Transformer Differential Protection feeding a aluminum smelter
Transformer Differential Protection feeding a aluminum smelter
(OP)
Hi,
We've had a few trips on our transformer differential relay that feeds an aluminum smelter. The differential relay is microprocessor-based, low impedance type.
Are there anyone who has seen any funnies with this load? What from the load side could affect the protection adversely?
The transformer is a 275/33kV, autotransformer. There are no paralleling of other transformers.
We've had a few trips on our transformer differential relay that feeds an aluminum smelter. The differential relay is microprocessor-based, low impedance type.
Are there anyone who has seen any funnies with this load? What from the load side could affect the protection adversely?
The transformer is a 275/33kV, autotransformer. There are no paralleling of other transformers.






RE: Transformer Differential Protection feeding a aluminum smelter
RE: Transformer Differential Protection feeding a aluminum smelter
or with modern relays incorrect settings for things that mimic what used to be done using CT connections)
Are you able to extract oscilography records from the relay, it usually provides some useful data.
RE: Transformer Differential Protection feeding a aluminum smelter
Few things:
1. Please search at the Forum, lot of threads on the issue.
2. Please send us DR file ( better in comtrade file) of fault.
3. Please try triggered DR by manual trigger and will send us too.
4. Please check on-line HMI diff and restraint currents per phase and angels too.
5. What is a setting of 87T diff protection?
Regards.
Slava
RE: Transformer Differential Protection feeding a aluminum smelter
It's more easier help.
Best Regards.
Slava
RE: Transformer Differential Protection feeding a aluminum smelter
Check relay manual for specific application details with auto transformer.
RE: Transformer Differential Protection feeding a aluminum smelter