Abstract Compared with 3p3l inverter, three phase legs of three-phase four-leg (3p4l) inverter could be decoupled by appropriate control, 3p4l inverter could also work with unbalanced load. 3p4l inverter can improve DC voltage utilization by injecting 3rd harmonic into fourth legs. In recent years, paralleled inverter technology is widely used in power electronic converter system to improve power level, and this technology can also be used in 3p4l inverter. But if current is out of control, circulating current will exist in four legs of paralleled 3p4l inverter, which could damages the inverter seriously exists in four legs. In 3p4l inverter controlled by method with 3rd harmonic injection, zero-sequence circulating current caused by unbalance parameters arises in four legs between parallel inverter modules. Based on novel 3rd harmonic average value injection method, this paper, therefore proposes control strategy for eliminating the circulating current in 3p4l inverter. Finally, simulation and experimental results verify the proposed method.
Chen Yihan,Ren Lei,Deng Xiang等. Current Sharing Control Method for Parallel Three Phase Four Leg Inverter Based on Third Harmonic Injection[J]. Transactions of China Electrotechnical Society, 2016, 31(4): 104-113.
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2016, Vol. 31 
