what is lightening surge?...Do you mean that you want to lighten the surge?..or install lightning surge?..How did you get job in a 132kV substation even without knowing electrical engineering?

This guy obviously has no comprehension of danger or any sense of responsibility to others.

Read some of his previous threads.

Assuming that the 132 kV supply to the substation is via overhead lines, the engineer would surely have installed surge arrestors on the incoming lines upstream of the transformers and these would have been connected to the substation earth mat, if the engineer installed such a thing. If not, you are in big do-do!!! get somebody qualified to sort it out on site, we cannot do this remotely.

Sounds to me like the OP has been given (i.e., is stuck with) the assignment of designing the ground grid / earth mat and lightning protection of the substation, and is totally ignorant of what that entails. Since his management is unwilling to hire a qualified professional to instruct or help, our poor OP is stuck asking a bunch of total strangers for assistance.

Mr. Matembo, here is a good, free general reference for you regarding substation design. See especially Chapter 9 on grounding. But PLEASE don't think it provides everything you need to become an expert in substation design! Find professional help to do the job right.

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

If your 132KV substation is a standard existing and operating substation, it must

already have wired surge arresters in place. If you are installing a makeshift substation

mount the arresters at the 132KV line receiving structure; For 3-phase incoming line

you need 3 arresters rated at 132KV/square root of 3 or about 75KV. If you have not

installed a low resistance ground mat, then drive 9 pcs ground rods 8ft deep in a

checker pattern, spacing the rods 10ft from each other. Then interconnect the rods together with No. 4/0 copper wire. Now connect the ground terminals of the

3 arresters to the nearest rods.

That's going to be a little difficult to install grounding rods into the lava flow. Oh, wait a minute I meant to say ocean ground. Maybe that was sandstone. Oh what the heck, we're all going to die anyway. Just take this pencil.....