Radiated Electromagnetic Disturbance for the DC Trolley Locomotive System in Underground Coal Mines

摘要

S78 the large amount of electro-mechanical equipments are used in underground coal mines, the electromagnetic environment become more and more complex. For the radiated electromagnetic disturbance from the DC trolley locomotive system in underground coal mines, the distributed parameter circuit model of the DC trolley locomotive system is established based on circuit theory. The mechanism of electromagnetic radiation from the pantograph arc is analyzed, and the expression of discharge current of electric arc is also deduced. Moreover, the radiated electromagnetic fields are measured when the DC electric locomotive is running. The measurement results show that the frequency spectrum of radiated electric-field mainly ranges from 250kHz to 3GHz; the maximum of electric field intensity is 93dBuV/m, which is about 40dBuV/m more than the background noise; the frequency spectrum of radiated magnetic-field intensity mainly distributes in the low frequency band, and the maximum is about 101dBpT. Besides, the overhead lines and other axial conductors in the tunnel are propitious to propagate electromagnetic waves. Therefore, the wireless communication system and personnel positioning system can be interfered by the radiated electromagnetic noise in locomotive haulage tunnels.