Control Strategy for Voltage Unbalance Compensation in Islanded Microgrids

This paper presents a decentralized voltage imbalance reduction approach in the islanded micro-grid under unbalanced condition of the nonlocal busbar. Control structure is implemented in the Positive and negative sequence synchronous reference frame. Then the proposed method of voltage imbalance compensation will be described. Under unbalanced condition, based on proposed negative sequence current-negative sequence impedance droop characteristic, the nonlocal busbar voltage compensation is done without any local bus voltage limit violation. The main target is to introduce a certain amount of imbalance in the local bus without exceeding the standard level, with the aim of improving voltage imbalance in the remote busbar. Finally, proper performance of the structure has been presented using PSIM simulation software.

Keywords:

Microgrid , negative sequence current- negative sequence impedance droop characteristic , voltage imbalance compensation