电动汽车用内置双层磁钢永磁同步电机优化设计与最优运行控制

The main direction of the new energy vehicle development and the automobile industry transformation in China is to cultivate and develop the electric vehicle. As the core component of the electric vehicle, motor and its control technology has been a key technology of the electric vehicle research. Multilayer interior magnet geometry which can improve the magnetic field distribution, increases the torque density and widen operation range will have a good application in the electric vehicle. The research is carried out from two aspects - motor design and operation control for the electric vehicle with multilayer interior permanent magnet synchronous motor (IPMSM). Considering the effects of cogging and iron saturation, a universal analytical magnetic field model of IPMSM is built by reference to the equivalent magnetic circuit method and subdomain model method, revealing the influences of motor structure parameters on electromagnetic properties. Considering the synergistic effect of the motor, invertor and controller, the field circuit coupled simulation platform is built. The pattern of the motor inductance parameters changing with the operating condition is revealed and the ideal optimal trajectory of the stator current is planned with simulation. Then a fuzzy controller is designed to compensate the reference value of current as well as a sliding mode controller is designed to control the current, that improve the anti-interference ability and rapid response ability of the system. Through accurate positioning and fast tracking the optimum value of the stator current, the full domain optimal operation of the IPMSM system is achieved, that may provide novel ideas for improving the performances of the motor drive system and promoting the technologies of the electric vehicle.

电动汽车是我国新能源汽车发展和汽车工业转型的主要方向。作为电动汽车的核心，电机及其控制技术一直是电动汽车领域研究的关键性技术。双层磁钢结构可以改善磁场分布、提高转矩密度、拓宽运行范围，在电动汽车领域具有广阔的发展空间和应用前景。本课题围绕内置双层磁钢结构，从车用电机设计和运行控制两方面进行研究，借鉴等效磁路法和子域模型法思想，探索计及齿槽效应和铁心饱和影响的内置式永磁同步电机磁场解析建模方法，揭示电机结构参数对系统性能的影响机制；从电机、逆变器和控制器间的协同关系出发，搭建场路耦合仿真平台，揭示电机电感参数随运行工况的变化规律，仿真预测理想最优电流轨迹，并结合模糊决策思想设计电流补偿器，基于滑模控制理论设计电流控制器，提高系统抗干扰能力和快速响应能力，通过准确定位并快速跟踪最优电流值实现系统的全速域最优运行控制，为进一步提升电动汽车电机驱动系统性能、推动我国电动汽车技术的发展提供新的思路。

作为电动汽车的动力核心，驱动电机系统运行品质的高低直接影响了汽车整车性能的优劣。电机系统发展至今已成为集电机和控制器为一体的集成系统，两者的性能以及匹配程度直接决定了系统的整体性能。因此，为提高电机系统性能，使其更好地满足电动汽车动力系统技术要求，本项目将内置双层磁钢结构用于电动汽车用永磁同步电机，从电机设计和运行控制两方面进行了研究。首先，围绕内置双层磁钢永磁同步电机的建模与优化设计，依照转子磁动势不变原则，将双层磁钢内置式结构等效为内嵌式结构，提出了一种高凸极率永磁同步电机磁场解析建模方法，兼顾了磁场计算的精确性和快速性。在此基础上，结合电动汽车电机系统应用需求，以拓宽电机弱磁扩速范围、增大输出转矩、减小转矩脉动等为优化目标，以双层磁钢结构参数为优化变量，构建了电机多目标优化模型，进而基于Taguchi法实现了内置双层磁钢永磁同步电机优化设计。其次，围绕内置双层磁钢永磁同步电机的的最优运行控制，提出了基于参数自整定的最大转矩电流比控制策略和基于模糊PI电压反馈控制的宽速域运行策略，解决了实际运行中电机磁链、电感等参数非线性时变导致的运行点漂移问题，提高了系统的参数鲁棒性，兼顾了系统的控制精度和响应速度，实现了内置式永磁同步电机的宽速域最优运行。最后，在理论研究基础上，研制了电动汽车用内置双层磁钢永磁同步电机样机，搭建了电机运行实验平台，验证了所提出方法的可行性和有效性。