Enhanced Control Strategy based on Virtual Impedance Loops to Achieve the Sharing of Imbalance and Harmonic in 3-Phase 4-Wire Isolated Microgrids

Abstract

An improved distributed control strategy for imbalance and harmonics sharing in 3-phase 4-leg droop controlled converters in a 3-phase 4-wire isolated Microgrid is presented in this letter. The proposed scheme improves a previous one proposed by some of the authors of this letter in the sense that both negative and zero sequence current components are independently controlled. This novel approach allows better performance in terms of harmonic, negative and zero sequence currents sharing of the proposed control scheme compared with the previous one. A comparison between the previous method and that presented in this letter is performed via simulations, showing a better performance of the enhanced control strategy presented in this letter.