SOS NERC Prep - RELIABILITY EXAM QUESTIONS & ANSWERS
The Reliability Coordinator just informed you of a slow time error correction
which will begin at the top of the next hour. Your EMS system will not let you
change your scheduled frequency. Your Frequency Bias Setting is -100 MW/.1Hz.
What action should you take?
A) Increase Net Interchange Schedule by 20 MWs.
B) Inform the Reliability Coordinator that you cannot participate in the time
error correction.
C) Decrease Net Interchange Schedule by 20 MWs.
D) Increase Net Interchange Schedule by 10 MWs. - A) Increase Net Interchange
Schedule by 20 MWs.
A Balancing Authority has a sudden loss of a large block of load in its area. This
loss will be seen instantaneously in the change of which of the following values?
1. Actual Net Interchange
2. Scheduled Frequency
3. Scheduled Net Interchange
4. Area Control Error
A) 4 only
B) 1 & 3
C) 1 & 4
D) 3 & 4 - C) 1 & 4
Metered Data included in the calculation of ACE are: dynamic schedules,
pseudo ties, actual frequency, and all .
A) Tie lines readings
B) Generators output
C) Scheduled frequency indications
,D) Transformer load - A) Tie lines readings
Balancing Authority A is currently reading a system frequency of 60.00 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,
what is ACE?
A) -100
B) 0
C) 10
D) 100 - A) -100
A Balancing Authority has a Net Interchange Schedule of -250 MWs from 1200 to
1600 on a summer day. The Net Interchange Actual for those same hours
respectively were -230 MW, -275 MW, -250 MW and -270 MW. What was the
Balancing Authority's Inadvertent Interchange for the 4-hour period?
A) 6 MWs out
B) 25 MWs in
C) 25 MWs out
D) 6 MWs in - B) 25 MWs in
For the ACE equation to work properly, dynamic schedules, pseudo
ties, frequency, and all must be metered.
A) Generation
B) Communications
C) Transformers
D) Tie lines - D) Tie lines
If 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, what will be the result?
A) The ACE will be zero and will take no AGC action
B) The ACE will be a negative value and AGC will increase generation
,C) The ACE will be a positive value and AGC will lower generation
D) This will not affect the ACE - B) The ACE will be a negative value and
AGC will increase generation
If 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, what will be the result?
A) The ACE will be a negative value and AGC will increase generation.
B) This will not affect the ACE.
C) The ACE will be a positive value and AGC will lower generation.
D) The ACE will be zero and will take no AGC action. - C) The ACE will be a
positive value and AGC will lower generation.
It is the responsibility of which entity/entities to develop, maintain, and implement
load shedding plans?
A) Transmission Operators and Balancing Authorities
B) Reliability Coordinator
C) Load Serving Entities
D) Balancing Authority - A) Transmission Operators and Balancing Authorities
A Transmission line is loaded 25% above its SOL. A parallel line is out for routine
maintenance and can be placed in service in 10 minutes. What is the first step the
Operator should take to reduce the line loading?
A) Shed load at the downstream bus.
, B) Open the line. d d
C) Re-Dispatch Generation. d
D) Initiate the restoration of the parallel line. - D) Initiate the restoration of the
d d d d d d d d d d d d d
dparallel line. d
As a Transmission Operator, you realize that the voltage level is starting to decline in
d d d d d d d d d d d d d d
the North West part of the system. Which of the following devices should you, as
d d d d d d d d d d d d d d d
a Transmission Operator, be able to operate, and/or have another entity operate to
d d d d d d d d d d d d d
raise the voltage level back to normal in the North West part of the system?
d d d d d d d d d d d d d d d
A) Transformer Underload Tap Changers d d d
B) Shunt Capacitor Banks d d
C) Generator Reactive Output d d
D) All answers are correct - D) All answers are correct
d d d d d d d d d
Voltage reduction for load relief should be made on the
d d d d d d d d d d .
A) Distribution system d
B) Entire Interconnection simultaneously
d d
C) Tie-lines with other Balancing Authority Areas
d d d d d
D) Transmission System - A) Distribution system d d d d d
Under Frequency Load Shedding (UFLS) is to stabilize the imbalance between
d d d d d d d d d d
generation and load that has been created by a system disturbance. This is
d d d d d d d d d d d d d
accomplished by
d . d d
A) Tripping generation first d d
B) Voltage reduction on the distribution system.
d d d d d
C) Shedding all load to arrest frequency d d d d d
D) Shedding load prior to generation tripping - D) Shedding load prior to
d d d d d d d d d d d
generation tripping
d d
The Reliability Coordinator just informed you of a slow time error correction
which will begin at the top of the next hour. Your EMS system will not let you
change your scheduled frequency. Your Frequency Bias Setting is -100 MW/.1Hz.
What action should you take?
A) Increase Net Interchange Schedule by 20 MWs.
B) Inform the Reliability Coordinator that you cannot participate in the time
error correction.
C) Decrease Net Interchange Schedule by 20 MWs.
D) Increase Net Interchange Schedule by 10 MWs. - A) Increase Net Interchange
Schedule by 20 MWs.
A Balancing Authority has a sudden loss of a large block of load in its area. This
loss will be seen instantaneously in the change of which of the following values?
1. Actual Net Interchange
2. Scheduled Frequency
3. Scheduled Net Interchange
4. Area Control Error
A) 4 only
B) 1 & 3
C) 1 & 4
D) 3 & 4 - C) 1 & 4
Metered Data included in the calculation of ACE are: dynamic schedules,
pseudo ties, actual frequency, and all .
A) Tie lines readings
B) Generators output
C) Scheduled frequency indications
,D) Transformer load - A) Tie lines readings
Balancing Authority A is currently reading a system frequency of 60.00 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,
what is ACE?
A) -100
B) 0
C) 10
D) 100 - A) -100
A Balancing Authority has a Net Interchange Schedule of -250 MWs from 1200 to
1600 on a summer day. The Net Interchange Actual for those same hours
respectively were -230 MW, -275 MW, -250 MW and -270 MW. What was the
Balancing Authority's Inadvertent Interchange for the 4-hour period?
A) 6 MWs out
B) 25 MWs in
C) 25 MWs out
D) 6 MWs in - B) 25 MWs in
For the ACE equation to work properly, dynamic schedules, pseudo
ties, frequency, and all must be metered.
A) Generation
B) Communications
C) Transformers
D) Tie lines - D) Tie lines
If 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, what will be the result?
A) The ACE will be zero and will take no AGC action
B) The ACE will be a negative value and AGC will increase generation
,C) The ACE will be a positive value and AGC will lower generation
D) This will not affect the ACE - B) The ACE will be a negative value and
AGC will increase generation
If 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, what will be the result?
A) The ACE will be a negative value and AGC will increase generation.
B) This will not affect the ACE.
C) The ACE will be a positive value and AGC will lower generation.
D) The ACE will be zero and will take no AGC action. - C) The ACE will be a
positive value and AGC will lower generation.
It is the responsibility of which entity/entities to develop, maintain, and implement
load shedding plans?
A) Transmission Operators and Balancing Authorities
B) Reliability Coordinator
C) Load Serving Entities
D) Balancing Authority - A) Transmission Operators and Balancing Authorities
A Transmission line is loaded 25% above its SOL. A parallel line is out for routine
maintenance and can be placed in service in 10 minutes. What is the first step the
Operator should take to reduce the line loading?
A) Shed load at the downstream bus.
, B) Open the line. d d
C) Re-Dispatch Generation. d
D) Initiate the restoration of the parallel line. - D) Initiate the restoration of the
d d d d d d d d d d d d d
dparallel line. d
As a Transmission Operator, you realize that the voltage level is starting to decline in
d d d d d d d d d d d d d d
the North West part of the system. Which of the following devices should you, as
d d d d d d d d d d d d d d d
a Transmission Operator, be able to operate, and/or have another entity operate to
d d d d d d d d d d d d d
raise the voltage level back to normal in the North West part of the system?
d d d d d d d d d d d d d d d
A) Transformer Underload Tap Changers d d d
B) Shunt Capacitor Banks d d
C) Generator Reactive Output d d
D) All answers are correct - D) All answers are correct
d d d d d d d d d
Voltage reduction for load relief should be made on the
d d d d d d d d d d .
A) Distribution system d
B) Entire Interconnection simultaneously
d d
C) Tie-lines with other Balancing Authority Areas
d d d d d
D) Transmission System - A) Distribution system d d d d d
Under Frequency Load Shedding (UFLS) is to stabilize the imbalance between
d d d d d d d d d d
generation and load that has been created by a system disturbance. This is
d d d d d d d d d d d d d
accomplished by
d . d d
A) Tripping generation first d d
B) Voltage reduction on the distribution system.
d d d d d
C) Shedding all load to arrest frequency d d d d d
D) Shedding load prior to generation tripping - D) Shedding load prior to
d d d d d d d d d d d
generation tripping
d d
