电动汽车中多相感应电机和飞轮混合动力系统的关键理论和技术研究

Aimed at improving the power density and energy utilization rate, enhancing the reliability, and prolonging the endurance of an electric vehicle (EV) drive system, this project is focused on the basic theories and key technological issues in a hybrid power system of multi-phase motor and flywheel for EV applications. In the hybrid power system, the multi-phase induction motor serves as the major drive motor, whereas the chemistry battery serves as the active source, and the flywheel is the auxiliary power source. The integrated modeling, analysis and design methods of the system will be studied to achieve the overall weight, volume, efficiency optimization of the systematic topology; the multi-phase induction motor control strategy under various EV operation conditions will be investigated, and the fault detection mechanism and fault-tolerant control strategy will be built; the control strategy of high-speed flywheel battery under charge and discharge mode, especially at the switch moment will be studied to realize the fast dynamic response of DC bus voltage, d-q axis current and active power; the system level control strategy will be explored to maximize the energy efficiency, improve the mileage, and prolong the service life of batteries. The multi-phase induction motor, the flywheel and the chemistry battery is accumulated as an integrated system in the project to explore the energy transfer organism, establish the theoretical system of the joint modeling, topology optimization, control strategy, energy utilization rate and reliability issues in the system level, and provide some key techniques and methods, which will be valuable theoretical basis and technical support for the engineering application of the proposed hybrid power system for EV applications.

为提高电动汽车驱动系统的功率密度、能量利用率、可靠性，续航能力，本项目提出了多相感应电机作为主驱动电机，化学电池作为主动力源，飞轮系统作为辅助动力源的混合动力系统。以此为基础，对其中的基础理论和关键技术进行研究。主要研究内容包括：混合动力系统的统一建模、分析和设计方法，一体化系统的整体拓扑（重量、体积、效率）优化；电动汽车多种工况下的多相感应电机控制策略，缺相等故障下故障检测机制以及容错控制策略；充、放电及充放电切换状态下高速飞轮的控制策略，实现母线电压、电流和功率的快速动态响应；系统级控制策略以实现混合动力系统能量利用率最大化，提高续航里程，延长化学电池使用寿命。该研究将多相感应电机、飞轮和动力电池作为一个整体，从系统层面探索机电能流转化和协调控制机理，建立一体化分析与计算模型、拓扑优化方法、控制策略、能量利用率和可靠性等问题的理论基础，为工程应用提供理轮依据和分析、计算方法。

电动汽车在城市交通环境下，频繁的启动与刹车会导致续航里程减少，长时间机械振动和大温差会引起传统三相电机驱动系统的故障。为此，本项目提出一种用于电动汽车的多相感应电机和飞轮混合动力系统，并对其对该系统进行了建模、分析、设计与相应实验平台的搭建。研究了多相感应电机的驱动控制、混合系统的能流转化与飞轮装置的协调控制。.基于Maxwell和Simplorer的场路耦合协同仿真技术，设计了七相感应电机、飞轮用高速永磁电机以及双向能量流动的新型低损耗三相与多相大功率能量转换器的总体硬件结构。基于有限元数值计算方法提出了一种适用于任意定子相数和任意转子条数的多相感应电机多平面参数估计方法。根据多相电机基波和谐波平面旋转气隙磁场的时空关系提出了谐波平面气隙磁场定向的非正弦供电控制策略。在不增大气隙磁场空间分布幅值的前提下，有效降低相电流有效值约10.5%。针对基于无功功率的基波和谐波平面转子电阻模型参考自适应系统，提出了基于误差项归一化的自适应律，实现了在大范围负载运行区间内获得近似的转子电阻动态收敛过程和稳态表现。设计了多相电机谐波电流自适应在线校正策略，实现谐波气隙磁场在任意负载工况下对基波气隙磁场幅值和相位的准确追踪。提出了用于多相电机的虚拟向量概念和结合占空比优化算法的序贯策略来减小谐波电流和转矩脉动。以保持故障前后磁动势不变为目标，提出基于正负序电流矢量解耦变换的多相电机容错控制策略，提高驱动系统的可靠性。基于电机动能、电容储能等建立了电动汽车在启动、加速、减速、制动阶段过程中主驱动电机和飞轮之间功率传输模型。对用于飞轮用高速永磁电机设计了一种基于精确离散模型和扩张状态观测器的电流内环控制方法，实现较低带宽和较低载波比下电流解耦控制和快速跟踪。针对再生制动能量回馈过程，提出了一种基于电容储能反馈、转速前馈补偿、非线性扰动观测器估计和总损耗功率直接补偿的飞轮装置控制策略，实现宽转速运行工况下的母线电压鲁棒控制。