Estimation of Temperature Rise in Stator Winding and Rotor Magnet of PMSM Based on EKF Xiaoliang Jiang 1+ , Zhongying Zhang 1 , Pindong Sun 1 and Z.Q. Zhu 2 1 School of Electrical and Automation Engineering, Nanjing Normal University Nanjing 210042, China 2 Department of Electronics and Electrical Engineering, University of Sheffield Sheffield S1 3JD, UK Abstract—This paper proposed an estimation approach of temperature rise in stator winding and rotor magnet of a surfaced-mounted permanent magnet (PM) AC motor. By using the 3rd-order extended Kalman filter (EKF) algorithm in rotating reference frame, stator winding resistance and rotor PM flux-linkage can be estimated independently. After comparing the estimation results of resistance and flux-linkage to the rated values measured at 20 respectively, the corresponding temperature rise in stator winding and rotor magnet ℃ can be calculated according to some certain rules. The proposed method was confirmed to be correct and effective by the simulation results from MATLAB/SIMULINK. Keywords-PMSM; extended Kalman filter; temperature rise estimation 1. Introduction Thermal condition monitoring and analysis is quite important and necessary for motor, especially under the circumstances of dynamic operation. Currently, several methods are able to fulfill the task[1-3]. Take the thermal equivalent circuit for example, problems related to temperature field can be transferred to calculation of thermal paths with lumped parameters through employing the thermal equivalent circuit organized by simplified thermal source and thermal resistance. Despite of small duty of calculation and approximate estimation of average temperature in iron core as well as winding, the estimation error is relatively large and it is not capable of real-time implementation. In addition, some computational methods are once proposed, such as FEM, equivalent thermal network, etc. However, those methods do not work until the internal structure of motor is well known. Furthermore, it is complicated to establish and analyze the corresponding model. Installation of thermistor or thermocouple during the manufacture process is another way to monitor dynamic thermal environment of motor, which is normally just applied to estimate the temperature of stator. So, it is difficult to measure the temperature of rotor directly. In the control system of AC PMSM, EKF is often applied to identify position and speed of rotor as well as the variation of stator winding resistance and rotor PM flux-linkage[4-8]. According to the relationship between winding resistance and temperature, the variation of temperature in stator can be evaluated by the variation of winding resistance in certain scope. Besides, the variation of PM flux-linkage also reflects the variation of temperature in rotor in terms of the relationship curve between flux and termperature. Therefore, temperature of motor can be estimated and observed without installing extra equipment or understanding motor structure well. Consequently, using EKF + Corresponding author. E-mail address: jxlgyqf@163.com 2010 3rd International Conference on Computer and Electrical Engineering (ICCEE 2010) IPCSIT vol. 53 (2012) © (2012) IACSIT Press, Singapore DOI: 10.7763/IPCSIT.2012.V53.No.2.37