Fence Grounding

Is your code referring to barbwire atop a wooden fence in general, or specifically for HV substations?

Roughly said, usually in substations you ground everything which can be grounded (e.g. all metallic door frames in and outdoor) and there are very good reasons to do so. There are detailed grounding schemes to follow.

And what does you lightning protection expert say?

I think that i would be grounding it if only to remove any induced voltages from the mix.

The prospect of a decision-maker at an HV installation who is unaware of the content of the local electrical code I find somewhat worrying.

It certainly is possible.

1. Look at your design drawings.
2. Check with your consultant.
3. Read the Scope of Works
4. Look at your BoM.
5. Use non conductive barbed wire.
6. Use insulators.
7. Read the Code again.
8. Change jobs.
9. Don't energise the sub.
10. Ask you PM.
11. Ask an electrician.
12. 

I do not understand why you want to install a barbed wire over wooden fence.Is it to prevent some one climbing over it? any way you can but ground the barbed wire fence .It can be connected to the same earth .

If using vertical boards, cut the top ends with a saw to make points. After boards are mounted, use a 1 1/2" hole saw and put the pilot at the vertex where boards meet. Result will be uncomfortable to climb over, non-conductive, and decorative. Use non-conductive stain or paint.

If fence is existing, mount a row of broken bottles along the top. An opportunity for a little creative artistry in an otherwise humdrum industrial environment...

In here, our regulation required all metal material around the substation need to be earthed as to prevent induction generated from the substation. But I think it a good practices to earth all metal material to ground.

Its a barbed wire to fend off intruders. I'd say leave it ungrounded.