【作者】 刘军；

【导师】 俞金寿；

【作者基本信息】 华东理工大学 ， 控制理论与控制工程， 2010， 博士

【摘要】 随着永磁材料、电力电子技术、先进控制技术的发展,永磁电动机由于结构简单、重量轻、体积小、损耗小、效率高等优点而引起人们的重视,并在国防、工农业生产和日常生活等方面获得越来越广泛的应用。根据永磁电动机感应电动势和驱动电流的不同,永磁电动机可以分为无刷直流电动机(Brushless DC Motor, BLDCM)和永磁同步电动机(Permanent Magnet Synchronous Motor, PMSM)。BLDCM由于功率密度高、控制简单、成本低等优点在电动汽车、家用电器等领域中被广泛应用,缺点是存在转矩脉动大、铁心附加损耗大,在高精度、高性能要求的伺服驱动系统中(尤其是低速直驱场合)的应用受到很大制约；PMSM由于具有功率因数高、动态响应快、调速范围宽且运行平稳、过载能力强等优点,逐步成为现代工业控制系统中驱动电机的主体,但其控制系统相对复杂,控制系统出现的各种问题一直是学者的研究焦点。论文在分析研究现有永磁电动机控制方式的基础上,对永磁电动机控制系统若干问题进行了较为深入研究,主要研究成果如下：1.在详细介绍无刷直流电动机结构、工作原理、数学模型以及三相六状态PWM控制方式的基础上,分析比较了五种PWM斩波方式的工作特点,给出了无刷直流电动机四象限运行的实现方法；针对制动时采用的低速能量回馈制动控制方法,提出了一种用来释放多余回馈能量的电压泵升电路,仿真和实验结果表明了电路的正确性和可行性。2.给出基于旋转坐标系dq坐标轴的永磁同步电机的各种矢量控制策略,并针对传统的速度调节器与位置调节器无法满足高性能永磁同步电动机快速动态响应的特点,提出在传统调节器的基础上,速度调节器引入变控制方式与微分负反馈相结合、位置调节器采用变控制方式的方法,仿真和实验结果均表明双变控制方式能够有效地优化系统的快速动态响应性能。3.从永磁同步电机的数学模型出发,着重分析了无位置传感器永磁同步电动机的控制方法。结合滑模变结构控制方法,设计了滑模状态观测器,实现永磁同步电机无传感器转子位置和速度进行估算；并通过测量电机的静态三相电感和电阻参数,给出计算永磁同步电机dq坐标系下电感参数(Ld、Lq)、相电阻rs及磁链系数Ψf计算方法,通过实验验证,该方法正确可行。4.针对无位置传感器永磁同步电机起动困难问题,从永磁同步电机数学模型及电稳态原理出发,建立永磁同步电机电稳态模型观测器,实现低速转子位置和转速估算,该方法可以有效地实现无位置传感器永磁同步电机稳定起动,具有算法简单、起动电流小、切换平滑、可靠性高等优点,实验结果表明了该方法的正确性和有效性。5.针对利用滑模变结构实现永磁同步电机无传感器矢量控制存在的滑模抖动问题,提出在反电动势输出端引入扩展卡尔曼滤波器,并引用饱和函数sat(s)代替符号切换函数sign(s),使得滑模观测器反电势波形更加平滑和准确,转子位置估算更加准确,仿真结果验证了算法的正确性和可行性。更多还原

【Abstract】 As the development of permanent magnetic materials and advanced control technology, permanent magnet motor draws people’s great attention by the advantage of its simple structure, smaller size, light weight, low loss, high efficiency and so on, and is also used more and more widely in industry, agriculture, national defense and daily life. According to the difference between induced electromotive force and drive current of permanent magnet motor, permanent magnet motor can be divided into permanent magnet brushless DC motor (Brushless DC Motor, BLDCM) and permanent magnet synchronous motor (Permanent Magnet Synchronous Motor, PMSM). BLDCM is applied great extensively into electric cars, home appliances and other control fields as the merit of its high power density, simple control and low cost, but also with the disadvantage of bigger torque ripple and large core excess loss. So, its application have much restrict in servo drive system with the requirements of high-precision and high performance (especially in low-speed direct drive occasions). Because of the excellence of its high power factor, fast dynamic response, wide speed range as well as stable operation, greater overload performance and so on, PMSM gradually becomes the main part of the drive motor in modern industrial control systems, but also with relatively complex control system. So, the various problems on PMSM control systems have benn highly concerned. Based on the analysis to the present control models of permanent magnet motor, profound research is carried on the several questions to permanent magnet motor control system in this paper, and the main research results are as follows:1. On the basis of having a explicit description about the structure, working principle, mathematical model, three-phase six-state PWM control mode of BLDCM, the characteristic of five kinds of chopped waves are analyzed and compared. Have given BLDCM out working four quadrants. Based on control method of adopting low-speed energy feedback in braking, a voltage pump-raised circuit is proposed to release excess feedback energy, and the simulation and experiment results both show correctness and feasibility of the circuit.2. Have given PMSM out various of vector control strategies based on rotary coordinates d-q axis. As conventional speed regulator and position regulator cannot meet the characteristic of fast dynamic response to high-performance PMSM, the method of variable structure combined with differential negative feedback as well as variable structure method are introduced respectively into speed regulator and position regulator. The simulation and experiment results both show that the dual variable structure control system can effectively optimize the fast dynamic response of the whole system.3. Taken the mathematical model of PMSM as the starting point, the control method of sensorless permanent magnet synchronous motor is analyzed profoundly. Sliding mode state observer is designed to achieve the estimation of permanent magnet synchronous motor rotor position and speed sensor, conbined with control method of sliding mode variable structure, and the strategy about inductance parameter(Ld,Lq) in dq coordinate system, phase resistance rs and the flux factor (?)f are calculated according to measuring the static three-phase motor inductance and resistance parameters of PMSM. The experimental results show that the method is feasible.4. For the starting difficulties about sensorless PMSM, steady-state model of PMSM is established to realize the estimation of low speed rotor position and velocity so as to complete permanent magnet synchronous motor starting process. This method can effectively achieve steady start of sensorless permanent magnet synchronous motor with a simple algorithm, starting current, switching smooth, high reliability, and experimental results show that the method is correct and effective5. For the probem of sliding mode shaking about using sliding variable structure to realize permanent magnet synchronous motor sensorless vector control, Kalman filter is applied at the output of EMF. Then, sign switching function sign(s) is replaced by saturation function sat(s), so as to make sliding observer-EMF waveform become more smooth and accurate, and also more suitable for high performance applications. Smulation results show the method is correct and feasible.更多还原