excel or software to assist transformer bias differential testing?

[dav08a]

dear all,

i am currently work on commissioning testing of transformer bias differential CRP. the client want to test a lot of test points, and scenarios, eg. heavy external fault.

anyone here have excel sheet or software (or recommend me software) could help me determine the value of secondary current to inject to relay for fault simulation (especially 2 phase and 3 phase fault.)

for example, i want a 3 phase fault at particular point, then the excel or software could help me calculate the secondary current i need to inject.

Thanks a lot in advance.

 

[veritas]

Hi dav08a

The test sortware you are looking for will depend on many variables:

1. Which biased differential relay you are testing (relay make and model)
2. Threephase or singlephase testing?
3. 1A or 5A
4. CTR's
5. All settings affecting the diff algorithm if a modern relay (e.g. CT ratio correction, phase shift correction, diff settings, etc.)
6. The complete setup of the differential protection scheme (CT's wired in star or delta, any interposing transformers or all compensation done inside the relay?, etc.

If you could provide the answers to the above I may be able to assist.

Regards.

 

[dav08a]

well, i am working for quite a number of panels. answer as you wish.
1. Which biased differential relay you are testing (relay make and model)
Areva Micom P643
2. Threephase or singlephase testing?
3 Phase testing
3. 1A or 5A
1A
4. CTR's
Various configurations, so prefer if the software could provide me selectable configuration.
5. All settings affecting the diff algorithm if a modern relay (e.g. CT ratio correction, phase shift correction, diff settings, etc.)
Various configurations. And the relay is Areva Micom P643, so all are relay internal compensation.
6. The complete setup of the differential protection scheme (CT's wired in star or delta, any interposing transformers or all compensation done inside the relay?, etc.
the relay is Areva Micom P643, so all are relay internal compensation.

 

[DiscoP]

Areva used to have a spreadsheet simulator for the P643 that may help you. Contact your local support (it's now either Alstom or Schneider now)

Often the software for the test sets (eg Omicron,Doble) have libraries for common relay types like the P633.

 

[ProtectionEngineer]

Hi,
I got this from Areva and have not use it since 2007.

Please try this excel.

Alex Lee

 

[dav08a]

Thank you DiscoP
the Omicron has the differential characteristic module, but it need you to buy that module before you can use it in their test..

Thank you ProtectionEngineer
that's helpful.

by the way, what is the characteristic of HV external fault?
does that mean, the current at HV side is much much higher than LV which until it trigger bias differential protection?