摘要

施工升降机是建筑施工中必不可少的机械设备之一。升降机作为现代高层建筑的垂直交通工具，与人们的生活紧密相关，随着人们对升降机运行安全性、高效性、舒适性等要求的不断提高，升降机得到快速发展。其拖动技术已经发展到了调频调压调速，其逻辑控制也由PLC代替原来的继电器控制。

升降机采用了PLC控制，用软件实现对升降机运行的自动控制，可靠性大大提高。控制系统结构简单，外部线路简化，可方便的增加或改变控制功能，也可以进行故障自动检测与报警显示，提高运行安全性，并便于检修。而电动机交流变频器调速技术是当今节电、改善工艺流程以提高产品质量、改善环境、推动技术进步的一种主要手段。变频器调速以其优异的调速性能和起制动性能、高效率、高功率因素和节电效果，广泛的适用范围及其它许多优点而获国内外公认为最有发展前途的调速方式。因此，PLC控制技术加变频器调速技术已成为现代升降机行业的一个热点。

本设计考虑到施工场地升降机的实际操作功能，所设计的控制系统针对的是四层升降机。代替传统的继电控制系统，由变频器实现对升降机的拖动调速，使PLC与调速拖动装置相结合，构成PLC集成控制系统，实现了升降机的各种控制功能，提高了升降机运行的可靠性，降低了故障率。

关键词：升降机；PLC控制；变频调速；变频器

Design of PLC-based control system for construction

elevator control system

Abstract: The Construction hoist is one of the essential mechanical devices in the construction. As the vertical transport of modern high-rise buildings, the elevator and the lives of people closely related with the continuous improvement of the people on the elevator operational safety, efficiency, comfort requirements, the elevator rapid development. Drag technology has developed to a FM variable voltage control, logic control instead of the original relay control by PLC.

The elevator uses PLC control software to achieve automatic control of the elevator operation, and reliability is increased. The control system structure is simple, external circuit is simplified, and can easily add or change of control functions can also be automatic fault detection and alarm display, improve operational safety and easy maintenance. Motor AC inverter speed control technology is today's energy-saving, and to improve the process t improve product quality, improve the environment, a major means of technological advancement. The inverter is its superior speed performance and from the braking performance, high efficiency, high power factor and energy-saving effect, the broad scope of application and many other benefits by the domestic and international public .that the most promising speed.

This design considering the actual construction site lift operation function, designed by four layers of elevator control system is aimed at. Drag the governor of the elevator instead of the traditional relay control system by the inverter, so that the combination of PLC and speed drag devices, constitute the PLC sets the election control systems, elevator control, improved elevator of operation, to reduce the failure rate.

Key words：Elevator；PLC control；VVVF；Inverter

2.1.2 升降机继电器控制系统存在的问题

2.2 PLC控制系统