Ground potential rise characteristics of urban step-down substations fed by power cables - A practical example

Journal Article · Sat Oct 01 00:00:00 EDT 1988 · IEEE Trans. Power Del.; (United States)

DOI:https://doi.org/10.1109/61.193956· OSTI ID:6537593

Sobral, S T ^[1]; Barbosa, J O; Numes, J V.C.; Chinelli, E; Netto, A F ^[2]; Costa, V S; Campos, J H ^[3]

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1. IESA - Internacional de Engenharia S.A. (BR)
2. Light - Servicos de Eletricidade S.A. (BR)
3. Eletrobras - Centrais Eletricas, Brasileiras (BR)

This paper shows some special ground potential rise characteristics of substations fed by power cables. These characteristics were detected during the study of the interconnected ground system of 14 step-down urban substations fed by the 138 kV underground cable network serving the South Zone of Rio de Janeiro city in Brazil. As this type of system is very common in large cities, the subject can be of general interest for the industry. It was verified that when a fault occurs at a ''cable substation'' (a substation fed exclusively by power cables), almost no ground potential effects were detected at the faulted substation or at the other ''cable substations'' of the 138 kV network. However, high values of ground potential occurred at the ''transition substations'' (substations in which the power cables are connected to overhead 138 kV transmission lines, with steel groundwires). That ground potential was enough to produce shocks and equipment damage in certain ''transition substations''. It was verified that this problem has no relation with potential transfer. The paper shows also that the utilization of overhead lines with ACSR groundwires on the initial spans closer to the ''transition substation'' would be enough to avoid the problem. Even if the ACSR conductor is used only at the initial section of one of the lines, a reduction of the problem would be obtained. The paper shows also that the utilization of ACSR ground-wires near the ''transition substations'' contributes to reduce the amount of the copper necessary to control step, touch and mess potentials in these substations. Additional mitigation procedures are also examined in the paper.

• OSTI ID: 6537593
• Journal Information: IEEE Trans. Power Del.; (United States), Vol. 3:4
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
20 FOSSIL-FUELED POWER PLANTS
ELECTRIC CABLES
PERFORMANCE
INTERCONNECTED POWER SYSTEMS
ELECTRICAL FAULTS
URBAN AREAS
BRAZIL
CONTROL SYSTEMS
COPPER
ELECTRIC CONDUCTORS
NETWORK ANALYSIS
OVERHEAD POWER TRANSMISSION
CABLES
CONDUCTOR DEVICES
DEVELOPING COUNTRIES
ELECTRICAL EQUIPMENT
ELEMENTS
ENERGY SYSTEMS
EQUIPMENT
LATIN AMERICA
METALS
POWER SYSTEMS
POWER TRANSMISSION
SOUTH AMERICA
TRANSITION ELEMENTS
200300* - Electric Power Engineering- Power Transmission & Distribution- (-1989)
200104 - Fossil-Fueled Power Plants- Components