Yea, i've done this test 2 times before. First time it didn't work because the test current was too great for the generator to handle, then it would trip its breaker. Second time, it worked fine because i had a large generator and it was able to withstand the test current.
Sadly, i don't have...
When its possible to do this test, its great because we can confirm that the CTs wiring is correctly executed and we can measure the differential current before the energization date, allowing us to prevent unwanted tripping by the 87 and REF protections during the assets energization.
Greetings,
If i convert the z% from p.u to ohms, considering the transformers nominal voltage, wouldnt the impedance be off for my test? as with the generators voltage being significantlly different than rated voltage, the leakage reactance would be way off than that calculated under nominal...
Thanks for the reply,
Let me give more context, the test's objective is to measure the differential relay's current in order to confirm correct CT's polarity and collect oscilograms during comissioning. I need to rate the diesel generator's correctly for it to be able to whitstand the test...
Hello,
I'd like some help to consider the calculation of a current in a transformer's SC test. Suppose i have this theoretical transformer :
Vpri = 230 kV
Srated = 100 MVA
Z% = 5 %
For testing purposes, i'll use a 440 V generator to energize the transformer's primary side with its secondary...
