Research on Control Strategy of Synchronous Voltage Source Converter Based on Complex Virtual Impedance in Microgrid

Due to not considering the impact of feeder impedance between distributed sources, conventional synchronous voltage source converter control based on droop characteristic curve will influence system stability and power sharing when applied in distributed resources of microgrid. In this paper, an improved synchronous voltage source converter control based on complex virtual impedance is proposed, in which complex virtual impedance is introduced to reduce the power coupling caused by resistive component in feeder impedance model, and an improved voltage/reactive power droop control is proposed to eliminate reactive power sharing errors due to unequal the line impedance per unit value by introducing voltage feedback on public load nodes. Accurate system power sharing can be achieved by the improved synchronous voltage source control, and the quality of power supply is improved. In the end, the validity of control algorithm is verified by simulations.