Patent ID: 8569986
Filing Date: 2013-10-29
Classification: G01R

Abstract:
1. A demagnetization detection device for use in a power control unit which is electrically connected to a testing permanent magnet motor, the power control unit being further electrically connected to a direct current power source, the demagnetization detection device comprising: a memory, being configured to store a corresponding relation of a standard power value corresponding to a standard torque and a standard rotation speed of a standard permanent magnet motor; a voltage detector, being configured to detect a testing voltage value of the direct current power source; a current detector, being configured to detect a testing current value of the direct current power source; and a processing unit, being electrically connected the memory, the voltage detector and the current detector and being configured to calculate a testing power value according to the testing voltage value and the testing current value, wherein the testing power value corresponds to a testing torque and a testing rotation speed of the testing permanent magnet motor; wherein the processing unit further determines a difference between the testing power value and the standard power value while the testing torque is equal to the standard torque and the testing rotation speed is equal to the standard rotation speed based on the corresponding relation, and further determines that the testing permanent magnet motor is in a demagnetization status according to the difference.