电动车用轴向磁场磁通切换型可控磁通记忆电机及其控制技术研究

This project presents a novel memory machine with permanent magnets in the stators which is termed as the axial field flux-switching controllable flux memory(AFFSCFM) machine for the electric vehicle applications. Incorporating the advanced features of dual outer stators and one inner rotor, the machine exhibits the advantages of simple and compact structure with high power/torque density.The hybrid permanent magnet structure makes the flux controllable and flux weakening operation much easier.Also,the starting torque is increased and the adjustable speed range is widen.The flux is modulated through DC pulse current,this decreases the copper loss and improves the operation efficiency of the machine running at the full speed range. This project aims at studying the new topology,the design principles, the electromagnetic characteristics, the accurate calculation of the parameters and the flux modulation method of the AFFSCFM machines. We will extend the research to various aspects including the electromagnetic and optimal design of the machine,the general method of the steady and transient performance analysis of the machine and its control system,the coordination control strategy between the online flux modulation and the drive control.The hardware control platform based on the dSPACE will be established. The machine control rules which could satisfy all kinds of operation performance requirements will be determined, and the experiments will be done. The project would resolve the key technique problems such as the design of stator-PM axial-field memory machine and the online flux adjustment-drive coordination control. These scientific questions will be put forward, and lay the foundation for the future investigation and application. The object is to supply a new selection schedule for EV drive system, and this is significant in both theoretical and practical application aspects.

提出一种新型定子永磁型记忆电机结构-轴向磁场磁通切换型可控磁通记忆电机。电机由两个外定子、一个内转子组成，结构简单、紧凑，功率密度和转矩密度高；可控磁通的混合永磁励磁结构，电机调磁运行更容易，提升了起动转矩,拓宽了恒功率调速范围；直流脉冲记忆调磁方式，减小了铜耗，提高了电机全速运行效率，在线调磁与驱动协调控制更易实现。项目研究其新型结构、设计原则、电磁特性、参数准确计算和调磁控制方法，开展电机的电磁和优化设计，探求电机及控制系统稳态和瞬态性能分析的普遍方法，在线调磁与驱动协调控制策略，构建以dSPACE为核心的硬件平台，制定满足不同性能要求的电机控制规律，进行试验研究，解决定子永磁型轴向磁场记忆电机设计、调磁驱动协调控制等关键技术问题，凝练科学问题，为后续研究和应用奠定基础。该定子永磁型轴向磁场磁通切换记忆电机的研制成功，为电动汽车提供新的备选驱动方案，具有重要的理论意义和广阔的应用前景。

本项目对新型AFFSCFM电机设计及其控制方法进行了研究，从理论分析、仿真计算和实验研究三方面验证了电机设计及其控制方法的正确性，取得了如下研究成果：.（1）建立了低矫顽力永磁体磁滞特性模型，分析了充、去磁过程中低矫顽力永磁体的局部磁滞特性。.（2）首次提出了具有混合永磁体和附加调磁绕组的串联混合永磁轴向磁场磁通切换型记忆电机，建立了AFFSCFM 电机的功率尺寸方程，提出了AFFSCFM电机的通用设计方法。以一台250W三相AFFSCFM电机为设计算例，计算、设计了电机结构参数，包括定/转子极数、调磁绕组、转子齿齿宽、永磁体厚度等，确定了电机设计方案。分析了电机的电磁特性，验证了所提出设计方法的可行性。.（3）基于三维有限元法，研究了三相12/10极AFFSCFM电机的永磁磁场和电枢磁场分布、气隙磁密、永磁磁链、感应电动势、齿槽转矩和电磁转矩等静态特性。结果表明，有限元分析结果与理论分析结果一致，验证了AFFSCFM电机电磁设计方法的正确性。.（4）研究了AFFSCFM电机磁化状态调节特性，分析了串联混合永磁轴向磁场磁通切换型记忆电机的基本结构和工作原理。建立了AFFSCFM电机在静止坐标系和两相旋转坐标系中的数学模型，研究不同磁化状态和电枢电流下的电机电感特性。基于 MALAB/Simulink，建立AFFSCFM电机仿真模型，为研究AFFSCFM电机电流控制策略奠定了理论基础。.（5）研究了AFFSCFM电机分段磁化状态调节原理，分析了基于自适应永磁磁链观测器的脉冲电流产生方式，提出了结合分段磁化状态调节的 id =0 控制和弱磁控制等电流控制策略。提出的结合分段磁化状态调节的 id =0 控制，在低速区内采用饱和磁化状态运行，在高速区内采用分段磁化状态调节，当直流母线电压一定时，电机的基速扩大了1.39倍。与结合分段磁化状态调节的 id =0 控制相比，在恒定直流母线电压下，提出的结合分段磁化状态调节的弱磁控制策略，是电机在不同的磁化状态下的速度范围的1.11倍。