Reactor Secondary Voltage Acselerator

[powereng1]

We are currently working on the protection for a variable 345kv, 100MVAR Reactor. We are planning on using a 487E and 387E for differential for primary and secondary protection. The reactor’s neutral side is grounded directly, so I am assuming that the voltage on that side is zero. I wonder if we can still use the following formula from the 387E instruction manual to set the CT TAP or check the CT Ratio. I am not sure what to input for the

TAPn =MVA • 1000• C /3 • VWDGn • CTRn (from 387E instruction manual – equation 3.6)

I am not sure what to input for the VWDGn, when I input zero in acselerator it gives me errors.


Thanks for all the help.

 

[waross]

Have you considered the impedance of the ground/neutral return path?
The single phase fault current times the ground return impedance may yield a non-trivial voltage.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[dpc]

You're trying to apply a relay with firmware intended for transformer protection to a reactor. I'd contact SEL support. They'll be happy to help. Sometimes you have to fudge some ratings to get the software to allow you to make the necessary settings. AcSELerator is pretty far down on the artificial intelligence spectrum of software.