High-voltage mobile station in open pit mine: Electrosafety analysis

The article addresses safety of a high-voltage (6 kV) mobile station to feed shovels in an open pit mine. The station is a mobile truck-mounted self-sustaining power plant including a diesel engine, a synchronous generator, an electrical switching center and a control system. The housings of the plant equipment have metallic bonding with the master truck frame. The mobile station and shovel connection uses a standard five-cord cable KGE with an earthing pilot. The electrical connection between the housings of shovels and the station uses the fourth cord of the cable. The mobile station–shovel system with voltage of 6 kV and with an insulated neutral represents a joint independent closed circuit with all metal housings electrically closed by the earthing cord in the cable. The insulated cords of the cable have a conducting layer which ensures their bridging to the earthing cord in case of damage and actuates the frame ground protection. The closed power supply system has no branching and is fitted with the frame ground protection. The special cable with metallic shield and semi-conducting filler, the metallic bonding between the housings of the shovels and ferry station, no additional linkages and the short-line electric connection between the machines ensure improved safety. The estimated parameters of the line-to-earth fault currents and contact voltages are lower than the limits set by the state standard (GOST 12.1.038-82: I=650 mA; U=550 V). Safe operation of the mobile station is ensured in case of effective protection of insulation damage. The protection package of the mobile station provides cutoff in case of line-to-earth fault within 70 ms.

Malafeev S. I., Mikryukov V. I., Malafeeva A. A. High-voltage mobile station in open pit mine: Electrosafety analysis. MIAB. Mining Inf. Anal. Bull. 2022;(3):143-153. [In Russ]. DOI: 10.25018/0236_1493_2022_3_0_143.

S.I. Malafeev^1,2, Dr. Sci. (Eng.), Professor; Chief Researcher, e-mail: simalafeev@gmail.com, e-mail: sim@jpc,
V.I. Mikryukov², Cand. Sci. (Eng.), Leading Researcher, e-mail: mikrukov@jpc.ru,
A.A. Malafeeva¹, Dr. Sci. (Eng.), Assistant Professor, Professor, e-mail: amalafeeva@rambler.ru,
¹ Alexander and Nikolay Stoletovs Vladimir State University, 600000, Vladimir, Russia,
² «Joint Power» Company, Ltd, 111672, Moscow, Russia.

S.I. Malafeev, e-mail: simalafeev@gmail.com.

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