二极管钳位型三电平逆变器共模电压抑制  

Common-Mode Voltage Suppression for Neutral-Point-Clamped Three-Level Inverter

作　　者：吴可丽 夏长亮[1] 张云[1] 谷鑫[2] 

机构地区：[1]天津大学电气与自动化工程学院,天津300072 [2]天津工业大学天津市电工电能新技术重点实验室,天津300387

出　　处：《电工技术学报》2015年第24期110-117,170,共9页Transactions of China Electrotechnical Society

基　　金：国家重点基础研究发展计划(973计划)(2013CB035602);国家自然科学基金(51207104)资助项目

摘　　要：二极管钳位型(NPC)三电平逆变器是一种应用广泛的多电平逆变器结构。中点电位不平衡是NPC三电平逆变器固有的缺点。传统虚拟空间矢量调制(NTV2)能在输出电压全范围内控制中点电位平衡,但其产生的共模电压较大。针对上述缺点,提出了一种新型NTV2方法,选用产生共模电压较小的基本电压矢量合成新的虚拟小矢量和虚拟中矢量。同时,提出相占空比法,降低了新型NTV2方法的开关频率,使其开关频率固定。仿真和实验结果验证了新型NTV2方法能够有效地抑制共模电压,且在输出电压全范围内控制中点电位平衡。Neutral point clamped（NPC） three-level inverter is a widely used multilevel inverter topology. The neutral-point potential imbalance is the main drawback of NPC three-level inverter. The traditional NTV2 modulation strategy can control the voltage balance over the full range of inverter output voltage. However, the inverter output side will produce high common-mode voltage. This paper proposes a new NTV2 modulation strategy to solve the high common-mode voltage problem generated by the traditional NTV2 modulation. This modulation selects the basic voltage vector that generates smaller common-mode voltage to synthesis a new small virtual vector and middle virtual vector. At the same time, the duty ratio method is put forward, to reduce and fix the switching frequency of the new NTV2 modulation. The simulation and experimental results show that the new NTV2 modulation can effectively suppress common-mode voltage, and it can also control the neutral-point voltage balance over the full range of inverter output voltage.

关 键 词：三电平逆变器 共模电压 中点电位平衡 虚拟空间矢量 相占空比法 

分 类 号：TM464[电气工程—电器]