Neutral Displacement Protection

You really need to revisit the commissioning records, Mildred. The reference to the design calculations and a comparison with actuals will be in there.

Hire a qualified electrician. Someone who is competent to work around an 11Kv system.

That person is not you.

sorry there is no such commissioning records ..now i am the one who is creating it . can any one guide me doing it !?

I hope you didn't mean that you are fabricating the commissioning records

Seriously, if you are, get someone who knows how these devices are set up, hire them and get them to commission the network you are working on before you kill someone.

You need to go back to the Designer, then, and ask. Do it by telephone - it's the quickest way.

A quick Google search on "ground fault on ungrounded system" will get you many resources to help you understand the conditions that occur, and how to detect and protect. I would recommend the following links as a good place to start:

I-Gard guide

Schneider - system grounding

But in any case, hire a good consultant with experience in this area to determine the relay connections, configuration, and settings so that you are truly protecting your system. This is not a job for the inexperienced.