Parallel operation of three-level inverters is a popular approach to achieve larger power capacity of the system. The interleaved operation can improve current distortion, but high-frequency circulating current inevitably emerges. To suppress the circulating current, this paper proposes a five-level carrier phase disposition modulation method for parallel three-level inverters. Based on the carrier phase disposition modulation, the parallel three-level inverters can be operated as a five-level system, and the pulse distribution is realized through the system state machine, which avoids complicated mathematical calculation. The simulation results verify that, compared with the interleaved operation, the proposed scheme has superior performance in term of circulating current suppression without increasing the output current harmonic.

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