Instantaneous Symmetrical Component Theory Based Parallel Grid Side Converter Control Strategy for Microgrid Power Management

Abstract

This paper proposes a centralized control strategy for power management of hybrid microgrid connected to the grid using a parallel combination of grid side converters (GSCs). An improved version of instantaneous symmetrical component theory is developed and is used for the control of parallel operated GSCs, which results in reduced sensor requirement, control complexity, and communication bandwidth. In addition, a simple power management algorithm is developed to test the efficacy of the proposed parallel grid side converter control strategy for all the microgrid modes considering state of charge limits of hybrid energy storage system, load changes, and renewable power variations. In the proposed system, a better dc link voltage regulation is achieved and usage of supercapacitor reduces the current stresses on the battery. With the proposed control strategy, the essential features of grid side converters like power quality, power injection, bidirectional power flow, and proportional power sharing are achieved. The effectiveness of the developed control strategy for the proposed system is tested using MATLAB based simulink environment and validated experimentally using a laboratory prototype.