Design And Realization Of Variable Frequency Drive For Scraper Conveyor In Guojiawan Coal Mine

With the improvement of automation and intelligence of fully mechanized coal face,scraper conveyor is developing towards high power,high reliability and intelligence.The traditional driving mode can not meet the requirements of modern scraper conveyor,such as difficult start-up,serious mechanical loss,high impulse current to power grid and unbalanced power between the head and Tail Motors.Therefore,it is of great significance to study and optimize the variable-frequency drive scheme of scraper conveyor.This topic aims at the problems of the original scraper conveyor frequency conversion drive scheme in Guojiawan Coal Mine,and carries on the optimization transformation to it.On the basis of expounding the basic structure,working principle,driving mode and power unbalance factor of the scraper conveyor,the frequency conversion driving scheme design of the start-up process and steady-state process of the scraper conveyor is given.The starting process uses the current average value+the method of adjusting the sequence starting time of the motor head and tail to realize the frequency conversion control and the power balance during the starting process of the scraper conveyor;the steady state process uses the Direct torque control method,in order to obtain high precision torque and speed,the scraper conveyor steady-state process of frequency conversion control and power balance,at the same time,complete the frequency conversion drive scheme protection mechanism;The communication mode between PLC controller and frequency converter is changed to Canopen communication mode,and the interface is reserved to upload data to the ground control room.In this paper,the principle of variable frequency drive is introduced in detail,and the software realization method and debugging process of the optimized variable frequency drive scheme for scraper conveyor are given.The design scheme has been completed in Guojiawan coal mine fully mechanized coal mining face industrial test.The test results show that the optimized drive scheme can ensure the safe,stable and continuous operation of the scraper conveyor,the power difference between the head motor and the tail motor is controlled within a reasonable range,and the running state and control precision meet the design requirements.