NERC
NERC - RESOURCE & DEMAND BALANCING / INTERCHANGE SCHEDULING / EMER OPS EXAM
QUESTIONS WITH ALL CORRECT ANSWERS.
Area Control Error ANSWER >> The instantaneous difference between a Balancing
Authority's net actual and scheduled interchange, taking into account the effects
of Frequency Bias, correction for meter error, and Automatic Time Error
Correction (ATEC), if operating in the ATEC mode. ATEC is only applicable to
Balancing Authorities in the Western Interconnection.
Control Performance Standard ANSWER >> The reliability standard that sets the
limits of a Balancing Authority's Area Control Error over a specified time period.
Dynamic Interchange Schedule or
Dynamic Schedule ANSWER >> A time-varying energy transfer that is updated in
Real-time and included in the Scheduled Net Interchange (NIS) term in the same
manner as an Interchange Schedule in the affected Balancing Authorities' control
ACE equations (or alternate control processes).
Inadvertent Interchange ANSWER >> The difference between the Balancing
Authority's Net Actual Interchange and Net Scheduled Interchange. (IA - IS)
Joint Control ANSWER >> Automatic Generation Control of jointly owned units by
two or more Balancing Authorities.
Overlap Regulation Service ANSWER >> A method of providing regulation service
in which the Balancing Authority providing the regulation service incorporates
,NERC
another Balancing Authority's actual interchange, frequency response, and
schedules into providing Balancing Authority's AGC/ACE equation.
Pseudo-Tie ANSWER >> A time-varying energy transfer that is updated in Real-
time and included in the Actual Net Interchange term (NIA) in the same manner
as a Tie Line in the affected Balancing Authorities' control ACE equations (or
alternate control processes).
Tie Line ANSWER >> A circuit connecting two Balancing Authority Areas.
Epsilon - Sub One (Ɛ1) ANSWER >> A constant derived from the targeted
frequency bound. It is the targeted root mean square of one-minute average
frequency error of the Interconnection for one minute. It is the same for every
Balancing Authority Area within an Interconnection. It is the limit for determining
a BA's compliance with CPS1.
Epsilon - Sub Ten (Ɛ10) ANSWER >> Is a constant derived from the targeted
frequency bound. It is the targeted root mean square of ten-minute frequency
error schedule based on frequency performance over a given year. It is the same
for every Balancing Authority Area within an Interconnection. It is used in the
calculation of a BA's L10 (L sub 10) for CPS2 compliance.
Every Balancing Authority shall ensure that data acquisition for the calculation of
ACE should occur at lease every ANSWER >> 6 seconds
The Frequency schedule for the Interconnection is 60.000 Hz. The Balancing
Authority operator notices that the actual frequency has been running from
60.035 to 60.045 for 30 minutes. This indicates to the Balancing Authority
Operator that there... ANSWER >> is more generation than load
,NERC
If a Balancing Authority does not comply with the Control Performance Standard,
the Balancing Authority is not permitted to provide ________ for any other
Balancing Authority entities. ANSWER >> regulation or other services related to
control performance
For a particular month, a Balancing Authority had 4,300 10-minute blocks with
sufficient ACE data to be included in its CPS2 calculation. How many of those 10-
minute blocks could the average ACE exceed the L10 for the BA and still be in
compliance for the month? ANSWER >> 430
What is the difference between the ACE equation's FA and FS values, which are
located in the frequency component of the ACE equation? ANSWER >> FA
represents the actual frequency; FS represents the scheduled frequency of the
Interconnection.
What happens when a Balancing Authority is being evaluated for its CPS1 Control
Performance, and a sustained interruption in the recording of ACE or Frequency
Deviation due to loss of telemetering or computer unavailability result in a one-
minute interval not containing at least 50% of samples of both ACE and Frequency
Deviation? ANSWER >> The one-minute interval shall be excluded from the CPS1
calculation.
CPS2 reflects the Balancing Authority's ability to limit unscheduled power flows.
____________establishes a limit for average unscheduled power flow to or from
a particular Balancing Authority Area for each clock ten-minute period. ANSWER
>> L10
Each Balancing Authority shall monitor its _______ against two standards: CPS1
and CPS2. ANSWER >> control performance
, NERC
The L10 for a Balancing Authority is 50 MW. If the Balancing Authority has an
average ACE of -75 MW during one clock ten-minute period, which NERC Control
Performance Standard score will be affected? ANSWER >> CPS2
In this problem, the L10 value for the Balancing Authority is 50 MW and the ten-
minute average ACE is -75MW. The absolute value of -75 MW is 75 MW. The
absolute value of 75 MW exceeds the L10 value of 50 MW and is outside the L10
limits. A clock ten-minute average ACE value outside the limits will lower the CPS2
score by a percentage based on how many days are in that month. A Balancing
Authority can violate up to 10% of the 10 minutes’ averages in a given month and
still be in compliance. The CPS2 score must be equal to or greater than 90%.
At 0620 local time, Interconnection frequency is 60.025 Hz. Balancing Authority
A's ACE at that time is -100 MW and its L10 value is 50 MW. By 0625, its ACE has
changed to -25 MW and the frequency has decreased to 60.012 Hz. By 0630, A's
ACE is -5 MW and frequency is 60.001 Hz.
For the 10-minute period, Balancing Authority A's average ACE was -55 MW.
What Control Performance Standard score has been affected (if any)? ANSWER
>> CPS2
Contingency Reserve ANSWER >> The provision of capacity deployed by the
Balancing Authority to meet the Disturbance Control Standard (DCS) and other
NERC and Regional Reliability Organization contingency requirements.
Disturbance Control Standard ANSWER >> The reliability standard that sets the
time limit following a Disturbance within which a Balancing Authority must return
its Area Control Error to within a specified range.
NERC - RESOURCE & DEMAND BALANCING / INTERCHANGE SCHEDULING / EMER OPS EXAM
QUESTIONS WITH ALL CORRECT ANSWERS.
Area Control Error ANSWER >> The instantaneous difference between a Balancing
Authority's net actual and scheduled interchange, taking into account the effects
of Frequency Bias, correction for meter error, and Automatic Time Error
Correction (ATEC), if operating in the ATEC mode. ATEC is only applicable to
Balancing Authorities in the Western Interconnection.
Control Performance Standard ANSWER >> The reliability standard that sets the
limits of a Balancing Authority's Area Control Error over a specified time period.
Dynamic Interchange Schedule or
Dynamic Schedule ANSWER >> A time-varying energy transfer that is updated in
Real-time and included in the Scheduled Net Interchange (NIS) term in the same
manner as an Interchange Schedule in the affected Balancing Authorities' control
ACE equations (or alternate control processes).
Inadvertent Interchange ANSWER >> The difference between the Balancing
Authority's Net Actual Interchange and Net Scheduled Interchange. (IA - IS)
Joint Control ANSWER >> Automatic Generation Control of jointly owned units by
two or more Balancing Authorities.
Overlap Regulation Service ANSWER >> A method of providing regulation service
in which the Balancing Authority providing the regulation service incorporates
,NERC
another Balancing Authority's actual interchange, frequency response, and
schedules into providing Balancing Authority's AGC/ACE equation.
Pseudo-Tie ANSWER >> A time-varying energy transfer that is updated in Real-
time and included in the Actual Net Interchange term (NIA) in the same manner
as a Tie Line in the affected Balancing Authorities' control ACE equations (or
alternate control processes).
Tie Line ANSWER >> A circuit connecting two Balancing Authority Areas.
Epsilon - Sub One (Ɛ1) ANSWER >> A constant derived from the targeted
frequency bound. It is the targeted root mean square of one-minute average
frequency error of the Interconnection for one minute. It is the same for every
Balancing Authority Area within an Interconnection. It is the limit for determining
a BA's compliance with CPS1.
Epsilon - Sub Ten (Ɛ10) ANSWER >> Is a constant derived from the targeted
frequency bound. It is the targeted root mean square of ten-minute frequency
error schedule based on frequency performance over a given year. It is the same
for every Balancing Authority Area within an Interconnection. It is used in the
calculation of a BA's L10 (L sub 10) for CPS2 compliance.
Every Balancing Authority shall ensure that data acquisition for the calculation of
ACE should occur at lease every ANSWER >> 6 seconds
The Frequency schedule for the Interconnection is 60.000 Hz. The Balancing
Authority operator notices that the actual frequency has been running from
60.035 to 60.045 for 30 minutes. This indicates to the Balancing Authority
Operator that there... ANSWER >> is more generation than load
,NERC
If a Balancing Authority does not comply with the Control Performance Standard,
the Balancing Authority is not permitted to provide ________ for any other
Balancing Authority entities. ANSWER >> regulation or other services related to
control performance
For a particular month, a Balancing Authority had 4,300 10-minute blocks with
sufficient ACE data to be included in its CPS2 calculation. How many of those 10-
minute blocks could the average ACE exceed the L10 for the BA and still be in
compliance for the month? ANSWER >> 430
What is the difference between the ACE equation's FA and FS values, which are
located in the frequency component of the ACE equation? ANSWER >> FA
represents the actual frequency; FS represents the scheduled frequency of the
Interconnection.
What happens when a Balancing Authority is being evaluated for its CPS1 Control
Performance, and a sustained interruption in the recording of ACE or Frequency
Deviation due to loss of telemetering or computer unavailability result in a one-
minute interval not containing at least 50% of samples of both ACE and Frequency
Deviation? ANSWER >> The one-minute interval shall be excluded from the CPS1
calculation.
CPS2 reflects the Balancing Authority's ability to limit unscheduled power flows.
____________establishes a limit for average unscheduled power flow to or from
a particular Balancing Authority Area for each clock ten-minute period. ANSWER
>> L10
Each Balancing Authority shall monitor its _______ against two standards: CPS1
and CPS2. ANSWER >> control performance
, NERC
The L10 for a Balancing Authority is 50 MW. If the Balancing Authority has an
average ACE of -75 MW during one clock ten-minute period, which NERC Control
Performance Standard score will be affected? ANSWER >> CPS2
In this problem, the L10 value for the Balancing Authority is 50 MW and the ten-
minute average ACE is -75MW. The absolute value of -75 MW is 75 MW. The
absolute value of 75 MW exceeds the L10 value of 50 MW and is outside the L10
limits. A clock ten-minute average ACE value outside the limits will lower the CPS2
score by a percentage based on how many days are in that month. A Balancing
Authority can violate up to 10% of the 10 minutes’ averages in a given month and
still be in compliance. The CPS2 score must be equal to or greater than 90%.
At 0620 local time, Interconnection frequency is 60.025 Hz. Balancing Authority
A's ACE at that time is -100 MW and its L10 value is 50 MW. By 0625, its ACE has
changed to -25 MW and the frequency has decreased to 60.012 Hz. By 0630, A's
ACE is -5 MW and frequency is 60.001 Hz.
For the 10-minute period, Balancing Authority A's average ACE was -55 MW.
What Control Performance Standard score has been affected (if any)? ANSWER
>> CPS2
Contingency Reserve ANSWER >> The provision of capacity deployed by the
Balancing Authority to meet the Disturbance Control Standard (DCS) and other
NERC and Regional Reliability Organization contingency requirements.
Disturbance Control Standard ANSWER >> The reliability standard that sets the
time limit following a Disturbance within which a Balancing Authority must return
its Area Control Error to within a specified range.
