Two-Level Algorithm for UPQC Considering Power Electronic Converters and Transformers

The optimal sizing of the unified power quality conditioner (UPQC) system has been investigated in this paper. The optimal VA ratings of the transformer and series/shunt converter of the UPQC system are designed by a two-level algorithm. The UPQC-P and UPQC-VAmin based systems are chosen as the benchmarks in this paper. Furthermore, the displacement angle control (DAC) is utilized to minimize the overall VA loading of the power converters for all operational points. Finally, the corresponding controllers are developed for the designed systems.