A stator and rotor resistance estimation technique for conductor temperature monitoring

A stator and rotor resistance (R_s,R_r) estimation technique for the purpose of stator winding and rotor conductor temperature (T_s,T_r) monitoring is presented in this paper. Since resistance is a direct indicator of temperature, resistance-based temperature estimation provides many advantages over conventional thermal model based methods. The proposed estimation scheme is a two-step procedure based on the voltage, current, and speed measurements. The first step is to estimate the rotor resistance and rotor flux linkage simultaneously based on a model reference adaptive system (MRAS) structure that is independent of R_s. In the second step, the stator resistance is updated based on the estimated rotor flux linkage using the q-axis stator voltage equation in the synchronous reference frame. Simulation and experimental results are given to confirm the validity of the proposed method. An analysis of the parameter sensitivity of both estimators is also included to examine the feasibility of the proposed technique