| The shaft hoist is the foremost equipment of mines , it is widely used to transport the materials, staff and equipment .The traditional shaft hoist control system is always controlled by the relay-contactor, and adopts the methods of connect series additional resistant in rotor's winding loop to start and adjust speed. The system has many disadvantages such as bad reliability, complicated operation, high fault rate, large energy-wasting and low efficiency. So, carrying on the research on the shaft hoist control system has realistic meanings, and it is a subject for research by relevant experts and scholars' both at home and abroad too.To these questions existing in the shaft hoist control system, the paper applied PLC(Programmable Logic Controller) and frequency converter to the system, and have carried on deeper research in feasibility.(1) According to the operation characteristic of the shaft hoist, the control system adopts industry computer to monitor the Shaft Hoist frequency conversion system. The system mainly include the host computer (industry computer or touch-sensitive screen), the slave machine (PLC control system ) and frequency conversion system.(2) To improving the system reliability, all the physical and control units of the shaft hoist are monitored. The dynamic monitor system for shaft hoist is composed of industry computer (or touch screens) and configuration software. The user can complete the animation designing, equipment connecting, programming the flow of control, getting the information and printing the result in the environment of configuration.(3) The main control system adopts PLC system. It has many advantages such as the simple hardware, flexible software, convenient debugging and less work for maintenance. We can control the brake with high pressure or lower frequency in conjunction with the control equipment of shaft hoist which is composed of specialized electronic module. At the same time, it can measure each motor's fault phenomenon and send the signal to computer to display, which reduced the intermediate link of traditional relay contactor control system, and the system stability and reliability be improved greatly.(4) The electrical driving unit adopts the most advanced frequency conversion technology, the vector control technology is suitable for the working environment of shaft hoist. We can make the elevator to run according to the specified spee curves to meet running stability at the upgrade state, just by giving the control orders of the inverter (reverse rotation, positive rotation etc) in the control unit. (5) The combination of hardware and software is used in fault protection. The fault signal changes to different fault operations according to the result of logic operation and judgment about the different grades of fault signal with fault protection system. At the same time these signals will be shown in PC and control the sound and light alarm. The system sets two kinds of security loop, and sends various serious signals to the security loop, breaks down the security circuit once the system has serious faults and brakes immediately.The runing indicates, adopting this control system, the shaft hoist works reliably, easy to use, energy-saving well, and have dynamical shown function.
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