Transformer Phase Capacitive Currents
Transformer Phase Capacitive Currents
(OP)
I am looking for some typical information on the phase capacitve currents of transformers.
I have a specific need for the selection of a neutral earth NET/NER on a small generator. The specification requires the sizing to be the greater of 10A or 3 x Icap where Icap is calculated from the generator, cable connection, LV of transformer
The generator is a 5MVA 0.9pf 11kV
Transformer is 5MVA 33/11kV YNd11 ( The Y on the 33kV not earthed)
I have gone to the transformer/generator manufacturer for this specific requirement but am interested in some general information for a design database
Anyone with some references, data?
I have a specific need for the selection of a neutral earth NET/NER on a small generator. The specification requires the sizing to be the greater of 10A or 3 x Icap where Icap is calculated from the generator, cable connection, LV of transformer
The generator is a 5MVA 0.9pf 11kV
Transformer is 5MVA 33/11kV YNd11 ( The Y on the 33kV not earthed)
I have gone to the transformer/generator manufacturer for this specific requirement but am interested in some general information for a design database
Anyone with some references, data?






RE: Transformer Phase Capacitive Currents
C=0.000469*Skva^0.4/VkV^0.25[microF]
R.A.Walling formula [from Electric Power Distribution Handbook by T.A.Short] ch.4.10.2 Ferroresonance.
Walling, R. A., “Ferroresonance Guidelines for Modern Transformer Applications [1992]
RE: Transformer Phase Capacitive Currents
I suspect your 33 kV/11 kV rating might be a three-legged core design. I'd be real cautious in using Reigh's formula unless you check it out.