无传感器轮毂驱动系统机电磁热多场耦合机理分析及建模方法研究

The motor rotor information could be softly measured in sensorless in-wheel motor drive system (SL-IWMD). The integration level of in-wheel motor electric vehicle could also be improved by SL-IWMD, which has a good application prospect. However, the multi-field, multi-parameter and strong coupling characteristics of SL-IWMD leads to difficult integration design and poor reliability. In order to solve the aforementioned problem, the SL-IWMD is studied in this proposal. The coupling interface of SL-IWMD is analyzed and partial coupling system is modeled. The coupling characteristics of electromagnetic vibration and rotor torsional vibration is revealed. The electromechanical coupling characteristics among electromagnetic torque, unbalanced radial force, electromagnetic and thermal field is uncovered. The coupling law between control circuit and power circuit parameters is analyzed. The multi-field unified modeling method is adopted to establish the system global coupling constraint model. The mechanical-electromagnetic-thermal multi-field coupling mechanism of SL-IWMD under complex integration environment is deeply clarified. The sensorless estimation and hybrid switching algorithm are explored with the consideration of characteristics of SL-IWMD. The integration dynamic model of SL-IWMD is built to achieve strong robustness and fault tolerance. The sensitivity analysis technique is employed to reduce system dimension and alleviate the difficulty of solving. The system coupling mechanism, modeling approach and decoupling algorithm are verified by the simulations and experiments. The research results will provide theoretical foundation and enabling technical support for SL-IWMD integration design.

无传感器轮毂驱动系统在实现轮毂电机转子信息软测量的同时提升了轮毂直驱电动汽车的集成化水平，具有很好的应用前景。然而，其多能域、多参数、强耦合特性导致系统集成设计难度增大、可靠性变差等问题。为此，本项目以无传感器轮毂驱动系统为研究对象，通过系统耦合界面分析，建立系统局部耦合模型，阐明系统在电磁振动与转子扭转振动下的耦合特性，明确电磁转矩与不平衡径向力、电磁场、温度场之间的耦合关系，掌握系统控制、功率参数之间的耦合规律；运用多领域统一建模方法，构建系统全局耦合统一约束模型，深入揭示复杂集成环境下系统机电磁热多场耦合内在机理；分析系统混杂特性，探究无传感器估算以及混杂切换策略，结合鲁棒容错理论，构建系统一体化动态模型，应用灵敏度分析技术，实现系统模型的降维与求解；通过仿真与实验验证系统耦合规律、建模方法以及解耦算法的有效性。研究成果将为无传感器轮毂驱动系统集成设计提供理论依据和关键使能技术支撑。

作为一种 新型驱动方式，轮毂电机驱动技术颠覆了传统汽车动力传动方式，使得轮毂电动机驱动系统成为纯电动汽车领域的重要研究方向。作为轮毂直驱电动汽车的关键动力部件，轮毂电机驱动系统逐渐成为研究热点。无传感器轮毂驱动系统不仅能够实现轮毂电机转子信息软测量，同时还提升了轮毂直驱电动汽车的集成化水平。本项目以无位置传感器轮毂电机驱动系统为研究对象，围绕轮毂电机驱动系统机电磁热多物理场耦合机理及建模方法问题进行了研究。本项目的主要研究工作及成果如下：(1)分别运用高频信号注入法和最小二乘支持向量机方法，对永磁轮毂电机在零低速和中高速范围的转子位置和速度进行估计，在此基础上提出了一种基于混杂系统理论的轮毂电机宽调速范围无传感器控制方法，该方法不仅能够有效降低算法设计难度和运算复杂度，还实现了宽速度范围内无位置传感器控制的平滑切换。(2)建立了气隙偏心下的轮毂电机、轮胎以及路面激励模型模型，研究了气隙磁密与不平衡磁拉力的耦合关系，揭示了气隙偏心情况下轮毂电机机电耦合振动机理，为轮毂电机的振动噪声抑制奠定了基础。(3)研究了逆变器供电轮毂电机的径向不平衡磁力、固有频率和噪声特性，提出了基于两状态马尔可夫链的随机脉冲开关频率控制方法。该方法有效降低了轮毂电机的振动噪声幅值。为改善轮毂直驱电动汽车的振动噪声特性提供了技术支持。(4)采用Ansys软件对轮毂电机有限元模型进行求解，得到了定子绕组、定子铁芯、永磁体以及转子损耗。运用磁热耦合方法分析了轮毂电机的瞬态温度场。对轮毂电机进行温升试验，为轮毂电机的冷却提供了依据。本项目的研究工作为无位置传感器轮毂电机驱动系统的集成设计提供了依据和关键使能技术支撑，具有重大的科学意义和广阔的应用前景。