Title :
Temperature effects on torque production and efficiency of PM motors using NdFeB magnets
Author_Institution :
General Motors Saginaw Div., MI, USA
Abstract :
The author investigates the temperature effects of PM (permanent magnet) motors using neodymium magnets on the torque production capability and on the efficiency of the motor. When PM motors are designed to operate in a wide temperature range, the reversible demagnetization of the neodymium magnets with temperature and the increase in winding resistance with temperature influence the maximum torque capability at rated speed and efficiency of the PM motor. The maximum torque at rated speed is limited due to the fixed DC link voltage of the inverter feeding the motor. It is shown that over an operating range of -40°C to 150°C the maximum torque capability and efficiency of the motor can vary over a wide range. It is also shown that for certain designs a nearly flat maximum torque versus temperature characteristics may be obtained. PM motors with trapezoidal back electromotive force waveform are considered
Keywords :
invertors; machine testing; machine windings; permanent magnet motors; permanent magnets; thermal analysis; torque; -40 degC to 150 degC; NdFeB magnets; PM motors; designs; efficiency; fixed DC link voltage; inverter; machine testing; rated speed; reversible demagnetization; temperature effects; torque production; trapezoidal back electromotive force waveform; winding resistance; Brushless DC motors; DC motors; Demagnetization; Magnetic analysis; Neodymium; Permanent magnet motors; Production; Synchronous motors; Temperature distribution; Torque;
Conference_Titel :
Industry Applications Society Annual Meeting, 1993., Conference Record of the 1993 IEEE
Conference_Location :
Toronto, Ont.
Print_ISBN :
0-7803-1462-X
DOI :
10.1109/IAS.1993.298907
