基于滑模观测器的永磁同步电机无位置传感器控制策略研究

发布时间：2018-06-24 17:07

本文选题：永磁同步电机 + 无位置传感器　；参考：《北京交通大学》2017年硕士论文

【摘要】：获取准确的转子位置及速度信号对于实现永磁同步电机闭环控制十分关键。传统的机械式传感器会增加系统成本,对使用环境也有限制,因此在工业应用中需要一种成本低、可靠性高的无位置传感器控制技术来实现对转子位置和速度的准确估计。滑模观测器方法由于对系统外界扰动和内部参数变化不敏感,具有较强的鲁棒性,因此可以满足参数变化频繁、动态性能要求较高的永磁同步电机调速系统的需求。针对滑模观测器方法中存在的高频抖振和相位滞后等问题,本文对其进行了改进,并提出了转子位置估计精度指标,实现了永磁同步电机在无位置传感器情况下的电机调速控制。首先建立了基于扩展反电动势的滑模观测器数学模型,并对传统滑模观测器转子位置估计原理进行了分析。为解决传统方法中存在的抖振严重和相位滞后等问题,本文采用连续函数作为控制函数,将低通滤波器改进为具有自适应结构的反电动势观测器,并结合锁相环系统完成了对传统滑模观测器方法的改进。改进后的滑模观测器抖振现象得到削弱,相位滞后问题得到改善,转子位置估计精度得到提高。通过理论推导和仿真分析验证了观测器的鲁棒性。基于5.5kW功率等级的永磁同步电机矢量控制系统,研究了瞬时转子误差对矢量控制系统的影响。以转子误差角作正弦振荡为特例,分析了误差角振幅与电磁转矩脉动振幅之间的关系。为使此系统在不同工况下都能保持良好的控制性能,考虑了电流iq不同时转子误差角振荡对电磁转矩的影响。以自动控制理论为基础,提出了无位置传感器控制下的转子位置估计精度指标。最后本文依托Myway系统永磁同步电机实验平台,进行了基于滑模观测器的永磁同步电机无位置传感器控制实验。首先进行了启动、恒速空载和变速空载观测实验,验证了该方法良好的观测性能;其后对滑模观测器的鲁棒性进行了实验验证;为证明改进型滑模观测器的转子位置估计精度高于传统方法,进行了对比实验;最后将估计的转子位置和转速作为反馈量,实现了无位置传感器闭环控制。实验结果表明,本文提出的基于滑模观测器的永磁同步电机无位置传感器控制策略,估计精度高,动态性能良好,鲁棒性较强,可以实现对转子位置和转速的准确观测。
[Abstract]:Obtaining accurate rotor position and speed signals is very important to realize the closed loop control of PMSM. Traditional mechanical sensors will increase the cost of the system and limit the use of the environment. Therefore, a low cost and high reliability sensorless control technology is needed to accurately estimate the rotor position and speed in industrial applications. The sliding mode observer method is insensitive to the external disturbance and internal parameter change of the system, so it can meet the requirements of the PMSM speed control system with frequent parameter changes and high dynamic performance. In order to solve the problems of high frequency buffeting and phase delay in sliding mode observer, this paper improves it, and presents the precision index of rotor position estimation. The speed control of permanent magnet synchronous motor (PMSM) without position sensor is realized. Firstly, the mathematical model of sliding mode observer based on extended backEMF is established, and the principle of rotor position estimation of traditional sliding mode observer is analyzed. In order to solve the problems of serious buffeting and phase delay in traditional methods, the continuous function is used as the control function, and the low-pass filter is improved to a self-adaptive backEMF observer. The traditional sliding mode observer method is improved by the PLL system. The chattering phenomenon of the improved sliding mode observer is weakened, the phase lag problem is improved, and the rotor position estimation accuracy is improved. The robustness of the observer is verified by theoretical derivation and simulation analysis. Based on the vector control system of permanent magnet synchronous motor (PMSM) with 5.5 kW power level, the effect of instantaneous rotor error on the vector control system is studied. The relationship between the amplitude of error angle and the amplitude of electromagnetic torque ripple is analyzed by taking the sinusoidal oscillation of rotor error angle as a special case. In order to keep good control performance under different operating conditions, the effect of rotor error angle oscillation at different current / iq on electromagnetic torque is considered. Based on the theory of automatic control, the precision index of rotor position estimation under sensorless control is proposed. Finally, based on the permanent magnet synchronous motor (PMSM) experiment platform of Myway system, the sensorless control experiment of PMSM based on sliding mode observer is carried out. At first, the experiments of no-load observation with constant speed and no load with variable speed are carried out to verify the good performance of the method, and the robustness of the sliding mode observer is verified by experiments. In order to prove that the rotor position estimation accuracy of the improved sliding mode observer is higher than that of the traditional method, a comparative experiment is carried out. Finally, the estimated rotor position and speed are taken as feedback variables to realize the sensorless closed-loop control. The experimental results show that the proposed sensorless control strategy of PMSM based on sliding mode observer has high estimation accuracy, good dynamic performance and strong robustness. It can realize accurate observation of rotor position and speed.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM341

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