Optimal Sizing of UPQC Considering VA Loading and Maximum Utilization of Power-Electronic Converters

This paper introduces an optimum method to design a unified power-quality conditioner (UPQC) system with the minimum possible VA rating based on the compensation requirements. A set of generalized VA loading equations for the UPQC is derived, which are valid for all of the UPQC control approaches (such as UPQC-P, UPQC-Q, and UPQC-VAmin). The variation in series and shunt inverters VA loadings of UPQC for the given compensation requirements is analyzed for all existing control approaches. A novel design method and the corresponding algorithm are proposed to size the major components in an UPQC, such as the series inverter, shunt inverter, and series transformer corresponding to the minimum possible overall VA rating. The VA rating and the utilization of power-electronic converters using the proposed design method are compared with those of UPQC-P, and UPQC-VAmin approaches to show the effectiveness of the proposed design method.