Application of 6000 series inverter in escalator

Escalator is a kind of manned lifting equipment commonly used in shopping malls, stations and airports.

I. Overview

Escalator is a kind of manned lifting equipment commonly used in shopping malls, stations and airports. There are two automatic escalators in a shopping mall. The escalator without speed control can only be idling at the rated speed. This operation is very uneconomical and wastes a lot of electrical energy. Moreover, the chains and belts are worn out and the maintenance period is short. Brought a lot of trouble. Therefore, the frequency conversion speed regulation of the escalator is modified, and the speed is reduced when no one is riding, and it is smoothly accelerated to the rated speed when someone is riding, so that the wear of the chain and belt can be reduced; after the speed is reduced, the output power of the motor is large The reduction in amplitude has brought a certain energy saving effect. The longer the unattended ride, the more significant the energy saving effect.

2. Working Principle

Generally, 11kW (four-pole) AC motor drive is used, and the escalator is dragged to run after being reduced by the reduction box. One of the two escalators acts as an upward movement and the other as a downward movement. After running for a period of time, it is manually exchanged, that is, the upward exchange is downward and the downward exchange is upward. In the course of operation, the flow of customers varies greatly at different times, and sometimes there may be no one to take the escalator. Due to the randomness of the customer's arrival, two 6000 universal inverters are used to control the motor of the escalator. When the passenger is running, the inverter is set to the external terminal control, and the speed control is set to the multi-stage mode, that is, the normal operating frequency (50Hz) and deceleration are set. Frequency (15Hz). When overhauling (crawling), the running frequency is low, about 25Hz. Infrared sensors must be installed at the entrance and exit of each escalator. Connect the output of these two sensors to the input of the timer in the inverter. When the escalator is running, the signal from the exit sensor is disconnected. The deceleration of the elevator when no one is riding, assuming that the sensor detects that someone is walking towards the escalator, the general sensor monitoring distance is 6m, the ground distance is about 4.2m, and it takes about t0=5s for people to walk through this distance. The frequency converter accelerates from 15Hz to 50Hz. For safety reasons, the acceleration must be completed before the person steps on the escalator. The acceleration time is t2. The time from when the person steps up to down the escalator is t1. When someone enters the entrance, the sensor signal is sent to the timer, the normally open contact of the timer is closed, the inverter starts to accelerate to normal speed, and the timer starts to count, and someone enters within (t0+t1+t2) seconds The signal input by the sensor resets the timer and restarts timing. The escalator has been running at normal speed. Within (t0+t1+t2) seconds, when no one walks into the entrance, after (t0+t1+t2) seconds, the inverter slows down to 15Hz, and the escalator automatically switches to slow speed.

3. System configuration