新型定子直流励磁及混合励磁双凸极电机工作机理及性能研究

针对电动汽车、混合动力汽车中两个关键问题：(1)高速弱磁性能；(2)低速转矩性能，研究一类新型可变磁通磁阻电机（VFRM）弱磁工作机理，该电机是申请人于2012年首先提出，主要解决开关磁阻电机和双凸极电机转矩脉动大、噪声和振动高的问题。但由于定子磁场容易饱和，限制了该类电机的转矩密度。因此，在该类电机基础上提出的新型混合励磁电机来提高转矩密度。最后，将VFRMs中的直流励磁全部替换，提出基于VFRMs新型永磁双凸极电机。.分析新型混合励磁双凸极电机的工作原理、不同定/转子极配合时该电机调磁性能、转矩、弱磁等性能。比较该类电机与开关磁链混合励磁电机、双凸极混合励磁电机的性能。在此基础上，分析两个科学问题（1）对称/非对称电枢电压（偶次谐波）对电机的弱磁性能影响；（2）兼顾高速弱磁性能与低速转矩性能时，电机的优化设计问题。分析该类电机应用于电动汽车、混合动力汽车等领域的可行性以及最优结构等。

This project will mainly focus on two main issues of the electrical vehicles (EVs) and hybrid electrical vehicles (HEVs), i.e. (1) high speed flux weakening performance (2) low speed torque density. First, this project will investigate the flux-weakening performance of variable flux reluctant machines, which was proposed by the applicant in 2012 to solve the high torque ripple, vibration and acoustic noise in SRMs. However, since the DC excited machines can be easily saturated, which limits the torque density of this type of machines, novel hybrid excited doubly salient machines based on the VFRMs are proposed to improve the torque density of VFRMs, and further to proposed novel doubly salient PM machines. .This project will analyze the principle of novel hybrid excited doubly salient machines, and novel doubly salient PM machines, and investigate the flux adjustment capability, torque density, torque ripple and so on. Compared this type of machines with hybrid excited switched flux machines, and conventional hybrid excited doubly salient machines. From the investigations, this project will try to answer two general questions, i.e. (1) influence of symmetric/asymmetric armature voltage (even order harmonics) on the flux weakening performance; (2) optimal design of hybrid excited machines accounting for both high speed and low speed performances. In addition, the investigations will also help to understand the potential of this type of machines, which can be further theoretic guidances for the electric vehicles and hybrid electric vehicles.