摘要在现代，科技进步日新月异，电梯成为生活中不能没有的工具，电梯控制系统性能的优异直接影响着电梯的使用效率。过去，老式的电梯都是以老式继电器来进行电梯系统的控制，老式继电器有许多的缺点，它有着很大的机械惯性和电磁惯性，使得老式由继电器作为控制系统的电梯的安全和可靠系数大大降低。电梯质量的好坏关系着人们的人生安全，传统的控制系统已经不能满足要求。随着可编程控制器PLC开始发展，PLC开始出现在现代生活中，PLC靠着处理速度快，可靠性高的特点，被应用在现代电梯控制系统中，既能够保证电梯安全运行又能节约成本。由于电力电子技术的发展，变频技术逐渐成熟，现在变频调速技术已经能比较完美的进行电机调速，老式的直流调速逐渐被淘汰，变频调速的优点在于能使电梯更加平稳的加速使乘客有更加好的乘坐体验，变频器还能很好的节约运行成本。本次设计将对老式电梯做出修改，应用新的由PLC控制的可调速电梯控制系统。73705

第一，我先将传统继电器控制与PLC控制进行介绍，指出传统继电器控制系统的缺点，还有PLC控制系统的有点，对变频器进行介绍。然后，简述一下现在电梯发展的现况，然后预测未来电梯发展的趋势。最后，对本次设计用到的变频器和PLC进行介绍，并根据电梯控制系统的需要编写出本次设计需要的PLC程序，并用MCGS进行仿真。最后设计出可实现变频调速的PLC电梯控制系统并进行调试试验。

该论文有图11幅，表3个，参考文献20篇。

毕业论文关键词:  电梯  可编程控制器  变频调速 

The Adjustable Speed Elevator Control System Based on PLC Control Design

Abstract In modern times, with the rapid development of science and technology, The elevator has become an indispensable instrument in people’s daily life。 The performance of the elevator control system directly affects the efficiency of the lift。In the past life,The old-fashioned elevator controls the elevator system by means of vintage electric relays yet, the of vintage electric relays have many disadvantages。 It has great mechanical inertias and electromagnetic inertias,which make the safety and reliability coefficient reduce。 The quality of the elevator influences people's personal safety。The triditional control system has already can’t appeal to requirements of people’s daily life。 With the development of programmable logic controller PLC。PLC is applied in modern elevator control system for it’s processing speed and reliability,and also it can ensure the safe operation of elevator and save the cost。 Due to the development of power electronic technology, frequency conversion technology is gradually mature。 frequency control technology can adjust the speed of electric machinery at a relatively high level now, old-fashioned dc speed regulation is being washed out gradually。 The advantages of the frequency control technology are as follows:firstly,it can make the elevator more stable when the elevator begins to accelerate。secondly,it gives passengers a better ride experience。 Thirdly, it can save the cost of operation my design will give a modification to the old-fashioned elevator,and apply PLC to the elevator control system。

 First of all, I will introduce the old-fashioned elevator control system and the PLC elevator control system,give out the disadvantages of the old-fashioned elevator control system and advantages of the PLC elevator control system。Also,I’m going to introduce the Frequency converter。And then,I’ll give analysis on the Current status of elevator development and predict the future development of the elevator boldly。Last but not the least,I’ll give introduce to the Frequency converter and PLC which has been used in this design,and write the PLC program according to the elevator control system,and then make simulation by MCGS。