【作者】 涂小涛；

【导师】 辜承林；

【作者基本信息】 华中科技大学 ， 电机与电器， 2012， 博士

【摘要】 传统汽车日益严重的燃油消耗和尾气排放不断加剧着能源危机和环境污染,也间接促进了电动汽车的快速发展。横向磁通永磁电机(Transverse Flux Permanent Magnet Motor, TFPMM)具有低速性能好、转矩密度高的突出特点,是电动汽车直驱式轮毂电机的优选实施方案之一。为此,本文以课题组研制的拟应用于直驱式电动汽车的一种新型TFPMM为控制对象,针对不同层面的应用需求,探讨有效的驱动控制方案,以为实际应用提供有重要指导价值的理论依据和技术支撑。首先,简要介绍新型TFPMM的基本结构、运行原理和电磁参数。在此基础上,分别建立永磁同步和无刷直流两种驱动模式下的数学分析模型,为后续驱动控制方案的研究奠定基础。接下来,从系统的开环控制入手,结合实际应用需要,对新型TFPMM的永磁同步和无刷直流两种驱动模式进行综合对比研究。结果表明,无刷直流驱动模式更适合于新型TFPMM,但需要采用提前换相方式削弱电枢反应影响、改善换相过程,使电机运行性能进一步提高。采用后轮双驱形式的现场装车试验证实了该结论的正确性和应用的可行性。更进一步地,针对120°导通方式的开环无刷直流驱动模式,以最大转矩电流比为控制目标,提出了基于提前换相的有位置传感器控制新方案。根据直流母线电流和电机转速在线计算确定提前换相角,实现了变负载运行的自补偿提前换相控制,获得了满意的效果,电机运行效率和过载能力显著提升。此外,鉴于电动汽车高可靠性对无位置传感器控制技术的实际需要,深入分析了相电压检测法在新型TFPMM中产生附加误差的机理,由此提出改进的补偿方案,并由仿真结果和实验结果证实该方案的有效性和实用性。新型TFPMM开环运行时,不可避免存在转矩脉动,但可以通过直接转矩控制加以改善。兼顾高转矩电流比和低转矩脉动,本文提出了基于提前换相的有位置传感器直接转矩控制新方案。根据转子位置和转矩滞环比较器选择电压矢量,规避了传统直接转矩控制中的定子磁链给定困难和起动困难。仿真结果和实验结果证实,该方案尤其适合于动态品质要求较高的新型TFPMM驱动应用场合。无位置传感器控制技术仍是电动汽车的高可靠性应用需求。在传统直接转矩控制基础上,针对定子磁链给定难问题,本文提出了无位置传感器磁链自适应直接转矩控制新方案,仅利用定子磁链位置和转矩滞环比较器决定电压矢量,配合换相补偿以修正定、转子磁链夹角与最佳提前换相角之间的偏差。系统仿真和实验研究结果表明,该方案不仅有效规避了定子磁链给定难问题,还能兼顾高转矩电流比和低转矩脉动,有效提升了电机的运行效率和负载能力,是新型TFPMM在直驱式电动汽车应用中的重要技术支撑。更多还原

【Abstract】 The aggravation of global energy crisis and environmental pollution is intensified by massive fuel consumption and serious exhaust emissions of traditional vehicles, which indirectly promotes the rapid development of electric vehicles (EV). With relatively high torque density and good performance at low speeds, transverse flux permanent magnet motor (TFPMM) has been expected to be a preferred embodiment of direct-drive EV. Therefore, as applied in direct-drive EV, a novel TFPMM designed by our research group is taken as the control object in this paper. And effective control schemes for different levels of application requirements are deeply researched to provide powerful theoretical basis and technical support for its application.Firstly, this paper gives a brief analysis on the basic structure, operating principle and electromagnetic parameters of the novel TFPMM. And the mathematical models of permanent magnet synchronous motor (PMSM) drive and brushless DC (BLDC) drive are respectively established as the foundation for control of the novel TFPMM.The next research work starts with open-loop control applications. In reference to practical application, the comparable investigations on the two drive modes (namely PMSM and BLDC drive) are implemented. And it is indicated from comparative results that BLDC drive is much more suitable for novel TFPMM. However, it should be cooperated with phase advance commutation to weaken the influence of armature reaction and shorten the commutation interval, which further improves the performance of the motor. The field test with two prototypes installed in a sample car is carried out to verify the correctness of the conclusion and the feasibility of its application.Furthermore, for open-loop BLDC drive with 120°conduction, a position-sensor approach based on phase advance commutation is proposed to obtain maximum torque per ampere (MTPA). Under varying load torque conditions, the required phase advance angle is automatically calculated by DC bus current and rotor speed, achieving satisfactory performance, including much higer efficiency and much stronger load capacity. Besides, with sensorless control regarded as the actual requirement of EV for much higher reliability, the mechanism of the additional detection error in novel TFPMM is deeply analyzed, which is produced by the phase-voltage method. A corresponding compensation scheme is proposed and then verified through both simulated and experimental results.When the novel TFPMM operates in open loop, relatively large torque ripple is inevitable. However, direct torque control (DTC) can be employed to reduce torque ripple. Hence, to obtain MTPA and reduce torque ripple, this paper presents a new position-sensor DTC based on phase advance commutation. The desired voltage vector is properly selected in terms of both rotor position signals and torque hysteresis comparator, avoiding the problems of stator flux reference and motor starting that exist in conventional DTC. Simulated and experimental results show that the proposed approach is especially suited to the drive applications of the novel TFPMM with relatively good dynamic quality.Sensorless control is still the ideal approach to meet application requirements of EV for much higher reliability. Based on the conventional DTC, direct torque and adaptive flux sensorless control is proposed as a solution to stator flux reference, where the desired voltage vector is only determined by stator flux position and torque hysteresis comparator. However, it should be cooperated with reasonable compensation angle for the difference of optimal phase advance angle and the angle between stator and rotor flux. The proposed sensorless DTC is demonstrated through both simulated and experimental results to avoid the problem of stator flux reference and obtain larger torque per ampere, smaller torque ripple, higher efficiency and stronger load capacity, which is an important technical support for further application of the novel TFPMM in direct-drive EV.更多还原