Variable Frequency Speed Regulation Of Luffing Mechanism With The Portal Crane

The portal crane is the main hoisting equipment for loading and unloading in the port. The multipurpose portal crane which can be used to carry out the loading and unloading task by container has began to be produced in China, in order to meet the requirement of the development of container. The crane fit for manifold operation condition is equipped with the special container spreader in addition to original grab bucket and hook. The development of crane is closely linked to control technology. With the coming forth of frequency conversion speed regulating, PLC, computer control and communication technology,the level of control of port crane is improve greatly.In this paper, the control and management of the crane are valued, PLC as the core, on the basis of PLC and frequency change assembled, starts from the frequency control system of the whole machine, the process of the turbine control, protection principles of the luffing mechanism, one of four control process, are focused on, introduced in detail its implementation methods, achieved the effectiveness of control, The stability of the system work, reliability of Protection system. The development of the frequency system with crane is reviewed; Programmable Logic Controller (PLC) is established as the control center, the control system of crane is designed, including the speed control system, PLC programming and monitoring system, pays more attention to researching the boom part automatic control, is finished on basis of the electric control design of MQ4035 multi-purpose portal crane in dongnan shipyard, and accumulates some good experiences for the development of similar automatic control of mechanism system.As one of the three supports of industry(PLC, robot, CAD/CAM),PLC which is based on the micro process and synthesizes the computer technology, automatic and communication is a growing universal industry auto control device. It has the advantages of little volume, powerful function, facility and maintenance convenience Specially its ability to be adaptive to dicky industry environment and high reliability is highly appraised by the users. So it is more and more wisely used in the fields such as metallurgy, source of energy, traffic, chemical industry and electric power etc, In the special field of crane, the exertion of frequency conversion speed regulating improves the monolithic performance of crane. Its good reliability, high quality speed regulating trait and distinct energy saving advantage make the crane equipped with frequency converter have the satisfying moving effect.