Study Of Online Monitoring And Protecting Technology Power Supply Lines In The Coal Mine

Because of the terrible plant conditions, working environment and the probability of cable faults, without elimination in time, it might blast. Therefore, a fast and effective monitoring of cable faults and faults distance is crucial needed.。Presently, the study of neutral non-grounding system has been made some achievements while small current neutral grounded system such as mine power supply line has not been given sufficient attention at home and abroad. According to the actual situation of power supply network and protection system under mine, a long distance faults online monitoring program is presented for overcoming the short protection distance. When the faults happened, the transient traveling wave contained abundant information is emitted to the ends of cables by the faults . Firstly, a cable model is built using ATP/EMTP and different types of faults are simulated, the transient faults current is also acquired. Secondly, a online cable fault location in single terminal for mine supply line is proposed based on wavelet transform muti-resolution analysis of transient traveling wave in partial mutation and weak variation signal processing is stated. The simulation results shows that it decreases the negative influence made by wave velocity, line length and faults grounding resistance factors, and also improves the accuracy of faults locations.Finally, a prototype is developed, containing main channel from the sensor simulation module, high-speed AD sampling module, logical control unit, data processing unit, liquid crystal display and keyboard interrupt. The mine supply line cable online location function is mainly achieved.