磁场调制型谐波混合励磁永磁电机及其驱动控制策略研究

Hybrid excitation permanent magnet (HEPM) motor is one of the most effective energy-efficient solutions for electric vehicles (EVs) propulsion. However, conventional HEPM motors usually suffer from complex configuration and limited magnetic field regulation capability. By incorporating magnetic field modulation principle, AC excitation theory and partitioned stator, a new harmonic hybrid excitation permanent magnet (HHEPM) motor with 2-D magnetic circuit is proposed for EVs in this project to achieve the expected performances of high power density, high efficiency and wide speed range. Partitioned stator is adopted in the proposed motor, so that the armature winding and excitation winding can be housed in the outer stator and inner stator, respectively, thus achieving the improvement of motor space utilization. And the rotor is composed of alternately arranged PMs and ferromagnetic pole-pieces. Based on the modulation function of ferromagnetic pole-pieces to the electric excitation field, a series of synchronous harmonics can be obtained, thus achieving the aim of hybrid excitation. So, the mutual effect between the PMs and the electric excitation field can be reduced. The purpose is to develop a new kind of HHEPM motors. And the basic operation principle, electromagnetic parameter calculation, mathematical modeling and simulation, as well as multi-objective and multi-physical field optimization design method will be investigated in details. Also, the multi-objective coordinated control strategy will be studied considering its AC excitation method to obtain high efficiency in the whole drive system. The successful development of this project will give a theoretical foundation and experimental results of the novel HHEPM motor drive system, thus exploring a new energy-efficient solution for EVs propulsion and promoting a stable development of EVs.

混合励磁电机是实现电动汽车宽调速高效运行的有效手段之一。针对现有混合励磁电机结构复杂及调磁率低等问题，本项目将“磁场调制”原理、“交流励磁”理论和“分区定子”设计理念与永磁同步电机相融合，提出一类二维磁路结构的磁场调制型谐波混合励磁永磁电机。该电机采用“分区定子”结构分别设置电枢和励磁绕组，有效增加了电机空间利用率；其转子由永磁体和导磁铁心间隔排列而成，基于导磁铁心对电励磁磁场的调制产生有效谐波磁场，降低了永磁体与电励磁磁场的相互影响。本项目旨在开发出结构新颖合理的谐波混合励磁永磁电机拓扑结构，研究其基本工作原理；建立该类电机电磁参数计算、数学建模、仿真分析以及多目标、多场耦合优化设计的一般方法；基于“交流励磁”特点研究其多目标协调控制策略。本项目将为谐波混合励磁永磁电机系统在电动汽车中的应用提供理论基础和技术支持，为电动汽车实现高效驱动探索新方案，为促进电动汽车长期稳定发展提供有益帮助。

电动汽车汽车驱动电机应具有高转矩密度、高效率和宽调速范围等特性，结合永磁电机和电励磁电机特点的混合励磁电机是满足电动汽车苛刻要求的有效方案之一。针对现有混合励磁电机结构复杂及调磁率低等问题，本项目将“磁场调制”原理、“交流励磁”理论和“分区定子”设计理念与永磁同步电机相融合，提出一类二维磁路结构的磁场调制型谐波混合励磁永磁电机设计思路。围绕这一思路提出了四种具有上述特征的电机拓扑结构，即两种直流励磁的定子分区混合励磁电机、一种直流偏置电流的定子分区混合励磁电机和一种双三相交流绕组的绕组分区式混合励磁电机；基于气隙磁场调制理论对所提出电机的运行原理进行了推演，从理论上验证了该类电机具有大转矩密度特征和实现混合励磁的原理；结合“磁场调制”原理和等效磁路法，构建该类电机气隙磁场等效模型，实现了气隙磁密、绕组磁链、空载感应电势和转矩等参数的准确解析计算，并以此构建了该类电机的通用设计方法；提出考虑电磁和温升反复迭代的多物理场设计方法，并采用相应面法实施了该类电机的多参数多目标优化设计；提出基于自抗扰观测器的混合励磁电机效率最优控制策略和双交流绕组混合励磁电机分区控制策略；在考虑车辆行驶需求、电池SOC等参数前提下，研究了混合动力汽车能量管理策略，有效改善了混合动力汽车动力匹配能力和燃油经济性。本项目首次将“磁场调制”原理和“交流励磁”引入混合励磁电机，并研究该类电机的拓扑结构创新、运行原理推演、电机优化设计及其驱动控制策略，相应成果为电动汽车驱动电机领域提供了理论基础和技术支持，为电动汽车实现高效驱动探索新方案，为促进电动汽车长期稳定发展提供有益帮助。