Power quality enhancement by hybrid DSTATCOM with improved performance in distribution system

Abstract

The current quality of the utility in distribution system is improved by using distribution static compensator (DSTATCOM). The voltage source inverter (VSI) of DSTATCOM is connected to utility through an interfacing inductor for smoothing the current. But the required inductance value is high in conventional DSTATCOM. Due to this, the requirement of DC-link voltage of VSI is increased to improve the current quality. In this paper, a hybrid DSTATCOM topology is proposed to reduce the inductance value, which will reduce the requirement of the DC-link voltage. In conventional hybrid DSTATCOM, DC-link voltage is maintained to a fixed value; due to this, the switching losses is more under the reduced load conditions. In order to minimize the switching losses, a variable DC-link voltage control is proposed, which is based on the ac series capacitor voltage and the compensation performance. The effectiveness of the proposed method is validated by simulation and experimental studies.