NERC Questions and Answers Latest Version
2025
Which entity would make the original request for an EEA event? - ANSWER A. Balancing
Authority
At 0620 local time, interconnection frequency is 60.025 Hz. Balancing Authority A's ACE
at that time is -100MW and it's L10 value is 50MW. By 0625, it's ACE has changed to -
25MW and the frequency has decreased to 60.012 Hz. By 0630, A's ACE is -5MW and
frequency is 60.001 Hz. For the 10 minute period, balancing authority A's average ACE
was 55MW. What control performance standard has the BA violated(if any)? - ANSWER
B. CPS 2
The daily plan is usually generated using unit committee and __________ software. -
ANSWER C.Power flow simulation
A severe lightning storm has hit your transmission system. Two 345KV lines have been
damaged and are unable to be reenergized. Two large generators of 500MW and
700MW have tripped off line. No additional generators are available to bring on line.
The parallel 230KV and 138KV lines are loaded at their emergency limits. As a system
operator, what should you do? - ANSWER A. Curtail load.
At the end of September, Balancing Authority C had CPS2 violations. Did Balancing
Authority C pass or fail their CPS2 requirements for the month? What was their final
CPS2 percentage score for the month of September? - ANSWER B. Passed. With 91.7%
Transmission Operators frequently use distance relays to protect their transmission
lines. These distance relay schemes quite often use ____ zones of protection. - ANSWER
A. three
,You are ready to restore power to a generator facility. Which of the following
transmission lines would be the best choice to energize the facility? - ANSWER A. 10
mile, over head TX line
When there is a problem in another part of the interconnection, a RC is expected to do
all of the following EXCEPT? - ANSWER b. Disseminate information outside the RC's area
You experience a full system shutdown. You are in the process of restoring load and you
are concerned about re-collapsing the system. Which is the best approach in the
restoration process that will help ensure your system will be restored successfully? -
ANSWER B. Maintain frequency 59.5 HZ and 60.5 HZ
If a high voltage direct current tie is on the Scheduling Path for a transaction, then the
_____, shall coordinate the Interchange Schedule with the Transmission Operator of the
HVDC tie. - ANSWER C. Sending and Receiving Authorities
A pseudo tie can be used to_____ - ANSWER b. Reflect jointly owned generation located
in another BA in ACE
If the frequency bias setting is equal to the frequency response of a balancing authority
and a frequency decline is caused by a sudden loss of generation in an external
balancing area, what will be the result? - ANSWER A. ACE will not change due to the
disturbance
Strategically placing generators on line in a Balancing Area to alter or change the flow of
active and reactive power on a transmission system is _____ - ANSWER B. generation re-
dispatch
When a system is on the verge of voltage collapse and nothing else can be done to
alleviate the problem, operating personnel should _______ - ANSWER A. reduce load in
the area with the low voltage
, If analysis tools are unavailable due to planned maintenance activities, it shall be the
responsibility of the Reliability Coordinator to have procedures in place to ____ -
ANSWER D. mitigate the effects of analysis tools outages
Generators are often equipped with protective relays to detect operation significantly
outside of the rated capability curve of the unit. When activated, these relays may
initiate an.. - ANSWER C. unit alarm, automatic runback and/or unit trip
Interchange Schedules may be implemented between________ - ANSWER C. adjacent
balancing authorities
A 500 MVA transformer has 400 MW of load with 300 MVAR. What is the power factor?
- ANSWER A. 80% (0.8)
Which of the following combinations represent the best generation control
performance (in terms of helping the interconnections frequency) by a Balancing Area? -
ANSWER B. ACE is positive while frequency error is negative
A 500 MW generator trips in a Balancing Authority external to your Balancing Authority
Area. Which of the following responses would you expect to see in your area? - ANSWER
A. Net Actual Interchange would be greater than Scheduled Interchange
In order to predict the system's near term load pattern, a system operator must have
information including weather forecasts and ____ - ANSWER A. past load patterns
When would be the best time to schedule a capacitor bank outage? - ANSWER C. during
projected light loading
2025
Which entity would make the original request for an EEA event? - ANSWER A. Balancing
Authority
At 0620 local time, interconnection frequency is 60.025 Hz. Balancing Authority A's ACE
at that time is -100MW and it's L10 value is 50MW. By 0625, it's ACE has changed to -
25MW and the frequency has decreased to 60.012 Hz. By 0630, A's ACE is -5MW and
frequency is 60.001 Hz. For the 10 minute period, balancing authority A's average ACE
was 55MW. What control performance standard has the BA violated(if any)? - ANSWER
B. CPS 2
The daily plan is usually generated using unit committee and __________ software. -
ANSWER C.Power flow simulation
A severe lightning storm has hit your transmission system. Two 345KV lines have been
damaged and are unable to be reenergized. Two large generators of 500MW and
700MW have tripped off line. No additional generators are available to bring on line.
The parallel 230KV and 138KV lines are loaded at their emergency limits. As a system
operator, what should you do? - ANSWER A. Curtail load.
At the end of September, Balancing Authority C had CPS2 violations. Did Balancing
Authority C pass or fail their CPS2 requirements for the month? What was their final
CPS2 percentage score for the month of September? - ANSWER B. Passed. With 91.7%
Transmission Operators frequently use distance relays to protect their transmission
lines. These distance relay schemes quite often use ____ zones of protection. - ANSWER
A. three
,You are ready to restore power to a generator facility. Which of the following
transmission lines would be the best choice to energize the facility? - ANSWER A. 10
mile, over head TX line
When there is a problem in another part of the interconnection, a RC is expected to do
all of the following EXCEPT? - ANSWER b. Disseminate information outside the RC's area
You experience a full system shutdown. You are in the process of restoring load and you
are concerned about re-collapsing the system. Which is the best approach in the
restoration process that will help ensure your system will be restored successfully? -
ANSWER B. Maintain frequency 59.5 HZ and 60.5 HZ
If a high voltage direct current tie is on the Scheduling Path for a transaction, then the
_____, shall coordinate the Interchange Schedule with the Transmission Operator of the
HVDC tie. - ANSWER C. Sending and Receiving Authorities
A pseudo tie can be used to_____ - ANSWER b. Reflect jointly owned generation located
in another BA in ACE
If the frequency bias setting is equal to the frequency response of a balancing authority
and a frequency decline is caused by a sudden loss of generation in an external
balancing area, what will be the result? - ANSWER A. ACE will not change due to the
disturbance
Strategically placing generators on line in a Balancing Area to alter or change the flow of
active and reactive power on a transmission system is _____ - ANSWER B. generation re-
dispatch
When a system is on the verge of voltage collapse and nothing else can be done to
alleviate the problem, operating personnel should _______ - ANSWER A. reduce load in
the area with the low voltage
, If analysis tools are unavailable due to planned maintenance activities, it shall be the
responsibility of the Reliability Coordinator to have procedures in place to ____ -
ANSWER D. mitigate the effects of analysis tools outages
Generators are often equipped with protective relays to detect operation significantly
outside of the rated capability curve of the unit. When activated, these relays may
initiate an.. - ANSWER C. unit alarm, automatic runback and/or unit trip
Interchange Schedules may be implemented between________ - ANSWER C. adjacent
balancing authorities
A 500 MVA transformer has 400 MW of load with 300 MVAR. What is the power factor?
- ANSWER A. 80% (0.8)
Which of the following combinations represent the best generation control
performance (in terms of helping the interconnections frequency) by a Balancing Area? -
ANSWER B. ACE is positive while frequency error is negative
A 500 MW generator trips in a Balancing Authority external to your Balancing Authority
Area. Which of the following responses would you expect to see in your area? - ANSWER
A. Net Actual Interchange would be greater than Scheduled Interchange
In order to predict the system's near term load pattern, a system operator must have
information including weather forecasts and ____ - ANSWER A. past load patterns
When would be the best time to schedule a capacitor bank outage? - ANSWER C. during
projected light loading
