共直流母线开绕组的少稀土混合磁材料永磁无刷电机系统零序电流抑制策略

Zero-Sequence Current Suppression Strategy for Open Winding Hybrid Permanent Magnet Material Brushless Motor with Common DC Bus

为提高少稀土混合磁材料永磁无刷电机的功率密度和转矩输出能力,采用了新型共直流母线开绕组的逆变器拓扑结构。该结构会在电机绕组内产生零序电流,一定程度上影响了电机的运行效率和稳定性。为此,提出了一种解耦空间矢量脉宽调制法,有效提高了电机端电压利用率。对共直流母线情况下共模电压和零序反电动势均会导致3、9次电流谐波的问题,采用了具有针对性的重复控制器对零序电流进行闭环控制,在简化控制系统结构的同时,有效地解决了共模电压和零序反电动势的影响。最后,通过试验验证了所提方法的正确性和可靠性。

A novel open winding topology with common DC bus was applied to hybrid permanent magnet material brushless motor for promoting power density and elevating torque output capacity.However,in this structure,zero-sequence current would be produced in the winding,which would reduce the efficiency and operation stability.In order to solve this problem,a decoupled space vector pulse width modulation strategy was proposed,which could improved the voltage utilization effectively.In addition,for eliminating the 3rd and 9th current harmonics caused by common voltage and zero-sequence components in back-EMF and simplifying the control system,a closed-loop system with repetitive controller in zero-sequence circuit was formed.The proposed control methods were illustrated by the experimental results.