永磁电机低载波比无传感器控制策略研究

发布时间：2018-10-26 09:57

【摘要】：随着功率电路和永磁材料的发展,永磁同步电机因其高功率密度、高效率、可靠性好等优点取代感应电机在工业和生产生活中得到应用。近些年电力电子技术和微电子技术发展迅速,在中小功率场合逆变器的开关频率得到提高。但是在某些大功率应用中,受开关损耗等原因的限制,逆变器开关频率仍然无法提高。另一方面高速永磁同步电机投入工业使用,使得永磁同步电机低载波比控制策略成为热点。在低载波比条件下,受到电流环耦合效应影响,电机的动态性能受到限制。同时,转子位置观测器的设计需要考虑延时和离散化方式对观测精度的影响。因此,本文对永磁电机低载波比无传感器控制策略进行研究,针对电流控制器和转子位置和转速状态观测器进行研究并改进。首先本文在连续域内对三种坐标系下的永磁同步电机的数学模型进行构建。然后在扩展反电动势概念的基础上建立电机复矢量模型。通过在连续域内对电机复矢量模型的微分方程求解,推导出旋转坐标系下内置式永磁同步电机的离散化数学模型。并以此为基础,开展后续研究工作。本文分析了耦合对于矢量控制的影响,并对解决策略进行研究。通过零极点分布图和伯德图,对传统PI控制器、前馈解耦电流控制器、反馈解耦电流控制器以及复矢量电流控制器进行了理论分析。仿真和实验结果都证明,在相同的控制器参数下复矢量电流控制器解耦性能优于其他控制器。为提高转子位置和转速的观测精度,本文研究了低载波比条件下的转子位置观测方法。相比于传统连续域设计观测器后再离散化的方法,本文研究了直接在离散域内设计观测器的方法。并通过实验对两种方法进行了对比。此外,本文使用了双采样双更新和数字系统延时补偿的策略以降低低载波对控制系统的负面影响。最后,通过Matlab/Simulink仿真和基于ARM平台的永磁同步电机对拖平台上实验,实现永磁同步电机低载波比无传感器运行。对比低载波比时传统PI控制器、反馈解耦、前馈解耦及复矢量电流控制器的解耦性能,验证复矢量解耦效果最优。并且在采用双采样双更新和延时补偿策略后实现离散域内转子位置观测器设计,实验结果表明所设计观测器对转子位置和转速的估测精度明显提高。
[Abstract]:With the development of power circuit and permanent magnet materials, permanent magnet synchronous motor (PMSM) has been used in industry and production because of its advantages of high power density, high efficiency and good reliability. In recent years, power electronics and microelectronics technology have developed rapidly, and the switching frequency of inverter in medium and small power situations has been improved. However, in some high power applications, the switching frequency of the inverter can not be improved due to the switching loss and other reasons. On the other hand, the high speed permanent magnet synchronous motor (PMSM) has been put into industrial use, which makes the low carrier ratio control strategy of PMSM a hot spot. Under the condition of low carrier ratio, the dynamic performance of the motor is limited by the current loop coupling effect. At the same time, the design of rotor position observer needs to consider the effect of delay and discretization on the observation accuracy. Therefore, the low carrier ratio sensorless control strategy of permanent magnet motor is studied in this paper, and the current controller and rotor position and speed state observer are studied and improved. Firstly, the mathematical model of PMSM in three coordinate systems is constructed in the continuous domain. Then the complex vector model of motor is established on the basis of extending the concept of backEMF. By solving the differential equation of complex vector model in continuous domain, the discretization mathematical model of built-in permanent magnet synchronous motor in rotating coordinate system is derived. And on this basis, carry out follow-up research work. In this paper, the effect of coupling on vector control is analyzed, and the solution strategy is studied. The traditional PI controller, feedforward decoupling current controller, feedback decoupling current controller and complex vector current controller are theoretically analyzed by zero-pole distribution diagram and Byrd diagram. The simulation and experimental results show that the decoupling performance of the complex vector current controller is better than that of other controllers under the same controller parameters. In order to improve the measuring accuracy of rotor position and rotation speed, the rotor position observation method under low carrier ratio is studied in this paper. Compared with the conventional method of discrete observer design in continuous domain, the method of designing observer directly in discrete domain is studied in this paper. The two methods are compared by experiments. In addition, the dual sampling dual update and digital system delay compensation are used to reduce the negative effects of low carrier on the control system. Finally, through the Matlab/Simulink simulation and the experiment on the PMSM pair drag platform based on ARM platform, the low carrier ratio sensorless operation of PMSM is realized. The decoupling performance of traditional PI controller with low carrier ratio, feedback decoupling, feedforward decoupling and complex vector current controller is compared to verify the optimal decoupling effect of complex vector decoupling. The design of rotor position observer in discrete domain is realized by using dual sampling double update and delay compensation strategy. The experimental results show that the precision of rotor position and speed estimation is improved obviously.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM351

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