基于PLC的施场地升降机控制系统设计毕业设计论文.doc

基于PLC的施工场地升降机控制系统设计 摘 要 升降机即简易的电梯，电梯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，随着人们对电梯运行安全性、高效性、舒适性等要求的不断提高，电梯得到快速发展。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。 电梯采用了PLC控制，用软件实现对电梯运行的自动控制，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电梯行业的一个热点。 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电梯。代替传统的继电控制系统，由变频器实现对电梯的拖动调速，使PLC与调速拖动装置相结合，构成PLC集选控制系统，实现了电梯的各种控制功能，提高了电梯运行的可靠性，降低了故障率。 关键词：电梯；变频器；PLC控制；变频调速 Abstract Lift that is, a simple lift. 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 a PLC control software to achieve automatic control of the elevator operation, and reliability are 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 todays energy-saving, and to improve the process to 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. Designed taking into account the practical features of the construction site lifts the control system design for a four-story elevator. Drag the governor of the elevator instead of the traditional relay co