Design Of A Load Lift PLC Control System

The demand for vertical transport is as old as the human civilization. The earliest lift uses human power, animal power and hydraulic power to promote weight. Until the18th century, mechanical force began to be used for the development of the lift.At present, the lift has become an indispensable means of transportation for people in and out of the high-rise buildings. With the development of the times, and the progress of science and technology, people have put forward a higher requirement for a series of dynamic and static performance such as stability, high speed, accuracy, high efficiency, etc.Mainly there are three ways of a load lift control system including relay control system, microcomputer control system and PLC control system. The sequence control system composed by relays is one of the earliest ways to realize lift control. But the relay control system has been eliminated gradually due to its shortcomings such as high failure rate, poor reliability, inflexible control mode, large power consumption, etc. Although the microcomputer control system has stronger function in intelligent control, it has defaults such as poor anti-jamming, complicated system design, and also it is hard for the general repair personnel to master the repair technology. However, PLC control system, with high reliability, long time between failure, working with force electricity in harsh conditions to realize electromechanical integration, easy programming, simple application design, short debugging cycle, convenient use and repair, etc., has been given much more attention. Now it has become the most control mode of the lift control system, and it is also widely used in the technology reformation of traditional relay control system.PLC control system in heavy lift improved the lift performance,it beceme more intelligent, simple operation and running, the lift can Complete necessary transportation tasks,at the same time, be more intelligence, stability, reliability, enhances greatly, and reduce labor input, improve the safety factor, in the history of the development of heavy lift has epoch-making significance. PLC control system with two system, speed load lift system and variable frequency speed regulation system, the latter is by changing the motor power supply voltage and frequency. the level of accuracy is high, and has remarkable energy saving effect, guarantee the load lift reliability, so it is the successful solution of the heavy lift operation comfort problems.The design is a sub-project of Phoenix villa project. This paper, taking Mitsubishi FX2-64MR as the main three-layer lift PLC control system, uses frequency converters as executive agencies to design a system to control3-layer lift, so as to realize the normal operation of its various work.