METHOD AND DEVICE FOR DETERMINING THE POSITON OF THE ROTOR OF A BRUSHLESS AND SENSORLESS ELECTRIC MOTOR

摘要

The invention relates to a method carried out with simple means for determining the position of the rotor in a sensorless and brushless multi-phase electric motor (1) in addition to a device particularly suitable for carrying out said method. According to said method, a phase voltage (U_v) on the clamping side on said motor phase is to be detected after clamping a first motor phase (V) from the reference potentials (U_Z,M) of an intermediate circuit (7) during a detection period (T_E), via which the detection period (T_E) determines a peak value (U_v*) of the detected phase voltage (U_v), the peak values (U_v*) are to be compared to the comparative value (U_c), and a positon signal (S_P) is to be produced when the peak value (U_v*) exceeds the comparative value (U0). The comparative value (U_c) is then determined digitally such that it corresponds to the value of the phase voltage (U_v) at a zero crossing of a voltage (U_Vind) induced in the first motor phase (V) or an increased or lowered value in relation to a predefined correction value (?Q).