NERC SOS Exam | Actual Questions and Answers Latest
Updated 2026/2027 (Graded A+)
•
If a Balancing Authority does not comply with the Control Performance Standard, the Balancing
Authority is not permitted to provide which of the following for any other Balancing Authority entities?
- ✔✔Regulation of other services related to control performance
•
1. It is the obligation of each Balancing Authority to fulfill its commitment to the Interconnection and not
________ the other balancing Authorities in the Interconnection
- ✔✔Burden
•
A Balancing Authority is performing Overlap Regulation Service for another Balancing Authority. Which
of the following statements applies to the Balancing Authority providing this service?
- ✔✔The Balancing Authority's Frequency Bias Setting shall be modified to reflect the
combined Frequency Bias Setting of both Balancing Areas.
•
Balancing Authority A is currently reading a system frequency of 59.95 Hz. Its Net Actual Interchange is
+100 MW and its Net Scheduled Interchange is +200 MW. If Balancing Authority A's frequency bias
setting is 100 MW/0.1 Hz, Balancing Authority A's AGC is pulsing its generators to do what?
- ✔✔Increase MW output
•
Which of the following is a Real-time measurement of a Balancing Authority's control performance
- ✔✔BAAL
•
Each Balancing Authority shall monitor which of the following against two standards: CPS1 and BAAL?
- ✔✔Control performance
•
In the calculating of CPS1, which of the below conditions would contribute to ta favorable score?
- ✔✔Negative ACE when frequency is high,
•
positive ACE when frequency is low.
•
If the frequency bias setting is a higher value than the frequency response of a Balancing Authority and
a frequency decline is caused by a sudden loss of generation is an external balancing area, what will be
the result?
- ✔✔A- The ACE will be a negative value and AGC will increase generation
,•
Which statement best describes the CPS1 requirement?
- ✔✔The Responsible Entity shall operate such that its CPS1 is greater than or equal to
100% for the preceding 12 month period.
•
To be in compliance with the BAL-001 requirements, a Balancing Authority must have which of the
following?
- ✔✔CPS1 greater than or equal to 100% and ACE does not exceed the BAAL more than 30
consecutive minutes
•
Actual System Frequency (FA) is 60.03 Hz, a Balancing Authority is under-generating slightly to
prepare for an upcoming interchange transaction. What is the Balancing Authority doing?
- ✔✔The BA is helping the Interconnection Frequency.
•
You are a Balancing Authority Operator. A neighboring Balancing Authority in the Interconnection
suddenly had a 500 MW generator to trip off line by generator differential. What part of the ACE
equation,
ACE = (NIA-NIS) - 10B (FA-FS) - IME, allows you and other Balancing Authorities in the
Interconnection to contribute to the stabilization of the Interconnection frequency error?
- ✔✔10B (FA-FS)
•
In your Interconnection, a generator tripped that was large enough to reduce the frequency from 60.000
Hz to 59.940 Hz. Your Balancing Authority's Frequency Bias is 200 MW/0.1 Hz. How many MW would
your system initially contribute to frequency support?
- ✔✔120 MW
•
Which of the following would be a use of the IME portion of the ACE equation?
- ✔✔Represent flow of a tie line with an out of service meter.
•
What happens to the Balancing Authority ACE Limit (BAAL) when frequency moves farther away from
scheduled frequency?
- ✔✔The limit gets more restrictive.
•
How is the Frequency Response Obligation (FRO) of a Frequency Response Sharing Group
determined?
- ✔✔By adding the individual FRO's of each member.
•
A Balancing Authority has an ACE reading of -100MWs and frequency is 60.12 Hz. Is the BA
exceeding the BAAL?
- ✔✔No
,•
A Balancing Authority that is a member of a Generation Reserve Sharing Group is the Responsible
Entity only in periods during which the Balancing Authority is not in active status under the applicable
agreement or the governing rules for the Generation Reserve Sharing Group.
- ✔✔False
•
The minimum compliance for NERC DCS is
- ✔✔100% for all reportable disturbances.
•
A generator tripped in your Interconnection that was large enough to cause frequency to drop to 59.950
Hz. Your Balancing Authority's Frequency Bias is 120 MW/0.1 Hz. How many MWs would your system
initially contribute to frequency support?
- ✔✔60 MWs
•
A Balancing Authority has a normal load of around 8500 MW. Its most severe single contingency is a
700-MW coal-fired steam unit. At 0810 the ACE value was at -55 MW when a 600-MW generator in the
Balancing Authority's northern area tripped off line as the result of a generator differential. This resulted
in a large negative ACE for the Balancing Authority. What value must the ACE return to and in what
time frame to avoid a DCS violation?
- ✔✔-55 MW ACE in 15 minutes
•
How is the Frequency Response Measure (FRM) of a Balancing Authority determined?
- ✔✔It is the median of the BA's frequency response for the frequency deviation events
identified by NERC for the previous year.
•
The Contingency Reserve Restoration period is ________.
- ✔✔ninety minutes
•
When does the Contingency Reserve Restoration Period begin?
- ✔✔At the end of the Disturbance Recovery Period.
•
A Balancing Authority has a normal load of around 8500 MW. Its most severe single contingency is a
700-MW coal-fired steam unit. At 0810 the ACE value was at -55 MW when a 600-MW generator in the
Balancing Authority's northern area tripped off line as the result of a generator differential. This resulted
in a large negative ACE for the Balancing Authority. What value must the ACE return to and in what
time frame to avoid a DCS violation?
- ✔✔-55 MW ACE in 15 minutes
, •
A Balancing Authority's largest single contingency is a unit rated at 1,000 MW. Which of the following
disturbances would constitute a reportable disturbance for DCS evaluation based on the NERC DCS
criteria?
- ✔✔The loss of a 950 MW generating unit at 100%.
•
If a Reserve Sharing Group member has experienced a Reportable Disturbance condition but does not
call for reserve activation from other members, the entire group shall still be considered to be in a
disturbance condition.
- ✔✔False
•
Which of the following is a potential source of Contingency Reserve?
1. Offline generation that takes 10 minutes to start at full output.
2. Online generation at 100% capacity
3. Controllable load resources.
4. Voltage reductions.
- ✔✔1 and 3
•
The minimum compliance for NERC DCS is _____________?
- ✔✔100% for all reportable disturbances.
•
How is the Frequency Response Measure (FRM) of a Balancing Authority determined?
- ✔✔It is the median of the BA's frequency response for the frequency deviation events
identified by NERC for the previous year.
•
In order to achieve sufficient Frequency Response, the Frequency Response Measure (FRM) of a
Balancing Authority or Frequency Response Sharing Group must be:
- ✔✔Equal to or more negative than the Frequency Response Obligation (FRO)
•
A Balancing Authority is performing Overlap Regulation Service for another Balancing Authority. Which
of the following statements applies to the Balancing Authority providing this service?
- ✔✔The Balancing Authority's Frequency Bias Setting shall be modified to reflect the
combined Frequency Bias Setting of both Balancing Areas.
•
Balancing Authority A is currently reading a system frequency of 59.95 Hz. Its Net Actual Interchange is
+100 MW and its Net Scheduled Interchange is +200 MW. If Balancing Authority A's frequency bias
setting is 100 MW/0.1 Hz, Balancing Authority A's AGC is pulsing its generators to do what?
- ✔✔Increase MW output
Updated 2026/2027 (Graded A+)
•
If a Balancing Authority does not comply with the Control Performance Standard, the Balancing
Authority is not permitted to provide which of the following for any other Balancing Authority entities?
- ✔✔Regulation of other services related to control performance
•
1. It is the obligation of each Balancing Authority to fulfill its commitment to the Interconnection and not
________ the other balancing Authorities in the Interconnection
- ✔✔Burden
•
A Balancing Authority is performing Overlap Regulation Service for another Balancing Authority. Which
of the following statements applies to the Balancing Authority providing this service?
- ✔✔The Balancing Authority's Frequency Bias Setting shall be modified to reflect the
combined Frequency Bias Setting of both Balancing Areas.
•
Balancing Authority A is currently reading a system frequency of 59.95 Hz. Its Net Actual Interchange is
+100 MW and its Net Scheduled Interchange is +200 MW. If Balancing Authority A's frequency bias
setting is 100 MW/0.1 Hz, Balancing Authority A's AGC is pulsing its generators to do what?
- ✔✔Increase MW output
•
Which of the following is a Real-time measurement of a Balancing Authority's control performance
- ✔✔BAAL
•
Each Balancing Authority shall monitor which of the following against two standards: CPS1 and BAAL?
- ✔✔Control performance
•
In the calculating of CPS1, which of the below conditions would contribute to ta favorable score?
- ✔✔Negative ACE when frequency is high,
•
positive ACE when frequency is low.
•
If the frequency bias setting is a higher value than the frequency response of a Balancing Authority and
a frequency decline is caused by a sudden loss of generation is an external balancing area, what will be
the result?
- ✔✔A- The ACE will be a negative value and AGC will increase generation
,•
Which statement best describes the CPS1 requirement?
- ✔✔The Responsible Entity shall operate such that its CPS1 is greater than or equal to
100% for the preceding 12 month period.
•
To be in compliance with the BAL-001 requirements, a Balancing Authority must have which of the
following?
- ✔✔CPS1 greater than or equal to 100% and ACE does not exceed the BAAL more than 30
consecutive minutes
•
Actual System Frequency (FA) is 60.03 Hz, a Balancing Authority is under-generating slightly to
prepare for an upcoming interchange transaction. What is the Balancing Authority doing?
- ✔✔The BA is helping the Interconnection Frequency.
•
You are a Balancing Authority Operator. A neighboring Balancing Authority in the Interconnection
suddenly had a 500 MW generator to trip off line by generator differential. What part of the ACE
equation,
ACE = (NIA-NIS) - 10B (FA-FS) - IME, allows you and other Balancing Authorities in the
Interconnection to contribute to the stabilization of the Interconnection frequency error?
- ✔✔10B (FA-FS)
•
In your Interconnection, a generator tripped that was large enough to reduce the frequency from 60.000
Hz to 59.940 Hz. Your Balancing Authority's Frequency Bias is 200 MW/0.1 Hz. How many MW would
your system initially contribute to frequency support?
- ✔✔120 MW
•
Which of the following would be a use of the IME portion of the ACE equation?
- ✔✔Represent flow of a tie line with an out of service meter.
•
What happens to the Balancing Authority ACE Limit (BAAL) when frequency moves farther away from
scheduled frequency?
- ✔✔The limit gets more restrictive.
•
How is the Frequency Response Obligation (FRO) of a Frequency Response Sharing Group
determined?
- ✔✔By adding the individual FRO's of each member.
•
A Balancing Authority has an ACE reading of -100MWs and frequency is 60.12 Hz. Is the BA
exceeding the BAAL?
- ✔✔No
,•
A Balancing Authority that is a member of a Generation Reserve Sharing Group is the Responsible
Entity only in periods during which the Balancing Authority is not in active status under the applicable
agreement or the governing rules for the Generation Reserve Sharing Group.
- ✔✔False
•
The minimum compliance for NERC DCS is
- ✔✔100% for all reportable disturbances.
•
A generator tripped in your Interconnection that was large enough to cause frequency to drop to 59.950
Hz. Your Balancing Authority's Frequency Bias is 120 MW/0.1 Hz. How many MWs would your system
initially contribute to frequency support?
- ✔✔60 MWs
•
A Balancing Authority has a normal load of around 8500 MW. Its most severe single contingency is a
700-MW coal-fired steam unit. At 0810 the ACE value was at -55 MW when a 600-MW generator in the
Balancing Authority's northern area tripped off line as the result of a generator differential. This resulted
in a large negative ACE for the Balancing Authority. What value must the ACE return to and in what
time frame to avoid a DCS violation?
- ✔✔-55 MW ACE in 15 minutes
•
How is the Frequency Response Measure (FRM) of a Balancing Authority determined?
- ✔✔It is the median of the BA's frequency response for the frequency deviation events
identified by NERC for the previous year.
•
The Contingency Reserve Restoration period is ________.
- ✔✔ninety minutes
•
When does the Contingency Reserve Restoration Period begin?
- ✔✔At the end of the Disturbance Recovery Period.
•
A Balancing Authority has a normal load of around 8500 MW. Its most severe single contingency is a
700-MW coal-fired steam unit. At 0810 the ACE value was at -55 MW when a 600-MW generator in the
Balancing Authority's northern area tripped off line as the result of a generator differential. This resulted
in a large negative ACE for the Balancing Authority. What value must the ACE return to and in what
time frame to avoid a DCS violation?
- ✔✔-55 MW ACE in 15 minutes
, •
A Balancing Authority's largest single contingency is a unit rated at 1,000 MW. Which of the following
disturbances would constitute a reportable disturbance for DCS evaluation based on the NERC DCS
criteria?
- ✔✔The loss of a 950 MW generating unit at 100%.
•
If a Reserve Sharing Group member has experienced a Reportable Disturbance condition but does not
call for reserve activation from other members, the entire group shall still be considered to be in a
disturbance condition.
- ✔✔False
•
Which of the following is a potential source of Contingency Reserve?
1. Offline generation that takes 10 minutes to start at full output.
2. Online generation at 100% capacity
3. Controllable load resources.
4. Voltage reductions.
- ✔✔1 and 3
•
The minimum compliance for NERC DCS is _____________?
- ✔✔100% for all reportable disturbances.
•
How is the Frequency Response Measure (FRM) of a Balancing Authority determined?
- ✔✔It is the median of the BA's frequency response for the frequency deviation events
identified by NERC for the previous year.
•
In order to achieve sufficient Frequency Response, the Frequency Response Measure (FRM) of a
Balancing Authority or Frequency Response Sharing Group must be:
- ✔✔Equal to or more negative than the Frequency Response Obligation (FRO)
•
A Balancing Authority is performing Overlap Regulation Service for another Balancing Authority. Which
of the following statements applies to the Balancing Authority providing this service?
- ✔✔The Balancing Authority's Frequency Bias Setting shall be modified to reflect the
combined Frequency Bias Setting of both Balancing Areas.
•
Balancing Authority A is currently reading a system frequency of 59.95 Hz. Its Net Actual Interchange is
+100 MW and its Net Scheduled Interchange is +200 MW. If Balancing Authority A's frequency bias
setting is 100 MW/0.1 Hz, Balancing Authority A's AGC is pulsing its generators to do what?
- ✔✔Increase MW output
