Method for operating an inverter feeding a single-phase synchronous motor with permanently excited rotor

摘要

The single phase synchronous motor (M) is fed through an inverter (WR) with a controllable output pulse pattern (Um) connected to its input circuit. The output of the inverter is controlled in accordance with a linear curve (i=f(n)) relating the motor current (i) and the motor speed of rotation (n), such that the synchronous motor acts in the manner of a dc shunt motor. At the one end, the maximum current (Isoll) limit of the curve between current and speed is defined by short circuit or starting conditions, or is arranged to be below the threshold value for demagnetising the rotor of the synchronous motor. At the other end, the maximum rotational speed limit of the curve is obtained by the motor idling value. IMAGE