Autonomous Load Sharing of Voltage Source Converters

An autonomous load-sharing technique for parallel connected three-phase voltage source converters is presented. An improved power-frequency droop scheme computes and sets the phase angle of the voltage source converter (VSC) directly to yield more rapid real power sharing without sacrificing frequency regulation. Reactive power sharing in the presence of a mismatch between the VSC output interface inductors is achieved by having each VSC regulate the high side voltage with a drooped voltage reference. Dynamics of the reactive power control can be tuned without interfering with steady-state reactive power sharing. Simulation results that validate the proposed technique are also provided.