Повышение безопасности и эффективности электроснабжения участков добычи руд на высокогорном руднике

Abstract

The results of study in the field of improving safety and efficiency of power supply to ore mining sites at a high mountain mine are presented. It is shown that safety and efficiency of power supply, as well as the hazard of electric shock in the electrical installations with a voltage of 6 kV, largely depends on the number of single-phase earth faults. It is established that high earth fault currents make it necessary to compensate for capacitive currents in 6 kV networks by installing compensating (arc-quenching) reactive coils. This will allow to reduce the ground fault currents to 3–5 A, increase the network insulation impedance by a factor of 4–6, reduce the over-voltages in the undamaged phases during ground faults, and improve conditions of ensuring electrical safety. It is substantiated that at the sections of the cable network leading to substations 25, 26, 28 and «Stvol», the resistance level is higher than the average for the high mountain mine, and in the sections of substations 31–35 and substation 33 it is slightly lower than the average. The worst state of insulation (maximum leaks) is observed at the sections of substations 31–106 and 31–34, where the insulation level is lower than the average by 16.6 and 3.56 times, respectively. It is recommended to carry out a preventive check of not only the condition of the cable, but also cable couplings, equipment at substations 31, 34 and 106 at these sites. And in the future, to continue study on high earth fault currents in the absence of control over the continuity of the earth network. Recommendations are given to improve the operation of electrical networks, to make fuller use of existing networks, and to ensure safe conditions for the maintenance of electrical installations of the networks with a voltage of 6 kV of the high mountain mine.