Patent ID: 7145303
Filing Date: 2006-12-05
Classification: H02P

Abstract:
1. A method for the commutation of a brushless direct current motor, the motor including a rotor, a stator, and at least one motor winding, in which the position of the rotor in respect of the stator is determined, and an external operating voltage is applied, at a preset commutation angle, to the at least one motor winding depending on the determined rotor position, the method comprising the steps of: initially operating the motor in a first mode of operation with a preset commutation angle and a first operating voltage; measuring the rotational speed of the motor in the first mode of operation; switching from the first mode of operation to a second mode of operation with a changed commutation angle; operating the motor in the second mode of operation; measuring the rotational speed of the motor in the second mode of operation; comparing the rotational speed of the motor measured in the first mode of operation with the rotational speed of the motor measured in the second mode of operation; and changing the operating voltage in such a way that the rotational speed in the second mode of operation matches the rotational speed in the first mode of operation if there is a deviation between the rotational speed of the motor measured in the first mode of operation and the rotational speed of the motor measured in the second mode of operation.