The Practical Method and Experimental Verification of Temperature Estimation in the Permanent Magnet of Electric Machine

  • Kang, Kyongho ;
  • Yu, Sukjin ;
  • Lee, Geunho ;
  • Lee, Byeong-Hwa
  • Received : 2015.07.21
  • Accepted : 2015.11.05
  • Published : 2015.12.31


This paper presents a practical method for estimation of average temperature in the permanent magnet (PM) of electric machine by using finite element analysis (FEA) and dynamo load experiment. First of all, the temperature effect of PM to the torque has been employed by FEA in order to evaluate the Temperature-Torque characteristic curve. The 1st order polynomial equation which is torque attenuation coefficient is derived by the FEA result of the Temperature-Torque curve. Next, torque saturation test with constant current condition is performed by dynamo load experiment. Then, the temperature trend can be estimated by adding the initial starting temperature using the torque attenuation coefficient and torque saturation curve. Lastly, estimated temperature is validated by infrared thermometer which measures temperature of PM surface. The comparison between the estimated result and experimental result gives a good agreement within a deviation of maximum $8^{\circ}C$.


temperature of permanent magnet;electric machine;demagnetization;permanent magnet


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