Single-phase unified power quality conditioner with optimum voltage angle injection for minimum VA requirement

The paper deals with an optimized Unified Power Quality Conditioner (UPQC), which aims at the integration of series and shunt active power filters with minimum VA loading of the UPQC. The series active filter is a Dynamic Voltage Restorer (DVR), that operates in two functioning modes. During the unbalanced voltage sag/swell at the input side, the DVR maintains the rated voltage at the load side. It regulates the load voltage with minimum VA loading of the overall UPQC by an optimum voltage angle injection. A technique of achieving both input current distortion compensation, power factor correction and also mitigating the supply-voltage variation (sag/swell) at the load side, is presented as well. To reduce the total cost, but to increase the performance, the system is fully digital-controlled using the fixed-point TMS320F240 digital signal processor. The present paper discusses the VA requirement issues of the proposed UPQC. The performances of the optimum UPQC have been verified on an experimental prototype.