A Cooperative Unbalance Compensation Method for Distributed Generation Interface Converters

Distributed generation has attracted great attention in recent years, thanks to the progress in new generation technologies and advanced power electronics. The Micro-grid has been a successful example by integrating various generation sources with the existing power distribution network through power electronics converters. The Micro-grid converters are required to operate in a de-centralized fashion, and the power- frequency droop control and reactive power-voltage droop control have been adopted for this purpose. In this paper, a droop control technique for imbalance compensation within the three- phase AC distributed generation system is proposed for Micro- grid converters. The proposed technique allows even sharing of imbalance current among various converters, can be seamlessly integrated with existing active power-frequency droop control and reactive power-voltage droop control to improve the power quality within the distributed power system. Its control functionalities are discussed, simulation and laboratory test results are also presented to validate the proposed method.