Methods for evaluating permanent magnet motors after manufacture and during service

摘要

A method evaluates a motor assembly having a first permanent magnet motor in a transmission of an automotive drive system at an end of manufacturing line evaluation. The first motor includes a first rotor with a first plurality of magnets mounted thereon, and a first stator with a first plurality of windings in proximity to the first rotor and coupled to a first inverter. The method includes spinning the first motor with an input dynamometer machine to a predetermined speed such that the first rotor of the first motor induces a first voltage on the first inverter; measuring the first voltage on the first inverter; calculating a first voltage constant of the first motor from the first voltage; comparing the first voltage constant to accepted voltage constants; and identifying the motor as not acceptable if the first voltage constant is outside of a range of the accepted voltage constants.