Over/Under excite

[kanjanathep]

Dear alls.

I would like to know that how to test Over/Under excite function of generator.

Regrads.

 

[ScottyUK]

Increase the field current -> over-excite
Decrease the field current -> under-excite

If you want more than that then post a question with enough detail to have some meaning. What are you trying to test?


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If we learn from our mistakes I'm getting a great education!

 

[7anoter4]

You have to draw the Vee-Curves [see attachment].For a certain load and a power factor [lag or lead] you'll find a certain field current. If the current lag the terminal voltage you'll get a PF less than 1.This is the underexcited region. If PF=1 you'll get the rated field current for this load. If you'll increase the field current further the PF will decrease again, but the stator current will lead the voltage. This region is overexcited region.
I think there is an IEEE standard 115-1995[R2002] Guide for testing synchronous machine, Part 1, but I am not sure you'll find more in this.
Best Regards

 

[kanjanathep]

Thank you for alls suggust.I will ask new question.