感应电机全阶磁链观测器设计及其控制性能对比分析

Design of full-order flux observer and comparision analysis for its control performance

针对以往在感应电机无速度传感器矢量控制中,全阶磁链观测器均是以静止坐标系下状态变量进行设计的,其基于欧拉法的离散化过程估算误差大,若采用梯形法、双线性法或龙格-库塔法,估算误差有所减小,但计算过程复杂,不适宜工程应用。提出以同步旋转坐标系下的定子电流和转子磁链作为状态变量来设计全阶磁链状态观测器,其离散化过程采用工程上常用的欧拉法,计算量小。同时给出了基于两种坐标系下全阶磁链观测器转速估算自适应律设计方法。仿真分析和实验结果对比表明,在低速和高速状态下,同步旋转坐标系下设计的状态观测器电流和转速估算准确快速,可以明显提高系统控制的精确性和实用性。

The full-order flux observer was designed based on the static coordinate state variable in the speed sensorless vector control system of induction motor in the past. If the full-order flux observer is discretized by the Euler method,the estimation error is big. If the Trapezoidal method,Bilinearity method or Runge Kutta method are used,the estimation error is reduced,but the calculation process is so complex and it is not suitable for engineering application. It was proposed that the full-order flux observer was designed based on synchronous rotating coordinate and the stator current and rotor flux are as the state variables. It was discretized by the euler method which is commonly used in engineering,and the amount of calculation is small. At the same time the speed estimation adaptive laws based on the two kinds of full order flux observers were designed. Simulation analysis and comparison of the experimental results show that the current and speed estimation are accurate and fast with the full-order flux observer of synchronous rotating coordinate. The accuracy and practicability of the control system can be significantly improved.