Patent ID: 6696804
Filing Date: 2004-02-24
Classification: H02H,H02P

Abstract:
An electronically commutated motor comprising:a control unit; a plurality of semiconductor output stages; field windings controllable by the control unit via the plurality of semiconductor output stages using a plurality of PWM control signals, a nominal setpoint speed being selectable for the control unit, an actual speed being comparable with the nominal setpoint speed, wherein in an event of a deviation of the actual speed from the nominal setpoint speed by a selectable speed difference, at least one of the control unit and the plurality of semiconductor output stages is capable of being switched off; wherein with at least one of a selection of the nominal setpoint speed and a switching on of at least one of the control unit and the plurality of semiconductor output stages as a function of the nominal setpoint speed, the control unit determines an acceleration time in which the plurality of PWM control signals increase the actual speed gradually to a final value associated with the nominal setpoint speed; wherein in the control unit, another setpoint speed is associated with each control value of the plurality of PWM control signals; wherein in each control phase of acceleration time, the actual speed is measured and compared with the other setpoint speed associated with the corresponding PWM control signal; and wherein a switching-off occurs during the acceleration time if in the control phase the actual speed deviates from the other setpoint speed associated with the corresponding PWM control signal by the selectable speed difference.