The Design And Research Of The Whole Variable Frequency Speed Control System Based On PLC

Escalator is an indispensable means of transportation in public places such as shopping malls,railway stations,flyovers.It has brought great convenience and convenience to our life.But,with the rapid development of social economy,the state is demanding more energy savings.As a kind of high-energy electromechanical equipment widely distributed in public buildings,escalators have always been a hot topic in domestic and international studies.At the same time escalators are special equipment.The frequent occurrence of escalator accidents in recent years has brought great attention to the safety performance of escalators.In terms of energy conservation,at present,the energy saving mode used by escalators has the star delta drive mode,the interrupt operation mode,the bypass frequency conversion control mode and the all-variable frequency control mode.The pros and cons of each of these energy-saving methods,and combined with the characteristics of escalator use and passenger flow characteristics,this design adopts the all-variable frequency speed control scheme for the fusion of the integrated time-sharing operation technique and the frequency converter light load energy saving technology.In terms of safety performance,this design according to the new national standard in the electrical part of escalator safety device has carried on the detailed hardware and software design,to realize the efficient energy saving of escalators under safe and reliable conditions.This project will study and design the application of PLC based all-variable frequency control system in escalator.Firstly,based on a large number of literatures,this paper reviews the development of escalator equipment and escalator technology.At the same time,the control scheme of all-variable frequency is determined by the comparison of the advantages and disadvantages of several kinds of energy-saving methods.Then,on the basis of completing the frequency converter,programmable controller and peak clock selection,the system hardware is set up.Finally,the program software is written according to the system control,and the parameter setting is completed.Through commissioning,the design can meet the expected energy saving and security purposes and meet the requirements of the system.