ELEVATOR SPEED CONTROL CIRCUIT

摘要

PROBLEM TO BE SOLVED: To suppress the vibrations of elevators in controlling the speed of ultra high-speed elevators having a resonance frequency. SOLUTION: In an elevator speed control circuit having a speed amplifier 3 which performs PI calculation of the deviation of a speed command ω*from a motor speed ωM' a car speed feedback circuit is provided in which the difference between the speed command ω* and a car speed ωcar is amplified by an amplifier 12 and passed through a band-pass filter 14 to extract car vibration components, which are in turn changed to an optimum phase by a phase filter 16 and fed back. A load torque observer 21 which estimates load torque from signals from the circuits (2 to 19) and the motor speed ωM is provided to enhance a speed follow-up characteristic and a disturbance suppressing effect in elevator speed control.