永磁同步电机无位置传感器快速启动方法研究

发布时间：2018-03-07 04:15

本文选题：永磁同步电机　切入点：矢量控制　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：永磁同步电机采用永磁体产生气隙磁通而不需要额外励磁,具有功率密度高、体积小、重量轻等独特优点,被广泛运用于许多工业应用中。当前永磁同步电机传动系统采用的控制方法主要是矢量控制和直接转矩控制,这两种方法都可以实现对电机转速和转矩的精确控制,从而获得优良的调速性能,但是都不可避免需要得到精确的转子位置信息。转子位置可由机械式传感器测得,但机械式传感器的安装增加了系统的成本和复杂程度,降低了系统的稳定性和抗干扰能力。因此永磁同步电机的无位置传感器控制成为了当前电机控制领域的热点课题,而在无位置传感器条件下的启动则是这一研究课题的难点。本文主要针对永磁同步电机无位置传感器快速启动方法展开相关研究。首先,简要介绍永磁同步电机的无位置传感器控制策略和常用的无位置传感器启动方法,建立永磁同步电机的数学模型,分析永磁同步电机矢量控制及基于滑模观测器的无位置传感器控制。其次,主要研究永磁同步电机在无位置传感器条件下的启动方法,按照三段式的方法实现电机启动,分别研究转子初始位置定位、开环加速、状态切换三个阶段。在转子初始位置定位阶段本文提出一种改进的电压矢量注入法,相比较于传统的电压矢量注入法,本文在第二批电压矢量后给电机施加一对方向相反的电压矢量,幅值和作用时间比前两批矢量都有所增加,导致响应电流对d轴N/S极增去磁作用更加明显,可以避免转子磁极判断错误;另外,在对第二批电压矢量的响应电流进行处理时,利用其反方向电感的差异对电流判断结果进行验证,确保电流判断结果的准确性。在开环加速阶段采用I-F速度开环、电流闭环控制方式,保证电机良好的动态性能。在状态切换阶段采用基于电流幅值变化的策略,本文提出一种电流按变化斜率递减的控制方法,状态切换过渡过程后期电流变化斜率慢于过渡过程前期,在保证状态切换点时刻电流无明显波动的前提下大大缩短过渡过程时间,实现电机从开环控制方式向双闭环控制方式的平滑切换。最后,在MATLAB环境下对开环加速和状态切换过程进行建模,同时构建以TI公司的TMS320F2808为主控芯片的实验平台对改进的电压矢量注入法以及在开环加速、状态切换的控制策略进行实验验证。仿真和实验结果证明了本文所提控制策略的有效性和可行性,可以实现永磁同步电机在无位置传感器条件下快速平滑启动,具有较高的工程实用价值。
[Abstract]:Permanent magnet synchronous motor uses permanent magnet to produce air gap flux without additional excitation. It has the advantages of high power density, small size, light weight and so on. It is widely used in many industrial applications. At present, the main control methods are vector control and direct torque control, both of which can achieve accurate control of motor speed and torque. In order to obtain excellent speed regulation performance, it is inevitable to obtain accurate rotor position information. The rotor position can be measured by mechanical sensor, but the installation of mechanical sensor increases the cost and complexity of the system. Therefore, the sensorless control of permanent magnet synchronous motor (PMSM) has become a hot topic in the field of motor control. The starting of PMSM without position sensor is the difficulty of this research topic. This paper mainly focuses on the PMSM position sensorless quick start method. First of all, This paper briefly introduces the sensorless control strategy of permanent magnet synchronous motor (PMSM) and the commonly used sensorless starting method, and establishes the mathematical model of PMSM. The vector control of PMSM and the sensorless control based on sliding mode observer are analyzed. Secondly, the starting method of PMSM under sensorless condition is studied, and the starting method of PMSM is realized according to the three-stage method. In this paper, an improved voltage vector injection method is proposed in the rotor initial position positioning phase, which is compared with the traditional voltage vector injection method. In this paper, a pair of opposite direction voltage vectors are applied to the motor after the second batch of voltage vectors, the amplitude and the action time are increased than those of the previous two batches, which results in a more obvious demagnetizing effect of the response current on the d axis N / S pole. In addition, when the response current of the second batch voltage vector is processed, the result of current judgment is verified by using the difference of the inductor in the opposite direction. In the open-loop acceleration stage, I-F speed open-loop and current-closed-loop control are adopted to ensure the motor's good dynamic performance. In the state switching phase, the strategy based on the change of current amplitude is adopted. In this paper, a control method of decreasing current with varying slope is proposed. The slope of current change in the late stage of state switching is slower than that in the early stage of transition. On the premise of no obvious fluctuation of current at the state switching point, the transition time is greatly shortened, and the smooth switching of motor from open-loop control mode to double-closed-loop control mode is realized. Finally, The open loop acceleration and state switching process are modeled in MATLAB environment. At the same time, the improved voltage vector injection method and the open loop acceleration are constructed using TI's TMS320F2808 as the main control chip. The simulation and experimental results show that the proposed control strategy is effective and feasible, and the PMSM can start smoothly and quickly under sensorless conditions. It has high engineering practical value.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM341

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