a novel hybrid droop-isochronous control strategy for microgrid management

The droop control strategy is the most common approach for microgrids control but its application is limited due to frequency deviation following a load change. complementary control strategy has then been proposed to solve the problem using a communication network. however, under this strategy, regular loads profile produces a continuous change of output power of all distributed generators (dgs) and their generation changes seem to be permanent. this also causes continuous data exchange between dgs through communication links. this paper shows the possibility of adapting the droop/isochronous control methodology used by synchronous generators in conventional power systems to provide frequency control and power balance to inverterbased distributed generation power systems. to this end, this paper presents a centralized complementary control framework for the management of powersharing and sustaining frequency in its nominal range in microgrids using a hybrid droopisochronous control system. the proposed method is eventtriggered based and communication between dgs is only needed when the output power of the isochronous generator exceeds its power limits. the method provides an efficient and reliable control system and has a simple concept, easy, and costeffective implementation. simulations in matlab/simpower are performed on a typical microgrid under various conditions to evaluate the performance of the proposed controller.