Bronzeado
Electrical
- Jan 6, 2008
- 271
Hi folks,
In general, transformer manufactures can not measure the complete B-H curve (based on the V-I curve) of large power transformers (above 100MVA). This is because of the small short-circuit power in their laboratories which is not enought to saturate deeply large transformers.
Normally, they measure the V-I (B-H) curve of the winding on the ferromagnetic core supplying voltage up to 120% of the nominal voltage. Then, they measure the V-I (B-H) curve of the winding without the transfomer core (air core reactance) and, graphically, join these two curves.
My question is:
1) At which point these two curves should be joined?
2) Is that point the "knee point" of the B-H curve?
Best regards,
Herivelto Bronzeado
In general, transformer manufactures can not measure the complete B-H curve (based on the V-I curve) of large power transformers (above 100MVA). This is because of the small short-circuit power in their laboratories which is not enought to saturate deeply large transformers.
Normally, they measure the V-I (B-H) curve of the winding on the ferromagnetic core supplying voltage up to 120% of the nominal voltage. Then, they measure the V-I (B-H) curve of the winding without the transfomer core (air core reactance) and, graphically, join these two curves.
My question is:
1) At which point these two curves should be joined?
2) Is that point the "knee point" of the B-H curve?
Best regards,
Herivelto Bronzeado
