Single Phase SOGI-PLL Based Reference Current Extraction for Three-Phase Four-Wire DSTATCOM

Abstract

This paper describes a novel control algorithm based on single-phase SOGI (Second Order Generalized Integrator) PLL (Phase Locked Loop) for a three-phase four-wire DSTATCOM (Distribution Static Compensator). The proposed DSTATCOM performs various functions such as load balancing, harmonic mitigation, reactive power compensation and neutral current compensation under distorted load conditions. This control algorithm extracts the fundamental component of the load currents for estimating the reference currents based on three single-phase SOGI-PLLs. The main objective of the SOGI-PLL is enhancing capability of reference current tracking for compensation. During the design procedure, the effects of load unbalancing and sudden increase/decrease in loads are also taken into account and performance is found satisfactory. The effectiveness of the design is simulated and shown using MATLAB/Simulink.