1、英文原文Electromagnetic environments in roadways of underground coal mines and a novel testing methodSUN Jiping1, WANG Fuzeng1,2,*, PAN Tao1, TANG Liang3, WANG Shuai1, MING Yanjie11State Key Laboratory of Coal Resources & Safe Mining, China University of Mining & Technology, Beijing 100083, China2Colleg
2、e of Information Science & Technology, Agriculture University of Hebei, Baoding 071000, China3China Software Testing Center, Beijing 100048, ChinaAbstract: The electromagnetic environment of laneways in underground coal mines is an important area for the design of new electronic products, as well as
3、 a fundamental space for mine monitoring, surveillance, communications and control systems. An investigation of electromagnetic interference in coal mines is essential for the enhancement of performances of these systems. In this study, a new field method is provided in which radiated emission tests
4、 in coal mine laneways have been carried out. We conclude that: 1) the wiring motor vehicles can radiate interference with a bandwidth up to 1 GHz and with an amplitude 10 dBV/m higher than the background noise; 2) the PHS (Personal Handy phone System) mobile communication system can cause
5、 interference 40 dBV/m higher than the background noise; 3) an interference 25 dBV/m higher than the background noise can be generated during the communication at a working bandwidth of 48.8 MHz; and 4) power cables, battery vehicles as well as mechanical and electrical dong room
6、s have little effect on the electromagnetic radiation environment in coal mine tunnels.Keywords: roadway; electromagnetic environment; electromagnetic radiation; electromagnetic interference1 IntroductionThe electromagnetic environment of a laneway in underground coal mines is an important area for
7、electronic designs and layout, as well a fundamental workspace for mine monitoring, surveillance, communications and control systems. So far however, there have been no reports about measurements and analyses in the electromagnetic environment of coal mines. We have carried out and describe some imp
8、ortant analyses and reached meaningful conclusions from test results in the electromagnetic environment of two coal mines.2 Test environmentMeasured electromagnetic radiation intensity was measured in the main roadways of the Yi-kuang and Er-kuang collieries of the Pingdingshan Coal Mine Group on Au
9、g. 6th16th and 19th23th, 2008. The production capacity of the Yi-kuang Mine of the Pingdingshan Coal Mine Group is 4500000 tons a year, at three production levels with lengths of 180, 240 and 517 m, a transport belt longer than 40000 m and 26 fixed power substations. The cross-section of the roadway
10、 is an arch with a width of about 3.5 m. There are power cables, battery powered electric vehicles, communication systems, as well as a PHS communication system in the roadway. The annual output of the Er-kuang Mine with 7 fixed substations in the roadway is 1100000 tons. There is a 1500 m long hori
11、zontal roadway at the 86 m level, 3 m wide, where a number of power cables, a communications leakage cable, monkey cars and wired motor vehicles are located. The sketch map of the cross section of two tunnels is shown in Fig. 1 and the on-site testing environment in Fig. 2.3 Test equipment and metho
12、dsThe data were acquired by an R&S spectrum analyzer FSP7, with antenna frequencies ranging from 20 MHz to 7 GHz14-15. The test frequency bandwidths and resolutions were as follows: 1) 20200 MHz, BWF: 10 kHz; 2) 200500 MHz, BWF: 10 kHz; 3) 0.53 GHz, BWF: 30 kHz; 4) 37 GHz, BWF: 30 kHz.The measuremen
13、t points deployed every 200300 m in the roadways, were near the doors of the electrical and mechanical services chambers or at the branch entrances of the roadways and at the site where the cross-section of the roadways change. A couple of additional measuring points were added. Hence, we were able
14、to acquire and study the effect of the electrical and mechanical dong rooms, as well as the branches of the tunnel turns. Each test point was measured vertically at depths of 0.5, 1.0 and 1.7 m. The distances from the test sites along the wall near the sidewalk were 0.5, 1.0 and 1.7 m in the same ho
15、rizontal plane.4 Results and discussionThe test results are set out in Figs. 3816.In Fig. 3, data of groups of electromagnetic radiation are shown where there are only power cables in the roadway, with distances between the measuring points and tunnel wall of 0.5, 1.0 and 1.7 m.In Fig. 4 data of gro
16、ups of electromagnetic radiation spectra are shown, which were obtained near the electrical and mechanical services department cave room with only power cables in the roadway, with distances between the measuring points and tunnel wall of 0.5, 1.0 and 1.7 m.In Fig. 5 electromagnetic interference spectra are shown a battery charged electric locomotive was passing by, t with power cables in the roadway, with distances between t measuring points and locomotive o
