paper. Two of them are regular control schemes applied in the previously published work, i.e., feedforward control with source voltage interference detection and feedback control with load voltage interference detection. Each of the regular schemes has advantages and disadvantages and both are not so satisfactory as considering the SPQC performance from the overall aspects. A composite control scheme combining the feedforward of source voltage and the feedback of load voltage is proposed in this paper. Through comparison in theoretical analysis, computer simulations and an SPQC prototype-experiments, this composite control scheme is verified to be superior to the previous two in the sense that it combines the advantages of them and the SPQC adopting this scheme has good compensation characteristics.