104. Research on Control System of Belt Conveyor in Coal Mine

The higher demands for control system of the belt conveyor in coal mines were analyzed and a control system based on PLC was developed. The control strategies of speed regulating and power balance of multi-motor drive were discussed in detail. Considering speediness and stability of speed regulation, a control strategy with dead band was proposed. When the error is greater than the given parameter, fuzzy-parameter PID control is adopted to stable the system quickly. When the error is smaller than the parameter, fixed-parameter PID control is adopted to reduce running time. The power balance of the motors is necessary for the normal running of the belt conveyor system. A tracking method is put forward for the power balance of the motors. One motor is selected as the major motor and the other motors are tracking motors. The speed of major motor is controlled to be in accordance with the speed curve, and currents of the other motors are regulated by using fuzzy PID control. These strategies were applied in the developed system and achieved good results.