Modeling of circulating currents for grid-connected parallel three-phase inverters

In this paper, the generating mechanism of circulating currents for grid-connected parallel three-phase inverters is first explored. Then, a new and practical definition of circulating currents for each phase and each converter is proposed. Third, a mathematical model of the circulating current is then derived by using the well-known state space averaging technique. Finally, some simulation results obtained from the proposed model are compared with that by definition to verify the validity of the proposed model.