阶梯波合成技术级联多电平变换器功率均衡策略

针对采用阶梯波合成策略级联型多电平逆变器存在的功率均衡问题，该文提出有功功率均衡法和循环脉冲功率均衡法两种功率均衡策略，前者的优点是不论级联单元个数多少，逆变器实现功率均衡所需时间仅为一个输出周期，缺点是会影响输出电压波形质量；后者的优点是不影响输出电压的波形质量，缺点是随着级联单元个数的增多，逆变器实现功率均衡的时间变长。该文详细分析两种均衡策略的工作原理及特点，并进行实验验证，实验结果表明两种功率均衡策略是可行的。

Power Balance Scheme for Staircase Controlled Cascaded Multilevel Inverters

The output power of each cell in the cascaded multilevel inverters is not balanced when the staircase waveform synthesis strategy is adopted. This paper proposes two power balance strategy, one is active power balance strategies, and the other is swapping pulse strategies. The former strategies can realize power balance in an output cycle, however the total harmonics distortion (THD) of output voltage has a slight increase. The latter strategy has no effect on the output voltage, but the time for the power balance increases as the munber of cascaded cells increases. This paper analyzes the two proposed strategies and their characteristics in detail. Experimental results are presented to verify the validity of the proposed two power balance strategies.