异步电机无速度传感器控制系统中磁场跟踪控制器设计

Magnetic Field Tracking Controller in Speed Sensorless Induction Motor Drive

在基于转子磁场定向的无速度传感器矢量控制系统中,利用电机稳态电压方程推导出同步角速度来获取电机磁场位置信息既简单又可节约成本。针对瞬态过程该计算不够准确的缺点,本文提出一种通过电流注入来获取磁场角度实际值与估算值之间误差的方法。向估算磁场方向注入一定频率与幅值的正弦电流,当磁场角度估算值偏离实际值时,根据电机的机械特性及电磁关系,电机的反电动势信号中含有一个与角度误差有关的分量,提取该分量并设计一种磁场跟踪控制器来有效地对该误差进行补偿使得估算磁场位置能够快速地跟踪电机实际磁场。将该方法用于无速度传感器矢量控制系统中进行低速仿真实验,结果表明有比较好的控制效果,有一定的应用前景。

In rotor flux oriented speed sensorless vector control system,the steady state equations based synchronous angular speed deduction method is both simple and cost saving to obtain the magnetic field position.For the disadvantage of inaccuracy in transient state,a method of angle error acquisition between practical and estimated magnetic field is proposed by means of current injection in this paper.Inserting sine current of some frequency and amplitude in the direction of the estimated magnetic field,when the estimated angle deviates from the actual one,the electromotive force of motor will contain a component related with the angle error according to the mechanical characteristics and electromagnetic relation of motor.The angle error can be effectively compensated by extracting the component and designing a magnetic field tracking controller so that estimated magnetic field position can fast track the practical one.Applied in speed sensorless low speed drive system simulation,the method makes satisfactory results and has some application prospects.