A lift and its control system

Abstract

The invention discloses a lifter and a control system thereof. The structure of a lifter and a mode of a control system are changed, the control system of the lifter is changed from open-loop control into close-loop control, the rotating speed of a driving motor (11) can be directly transited from 0 to a high-speed section, a low-speed section is omitted, and the take-time requirement of the lifter is guaranteed; meanwhile the torque of the motor is controlled through the speed, torque output under any frequency is guaranteed, and stability of operation of the lifter is guaranteed.

Description

technical field [0001] The invention belongs to the field of construction machinery equipment, in particular to an elevator and a control system thereof. Background technique [0002] Existing elevators are prone to jitter, causing the entire elevator to shake, run unstable, and many line stops cannot meet the production cycle requirements. [0003] The elevator control scheme generally adopts two-stage deceleration. First, it accelerates from 0 to the slow section, and then accelerates from the slow section to the fast section. Increase the speed and increase the load. Because the motion curve has many inflection points, the low-speed section is low-frequency operation, and the stability will drop rapidly, and it may even fail to operate normally. [0004] The elevators in the early stage were all controlled by open-loop control. There was no motor speed feedback during operation. The elevator raised the beat and increased the speed. When running at high speed, it could no...

AI Technical Summary

Problems solved by technology

[0002] Existing elevators are prone to vibrations, causing the entire elevator to shake, unstable operation, and many line stops that cannot meet the production cycle requirements

[0003] The elevator control scheme generally adopts two-stage deceleration. First, it accelerates from 0 to the slow section, and then accelerates from the slow section to the fast section. Increase the speed and increase the load. Due to the many inflection points of its motion curve, the low-speed section is low-frequency operation, and the stability will drop rapidly, and it may even fail to operate normally.

[0004] The elevators in the early stage were all controlled by open-loop control. There was no motor speed feedback during operation. The elevator raised the beat and increased the speed. When running at high speed, it could not detect the motor speed change and could not decelerate smoothly; when the heavy vehicle was produced, the speed change could not be passed when the load increased. Adjust the torque, resulting in unstable operation, many line stops and unable to meet the production beat

[0005] The beat of the elevator is increased. When the fast and slow speed is switched, the frequency change is large and the conversion time is short when the frequency converter is controlled by the frequency converter. The control curve is not smooth, the motor speed is unstable, and the elevator shakes.

cause the whole lift to shake

[0006] When the frequency converter controls the fast and slow speed conversion, because the frequency changes greatly, and the slow speed section is low-frequency operation, when the ordinary frequency converter is controlled at low frequency, the motor torque cannot reach the rated torque, which may easily cause the motor to stall and the vehicle body to fall

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