载波调制的三电平光伏逆变器共模电压抑制研究

Research on Common-mode Voltage Mitigation of Photovoltaic Inverter with Three-level Based on Carrier Modulation

针对中高压大功率三电平光伏逆变器应用中共模电压的负面效应,分析其产生机理,结合同相载波调制策略对逆变器共模电压的抑制效果,通过改进开关序列组合,提出一种改进的反相载波调制策略,该策略有效地将三电平光伏逆变器共模电压减小为同相载波调制策略下的一半,仿真和实验结果证明了所提出的改进的可行性和对共模电压抑制的有效性.

For the negative effects caused by common-mode voltage existing in the application of photovoltaic in- verters with high voltage and power three-level, this paper analyzes the principle and compares with same phase carrier SPWM modulating strategy of effectiveness to suppress the common-mode voltage of inverter. Through opti- mizing the combination of switch sequence, an improved opposite phase modulating strategy is proposed, which can confirm that the amplitude of common-mode voltage is one half of the former. Simulations and experiments vali- date its feasibility and effectiveness.