High Voltage Substation Grounding (Earthing) 1

[Deansharafi]

Dear all,

Do you know of any useful information or literature in relation to high voltage substation earthing, concept, design criteria, testing and commissioning etc.

Thanks and merry Christmas and Happy New Year.

 

[alehman]

Did you try searching this forum? You should find a fair number of threads on this subject. IEEE 80 is one common standard in use.

 

[Deansharafi]

Hello alehman,
I tried searching first, and I was supprised that there were nothing under "earthing" and the topics under "Grounding" was limited to one. However thanks for the advice. Do you have a link to the standard?

 

[RalphChristie]

The design of substation earthing require attention to detail of plant and services connected to it. In the case where customers take supply at MV or HV from the supply authority, careful consideration has to be given to the transfer of GPR under fault conditions to avoid dangerous situations to the public, customer staff and utility staff. Design normally aim to limit the current that would go through the body of a person exposed during a Ground Potential Rise - thus to limit step and touch potentials around a substation.

Some standards, but you'll have to search their websites:

IEEE Std 80-2000 IEEE Guide for Safety in AC Substations Grounding. (

http://www.ieee.com)

IEC 60479 Effects of current passing through the human body. (

http://www.iec.ch)

Regards
Ralph

 

[Kim69]

Hi,
European standard is HD 637 S1:1998-12.
Just for reference, you can check on this Italian site (sorry it is in Italian language):

http://www.elektro.it/cei_11_1_terra_html/cei_11_1_terra_01.html

CEI 11-1 (assimilated by HD637) is the Italian standard about electrical system up to 1 kV.
By
Kim69

 

[RalphChristie]

Deanaharafi:

What voltage-level do you classify as high voltage ?

Maybe a little off-track, but check the IEEE Green Book:

http://standards.ieee.org/colorbooks/sampler/Greenbook.pdf

 

[RRaghunath]

RalphChristie,

If my memory serves me right, IEC classifies 33kV to 220kV band as High voltage (and beyond extra-high voltage).

 

[RalphChristie]

Rraghunath

Thanks, I actually want to know at what voltage-level the originator of the question is talking about.

I do have some pdf-files from Eskom (Local South-African electricity supplier) for MV-substation earthing. (up to 44kV)

Regards
Ralph

 

[Deansharafi]

Hello RalphChristie and others,
Thanks for your responses. I am talking about 132 230 and 330KV. I have IEEE Green book and I will appreciate if you could send me the link to the ESKOM document.
Merry Christmass to all.

 

[jghrist]

The Green Book deals mainly with industrial systems. For high voltage substations, I would strongly recommend

IEEE Std 80-2000, IEEE guide for safety in AC substation grounding
----------------------------------------------------------
Abstract:
Outdoor ac substations, either conventional or gas-insulated, are covered in this guide. Distribution, transmission, and generating plant substations are also included. With proper caution, the methods described herein are also applicable to indoor portions of such substations, or to sub-stations that are wholly indoors. No attempt is made to cover the grounding problems peculiar to dc substations. A quantitative analysis of the effects of lightning surges is also beyond the scope of this guide.

This is a full size book and is available from

http://shop.ieee.org/ieeestore/,

but not for free.

 

[tinfoil]

jgrist: We are still referencing from 80-1986. Do you know if there is much of a difference between the 1986 and 2000 editions?

 

[BJC]

DeanShara
Have you looked at this?

http://www.usda.gov/rus/electric/pubs/1724e300/1724e300.pdf

May not be exactly what you want but it's free.

 

[jghrist]

Tinfoil,

From the Introduction to IEEE std 80-2000:

"Major modifications include the further extension of the equations for calculating touch and step voltages to include L-shaped and T-shaped grids; the introduction of curves to help determine current division; modifications to the derating factor curves for surface material; changes in the criteria for selection of conductors and connections; additional information on resistivity measurement interpretation; and the discussion of equations for the calculation of grid resistance, and the annexes."

 

[alehman]

You need to be sure you search within the Power Engineering forum using the search button right above the thread list, not the general eng-tips search. I get 42 threads for "substation earthing" and "hundreds" for "substation grounding".