无刷直流电机无位置传感器控制系统的研究与设计

发布时间：2018-05-07 06:38

本文选题：BLDCM + 无位置传感器　；参考：《西安科技大学》2017年硕士论文

【摘要】：无刷直流电机(Brushless DC Motor,BLDCM)因其结构简单、调速性能好、运行可靠,在家电、电动车和工业等领域得到了广泛应用。BLDCM无位置传感器控制省略了位置传感器,避免了位置传感器安装使用带来的不利影响,因此受到人们的极大关注。本文以电动三轮车用BLDCM为被控对象,对BLDCM无位置传感器控制系统进行分析与研究。本文首先对BLDCM的组成结构和工作原理进行研究,且推导了其数学模型。并对BLDCM的机械特性和调速特性进行研究与分析,为后续BLDCM无位置传感器控制系统的设计奠定了理论基础。其次,针对电动车负载大小的不确定性,对于不同转速下反电势过零点产生的移相问题,通过理论分析与实验验证,得出了补偿角的拟合曲线,有效提高了转子检测的精度。针对BLDCM无位置传感器控制系统在静止或低速时启动困难的问题,通过转子二次定位方式,提高转子位置定位的准确性;采用软件升频升压方式使电机外同步加速,不依赖硬件电路,实现了电机带负载启动能力的提升,启动过程中实时检测电流大小,避免因长时间通过大电流而损坏系统;电机启动过程中检测反电势过零点信号,当连续k次检测到反电势过零点信号,系统由外同步加速切换到自同步运行状态。针对BLDCM换相转矩脉动问题,设计了一种基于Cuk变换电路的转矩脉动抑制方法,根据Cuk变换电路升降压的特点,改变母线电压大小,从而抑制换相转矩脉动。最后,采用LabVIEW建立了 BLDCM无位置传感器控制系统仿真模型,验证了系统的可行性。通过设计无位置传感器控制系统硬件电路和软件功能模块,搭建了电动三轮车控制系统实验平台,并进行了实验测试。实验结果验证了本文所设计的复合式启动方法和反电势过零点移相补偿方法的可行性和合理性。
[Abstract]:Brushless DC Motor BLDCM (Brushless DC Motor) is widely used in household appliances, electric vehicles and industry because of its simple structure, good speed regulation and reliable operation. Avoid the adverse effect of position sensor installation and use, so people pay great attention to it. In this paper, the position sensorless control system of BLDCM for electric tricycle is analyzed and studied. In this paper, the composition and working principle of BLDCM are studied, and its mathematical model is derived. The mechanical characteristics and speed regulation characteristics of BLDCM are studied and analyzed, which lays a theoretical foundation for the design of the subsequent BLDCM position sensorless control system. Secondly, aiming at the uncertainty of the load size of electric vehicle, the phase shift problem caused by the zero crossing point of reverse EMF at different speed is analyzed and verified by theory and experiment, and the fitting curve of compensation angle is obtained, which effectively improves the precision of rotor detection. In view of the difficulty of BLDCM position sensorless control system starting at rest or at low speed, the accuracy of rotor position location is improved by means of secondary rotor positioning mode, and the external synchronous acceleration of motor is made by using the method of increasing frequency and voltage by software. Independent of the hardware circuit, it can improve the starting ability of the motor with load, detect the current size in real time during the starting process, avoid damaging the system through the large current for a long time, detect the zero crossing signal of the back EMF in the starting process of the motor. When the backEMF zero-crossing signal is detected continuously for k times, the system changes from external synchronization to self-synchronous operation. Aiming at the problem of commutation torque ripple of BLDCM, a torque ripple suppression method based on Cuk transform circuit is designed. According to the characteristic of Cuk transform circuit, the voltage of bus is changed to restrain commutation torque ripple. Finally, the simulation model of BLDCM sensorless control system is established by using LabVIEW, which verifies the feasibility of the system. By designing the hardware circuit and software function module of the sensorless control system, the experimental platform of the electric tricycle control system is built, and the experimental test is carried out. The experimental results verify the feasibility and rationality of the compound starting method and the inverse EMF phase shift compensation method designed in this paper.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM33;TP273

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