【作者】 陈强；

【导师】 沈安文；

【作者基本信息】 华中科技大学 ， 控制理论与控制工程， 2007， 硕士

【摘要】 70年代提出的细分控制较好的解决了电机在开环控制下常常出现的低频振动,运行时输出力矩下降,定位精度受电机自身影响等问题。本文以三相混合式步进电机为控制对象,在分析了细分控制原理的基础上,数字化实现了步进电机的步距角细分控制。首先分析了步进电机在细分状态下的磁场特点,步进电机在通入正弦阶梯电流时的离散磁场与永磁同步电机的连续磁场有相似之处。从步进电机的结构和运行原理出发,在一定的假设条件下,步进电机可以看作是多极的低速同步电机。在整个控制系统的实现上,借鉴交流电机的电流控制方法,将步进电机细分控制时的正弦阶梯电流通过同步旋转坐标变换成直流量进行控制,同时采用广泛应用于交流电机的SVPWM调制方式减小电流谐波和噪声。然后利用仿真软件Matlab/Simulink搭建了基于转子磁场定向的步进电机数学模型,并在不同频率的给定下,分析了步进电机的电流响应与转子位置响应曲线。最后在以DSP TMS320LF2407A为控制器核心的硬件平台上实现了电机的正弦电流步距角细分控制。通过实验证明了方案的可行性,取得了较为理想的电流波形。更多还原

【Abstract】 At 70s the subdivision control of stepping motors was proposed to solve the problems such as resonance, output torque reducing and low accuracy when the stepping motor is running at open-loop. This thesis mainly analyzes the theory of subdivision and realizes the subdivision of the three phase hybrid stepping motors with digital control.Firstly, this thesis study the characteristic the magnetic filed and stator current of stepper between the PMSM and stepping motors, which indicates that they are similar. From the structure and operation principle and in a certain assumption, the stepping motor can consider as a PMSM running at low speed. When subdivision is adopted, the current in the stator is sinusoidal. Reference on the AC variable speed theory, the sinusoidal current in the stator can transform into direct current through rotational coordinate transform. The modulation policy is SVPWM which is widely adopted in AC motors control to reduce current harmonics and noise. Secondly, with the simulation software Matlab/Simulink, the model of the stepping motor is established base on the d-q coordinate. When the different frequency and step angle are set, the responses curves of current in the stator and the position of the rotor are analyzed. The simulation shows that the method is effective. Finally, with the TI DSP TMS320LF2407A as the controller, the subdivision of the stepping motor is realized. Some suggestions are made to make improvements.更多还原