多三相分布式绕组和集中式绕组永磁磁阻电机对比研究

Comparative Study on Triple 3-Phase PMA-SynRM with Distributed Winding and Concentrated Winding

利用磁阻转矩替代永磁转矩,永磁磁阻电机可减少永磁用量,以较低的成本实现相同的性能,该电机在相关行业应用正愈发得到重视。得益于较低的永磁磁链,该类电机短路电流小,非常适合容错设计。电机运行性能和容错能力与绕组紧密相关,因此该文研究了两台分别采用分布式绕组和集中式绕组的多三相永磁磁阻电机,两台电机基于相同性能指标进行设计加工。通过深入的有限元仿真和实验测试,比较了两台电机的反电动势、最大转矩电流比(MTPA)曲线、输出转矩以及不同故障模式下的故障行为和容错能力。结果表明,对于中低速应用场合,采用集中式绕组永磁磁阻电机较之分布式绕组结构具有更好的容错表现。

PM Assisted Synchronous Reluctance Machine(PMA-SynRM)receives increased interest in industry applications.It reduces the PM usage and offsets the torque reduction by employing reluctance torque,achieving comparable performance with a lower cost.This type of machine features low PM flux linkage,suitable for fault-tolerant applications.The machine drive performance and fault-tolerant ability are closely related to their windings.Therefore,this paper compares two fault-tolerant motor topologies with multiple 3-phase distributed winding and multiple 3-phase concentrated winding.First,the two motors are designed under the same technical specifications and operate at the rated point with 24 N·m torque at 2000 r/min.For each design sample,simulation calculations are conducted in Flux,and the relevant data is imported into Hyper Study.Then,Hyper Study uses a genetic algorithm to calculate the relevant parameters of the next iteration until the two motors’final optimization parameters are achieved.Secondly,2D finite element simulation models of the distributed and centralized winding motors are established using Flux finite element simulation software.The two motors are simulated and analyzed,and the back electromotive force,MTPA curve,output torque,fault behavior,and fault tolerance capability under different fault modes are compared.The results show that the efficiency of the concentrated winding motor is 1.1%higher than that of the distributed winding motor.The concentrated winding motor has a lower proportion of reluctance torque,and its output torque is 1.2 N·m higher than that of the distributed winding motor under open circuit conditions but lower under short circuit conditions.Under inter-turn short circuit,after taking the terminal short circuit(TSC)protection action,the short circuit current of the centralized winding motor is only 80%of that of the distributed winding motor,indicating that the centralized winding motor has more robust fault tolerance performance.Finally,by processing the prototype and building an experimental platform,different load currents are applied to the two motors under healthy operation conditions and fault modes.It is found that the output characteristics and fault tolerance characteristics of the two motors are consistent with the FE simulation results.The experimental results verified the accuracy of the simulation model.The following conclusions can be drawn:(1)Distributed winding motors rely more on reluctance torque,while centralized winding motors rely more on permanent magnet torque.The centralized winding motor has higher efficiency due to much lower end windings,smaller torque ripple,and better performance.(2)Under open circuit conditions,two motors can achieve fault operation through the remaining healthy three-phase windings,and the concentrated winding motor exhibits higher output torque capacity.(3)Under short circuit fault conditions,both motors could effectively suppress the short circuit current after TSC,but the distributed winding motor has higher output torque.(4)Under inter-turn short circuit fault,after adopting TSC protection action,the inter turn short circuit currents of both motors are significantly weakened,and the fault current of the concentrated winding motor is smaller.The fault tolerance performance of the concentrated winding motor is better than that of the distributed winding motor under the inter-turn short circuit.The two multiple 3-phase PMA-SynRMs are good candidates for safety-critical applications.The distributed winding machine is suitable for a relatively high-speed range,while the concentrated winding machine is more suitable for medium and low-speed ranges.