基于双滑模的永磁同步电机无传感器控制研究

发布时间：2018-08-17 09:34

【摘要】：永磁同步电机(7)PMSM(8)的构造简单且能够长时间可靠工作,使其被广泛应用于各个领域。PMSM调速系统在工程中存在内部参数摄动以及外部扰动等不确定性因素,为了实现PMSM的高性能控制,亟需进行PMSM控制方法的研究。为了提高PMSM控制系统的鲁棒性,提升调速系统性能,本文提出了一种基于双滑模控制策略的PMSM控制系统,分别设计了滑模速度控制器和滑模位置观测器,取代传统PMSM控制系统中的PI控制器和机械位置传感器。在对滑模速度控制器的设计中,为了提高动态品质,本文采用了基于趋近律的方法,在对等速趋近律产生抖振的原因进行分析的基础上设计了一种新型的具有时变切换增益的变指数趋近律滑模速度控制器。该方法通过在趋近律的等速项中加入时变系数构成时变切换增益,并且在指数项中引进状态变量的幂函数,加快了趋近速度,解决了等速趋近律不能兼顾快速性和削弱系统抖振的矛盾,使系统的动态性能得到改善了,提高了控制器的性能。滑模观测器可以通过测量PMSM的电压、电流来获得转子位置和转速信息,但是观测反电势中存在的高频噪声和纹波会直接影响到估测精度。因此,本文对传统滑模观测器做出了一系列改进,包括采用饱和函数、设计截止频率随转速变化的变截止频率低通滤波器、引入卡尔曼滤波器对反电势再次平滑滤波以及采用锁相环提取转子位置和转速信息等方法,经过改进的滑模观测器能够明显降低抖振,有效抑制了因测量误差和系统误差带来的干扰,得到了更加平滑的反电势信息,使得估测信息更准确,系统性能得到了较大程度的提高。最后根据本文所设计的控制方法,在MATLAB/simulink软件中完成了对PMSM调速系统的仿真验证。同时,搭建了以STM32F103芯片为核心的PMSM控制系统实验平台,并完成了系统的软件设计,仿真和实验结果证明了本文所提控制策略的有效性,达到了预期成果。
[Abstract]:The structure of permanent magnet synchronous motor (7) PMSM (8) is simple and can work reliably for a long time, which makes it widely used in various fields. PMSM speed control system has some uncertain factors, such as internal parameter perturbation and external disturbance. In order to realize the high performance control of PMSM, the research of PMSM control method is urgently needed. In order to improve the robustness of PMSM control system and improve the performance of speed regulating system, a PMSM control system based on double sliding mode control strategy is proposed in this paper. The sliding mode speed controller and the sliding mode position observer are designed respectively. Replace Pi controller and mechanical position sensor in traditional PMSM control system. In the design of sliding mode speed controller, in order to improve the dynamic quality, the approach based on approach law is adopted in this paper. Based on the analysis of the causes of buffeting in constant velocity approach law, a new sliding mode velocity controller with variable exponential approach law with time-varying switching gain is designed. In this method, the time-varying coefficient is added to the constant velocity term of the approach law to form the time-varying switching gain, and the power function of the state variable is introduced into the exponential term to accelerate the approach speed. The contradiction that the constant velocity approach law can not take into account the rapidity and weaken the chattering of the system is solved. The dynamic performance of the system is improved and the performance of the controller is improved. Sliding mode observer can measure the voltage and current of PMSM to obtain the information of rotor position and speed, but the high frequency noise and ripple in the observation of back EMF will directly affect the estimation accuracy. Therefore, a series of improvements have been made to the traditional sliding mode observer, including the design of low-pass filter with variable cutoff frequency with varying cutoff frequency by using saturation function. The modified sliding mode observer can reduce buffeting obviously by introducing Kalman filter to smoothing back EMF and extracting rotor position and rotational speed information by phase-locked loop (PLL). The interference caused by the measurement error and the system error is effectively suppressed, and more smooth back EMF information is obtained, which makes the estimation information more accurate and the system performance improved to a large extent. Finally, according to the control method designed in this paper, the simulation of PMSM speed control system is completed in MATLAB/simulink software. At the same time, the experimental platform of PMSM control system based on STM32F103 chip is built, and the software design of the system is completed. The simulation and experimental results show that the proposed control strategy is effective and achieves the expected results.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM341

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