Dimensioning of nearby substations interconnected ground system

Journal Article · Sat Oct 01 04:00:00 EDT 1988 · IEEE Trans. Power Del.; (United States)

DOI:https://doi.org/10.1109/61.193961· OSTI ID:6798801

Sobral, S T ^[1]; Costa, V S ^[2]; Campos, M S; Goldman, B ^[3]; Mukhedkar, D ^[4]

---

1. IESA - Internacional de Engenharia S.A., Rio de Janeiro (BR)
2. Eletrobras, Rio de Janeiro (BR)
3. IESA-Internacional de Engenharia S.A., Rio de Janeiro (BR)
4. Ecole Polytechnique, Montreal (CA)

This paper deals with the ground mat dimensioning of two or more neighbor interconnected substations, a situation that is very common in the Electrical Industry. The paper recalls that the external ground circuits connected to the ground grid of each substation can drastically reduce the percentage of total ground current injected into the soil through the mat (from 40% up to 2% of the total fault current). The paper presents a set of specific calculation procedures to deal with nearby interconnected ground mats. These procedures correspond to a particular illustration of the general ''Decoupled Method'' (3,4,5), showing how to apply its 8 sequencial steps to solve this type of circuit. The paper shows that the electric neighborhood of nearby substations depends on the ''Space Constant'' (or ''Characteristic Length'') of the ground circuits interconnecting them such as transmission line ground-wires, power cable sheaths, etc. This paper complements also Ref. (3,4), introducing the complete derivation of useful expressions used to solve lumped parameter ladder circuits of any size (from one pi to an infinite number of pis). The derivation of these expressions also used in (3,4) were not included in these References due to lack of space. In the paper it is also shown a simple procedure to determine the suitable number of ACSR ground-wire spans near a substation necessary to allow a reduction of the ground grid conductor extension.

• OSTI ID: 6798801
• Journal Information: IEEE Trans. Power Del.; (United States), Journal Name: IEEE Trans. Power Del.; (United States) Vol. 3:4; ISSN ITPDE
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104 -- Fossil-Fueled Power Plants-- Components
200300* -- Electric Power Engineering-- Power Transmission & Distribution-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
CABLES
CONDUCTOR DEVICES
CURRENTS
DESIGN
ELECTRIC CABLES
ELECTRIC CONDUCTORS
ELECTRIC CURRENTS
ELECTRICAL EQUIPMENT
ELECTRICAL FAULTS
ENERGY SYSTEMS
EQUIPMENT
INTERCONNECTED POWER SYSTEMS
POWER SYSTEMS
SOILS