The Control Of Variable Frequency Speed Regulation Of Ventil Ating Machine System Based On PLC

Ventilating machine is one of the important equipment in coal mine production, which undertakes the important task of mine ventilation. Ventilation is to convey fresh air to the underground, and the only ventilation equipment to guarantee the safety of mine production and is also a high energy-con sum ing mechanical and electrical equipment. Because of the requirements of the large current, the high voltage and the poor working environment, therefore, the ventilation machine has a higher accident. Under the station carrying on the on-line real-time monitor and control, ensuring the normal operation of ventilation machine, coal mine safety production is of great significance.The paper take the Zuo Quan jiarui coal mine ventilator transformation as the background, with three sets of rotary ventilating machine as the control objection, using advanced inverter technology, configuration monitoring technology, field bus control technology, PROFIBUS-DP protocol and Ethernet communication protocol, develop " PC+PLC+converter" as the basic pattern of digital mine ventilating machine on line monitor and control system. PC using explosion-proof industrial control machine, and communicates with the PLC programmable logic controller (programmable logic controller), the Ethernet protocol, through hard wiring way to control the frequency converter, to complete the ventilating machine system control and online monitor. PLC selects high reliability H system S7-400H (CPU412-3H), redundant configuration includes CPU, PS407power supply module (10A) and synchronous communication module, data on-line detecting and processing, and with the host computer (using the Ethernet protocol) and frequency (PROFIBUS-DP protocol used for communications). Converter uses6Siemens frequency converter to control of’6motors’start and stop.According to the requirements of the ventilation system control and monitor function, this paper designs the control circuit to the system of high and low switch cabinet, the PLC, inverter, touch screen and other equipment selection and configuration. The system has three control modes; PC control, operation desk control and local control. PC control using PROF1BUS-DP communication protocol and Ethernet protocol frequency converter remote control, console control by hard wiring mode of frequency converter remote control, at the same time in the frequency field can also be carried out in situ control. Through these three kind of control method can control inverter drive motor, realize the soft start and switch.The system using WINCC software, combined with touch screen technology, completes the communication between PC and PLC parameter settings, using the modular programming method, draw up the ventilating machine system online monitoring and control procedures, CPU fault handler. Finishing the variable connection between the WINCC configuration screen and the touch screen, which enables the real-time display of the ventilator system’s status and parameters.Since this system has been put into operation in October,2011, it runs in stable state, and successfully, realizes the implementation of the ventilating machine controlling and monitoring, which has practical application value, has received good economic and social effects.