永磁同步电机改进滑模观测器矢量控制

Improved sliding mode observer vector control for permanent magnet synchronous motors

针对滑模观测器在永磁同步电机无位置传感器控制系统存在的高抖振、收敛速度较慢、观测精度差等问题,提出一种基于自适应滑模增益的变幂次趋近律的新型滑模观测器,该趋近律在幂次趋近律的基础上,增加由观测转速、磁链和外部输入预期目标电流误差组成的自适应滑模增益变指数项,自适应滑模增益变指数项具有时变的较快收敛速度,有效解决原有趋近律趋近模态时间过长的问题,使用李雅普诺夫稳定判据对系统进行了稳定性分析。通过新型滑模观测器和传统滑模观测器进行对照实验,结果表明,相对比较而言所提出的新型滑模观测器收敛速度更快,高频抖振削弱和带载能力加强,自适应滑模增益能有效控制电流误差幅值,最后观测精度提高了20%以上。

Aiming at the problems of high chattering,slow convergence speed and poor observation accuracy of sliding mode observer in permanent magnet synchronous motor position sensorless control system,a new sliding mode observer based on adaptive sliding mode gain variable power reaching law is proposed.Sliding mode observer,this reaching law adds an adaptive sliding mode gain variable exponential term consisting of the observed rotational speed,flux linkage and external input expected target current error on the basis of the power reaching law.The exponential term has a fast time-varying convergence rate,which effectively solves the problem that the original reaching law takes too long to reach the modal.The stability of the system is analyzed by Lyapunov stability criterion.Control experiments were carried out with the new sliding mode observer and the traditional sliding mode observer,the results show that the proposed new sliding mode observer has faster convergence speed,it can weaken high-frequency chattering and enhance load carrying capacity,and the adaptive sliding mode gain can effectively control the current error amplitude,Finally,the observation accuracy is improved by more than 20 percent.