Design Of Mine Ventilator Centralized Control System Based On PLC And Frequency Converter

The main ventilator is one of the coal mine four fixed equipment, it is vividly called "the heart of mine". It takes on the heavy responsibilities of conveying fresh air, discharging dust and all kinds of poisonous gas to the pit. It plays a vital role on the whole mine safety production.Because its power is great and the ventilator needs to work round the clock. According to statistics, its power consumption accounts for15%and20%in the total power consumption of the whole mine, the power consumption of some coal mines even reaches more than30%. Traditional ventilators use mostly the asynchronous motor-drive to conduct constant speed control, to reduce the amount of wind through the air door or butterfly valve throttle energy, causing great waste of energy. At the same time, because of the existing old ventilation equipment, control technology, and the high voltage, high current and bad working environment, leading to an increased failure rate. Therefore, it is very important to design a set of safe, reliable and efficient ventilator control system.In this paper, the electric control system of the ventilator of a coal mine in shanxi conducts technical transformation and upgrading, using two stage axial flow fan as control object, on the premise of safe and reliable,using "redundant" as the core thought of the system design, and combined with the technique of frequency conversion technology, PLC control technology and WinCC configuration technology, and designed a set of Siemens S7-400H and high reliability PLC as the core controller of the ventilator frequency centralized control system.The centralized control system consists of power distribution, transmission, control, on-line monitoring, each part adopts redundancy design, to avoid ventilator to cause accident because of the particular failure or system maintenance.It fully guarantees the high reliability of the system.The system has three kinds of control modes including upper computer operation, operation floor operation, local operation. The operation is simple. It centralizes control the dynamic process of soft start and soft stop between two ventilator. It could change the motor speed according to the actual necessary at any time. The equipment design margin leads to the energy waste problem of the "big horse pulls small car" to have been solved,and to overcome the energy consumption of traditionally controlling big or small of the damper to control the amount of wind.Under friendly central computer’s monitoring and controlling, controlling the ventilator. The operating status of the site ventilator can graphically real-time display on the LCD screen and touch screen in real-time, the monitor screen can achieve the transfinite alarm and historical data storage, query, history curves drawing. Users can easily analyze the failure causes, and to lay a solid step for the construction of digital mine. The system has put into operation since September2012, running status is stable, energy-saving effect is remarkable. According to the actual demand we can easily to adjust air volume of ventilator, and monitor the various data of the ventilator on the line, improved the automation level of the mine ventilation.