Effect of Negative Sequence Controller on Voltage Unbalance Mitigation in a Stand-Alone Microgrid

The severe drawbacks of conventional energy sources have led to several microgrids being established to promote the generation of power using renewable energy sources. However, issues like power quality make a microgrid vulnerable. One of the significant contributors to the problems of power quality is unbalance in voltage. The growing number of single-phase power consumers could cause an unbalance in a microgrid. In this paper, an inverter-based distributed generator has been employed for the purpose of minimizing voltage unbalance in an unbalanced isolated microgrid. The control design involves a positive sequence controller along with a negative sequence controller for voltage unbalance factor reduction. The controller strategy has been implemented in the presence of time-varying loads to demonstrate its behaviour with increasing load on voltage unbalance. The capability of the controller has also been exhibited during transient conditions. MATLAB/ Simulink environment has been utilised to analyse the implementation of the proposed control strategy.