NERC RC Exam Questions and Correct
Answers
What is ACE?
✓ ~~~ (NIa - NIs) - 10β(fa - fs) - Ime
Calculated every 6 seconds
Uses Tie line Frequency Bias
What is Tie line deviation?
✓ ~~~ Largest offset to ACE
What is NIA?
✓ ~~~ Net Interchange Actual (sum of all tie-line values)
What is NIS?
✓ ~~~ Net Interchange Scheduled (sum of all interchange schedules)
What is the multiplier for frequency bias?
✓ ~~~ 10
What is β?
✓ ~~~ Frequency bias - represented as negative number in ACE calculation - reflects
area natural response to frequency changes (Inertia, Governor, Load) - atleast 1% of
annual peak load for areas with native load - 1% of peak generation output for area
with no load
,What is FA?
✓ ~~~ Frequency Actual
What is FS?
✓ ~~~ Frequency Schedule - normally 60.00 HZ except for time corrections - +/- .02
Hz
What is IME?
✓ ~~~ Meter error
fudge factor
used for inadvertent bilateral payback
Negligible
What should be done if unable to calculate ACE for 30 minutes?
✓ ~~~ Contact RC
How often should time error and frequency devices be checked/calibrated?
✓ ~~~ Annually
Negative Ace
✓ ~~~ The BA is Undergenerating
Positve ACE
, ✓ ~~~ The BA is Overgenerating
What happens during Internal Loss of Load?
✓ ~~~ Frequency and ACE increase.
What happens during External Loss of Load?
✓ ~~~ Frequency increases, no change in ACE.
What is the Frequency Bias Setting?
✓ ~~~ Monthly average >= 1% of estimated yearly peak demand per 0.1 Hz
When should the Balancing Authority recalculate its Frequency Bias Setting?
✓ ~~~ By January 1 of each year
What happens when there is internal generation loss?
✓ ~~~ Frequency and ACE drop, tie-line flows increase into the system
What happens when there is external generation loss?
✓ ~~~ Frequency drops, no change in ACE, net tie-line flows increase out of the
system
What happens when Frequency bias setting is lower than frequency response?
✓ ~~~ ACE will be positive causing the AGC to lower generation
, What is the percentage change in load required for a 1% change in frequency?
✓ ~~~ 1% - 2% change in load
What is the load reduction when Transmission Customer Voltage is reduced by 5%?
✓ ~~~ Load will reduce by 3%
What happens to ACE and AGC when the frequency bias setting is set to a less
negative value than the frequency response of a Balancing Authority and a
frequency increase is caused by a sudden loss of load in an external balancing
area?
✓ ~~~ ACE will be a negative value and AGC will increase generation
What happens to ACE and AGC when the frequency bias setting is less negative
than the frequency response of a Balancing Authority and a frequency decline is
caused by a sudden loss of generation in an external balancing area?
✓ ~~~ ACE will be a positive value and AGC will lower generation
What is the normal schedule frequency?
✓ ~~~ 60.00 Hz
What is the frequency correction for fast clock schedule?
✓ ~~~ 59.98 Hz
What is the frequency corrections for a slow clock schedule?
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller MASTER01. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.49. You're not tied to anything after your purchase.
