Optimum sizing of PV based UPQC-DG with improved power angle control

Abstract

Unified power quality conditioner with distributed generation (UPQC-DG) is a solution to the problems of power quality and integration of distributed renewable sources. UPQC, being a combination of series and shunt converters, can compensate for most power quality issues, but the use of two power converters increases the cost, and hence optimal sizing methods have been proposed in the literature. Sizing of UPQC-DG components, however, requires special consideration of power injected by DG. This paper proposes an optimum sizing method for UPQC-DG based on an improved power angle control (PAC) technique, which shares reactive power burden between series and shunt converters. Apart from optimal-sizing, this paper incorporates Volt-Ampere (VA) limits in the PAC method to ensure the operation of converters within designed ratings under all conditions. The performance of the proposed power angle control method has been tested for a case study system using Controller Hardware in Loop (CHIL), implemented with Opal-RT and Dspace/micro-labbox, and has been found superior to existing methods.