KNOWN NERC EXAM QUESTIONS From
Class (2023)
A Balancing Authority notices that Operating Reserve has steadily declined throughout the hour. What is
... [Show More] the most likely cause?
a) Loss of a large generator in the area
b) An inaccurate load forecast
c) Loss of a major transmission line
d) A malfunction of EMS
b) An inaccurate load forecast
Balancing Area A notices that the Interconnection frequency is 59.94 Hz and their ACE is 0. Which of the following could be the cause of this reading?
in Balancing Area A
generation in the Interconnection
a) A net under-generation
b) A net under-
c) A loss of load in Balancing Area A
d) A loss of load in the Interconnection
b) A net under-generation in the Interconnection
e Disturbance Control
What is the penalty for a Balancing Authority violating th Standard?
a) Must carry additional Contingency Reserve
b) Must develop a correction action plan
c) Must re-evaluate and change its Frequency Bias Setting
d) Must increase its Regulating Reserve
a) Must carry additional Contingency Reserve
Your ACE is a large negative value and system frequency is 59.80 Hz. Your AGC system is pulsing your units down. What should you do?
a) Place AGC in flat frequency control
b) Place AGC in flat tie line control
c) Suspend AGC and investigate
d) Do nothing as this is normal
c) Suspend AGC and investigate
When two identical generating units are operated in parallel on governor control, and on machine has a 5% droop and the other has a 10% droop, the unit with the greater
(10%) governor droop will:
a) Respond less to frequency deviations
b) Respond more to frequency deviations
c) Respond the same to frequency deviations
d) Not adjust for frequency changes
a) Respond less to frequency deviations
On a radial transmission system a generator has a capacity of 600 MWs. The Droop characteristic is at 5% and the generator is currently loaded at 300 MWs. If frequency suddenly drops to 59.3 Hz, what would be the total generator output?
a) 350
b) 400
c) 440
d) 600
c) 440
What is the main purpose of the Frequency Bias Setting in the ACE equation?
a) Control frequency to 60 Hz for the entire Interconnection
b) Assist with arresting frequency deviations
c) Restore frequency to 60 Hz after a disturbance
d) maintains frequency between 59.95 and 60.05 Hz
b) Assist with arresting frequency deviations
A Balancing Authority has a Frequency Bias Setting of -200 MW/.1Hz. What is the Balancing Authority's Frequency Response for a frequency of 59.95 Hz?
a) 10 MWs
b) 50 MWs
c) 100 MWs
d) 200 MWs
c) 100 MWs
Scheduled Interchange is 250 MWs and Actual Interchange is 285 MWs. The Bias
Setting is 35 MW/.1Hz and frequency is 60.00 Hz with no time error correction in effect.
Frequency suddenly drops to 59.80 Hz. What does ACE indicate after the disturbance?
a) 70 MW under-generating
b) 70 MW over-generating
c) 35 MW under-generating
d) 35 MW over-generating
d) 35 MW over-generating
Inadvertent energy accumulation occurs due to a difference in Net Actual Interchange and Net Interchange Schedule over time. This energy accumulation can be paid back unilaterally by adjusting delivery of power:
a) During off-peak periods
b) During periods corresponding to those in which the inadvertent energy was accumulated
c) On weekends
d) Unilaterally when economically beneficial
B) During periods corresponding to those in which the inadvertent energy was accumulated
You are the Source Balancing Authority for an Arranged Interchange Transaction request. The request has a non-standard ramp rate specified. What action should you
take?
a) Deny the request
b) Approve the request if able to accommodate
c) Ignore the request
d) Call the Reliability Coordinator for guidance
b) Approve the request if able to accommodate
Who must approve an Interchange Transaction before it becomes Confirmed Interchange?
a) Balancing Authority
b) Reliability Coordinator
c) Transmission Operator
d) Interchange Coordinator
a) Balancing Authority
00:0201:28
A Balancing Authority is scheduled to receive 300 MWs from the north and 400 MWs from the south for hour ending 1300. The north schedule is curtailed starting at 1220 with a 10-minute ramp. What is the Net Interchange for the hour?
a) 450 MWh
b) 500 MWh
c) 550 MWh
d) 600 MWh
b) 500 MWh
A transaction of 100 MWs is scheduled out of your area at the top of the hour with a 10minute ramp. You have the following generation available: What combination of generation would need to be used?
Generator________MWs_________ Curren MWs________ Ramp Capability
1_____________________100 MW______50 MW________________5 MW/min
2____________________100 MW______40 MW________________3 MW/min
3____________________100 MW______50 MW________________1 MW/min 4____________________100 MW______60 MW________________2 MW/min
a) Generators 1, 2 & 3
b) Generators 1, 3 & 4
c) Generators 1, 2 & 4
d) Generators 2, 3 & 4
c) Generators 1, 2 & 4
When current flow increases in the power system, losses in the system will increase based on which of the following relationships?
a) I2R
b) VI
c) I2Z
d) IR2
a) I2R
Which curve represents the results of a study on voltage response to power flow?
a) D Curve
b) P-V Curve
c) Ferranti Curve
d) VRS Curve
b) P-V Curve
Two adjacent lines exist in a Balancing Area that are the same length and have the same ratings. One line is overhead and the other is underground. How do these two lines respond as load picks up through the day?
a) The overhead line will carry more of the load increase
b) The underground line will carry more of the load increase
c) The load increase will be distributed evenly over the two lines
d) The line with the higher impedance will carry more of the load
b) The underground line will carry more of the load increase To be effective, reactive resources should be:
a) Centrally located in the system
b) Located close to generation
c) In areas subject to high voltages
d) Located close to load areas
d) Located close to load areas
Voltage is high in an area due to off-peak demand. There are several lightly loaded high voltage transmission lines going to radial loads. All capacitor banks are out of service. Generators still have reactive reserves both leading and lagging. What should be done first to lower the voltage?
a) De-energize the lightly loaded lines
b) Use generators to absorb VARs
c) Place capacitor banks in service as needed
d) Increase voltage to increase load
b) Use generators to absorb VARs
A 50 MVA generator is currently producing 40 MWs and 10 MVARs. What are the dynamic reactive reserves currently on this generator?
a) 50
b) 30
c) 0
d) 20
d) 20
In the diagram below, all three lines have the same impedance. What will be the flow on Line 2 if Line 1 is placed in service after an outage? [Show Less]