Current balancing strategy in parallel-connected legs of power inverters

Abstract

The parallel connection of inverter legs is a way to increase the output currents and thus the converter rated power. The connection is made by inductors and a critical issue is to achieve balanced currents among the legs. Circulating currents produce additional losses and stress to the power devices of the converter. Therefore, they should be controlled and minimized. An efficient technique to achieve such a balance is presented in this paper. The proposed strategy does not include proportional-integral (PI) controllers and parameter tuning is not required. The exact control action to achieve current balance is straightforward calculated and applied. Simulation and experimental results are shown in this paper to verify efficiency of the proposed balancing method.