Substation Bus Differential Protection - Best Practices When Using Modern Protective Relays

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In this video we discuss how current differential (87P) protection schemes work, using the modern microprocessor-based SEL-487B protection relay as an example.
We go over what operating and restraining currents are in protection relays, how the SEL-487B relay defines these, as well as how to calculate these currents during internal and external faults to determine protective relay operation.
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[@downunder507]

I’m a protection tech and this is gold thanks for the explanation very easy to understand and follow. Keep up the awesome work

[@romeroengineering]

Thanks! You can also find more resources that may help you here: www.romeroengineering.co/resources

[@synapticmemoryseepage4447]

Thank you for this video on Bus Diff Protection.

[@poopface011]

So essentially the restrained differential element exists to prevent a false positive differential trip as would happen if one CT saturates. Great video!

[@romeroengineering]

Yes! We have to make sure the differential element can tolerate some CT saturation for external faults

[@BG-ro3pu]

Great explanation

[@samuelmorales8551]

Excellent. Thanks for sharing your knowledge.

[@romeroengineering]

Thanks Samuel, glad you found this video helpful.

[@samuelmorales8551]

@@romeroengineering One question, when using this type of bus protection, should every CT wired to an input of the differential relay have a ground? Or, should all the neutral be brought together to a node and then be grounded there? Is there a preferred method for wiring the ground?

[@joshe5180]

Very good video. Please keep it up

[@romeroengineering]

Thanks!

[@surendrakverma555]

Very good. Thanks 🙏🙏🙏🙏🙏

[@romeroengineering]

Thanks Surendra!

[@unguisan001]

Excellent explanation. Question: how is the 087p set/defined? You mentioned playing with the setting…

[@raafeterguez]

Thank you

[@romeroengineering]

You're welcome!

[@marcosspagnol7488]

Congrats on the video, thank you for sharing. May I ask you a question: how to define the slope properly? What must be taken attention to defining the slope? Maybe this can be a topic for a future video. Thank you