METHOD OF DRIVE OF LINE-FED INDUCTION MOTOR WHOSE ROTOR WINDING IS CONNECTED TO LIFT CABIN DOOR

摘要

FIELD: electrical engineering. SUBSTANCE: lift cabin door is moved by a line-fed induction motor with regulated voltage and frequency, which is actuated by an open current circuit so as to attain the necessary voltage profile indicated by an incremental line-fed coder at an exclusion of the gain factor of the proportional-plus-integral regulator. Magnetizing current insufficient to overcome the door weight is added in phase quadrature relative to the line-strength current, and frequency is determined by the open circuit by a preset method. The pulse-width modulation control signals are used to feed constant polarity voltages via a three-phase low-pass filter to the motor windings during precise time intervals so as to synthesize the necessary sinusoide currents of the windings. Addition of current is provided after each crossing of the zero of windings sinusoidal currents with the aim of overcoming of its delays. A decrease of the line voltage eliminates a voltage drop at the end of door opening and closing. EFFECT: enhanced reliability.