基于滑模观测器的内永磁同步电机无位置传感器控制

发布时间：2018-11-11 08:32

【摘要】：永磁同步电机无位置传感器控制技术能够降低系统成本,增强系统的可靠性,因此成为电机控制领域的研究热点。本文主要针对适用于高速的滑模观测器法进行了研究,采用适用于零速和低速的高频电压注入法估计转子初始位置并起动,然后选择合适的切换方式实现低速区到高速区的平滑衔接。首先,根据内永磁同步电机的高频数学模型,通过脉振电压注入并解调高频响应电流,提取出转子磁极位置；然后根据定子铁心饱和磁化特性,采用脉冲电压注入并比较响应电流的峰值,判断出转子磁极极性,从而实现零速和低速时转子磁极角度及转速的检测。其次,根据内永磁同步电机的基频数学模型,利用滑模变结构原理,设计了基于扩展反电动势的内永磁同步电机滑模观测器。通过以边界层可变的饱和函数代替符号函数,减小了滑模抖振；通过采用一种转折频率随转速实时调整的自适应数字低通滤波器,使得观测器在不同转速时的角度滞后值恒定,从而实现高速时转子磁极角度及转速的观测并具备良好的动态观测性能。最后,根据设计方案搭建了内永磁同步电机无位置传感器控制的软硬件平台,并通过实验对理论推导进行验证。实验结果表明：高频电压注入法的估计结果精度较高,可以使电机在零速时可靠起动并在低速区稳定运行；改进的滑模观测器改善了系统的动态性能,可以使电机在高速区稳定运行;所选定的切换点及切换方式保证了两种估计方法的平滑衔接,从而实现完整的无位置传感器矢量控制。
[Abstract]:The position sensorless control technology of permanent magnet synchronous motor (PMSM) can reduce the cost of the system and enhance the reliability of the system, so it has become a research hotspot in the field of motor control. In this paper, the sliding mode observer method suitable for high speed is studied. The high frequency voltage injection method, which is suitable for zero speed and low speed, is used to estimate the initial position of rotor and start. Then choose the appropriate switching mode to realize the smooth connection from the low speed region to the high speed zone. Firstly, according to the high frequency mathematical model of the inner permanent magnet synchronous motor, the rotor pole position is extracted by injecting and demodulating the high frequency response current. Then according to the saturation magnetization characteristics of stator core the polarity of rotor magnetic pole is determined by injecting pulse voltage and comparing the peak value of response current so as to realize the detection of rotor pole angle and rotation speed at zero speed and low speed. Secondly, according to the fundamental frequency mathematical model of inner permanent magnet synchronous motor and the principle of sliding mode variable structure, the sliding mode observer of internal permanent magnet synchronous motor based on extended backEMF is designed. The sliding mode chattering is reduced by replacing the symbolic function with the boundary layer variable saturation function. By adopting an adaptive digital low-pass filter, which adjusts the turning frequency with the rotation speed in real time, the angle lag value of the observer at different rotational speeds is constant. Thus, the rotor pole angle and rotational speed can be observed at high speed and have good dynamic observation performance. Finally, the hardware and software platform of position sensorless control of PMSM is built according to the design scheme, and the theoretical derivation is verified by experiments. The experimental results show that the high frequency voltage injection method has a high accuracy and can make the motor start reliably at zero speed and run stably in the low speed region. The improved sliding mode observer can improve the dynamic performance of the system and make the motor run stably in the high speed region. The selected switching points and switching methods ensure the smooth connection of the two estimation methods, thus the complete sensorless vector control is realized.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM341

【参考文献】