一种感应电机磁链观测器的稳定性研究及改进

Stability improvements for closed-loop flux observer of induction machine

基于电压电流模型的闭环磁链观测器在无速度传感器感应电机矢量控制中获得了良好的控制性能,且具有较小的参数敏感性,但在低速发电模式下存在部分不稳定区域,导致电机在该区域不能正常运行。根据对该闭环磁链观测器稳定性分析及其对应不稳定区域条件,本文提出了一种改进方法使之能够在在低速发电模式下稳定运行。仿真和实验都证明了该改进方法的有效性和实用性。

Accurate flux estimation is essential in the speed sensorless vector control system of induction machine.The reduced order flux observer （including the voltage mode and current mode flux observer） has the advantages of both simple structure and reduced sensitivities of parameters.However,the pure voltage mode flux observer has the integral problem whereas the pure current mode flux observer needs the speed information.The voltage and current model based closed-loop flux observer combines the voltage mode and current mode flux observers together and obtains good control performance with small parameter sensitivity but has some drawbacks in the stability characteristics under the low-speed generation mode,thus the motor cannot run normally in this region.Based on the stability analysis of the flux observer and the corresponding conditions,this paper proposes a reasonable method to eliminate the unstable region.Both simulation and experimental results show validity and effectives of this proposed method.