Voltage Balancing Control of a Four-Level Hybrid-Clamped Converter Based on Zero-Sequence Voltage Injection Using Phase-Shifted PWM
Voltage Balancing Control of a Four-Level Hybrid-Clamped Converter Based on Zero-Sequence Voltage Injection Using Phase-Shifted PWM
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DOI：
10.1109/tpel.2015.2491779
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发表时间：
2016-08
影响因子：
6.7
通讯作者：
Kui Wang;Lie Xu;Zedong Zheng;Yongdong Li
中科院分区：
文献类型：
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作者：
Kui Wang;Lie Xu;Zedong Zheng;Yongdong Li
四电平混合箝位（4L-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。这种拓扑的每一相由八个开关和一个飞跨电容器组成，直流链路被两个中性点分成三个部分。为了确保拓扑正常工作，跨飞跨电容器和三个直流链路电容器的电压应被控制并保持在其标称值的平衡。本文提出了一种解耦的4L-HC逆变器的电压平衡方法，包括直流侧电容和飞跨电容的电压平衡。一种改进的相移脉宽调制方法被用来调节飞跨电容器和中心直流环节电容器的电压。研究了中性点电流与输出电压的关系，通过注入最佳零序电压来平衡上、下直流侧电容电压。仿真和实验结果验证了该方法的有效性。
Four-level hybrid-clamped (4L-HC) inverter is a newly proposed topology which is suitable for high-performance medium-voltage drives. Each phase of this topology consists of eight switches and a flying capacitor and the dc-link is split into three parts by two neutral points. In order to ensure the topology operating properly, the voltages across the flying capacitors and three dc-link capacitors should be controlled and maintain balanced at their nominal values. This paper presents a decoupled voltage balancing method for this 4L-HC inverter, including the voltage balancing of dc-link capacitors and flying capacitors. A modified phase-shifted pulse-width modulation method is used to regulate the voltages of flying capacitors and the central dc-link capacitor. The relationship between the neutral-point currents and the output voltage is studied and the upper and lower dc-link capacitor voltages are balanced by injecting an optimum zero-sequence voltage. Simulation and experimental results are presented to verify the validity of this method.