三电平逆变器直流侧电压平衡控制方法的改进.pdfVIP

第22 卷第9 期 中 国 电 机 工 程 学 报 Vol.22 No.9 Sep. 2002 2002 年9 月 Proceedings of the CSEE ©2002 Chin.Soc.for Elec.Eng. 文章编号：0258-8013 (2002) 09-0094-04 三电平逆变器直流侧电压平衡控制方法的改进 翁海清，孙旭东，刘丛伟，韦立祥 （清华大学 电机工程与应用电子技术系，北京 100084 ） IMPROVEMENT ON DC-VOLTAGE BALANCE CONTROL METHOD OF THREE-LEVEL INVERTER WENG Hai-qing, SUN Xu-dong, Liu Cong-wei, WEI Li-xiang (Department of Electrical Engineering, Tsinghua University,Beijing 100084,China) ABSTRACT: DC-voltage balance is one of the key aspects 率开关器件（如IGBT 、GTO 等）联结在一起，实 that affects the reliability of three-level inverter and its electric 现了高电压、大容量电机调速，有效地避免了传统 drive system. Therefore, the effects of separate voltage 的功率开关器件串联所带来的动、静态均压问题。 space-vectors on the DC-voltage balance are deeply 现在实用的三电平变流器主电路采用的是二极管 investigated, and a novel DC-voltage balance control method [1] 中点箝位(Neutral Point Clamped)方式 ，通过一对 based on the instantaneous current detection is presented in this 中点箝位二极管分别与上下桥臂串联的二极管相 paper to meet the demands of AC drive four -quadrants 联。 operation. With this method, regardle ss of the power flow direction and the magnitude of power factor, the DC-voltage 三电平变流器每个开关管所承受的电压等于 can be quickly balanced under all kinds of operation states, 直流侧一个直流电容上的电压。显然，只有在电容 especially in the state of energy regeneration under low output 电压保持平衡时，每个开关管承受的电压为直流电 voltage. The new method is verified by experiments on a 压的一半，才能保证系统可靠运行。如果电容电压 prototype of dual-PWM three-level induction motor drive 不平衡，不仅会增大输出电压波形的谐波含量，而 system. 且变流器中