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I have a problem that we are facing

I have a problem that we are facing

I have a problem that we are facing

(OP)
I have a problem that we are facing currently at few of the 500KV substation. The problem we face as describe below.We have receive at least 10 trips in 2 months.
The station is a 1 1/2 breaker system,reactor and capacitor.

1. The current is not symmetrical and the angle was floating. So we beleive it was the star point that was the problem where it could be it was not properly thighten or intact as it should. So we thighten all the earthing and the angle and the magnitude of the current was stable.But the result at V phase was not satisfactory where Ia-256A,Ib-257A and Iv-126A. The neutral current was 24A (In). All the core that are connected to the protection shows the same value. So we beleive it could be the CT because the ratio should be 2000/1A and the Iv shows like it's connected to 3000/1A. When we check the internal connection and did the primary injection we found there aren't any problem with the CT and it is correctly connected to the appropriate ratio.Furthermore we found that the other station has the same value as above where the Iv is quite low. Could it be the system? But the other station we could find some strange phenomena like sometime B phase is efected as like Iv at the same line or another line.

I would appreciate if could get some tip and help on above description.

Thank you in advance everyone.

RE: I have a problem that we are facing

Need a bit more detail -
* is this just a filter bank?;
* what protection is tripping;
* the phase angle of what relative to what was "floating";
* You have named the phases "a", "b" and "v" - that is a bit unusual and is confusing.  Do you mean a,b,c?;
* where are the CTs located?
But one thing is certain - I wouldn't be too keen to re-energise for the 11th time on an unexplained trip at 500kV.  Sounds like plenty potential to try out the efficacy of your black start plans!

Bung
Life is non-linear...

RE: I have a problem that we are facing

What are the phase angles of the currents?

Norm

RE: I have a problem that we are facing

Suggestion: What is the connection of the voltage system since there are posted currents Ia, Ib, and Iv?

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