基于变频器的异步电机离线参数辨识

摘要

分析了基于变频器控制的异步电机参数辨识方案.对传统测定子电阻的直流试验方法进行改进,提出了一种消除功率开关器件压降影响的定子电阻辨识方法.通过向电机施加单相电压信号,得到了电机参数的计算公式.针对单相试验中电机定子电流准幅值和相位的对电机参数精确估计的需求,提出了一种基于离散傅里叶变换测量电机定子电流幅值与初始相位的方法,所述算法考虑到由于非同步测量误差以及频谱泄漏和栅栏效应引起的离散傅里叶变换计算误差的修正问题.MATLAB/Simulink仿真结果证实了所提方法的有效性.%A motor parameter identification method to asynchronous motor controlled by frequency converter was proposed. First, an improved method was proposed to identify the stator resister, compared with the traditional DC test new method could eliminate the influence of voltage drop caused by power switching device. Second, the calculate formula of motor' s parameter could be deduced by excite a single-phase signal to motor. Since the accurate value of motor stator current's amplitude and initial phase obtained through single-phase test was essential, a method based on DFT theory was proposed to calculate those values. Considering the errors caused by asynchronous measurement and DFT calculation process, an improved method based on DFT theory to calculate the stator current' s amplitude and initial phase was proposed. To confirm the validity of this method, a simulation model was built on the MATLAB/ Simulink environment and the result proved the effectiveness of this method.