基于双旋转坐标的永磁同步电机无速度控制切换方法

Switching Method for Sensorless Control of Permanent Magnet Synchronous Motor Based on Double Rotating Coordinates

针对永磁同步电机无速度反馈控制在全速范围内存在开环和闭环切换的问题,本文提出了切换时对电流和电压矢量采用双旋转坐标轴的控制方式。通过电压矢量偏移,使控制系统内同时存在电流和电压双旋转坐标。该方案在采用反电动势作为转速估计的应用场合下,开环控制时能保证轴电压矢量接近真实闭环值。从而使估算的电机速度逼近真实值,最大限度降低电机运行过程中因两种控制算法切换而造成的不稳定现象。通过分析和实验相结合的方式验证了此方案的有效性,使电机在流频法控制下顺利切换到假定旋转坐标法的闭环控制,具有较强的通用性和鲁棒性。

In order to solve the switching problem used sensorless speed control of permanent magnet synchronous motor,a double rotating coordinates control scheme for current and voltage vectors was proposed.This method controls different current and voltage vector angles in the double rotating coordinates.When the back-EMF was used as speed estimation,the scheme can ensure that the voltage vector was closed to the real closed-loop value.Then the estimated speed approximated the actual value,which can minimize the system instability caused by the switching process between two control algorithms.The validity of this scheme was verified by theoretical analysis and experiment,and this scheme can make the speed control switching smoothly from I/F to the closed-loop control,and the proposed scheme has the advantages of the versatility and robustness.