Automatic escalator speed regulating method

Abstract

The invention relates to an automatic escalator speed regulating method. The automatic escalator speed regulating method includes the following steps that when an escalator operates without being loaded, the corresponding relation between an operation frequency and torque of a motor is learned on its own; the corresponding relation between the load rate of the escalator and the operation speed of the escalator is set; when the escalator goes upwards, the torque of the current motor of the escalator is detected and the current load rate is calculated; according to the current load rate, the corresponding operation speed is set; when the escalator goes downwards, the size of the voltage and a change trend of a bus of the escalator are detected; if the voltage of the bus is larger than G1 but smaller than G2 and upward going does not exist, the mode of the escalator is going to be switched to a working frequency mode; if the voltage of the bus is lager than G1 and upward going exists or if the voltage of the bus is larger than G2, the mode of the escalator is switched to the working frequency and operate; if the voltage of the bus is smaller than G3, the torque of the motor is detected and the current load rate is calculated; according to the current load rate, the corresponding operation speed is set. According to the method, no hardware is needed for controlling variation of the operation speed of the escalator and frequent switching of the working frequency will not happen. Thus, cost can be saved and damage to elements of the escalator is reduced.

Description

technical field [0001] The invention relates to a frequency conversion escalator control method, in particular to a low-cost, energy-saving escalator automatic speed regulation method. Background technique [0002] The photoelectric switch is generally an induction switch installed at the bottom or top of the escalator to judge whether someone has entered. It is an input judgment condition for the frequency conversion speed regulation of the escalator. When the escalator is going up, there is no power generation running state, only the electric state. When the escalator is going down, there will be a power generation operation state, which is equivalent to the passenger pulling the escalator by gravity. The four-quadrant inverter is an inverter with PWM rectification, that is, the generated energy can be fed back to the grid through its own PWM rectification. [0003] With the country's requirements for energy saving and emission reduction, escalators also have frequency ...

AI Technical Summary

Problems solved by technology

Moreover, in the process of switching the inverter from power frequency, if someone takes the elevator, there will be a certain delay

[0006] For the scheme PLC (or escalator main board) + four-quadrant inverter (full frequency conversion): the four-quadrant inverter is a development direction in the future, and it can feed back the generated energy to the grid through its own PWM rectification, but the current problems are , the cost of the four-quadrant inverter is relatively high, which is not attractive to cost-sensitive customers

Moreover, the voltage harmonic control of the current inverter with PWM rectifier is not ideal for feeding back to the grid

[0007] In addition, the energy-saving operation of the escalator depends entirely on the photoelectric switch to determine whether there are passengers. (i.e. the situation where passengers are sensed all the time)

When there is no action, the load may not be driven by frequency conversion at low speed, and the escalator may be reversed, or the escalator may run at high speed for a long time, and cannot enter the low-speed energy-saving state.

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