Research On The Variable-frequency Regulating-speed Control System Of Mine Hoist

The mine hoist is often been called the throat of mine mountain by people, which is the most important equipments in mine mountain.It is the only road of contactting the ground and the bottom of a well in the whole mineral well. It takes the important carriage responsibility of ore, material and personnel etc. It is crucial for mine hoist that stability and reliability .The electricity controls system of traditional mine hoist exist many safe questions. Although the electron-control system of the elevator through the development of quite a few generation, people carried on an improvement from the machine, electronics, maintenance ...etc., obtaining certain result. There are also many other questions in controlling speed by using rotor—ring resistance in which many AC relay—contactor are used, such as ,too much energy consumption, very complicated controlling circuits, breaks down easily; in addition, the bad condition(dust, pour water and the whereabouts heavy thing of blunt hit etc.) of the spot usage resulted in the function of various machinery fitting and electric element lose efficacy;At last, the artificial mistake of the operation and the limit study to the route of tramcar, make existing the protection can not attain an expectation of result, cause trouble to the promote system ,so colliery accident take place sometimes, endanger life, affectting the mineral well to produce normally. Therefore, the control system of mine hoist speed regulation which develops a high performance is the topic of the utmost urgency.The research target of this thesis is to promote its function of mine hoist by carrying on a reformation to the traditional control system and try to combine the programmable controller (PLC) strong control function with Variable-requency Regulating-speed technology together and apply in mine. This paper introduces the developing situation of the electric controlled system of the mine hoist, analyzes on the features and the functions of the PLC control system, and connecting with the actual conditions, expounds the practicability of the The Variable-frequency Regulating-speed Control System of the Mine Hoist adopting The PLC Control Mode.All functions of the traditional system are reserved in the reformation, andmake good use of the PLC intelligence control function. So raised the system safety and efficiency of the mine.(1) Intensified a safety protection function. The new control system after reformed adopts double redundancy structure—software security circle and relay hardware security circle, once one of them working, the safe return then acts. The signal of safe return, such as, overwind, overspeed, decelerate etc, all double protection and assure the system safety protection .(2) Make use of PLC to carry on an intelligence treatment towards running - time retardance dot, highly shorten to promote cycle, raising produce efficiency, can carry out zero creeping but accurate stop.(3) Reliability good, control precision higher .Make use of the PLC to give a reference velocity and raise a control precision. The original system adopting rotor- ring resistance have stage speed regulation, speed regulation performance difference, and fluctuation big, failure rate higher .(4) Raise protection reliability, carry out a numerical type protection. Make use of the PLC implementation numerical relaying protection, raised protection reliability, in the original system many relay are used to protecting the system. The relay is an old style mechanical structure, sometimes the residual magnetism of coil will cause a mis-operation, the new system makes use of current or voltage transmitter to carry out protection through the A/D module , compare with the reference signal, and then send out corresponding guard signal, thus carry out a dependable protection .(5) Make use of the PLC achieve the whole process numerical type stroke control. The old system control precision is low, adaptation capacity difference, protect function weak, just these faults are the important reasons which result in the sever promote accident. The new system makes use of The count module to calculate the bidirectional pulses from encoder, and then do some work, thus we can get position and the speed of the cage at present , also PLC can carry on other protection that have something to do with position and speed of the cage .such as , overwind , overspeed and lose-rope etc.The whole simulation system that The Variable-frequency Regulating-speed Control System of Mine Hoist divide three stages to carry on, first according to the function of the electric control system with match an industrial department of coalthe coal mine appropriation equipments to standardize the technique committee to put forward of the promote machine electric control system standard, make sure the hardware constitutes and software of technique index of the electric control system; Secondly , make use of the strong simulation system of the MATLAB to create the mathematical model of three phase asynchronous motor, set up the simulation model of The Variable-frequency Regulating-speed Control System ;Finally, on those base of work, complete the whole system simulation, analysis simulated data in order to identify whether the system's function can satisfy with the design index or not.After do many work about the electric control ,such as ,Simulation and The promote machine machinery characteristic analysis ;From the results can see the electric control system can attain the design request, the control scheme of the system is reasonable, the function can attain the request of the mine safe production.