MÉTODO DE CONTROLE E DISPOSITIVO DE ARRANQUE DE MOTOR

摘要

This invention concerns a softstarter device adapted for controlling an electric motor connected to the device especially during a start or a stop of the motor. The softstarter device comprises calculating means for calculating a difference between a determined motor torque and a reference value for said motor torque, and calculating an error signal from the comparison between said calculated torque and the reference value to change the speed of said motor. The softstarter device also comprises means for reducing the speed of said motor and the rate of change of motor speed with respect to time during a stopping time interval is lower during a first part of the interval. The speed of said motor is reduced dependent on said error signal so that the rate of change of motor speed with respect to time during a stopping time interval varies at least between a first part of the time interval and a second part of the time interval.