Conti Temic Microelectronic Gmbh

Brose Fahrzeugteile Gmbh&co.kg, Hallstadt

Thomas Dorner

Juergen Groth

Heiko Engelhardt

A method and a control device operate a three-phase brushless direct current motor with phase windings that are fed by an inverter connected to a voltage source having a high potential and a low potential. The semiconductor switches of the inverter are arranged in a bridge circuit and are controlled such that current always flows through two phase windings during motor operation. The motor is operated with normal commutation when the rotational speed is greater than or equal to a minimum rotational speed, wherein the angles are shifted by 60&#xb0;. During start-up operation, up to the minimum rotational speed, a high-potential-side commutation angle of a phase winding is shifted toward a low-potential-side commutation angle of the phase winding by an angle greater than 0&#xb0; and less than or equal to 60&#xb0; with respect to the normal commutation.

Method and control device for operating a three-phase brushless direct current motor

According to the invention, in a method for determining the angular position of a rotor, a reference voltage is set in a calibration phase, such that when the rotor, rotating at a calibration speed, passes through a particular detection position, said voltage is the same as the electromotive force induced in the one winding coil. In a subsequent measuring phase the reference voltage is updated to a value (U) which is equal to the product of the voltage value set in the calibration phase and the ratio of the instantaneous motor rotational speed to the calibration rotational speed. The angular position of the rotor (&#x3c9;) at which the electromotive force corresponds to the updated reference voltage is thus identified as the detection position.

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Nuremberg, Germany

Thomas Dorner