【作者】 李发启；

【导师】 纪志成；

【作者基本信息】 江南大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 永磁无刷直流电机(BLDCM)是永磁同步电机的一种,其理想反电动势波形为梯形波,驱动电流为方波信号,因此它兼有永磁同步电机和直流电机的优点,成本低,控制方法简单易实现,控制系统开发周期短,运行可靠性高等,在国民经济的各行业中得到广泛应用。然而无刷直流电机的特殊结构及控制方式也带来了难以克服的转矩脉动问题,严重阻碍了其位置和转速控制性能的进一步提高和发挥,无法满足一些高精度场合的性能要求。为此,本文围绕无刷直流电机的转矩脉动问题,开展转矩脉动抑制技术的研究工作。首先,在分析无刷直流电机工作原理的基础上,建立其数学模型,并借助Simulink /PLECS仿真工具,建立了无刷直流电机的控制系统仿真模型,验证了仿真模型的可行性,指出转矩脉动的存在。其次,分析了无刷直流电机转矩的特性,脉动产生的原因,以及转矩的影响因素。着重分析了换相过程中反电动势和电流对转矩脉动的影响,讨论了换相转矩脉动的主要产生机理。针对换相过程中的转矩脉动,在深入研究转矩脉动控制方法—换相角积分法的基础上,提出了换相电流控制法,以实现对换相转矩脉动的有效抑制,并对这两种方法进行了仿真验证和比较。最后,基于DSPACE实时仿真平台,开发了无刷直流电机控制系统的实验平台,将换相电流控制法应用到该系统中,实验验证了该方法的有效性。本文的研究对进一步提高无刷直流电机的控制性能,拓展其应用范围具有积极的理论研究意义和应用价值。更多还原

【Abstract】 Actually, the permanent magnet brushless DC motor (BLDCM) belongs to the family of permanent magnet synchronous motor. With its trapezoidal back-EMF waveform and rectangle current waveform, BLDCM combines the advantages of permanent magnet synchronous motor and DC motor together. BLDCM has been popular with various sectors in national economy because of its’low cost, achievable control method, short development period and high reliability. However, torque ripple problem due to the special structure and control method for BLDCM would seriously hamper further improvement of its performance in position and speed control, which make it unable to satisfy the requirements of some high-precision fields. Therefore, this paper carried out the research work in torque ripple suppression about the torque ripple in BLDCM.First of all, mathematical model was built based on the principle of BLDCM, and further constructed BLDCM control system using Simulink/PLECS, proving the feasibility of simulation model, point out the torque ripple existing. Secondly, this paper analyzed the characteristics of torque, causes of torque ripple, and influencing factors with torque in BLDCM. Particularity, Influences of back-EMF and current in commutation on torque ripple was emphatically analyzed. This paper also discussed main mechanism of torque ripple in commutation. To suppress torque ripple, the commutation current control method was proposed on the basis of commutation angle integral method. Compared with commutation angle integral method, this new method can inhibit torque ripple more effectively. Finally, BLDCM control system experiment platform was developed based on DSPACE real-time simulation platform. After brought commutation current control method into this control system, simulation results proved the validity of this method. The study in this paper has a positive theoretical meaning and application value for further enhancing control performance and expanding scope of application of brushless DC motor.更多还原