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The effects of cable capacitance on longwall power systems.

Authors
Novak-T; Basar-J; Sottile-J; Kohler-JL
Source
Proceedings of the 38th IEEE Industry Applications Society Annual Meeting. Vol. 3. Los Angeles, CA: IEEE Industry Applications Society, 2003 Oct; :1615-1621
NIOSHTIC No.
20024185
Abstract
Utilization voltages used on longwall equipment operating in U.S. coal mines have increased steadily over the past 15 years from 1,000 V to 4,160 V. This voltage increase has directly influenced the 200% gain in overall longwall productivity from 1987 to the present. The transition from medium voltage (661 V-1,000 V) to high voltage (>1,000 V) has permitted significant increases in face widths and equipment sizes. Longwall systems with total connected loads of over 5,000 hp are now common, and all U.S. longwalls now use high-voltage equipment, with most using 4,160 V. Shielded cables, which have significantly more capacitance than unshielded cables, are required for high-voltage applications in the mining industry. This capacitance can have detrimental influences on system overvoltages and relay selectivity during ground-fault conditions if the values for the grounding resistor and the ground-fault-relay pickup settings are improperly chosen. These issues are addressed in this paper.
Keywords
Longwall-mining; Mining-equipment; Coal-mining; Electrical-systems; Electricity
Contact
NIOSH Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236
Publication Date
20031013
Document Type
Conference/Symposia Proceedings
Fiscal Year
2004
NTIS Accession No.
NTIS Price
ISBN No.
0780378830
NIOSH Division
PRL
Source Name
Proceedings of the 38th IEEE Industry Applications Society Annual Meeting
State
PA; VA; KY
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