Extensive Application of UPQC-L for a Dual Point of Common Coupling System with Multiple Loads under Unbalanced Source Condition

Abstract

—This paper presents a synchronous reference frame (SRF)-based power angle control (PAC) approach for a specific unified power quality conditioner (UPQC) arrangement, termed as UPQC-L for dual point of common coupling system under unbalanced source voltage condition. In contrast to a conventional configuration of UPQC, the static compensator (STATCOM) part is on left side of UPQC-L, while dynamic voltage restorer (DVR) is on the right side. The UPQC-L configuration is specifically adapted for protection of sensitive and critical load types from voltage disturbances. Along with its basic compensation capability of current harmonic compensation and voltage compensation, it efficiently handles reactive power demand from sensitive load. This is achieved with the introduction of PAC concept for effective sharing of reactive power between STATCOM and DVR. The extraction of instantaneous power angle faces difficulty with unbalanced voltage and UPQC-L configuration. Thus, the control algorithm for UPQC-L is designed based on SRF and numerical analysis approach with equal reactive power sharing phenomena by STATCOM and DVR of UPQC-L. UPQC-L with the proposed control approach is successfully implemented in MATLAB/SIMULINK (The Mathworks, Inc. USA) and verified experimentally for mitigation of voltage disturbances (such as sag/swell, unbalancing, and harmonics), current harmonics, and high-reactive power demand.