低速段异步电动机直接磁场定向控制

Low Speed Direct Field Oriented Control on Induction Motor

为了改善交流异步电动机无速度传感器控制系统低速运行时转速脉动的问题,采用直接磁场定向控制算法.该算法利用电流模型磁链观测器与反电势积分模型相结合的方法对电动机转子磁链的幅值和相位进行检测,并通过电流模型对转子转速进行辨识构成速度反馈回路.仿真结果表明,所采用的异步电动机直接磁场定向控制可以提高电动机的动态响应速度,使电动机有较好的参数不敏感性,能够在低速运行时取得较好的动静态性能.电流模型与反电势积分模型相结合的磁链观测方法,能够使交流异步电动机无速度传感器控制系统在高速及低速运行时都具有良好的动静态性能,增加了电动机的有效调速范围.

The direct field oriented control was adopted to improve motor＇s low speed problem of speed ripple.Based on this method,the combination way of current model flux observer and emf was used to estimate the flux amplitude and thd phase of rotor,and the speed feedback loop formed by current model was used to estimate the rotor speed.As is showed in the simulation results,the method of direct field oriented control of induction motor can improve the dynamic response speed of motor,make motor have better parameters insensitivity,and acquire better static,dynamic performance when motor moves at low speed.The method of flux observer combining current model and emf can make induction motor speed sensorless control system have good static,dynamic performance at high and low speed,which increases the effective speed range of the motor.