摘要
用于中高压电机驱动的级联H桥变频器具有输出波形谐波含量低、器件电压应力小以及效率高等优势。然而与传统的两电平变频器一样,当其经长电缆驱动电机时存在电机端过电压的问题。为此,本文对级联H桥变频器的结构进行了改进,将一个辅助双向开关放入每一相的某一子单元中,使该子单元能够产生±Vdc/2电平,即在总输出电压的每个上升和下降沿中插入一个短暂的固定时间的中间电平。此举可将上升/下降沿分为两段,并且两者之间存在两倍于电压波在电缆上传播时间的延迟。由于延迟的存在,第二段正好可以抵消第一段的反射波,所以电机端由反射现象导致的过电压会被明显抑制。最后,仿真及实验均验证了所提出方案的有效性。
The cascaded H-bridge inverter used for medium and high voltage motor drive has the advantages of low output waveform harmonic content small device voltage stress and high efficiency.Like the traditional two-level inverter when it drives the motor through a long cable there is also the problem of overvoltage at the motor terminal.For this reason the structure of the cascaded H-bridge inverter is improved in this paper and an auxiliary bidirectional switch is placed in a subunit of each phase so that it can generate±Vdc/2 level that is a short fixed time intermediate level is inserted into each rising and falling edge of the total output voltage.The intermediate level can divide the rising/falling edge into two sections and there is a delay between the two that is twice the propagation time of the voltage wave on the cable.Due to the existence of delay the second section can just cancel the reflected wave of the first section and the overvoltage caused by the reflection phenomenon at the motor terminal will be significantly suppressed.Finally the effectiveness of the proposed scheme is verified by simulation and experiment.
作者
骆志伟
张敏
李昕
孙孝峰
LUO Zhiwei;ZHANG Min;LI Xin;SUN Xiaofeng(Beijing Institute of Space Launch Technology,Beijing 100076,China;School of Electrical Engineering,Yanshan University,Qinhuangdao,Hebei 066004,China)
出处
《燕山大学学报》
CAS
北大核心
2023年第4期319-328,336,共11页
Journal of Yanshan University
基金
河北省自然科学基金重点项目(E2021203162)
河北省重点研究发展计划资助项目(19214405D)。
关键词
电机
多电平
变频器
传输线
过电压
motor multilevel
inverter
transmission line
overvoltage
