NERC Class Exam | Actual Questions and Answers Latest
Updated 2026/2027 (Graded A+)
•
Frequency Bias and Jointly Owned Units (JOU)
i. - ✔✔BAs that use dynamic schedule or pseudo-ties for a jointly owned unit share
responsibility for it in their bias settings.
ii. Fixed schedules for JOU require host BA to include total response for them in their bias
setting.
•
Frequency Bias and BA frequency response
i. - ✔✔BAs must maintain a frequency bias that is equal to or greater than the BA frequency
response.
ii. If the frequency bias is less than the frequency response, ACE remains positive and
pulses units down, hurting the frequency.
iii. If the frequency bias is greater than the frequency response, ACE remains negative and
pulses units up, helping the frequency.
•
Frequency Response Characteristic (FRC)
- ✔✔BAs respond to frequency deviations through a proportional change in load and an
inversely proportional change in generation
•
A 1% drop in frequency causes how much load to drop?
- ✔✔2% load
•
Dynamic Schedule
i. - ✔✔Included in the NIS.
ii. A telemetered reading updated in RT and used as a schedule in the AGC/ACE EQ and the
integration of which is treated as a schedule for interchange accounting purposes.
•
Pseudo-Tie
i. - ✔✔Included in the NIA.
ii. A telemetered reading updated in RT that represent generation or load assigned
dynamically between BAs and used as an imaginary tie-line. No physical tie exists. the
integration of which is treated as a schedule for interchange accounting purposes.
•
MSSC
i. - ✔✔This can be a loss of load, generation, or transmission. Usually loss of generation.
ii. A BA must carry enough contingency reserve to cover the MSSC
, •
Operating Reserve
i. - ✔✔The energy on hand above system demand required for regulation, load forecasting
error, outages, and protection.
ii. Consists of spinning, non-spinning, and regulating reserves
iii. Used to meet CPS and DCS
•
Contingency Reserves
i. - ✔✔Consists only of spin and non-spin
ii. Must be sufficient to meet DCS criteria following the MSSC
•
Regulating Reserve
i. - ✔✔Responsive to AGC
ii. Used to meet CPS
•
DCS Compliance
i. - ✔✔A BA must return the ACE to 0 if prior to the disturbance it was positive or equal to 0.
ii. If the ACE before the disturbance was negative, then the BA must return the ACE to
pre-disturbance value
•
Contingencies
- ✔✔Multiple contingencies occurring within 1 minute or less of each other are treated as 1
single contingency
•
How long will the Time Error correction last?
- ✔✔To find the hours needed to correct for a time error, multiply 0.833 by the seconds of
accumulated time error
•
AGC modes
i. - ✔✔CF - AGC responds to frequency deviations
ii. Constant Interchange - AGC responds to inadvertent flows
iii. TLB - AGC responds to frequency and inadvertent
•
Inadvertent Interchange
- ✔✔Each BA, by the end of the next business day, must agree on the hourly NSI and NAI
•
Generation Shift Factor
i. - ✔✔Generation Participation Factor
Updated 2026/2027 (Graded A+)
•
Frequency Bias and Jointly Owned Units (JOU)
i. - ✔✔BAs that use dynamic schedule or pseudo-ties for a jointly owned unit share
responsibility for it in their bias settings.
ii. Fixed schedules for JOU require host BA to include total response for them in their bias
setting.
•
Frequency Bias and BA frequency response
i. - ✔✔BAs must maintain a frequency bias that is equal to or greater than the BA frequency
response.
ii. If the frequency bias is less than the frequency response, ACE remains positive and
pulses units down, hurting the frequency.
iii. If the frequency bias is greater than the frequency response, ACE remains negative and
pulses units up, helping the frequency.
•
Frequency Response Characteristic (FRC)
- ✔✔BAs respond to frequency deviations through a proportional change in load and an
inversely proportional change in generation
•
A 1% drop in frequency causes how much load to drop?
- ✔✔2% load
•
Dynamic Schedule
i. - ✔✔Included in the NIS.
ii. A telemetered reading updated in RT and used as a schedule in the AGC/ACE EQ and the
integration of which is treated as a schedule for interchange accounting purposes.
•
Pseudo-Tie
i. - ✔✔Included in the NIA.
ii. A telemetered reading updated in RT that represent generation or load assigned
dynamically between BAs and used as an imaginary tie-line. No physical tie exists. the
integration of which is treated as a schedule for interchange accounting purposes.
•
MSSC
i. - ✔✔This can be a loss of load, generation, or transmission. Usually loss of generation.
ii. A BA must carry enough contingency reserve to cover the MSSC
, •
Operating Reserve
i. - ✔✔The energy on hand above system demand required for regulation, load forecasting
error, outages, and protection.
ii. Consists of spinning, non-spinning, and regulating reserves
iii. Used to meet CPS and DCS
•
Contingency Reserves
i. - ✔✔Consists only of spin and non-spin
ii. Must be sufficient to meet DCS criteria following the MSSC
•
Regulating Reserve
i. - ✔✔Responsive to AGC
ii. Used to meet CPS
•
DCS Compliance
i. - ✔✔A BA must return the ACE to 0 if prior to the disturbance it was positive or equal to 0.
ii. If the ACE before the disturbance was negative, then the BA must return the ACE to
pre-disturbance value
•
Contingencies
- ✔✔Multiple contingencies occurring within 1 minute or less of each other are treated as 1
single contingency
•
How long will the Time Error correction last?
- ✔✔To find the hours needed to correct for a time error, multiply 0.833 by the seconds of
accumulated time error
•
AGC modes
i. - ✔✔CF - AGC responds to frequency deviations
ii. Constant Interchange - AGC responds to inadvertent flows
iii. TLB - AGC responds to frequency and inadvertent
•
Inadvertent Interchange
- ✔✔Each BA, by the end of the next business day, must agree on the hourly NSI and NAI
•
Generation Shift Factor
i. - ✔✔Generation Participation Factor
