The Mine Ventilation Monitor And Control System Based On Power Line Carrier Communication

This paper proposes a kind of mine ventilation monitor and control system based on power line carrier communication. The main research contents of this paper are key technology of power line carrier communication and hardware and software design of monitoring substation. Using the concept of SCADA, this paper proposes a data transmission plan which use existing downhole lighting cable as the communication links, which can not only provide enough monitoring coverage, but also reduce the system failure caused by broken lines. This paper also designs an monitoring substation based on ATmega128 and takes the substation as remote terminal unit, which can collect several parameters such as gas, CO, temperature, wind speed and running status of local fan and other mechanical and electrical equipment.Aimed at the poor quality of traditional modulation technology applied in power line communication, the paper chooses Spread Spectrum method as the key technology of PLC. The good anti-interference and resistance to decline make PLC has great possibility applied in the mine ventilation monitor and control system.The hardware of this substation contains power supply module, data acquisition module, a storage unit, communication module and man-machine interface. Current sensors are commonly used in mine, on this basis, I/V conversion circuit is designed, and works with 10 bits ADC of ATmega128, it can achieve cycle of 8 channels underground environment parameters gathering, and digital filtering technology is used in the software for reducing error. Carrier module based on PL2102 is designed and works with relevant carrier sending, receiving and coupling circuits, MODBUS-RTU protocol is used in software to achieve bus communication between master station and substation. To achieve real-time, rapid and accurate save, PM25LV016 with SPI interface and 2MB storage capacity Flash memory is designed and works with a T/C as a storage module. Extensional LCD and keys support monitoring variables real-time display and parameters modification manually and in-place, it makes the substation fully functional.Experimental verification shows that the test precision of this substation can reach to 1.2%, and other functions such as display, storage and parameter change, have been realized one by one. It turns out to be a reasonable design and meets the design requirement of the monitoring substation.