Performance Comparison of DSTATCOM, DVR and Open UPQC in a Distribution Network with Dynamic Load and Industrial Drive

Abstract

Dynamic Voltage Restorer (DVR) is a series compensator which can compensate for power quality problems such as voltage harmonics, voltage unbalance, voltage flickers, voltage sags, and voltage swells. Distribution Static Compensator (DSTATCOM) is a shunt compensator which can compensate for power quality problems such as current harmonics, current unbalance, reactive current, etc. Unified Power Quality Conditioner (UPQC) is a custom power device that consists of shunt and series converters connected back to back and deals with load current and supply voltage imperfections. Open UPQC consists of DVR and DSTATCOM without common DC link. The chief objective of this thesis is to develop models of DVR, DSTATCOM and OPEN-UPQC for enhancement of power quality under various operating conditions. In this work, an open UPQC is used to compensate for high power load of 250MVA consisting of Dynamic load and DTC motor drive. It is then simulated experimentally to mitigate voltage sag/swells and harmonic currents. Traditional dq-theory is applied with PI controller to investigate the performance of series, shunt, and combination of series-shunt compensators. The operation of open UPQC isolates the utility from current quality problems of load and in the same time, isolates the load from voltage quality problems of utility. In this work, the effectiveness of DVR, DSTATCOM and Open UPQC are compared for a 3-phase distribution network with Dynamic load and DTC induction motor drive.