基于虚拟电压注入的闭环磁链观测器的感应电机无速度传感器矢量控制系统

Induction Motor Speed Sensorless Vector Control System Based on Closed-Loop Flux Observer with Virtual Voltage Injection

多年来,感应电机无速度传感器矢量控制系统在低同步转速区域的不稳定问题一直没有得到解决。该不稳定问题由系统状态变量不能观、极点分布不稳定以及电机参数鲁棒性弱共同导致。当且仅当三个问题被同时解决时,低同步转速区域的不稳定问题才能够得到解决。该文以经典的闭环磁链观测器为基础,采用虚拟电压注入法改进其低速稳定性。与传统高频/低频信号注入法不同,虚拟电压注入法不在电机中注入信号,而是在观测器中注入虚拟电压。虚拟电压注入能同时解决系统状态变量能观性、极点分布稳定性和电机参数鲁棒性问题,最终实现系统在低同步转速区域的稳定运行。

For many years,the instability problem of the induction motor speed sensorless vector control system in the low synchronous speed range has not been solved.It results from the unobservable system state variables,the unstable pole distribution and the poor robustness of the motor parameters.If and only if the three problems are solved simultaneously,the instability problem in the low synchronous speed range can be solved.In this paper,a virtual voltage injection method is adopted based on the classical closed-loop flux observer to improve its stability in the low speed range.Different from the traditional high frequency/low frequency signal injection method,the virtual voltage is injected into the observer rather than the motor.It can solve the observability of the system state variables,the stability of the pole distribution and the robustness of the motor parameters at the same time.Finally,the stable operation of the system can be achieved in the low synchronous speed range.