Electronic starting and operating control system for a single-phase synchronous motor with a permanent magnetic rotor, also in case of failure

Abstract

Control of the start-up and operation of a single phase synchronous motor with a permanent-magnet rotor (9) is proposed, wherein the single-phase synchronous motor (1) comprises at least one stator winding (5, 6) which is connected in series with an AC voltage sources, in which there are a sensor (10) for measuring the rotor magnetic field and an arrangement for phase-gating (11, 13), which connect the AC voltage source to the stator winding as a function of the magnetic-field sensor signal, in such a manner that the current which flows in consequence in the stator winding produces a rotor torque in the rotation direction without any critical states occurring with respect to demagnetization of the rotor. To this end, after the end of a delay time for phase-gating control, the stator current is not triggered until predefined conditions are satisfied. Momentary overloading of the motor and stalling are reliably prevented. A signal which reflects the load level on the motor is produced for external use. The control sequence is carried out for each running phase, as a function of the voltage signal and current signal, as well as the magnetic-field sensor signal and its time derivative, such that a driving torque is produced. In the operating phase, the phase difference between the magnetic-field sensor signal and the current signal is evaluated and regulated so as to achieve maximum efficiency. The effective power output of the motor is determined from the current signal and this phase difference.

Dependencies are inferred from the claim text.