Control circuit for a short- circuit rotor asynchronous motor with commutable poles

摘要

The circuit provides reversal of rotation, a smooth start and electric braking and includes means by which both the starting torque and accelerating process are able to be controlled, and also braking can take place electrically with variable moment. A circuit includes an electronic switch (2) connected in series to at least one phase of the motor windings (1), and controlled such that during starting the forward flow angle, following a time- dependent function, rises from an adjustable initial value up to the full value of the sine half wave, such control being linked by an instrument (4) to the rotational speed of the motor to cause a switchover from the high-polar windings to the low-polar winding, on reaching the high-polar rotational speed. On switchover from the low-polar windings to the high- polar windings in the braking process, the forward flow angle from the switch (2) is limited to the set initial value and is then increased dependent on time. IMAGE