The Research On Coal Mine Emergency Moter Speed Control System

As a kind of basic energy source in China, coal is consumed more than70%of China's primary energy consumption, which plays an important role in the national economy. And the main power equipment for coal production is motor. In all kinds of motor, AC motor with many advantages (lower cost, very strong overload capacity, more simple operation, easier control etc.) has become the most widely used, the greatest demanded motor. According to statistics, total motor power consumption accounted for about70%in the total electricity consumption of China, while the AC asynchronous motor total electricity consumption accounted for more than70%of the total electricity consumption of motor.Along with electric power electronic technology, the microprocessor technology, development of inverter technology, the inverter with its superior performance on speed governing that was popularized and applied in various coalmine equipments, has become the main device to control operation of the motor. Due to its longer inverter repair cycle, once fault occurs, the normal production of coalmine will be influenced immediately, thus causing huge economic loss. In order to reduce the economic loss that inverter failure brought about, it requires emergency speed control system to replace the motor control timely and effectively when the fault in inverter happen, as well as, ensure the orderly production in coal mine.Aiming at the current situation of frequency convert were widely applied in the electronical equipments of coalmine, and taking the widely used asynchronous motor as objects, this paper conduct a study on the speed governing system in emergency of coalmine motor. Based on the research of principle of asynchronous motor, to devise the systematical structure, to choose reasonable system controlling scheme, and a hardware system which kept the core of frequency convert, touch screen and PLC was designed. In order to enhance the speed performance, on the basis of asynchronous motor vector controlling system of original frequency convert, using PLC that from SENLAN frequency convert to make the original and traditional revolving speed into the fuzzy PID by self-adaptation, thus the setting to three coefficients of PID online is realized in time. Through the simulation experiment, we can get a conclusion that controller from fuzzy adaptive PID has many advantages, such as good dynamic performance, lower overshoot, higher accuracy steady state and so on. In accordance with the functional requirements of speed governing system in emergency of coalmine motor, combining with touchscreen technique and configuration software application, frequency convert controlled on site and remote by the means of Modbus highway, it has been finisined the monitoring and controlling system design to speed governing system in emergency of coalmine motor. Finally, debug the whole system, and carry a research and analysis on the working scheme and running state of system in coalmine hoister.