定子电阻辨识用于异步电机温度监测的研究

定子绕组温度监测是电机安全运行的重要保障.利用定子电阻值与温度的密切关系,提出了一种定子电阻估计方法以反映绕组温度的变化.在电流定向的坐标系中,异步电机数学模型中与定子电阻相关的部分得到简化.基于异步电机稳态模型,得到了独立于定、转子电阻和转速的稳态磁链估计,然后利用稳态磁链建立了定子电阻在线整定律.该整定律只需量测定子电流电压,简单易行.所提出的定子温度监测方法可以作为电机过热保护的一种辅助措施.

A New Method for Stator Temperature Monitoring of Induction Motor Based on Stator Resistance Estimation

Temperature monitoring is one of the fundamental protections required for induction motors. Because the stator resistance is a direct indicator of stator winding temperature responding to all of the situations, a new stator resistance estimation method for stator winding temperature monitoring is presented. The current oriented coordinate, the terms related to stator resistance in the mathematic model of induction motor are simplified. Consequently, the problem of stator resistance tuning becomes very straightforward. Based on the steady model of induction motor, steady flux estimation is obtained independently on rotor speed and stator and rotor resistances. With the steady flux, stator resistance on-line tuning law is established. The proposed method could be a secondary protection of thermal protection of induction motor.