EPRI Exam Study Guide New Latest Version with All Questions from Actual
Past Exam Updated 2024/2025 SOS NERC Prep- RElIABILITY Exam
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. - ANSWER >> 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 - ANSWER >> C) 1 & 4
Metered Data included in the calculation of ACE are: dynamic schedules, pseudo ties, actual frequency, and all
.
1|Page
, EPRI Exam Study Guide New Latest Version with All Questions from Actual
Past Exam Updated 2024/2025 SOS NERC Prep- RElIABILITY Exam
A) Tie lines readings
B) Generators output
C) Scheduled frequency indications
D) Transformer load - ANSWER >> 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 - ANSWER >> 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 - ANSWER >> 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 - ANSWER >> 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?
2|Page
, EPRI Exam Study Guide New Latest Version with All Questions from Actual
Past Exam Updated 2024/2025 SOS NERC Prep- RElIABILITY Exam
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 - ANSWER >> 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. - ANSWER >> 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 - ANSWER >> A) Transmission Operators and Balancing Authorities
3|Page
, EPRI Exam Study Guide New Latest Version with All Questions from Actual
Past Exam Updated 2024/2025 SOS NERC Prep- RElIABILITY Exam
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.
C) Re-Dispatch Generation.
D) Initiate the restoration of the parallel line. - ANSWER >> D) Initiate the restoration of the parallel
line.
As a Transmission Operator, you realize that the voltage level is starting to decline in the North West part of the
system. Which of the following devices should you, as a Transmission Operator, be able to operate, and/or have
another entity operate to raise the voltage level back to normal in the North West part of the system?
A) Transformer Underload Tap Changers
B) Shunt Capacitor Banks
C) Generator Reactive Output
D) All ANSWER >>s are correct - ANSWER >> D) All ANSWER >>s are correct Voltage reduction for
load relief should be made on the .
A) Distribution system
B) Entire Interconnection simultaneously
C) Tie-lines with other Balancing Authority Areas
D) Transmission System - ANSWER >> A) Distribution system
Under Frequency Load Shedding (UFLS) is to stabilize the imbalance between generation and load that has
been created by a system disturbance. This is accomplished by .
A) Tripping generation first
B) Voltage reduction on the distribution system.
4|Page
Past Exam Updated 2024/2025 SOS NERC Prep- RElIABILITY Exam
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. - ANSWER >> 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 - ANSWER >> C) 1 & 4
Metered Data included in the calculation of ACE are: dynamic schedules, pseudo ties, actual frequency, and all
.
1|Page
, EPRI Exam Study Guide New Latest Version with All Questions from Actual
Past Exam Updated 2024/2025 SOS NERC Prep- RElIABILITY Exam
A) Tie lines readings
B) Generators output
C) Scheduled frequency indications
D) Transformer load - ANSWER >> 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 - ANSWER >> 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 - ANSWER >> 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 - ANSWER >> 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?
2|Page
, EPRI Exam Study Guide New Latest Version with All Questions from Actual
Past Exam Updated 2024/2025 SOS NERC Prep- RElIABILITY Exam
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 - ANSWER >> 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. - ANSWER >> 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 - ANSWER >> A) Transmission Operators and Balancing Authorities
3|Page
, EPRI Exam Study Guide New Latest Version with All Questions from Actual
Past Exam Updated 2024/2025 SOS NERC Prep- RElIABILITY Exam
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.
C) Re-Dispatch Generation.
D) Initiate the restoration of the parallel line. - ANSWER >> D) Initiate the restoration of the parallel
line.
As a Transmission Operator, you realize that the voltage level is starting to decline in the North West part of the
system. Which of the following devices should you, as a Transmission Operator, be able to operate, and/or have
another entity operate to raise the voltage level back to normal in the North West part of the system?
A) Transformer Underload Tap Changers
B) Shunt Capacitor Banks
C) Generator Reactive Output
D) All ANSWER >>s are correct - ANSWER >> D) All ANSWER >>s are correct Voltage reduction for
load relief should be made on the .
A) Distribution system
B) Entire Interconnection simultaneously
C) Tie-lines with other Balancing Authority Areas
D) Transmission System - ANSWER >> A) Distribution system
Under Frequency Load Shedding (UFLS) is to stabilize the imbalance between generation and load that has
been created by a system disturbance. This is accomplished by .
A) Tripping generation first
B) Voltage reduction on the distribution system.
4|Page
