可调磁通电机系统及其关键技术发展

针对传统汽车工业发展面临的能源危机和环境污染等问题,为满足新能源汽车驱动电机在宽调速范围内高效率运行的需求,对可调磁通电机（variable-flux machine,VFM）系统及其关键技术发展进行综述.首先,介绍了可调磁通电机的应用背景与工作原理；之后,简要分析了各类可调磁通电机（包括交流调磁型、直流调磁型和机械调磁型）的拓扑结构和优缺点,总结了不同种类可调磁通电机的结构特点和设计方法；最后,针对可调磁通电机特殊的工作原理,以及电机在负载运行和在线调磁控制时对参数在线辨识、调磁电流控制和转矩波动抑制等方面的需求,总结了专用于可调磁通电机的控制策略（包括磁链观测器、电流与转矩控制策略以及调磁与调速控制策略）,分析了各种控制策略的理论依据、实现方法、系统框架及优缺点.结果表明:可调磁通电机能够调节电机气隙磁场强弱,从而扩宽电机的转速范围,同时提高电机在高速区的运行效率；采用先进的控制策略,能够实现电机的在线调磁及调速控制,并降低转矩波动和调磁损耗,保证系统高效、稳定运行.新型可调磁通电机系统的提出及相关技术发展,将使可调磁通电机系统在电动汽车、数控机床等领域得到更广泛的应用,是未来新能源领域重点发展的核心技术之一.

Development of variable-flux machine system and its key technologies

Variable-flux machine (VFM) is designed to solve the problems of energy crisis and environmental pollution for traditional automotive industry, which satisfies the requirements of high-efficiency operation of new energy vehicle driving machines in a wide speed range. The development of VFM system and its key technologies were reviewed. First, the application background and operating principle of VFMs were introduced. Then, the topologies, advantages, and disadvantages of various VFMs (including VFMs using AC flux-adjustment coils, DC flux-adjustment coils, and mechanical structures) were analyzed, and the structure characteristics and design methods of different VFMs were summarized. Finally, in view of the special working principle of VFMs and the requirements of on-line parameter identification, flux-adjusting current control, and torque ripple suppression during load and on-line flux-adjustment operations, the control strategies specific to VFMs (including flux observer, current and torque control strategies, flux-adjustment, and speed regulation strategies) were summarized. The theoretical method, implementation approach, system structure, advantages, and disadvantages of various control strategies of VFMs were analyzed. Results show that the air-gap magnetic field of VFMs could be adjusted to expand the speed range and improve the efficiency of machines in high-speed range. By adopting advanced control methods, the on-line flux-adjustment and speed regulation could be realized, and the system could operate efficiently and steadily with torque ripple and flux-adjusting loss reduced. Thus, with the development of VFM topologies and related technologies, VFMs have great application prospects in the fields of electric vehicles and numerically controlled machines, and will become one of the key technologies in the future development of new energy fields.