VSG Coordinated Control Based on Adaptive Weight Factors in Islanded Microgrids

A control strategy for converters with energy storage units in islanded microgrids using diesel generator sets（DGS） as the main source was presented. The converter uses virtual synchronous generator（VSG） control algorithm, the active power reference consists of a frequency control module and a state of charge（SOC） control module. An adaptive weight factor was introduced to coordinate the proportion of the two modules. When the SOC of energy storage is closed to the SOC reference, the proportion of SOC is increased and the frequency of microgrid fluctuation is restrained, whereas when SOC goes far away from the SOC reference, the SOC control proportion is increased to enhance the ability of maintaining the SOC of energy storage. The value range of the weight factor was established by analyzing the stability of dynamic response of the small signal model of systems. Finally the proposed strategy was validated with a 100 k VA islanded mircogrid system.