MOTOR DEMAGNETIZATION DETECTION METHOD AND MOTOR DEMAGNETIZATION DETECTION DEVICE

A motor demagnetization detection device includes the following steps. An encoder is used to measure a rotation angle of a motor device. A current sensing device is used to measure a three-phase current value of the motor device. A speed of the motor device is calculated according to the rotation angle. When determining that the motor device maintains at a first steady state according to the speed, the three-phase current value is received to obtain and store first steady state data. When determining that the motor device maintains at a second steady state according to the speed, the three-phase current value is received to obtain and store second steady state data. An equivalent magnetic flux is calculated and stored according to the first steady state data and the second steady state data. The motor device is repeatedly driven to maintain at the first steady state and the second steady state, the first steady state data and the second steady state data are updated according to the three-phase current value,