A current sharing technique for parallel-operated unipolar-PWM inverters

摘要

This paper presents a technique to balance inductor currents of parallel-operated unipolar-PWM inverters. Firstly, the problem of unbalanced currents in parallel-operated unipolar-PWM inverters is defined and analyzed in the paper. Secondly, a technique to eliminate unbalanced currents is proposed. The proposed technique only requires one more current sensor in an inverter module rather than changing converter topology or modulation method, which makes it possible to apply unipolar-PWM inverters in parallel-operation while keeping the advantages of high power efficiency and small output chokes. Performance of the proposed current balancing method is experimentally verified. Experimental results show a good agreement to the analytical study.