Circulating current control and reduction in a paralleled converter test-bed system

It is a flexible and effective approach to emulate the behaviors of electric power system components using interconnected parallel power converters. The reduction of unnecessary circulating current is essential for the validity of the test-bed system. The types of the circulating current in the test bed system are discussed in this paper. The causes and the reduction strategies for the switching period circulating current, zero sequence circulating current and lower order harmonics are presented. Simulation and experimental results are given to verify the feasibility.