A capacitor voltage balancing strategy for a five-level hybrid-clamped inverter
A capacitor voltage balancing strategy for a five-level hybrid-clamped inverter
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DOI：
10.1109/iecon.2015.7392197
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发表时间：
2015-11
期刊：
影响因子：
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通讯作者：
Kui Wang;Yongdong Li;Zedong Zheng;Lie Xu;B. Fan
中科院分区：
文献类型：
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作者：
Kui Wang;Yongdong Li;Zedong Zheng;Lie Xu;B. Fan
五电平混合箝位（5L-HC）逆变器是一种新提出的适用于高性能中压变频器的拓扑结构。提出了一种5L-HC逆变器的电容电压平衡策略，包括直流侧电容和飞跨电容的电压平衡。该变换器采用经典的移相PWM控制，建立了飞跨电容和中点电流的均值模型。通过调节四个PWM信号的宽度来调节中央直流链路和飞跨电容的电压，这实质上改变了每个开关周期中冗余开关状态的操作时间。研究了中性点电流与输出电压的关系，并通过零序电压注入来平衡上、下直流侧电容电压。实验结果验证了该策略的有效性。
Five-level hybrid-clamped (5L-HC) inverter is a newly proposed topology which is suitable for high-performance medium-voltage drives. This paper presents a capacitor voltage balancing strategy for a 5L-HC inverter, including the voltage balancing of DC-link capacitors and flying capacitors. Classic phase-shifted PWM is used to control this converter and a mean value model of flying capacitor and neutral point currents is established. The voltages across the central DC-link and flying capacitors are regulated by adjusting the width of four PWM signals, which varies the operation time of redundant switching states in each switching period essentially. The relationship between the neutral-point currents and the output voltage is also studied and the upper and lower DC-link capacitor voltages are balanced by zero-sequence voltage injection. Experimental results are presented to verify the validity of this strategy.