Research on Temperature Measuring System of Permanent Magnet Motor Rotor

High power density permanent magnet motors produce significant eddy current loss in their rotors, leading to a risk of permanent demagnetization due to excessive temperature rise. To ensure proper design and operation of the motor, it is crucial to obtain an accurate temperature distribution of the permanent magnet within the rotor. Since the existing test methods are difficult to accurately obtain the temperature inside the rotor, this paper proposes a permanent magnet motor rotor rotation temperature measurement system. Based on the design principle of rotating temperature measurement system, the paper discusses the system’s design principle, permanent magnet measuring points layout scheme, and iron core and rotating shaft design method. Finally, the test platform of the experimental prototype is built, and the distribution characteristics of the axial temperature of the permanent magnet motor rotor are obtained through the experimental test. It is proved that the system can measure the internal temperature of the permanent magnet motor rotor well and fulfill the needs of engineering practice and research.