共直流母线开绕组电机系统零序电流抑制技术综述

Overview of Zero-sequence Current Suppression Technology for Open-end Winding Motor System With Common DC-Bus

开绕组电机系统是将星形绕组中性点打开,两端各接一个逆变器的特殊级联供电方式。在只能提供单一直流电源时,2个逆变器共用同一个直流电源,称为共直流母线结构。由于其具有所需电源数目少、输出功率高、有效电压矢量多样,以及冗余性和容错性强的优点,在高电压、大功率、安全性要求高的场合下有广泛的应用前景。同时,由于该结构存在零序通路,零序电流会产生额外损耗和转矩脉动。因此,有效地抑制零序电流是该结构能够广泛使用的必要条件。通过总结共直流母线开绕组电机系统在国内外的研究和发展现状,介绍共直流母线开绕组电机系统的拓扑结构及其零序电流产生机理,并对零序电流抑制技术进行全面归纳总结。最后,讨论共直流母线开绕组电机系统零序电流抑制技术的发展趋势。

The open winding electric machine(OWEM) is a special cascaded power supply mode, which opens the neutral point and connects each end with an inverter. In the case that only a single DC power supply can be provided, two inverters share one common DC power supply, which is called as the common DC bus topology in this paper. Due to its advantages of single DC power supply, high output power, multiple effective voltage vectors, strong redundancy, and fault tolerance, it has broad applications in high voltage, high power, and high safety requirements. At the same time, due to the existence of the zero-sequence path, the zero-sequence current will occur, which can cause additional losses and torque ripples. Therefore, the effective suppression of the zero-sequence current is necessary for the common DC bus topology. In this paper, the common DC bus topology was presented firstly. And then the causes of the zero-sequence current were analyzed. Thirdly, the zero-sequence current suppression strategies were overviewed. Finally, these strategies were summarized, and their future development trends were discussed.