NERC RANDOM Questions
___________________ is a term used to describe the loss of a generating unit or plant
after a close-in fault, or short circuit that is not cleared quickly enough.
a) Voltage Collapse
b) Cascading Outages
c) Dynamic Instability
d) Transient Instability - ANS d) Transient Instability
Feedback:
Transient Instability is a term used to describe the loss of a generating unit or plant after
a close-in fault, or short circuit that is not cleared quickly enough. Transient instability is
not likely to occur as part of cascading events leading to a blackout, but it could be an
initial event that gets the ball rolling if the system is particularly heavily stressed. Since
such instability causes generation to lose synchronism in a second or less, operators
would only see the result.
\A Balancing Authority has an ACE reading of -100MWs and frequency is 60.12 Hz. Is the
BA exceeding the BAAL?
a) It is impossible to determine from the given information.
b) Yes
c) Yes, but as long as the BA gets within its BAAL in 30 minutes, there is no violation.
d) No - ANS d) No
Feedback: When frequency is above schedule, as in this case, the BAAL LOW does not
apply. Therefore, there is no negative ACE limit in effect.
\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.
True or False - ANS False
Feedback:
A Balancing Authority that is a member of a REGULATION 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 REGULATION
Reserve Sharing.
\A generator is a machine that produces energy. Which of the following statements best
describes this process?
,a) A generator converts mechanical energy to electrical energy
b) A generator produces imaginary power using real fuel
c) A generator does not convert energy it makes it
d) A generator converts electrical energy to mechanical energy - ANS a) A generator
converts mechanical energy to electrical energy
\A Reliability Coordinator performs an Operational Planning Analysis for the next day,
and studies indicate a scheduled outage will cause an SOL violation. What is the best
course of action for the system operator?
a) Deny all requests submitted within that short time frame.
b) Inform the Transmission Operator and delay the decision to approve the outage.
c) Reschedule the outage for a later date.
d) Approve the outage with the understanding the line cannot be out during peak. - ANS
c) Reschedule the outage for a later date.
\A storm blows the A phase and B phase conductors of a 138 kV transmission line
together, creating a phase-to-phase fault. The magnitude of the current and voltage on
the line immediately change, causing the distance relays at each end of the line to
operate. How did the current and voltage on the line change causing the relay to indicate
a fault?
a) The voltage increased and current decreased.
b) The voltage increased and current increased.
c) The voltage decreased and current increased.
d) The voltage decreased and current decreased. - ANS c) The voltage decreased and
current increased.
Feedback:
When a fault occurs on the power grid, the voltage decreases and the current increases
resulting in a decrease in the impedance in the vicinity of the fault. the change in voltage
and current is the input causing the distance relay to respond.
\A transmission system must be operated so that which of the following will not occur as
a result of the most severe single contingency?
a) Power swings
b) Transient instability
c) Instability, uncontrolled separation, or cascading outages
d) Current overloads - ANS c) Instability, uncontrolled separation, or cascading outages
\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?
a) The BA is hurting the Interconnection Frequency.
b) The BA is in CPS1 violation.
c) The BA is helping the Interconnection Frequency.
, d) The BA is in BAAL violation - ANS c) The BA is helping the Interconnection Frequency.
Feedback:
Since frequency is above schedule, the Interconnection as a whole is over-generating.
The BA is under-generating, therefore doing its part to help return frequency to schedule.
This will help the BAs CPS1 score at the end of the month
\An electric power system that is experiencing low voltage is an indication of which of
the following?
a) A deficiency in reactive power
b) Not enough reactors in service
c) A surplus of reactive power
d) Planned transmission line outages - ANS a) A deficiency in reactive power
\Angle stability are the result of?
A) high torque and power angles
B) the thermal capacity of system equipment
C) a reactive power deficiency
D) all the above - ANS A) high torque and power angles
\As the demand for electricity varies, which parameter is monitored to ensure a
generation-load balance in each interconnection?
a) Tie-line flow
b) Frequency
c) ACE
d) Interchange - ANS b) Frequency
Feedback:
Frequency is the indication of total generation load balance in the interconnection. Each
Balancing Authority must ensure generation-load and interchange balancing within their
area.
\At what power angle does the next transfer across a transmission path equal 1/2 of the
max?
A) 15 degrees
B) 20 degrees
C) 30 degrees
D) 45 degrees - ANS C) 30 degrees
\Automatic Generation Control automatically and ____________ adjusts a Balancing
Authority's generation in response to changes in the Balancing Authority's ACE.
a) positively
b) economically
c) precisely
___________________ is a term used to describe the loss of a generating unit or plant
after a close-in fault, or short circuit that is not cleared quickly enough.
a) Voltage Collapse
b) Cascading Outages
c) Dynamic Instability
d) Transient Instability - ANS d) Transient Instability
Feedback:
Transient Instability is a term used to describe the loss of a generating unit or plant after
a close-in fault, or short circuit that is not cleared quickly enough. Transient instability is
not likely to occur as part of cascading events leading to a blackout, but it could be an
initial event that gets the ball rolling if the system is particularly heavily stressed. Since
such instability causes generation to lose synchronism in a second or less, operators
would only see the result.
\A Balancing Authority has an ACE reading of -100MWs and frequency is 60.12 Hz. Is the
BA exceeding the BAAL?
a) It is impossible to determine from the given information.
b) Yes
c) Yes, but as long as the BA gets within its BAAL in 30 minutes, there is no violation.
d) No - ANS d) No
Feedback: When frequency is above schedule, as in this case, the BAAL LOW does not
apply. Therefore, there is no negative ACE limit in effect.
\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.
True or False - ANS False
Feedback:
A Balancing Authority that is a member of a REGULATION 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 REGULATION
Reserve Sharing.
\A generator is a machine that produces energy. Which of the following statements best
describes this process?
,a) A generator converts mechanical energy to electrical energy
b) A generator produces imaginary power using real fuel
c) A generator does not convert energy it makes it
d) A generator converts electrical energy to mechanical energy - ANS a) A generator
converts mechanical energy to electrical energy
\A Reliability Coordinator performs an Operational Planning Analysis for the next day,
and studies indicate a scheduled outage will cause an SOL violation. What is the best
course of action for the system operator?
a) Deny all requests submitted within that short time frame.
b) Inform the Transmission Operator and delay the decision to approve the outage.
c) Reschedule the outage for a later date.
d) Approve the outage with the understanding the line cannot be out during peak. - ANS
c) Reschedule the outage for a later date.
\A storm blows the A phase and B phase conductors of a 138 kV transmission line
together, creating a phase-to-phase fault. The magnitude of the current and voltage on
the line immediately change, causing the distance relays at each end of the line to
operate. How did the current and voltage on the line change causing the relay to indicate
a fault?
a) The voltage increased and current decreased.
b) The voltage increased and current increased.
c) The voltage decreased and current increased.
d) The voltage decreased and current decreased. - ANS c) The voltage decreased and
current increased.
Feedback:
When a fault occurs on the power grid, the voltage decreases and the current increases
resulting in a decrease in the impedance in the vicinity of the fault. the change in voltage
and current is the input causing the distance relay to respond.
\A transmission system must be operated so that which of the following will not occur as
a result of the most severe single contingency?
a) Power swings
b) Transient instability
c) Instability, uncontrolled separation, or cascading outages
d) Current overloads - ANS c) Instability, uncontrolled separation, or cascading outages
\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?
a) The BA is hurting the Interconnection Frequency.
b) The BA is in CPS1 violation.
c) The BA is helping the Interconnection Frequency.
, d) The BA is in BAAL violation - ANS c) The BA is helping the Interconnection Frequency.
Feedback:
Since frequency is above schedule, the Interconnection as a whole is over-generating.
The BA is under-generating, therefore doing its part to help return frequency to schedule.
This will help the BAs CPS1 score at the end of the month
\An electric power system that is experiencing low voltage is an indication of which of
the following?
a) A deficiency in reactive power
b) Not enough reactors in service
c) A surplus of reactive power
d) Planned transmission line outages - ANS a) A deficiency in reactive power
\Angle stability are the result of?
A) high torque and power angles
B) the thermal capacity of system equipment
C) a reactive power deficiency
D) all the above - ANS A) high torque and power angles
\As the demand for electricity varies, which parameter is monitored to ensure a
generation-load balance in each interconnection?
a) Tie-line flow
b) Frequency
c) ACE
d) Interchange - ANS b) Frequency
Feedback:
Frequency is the indication of total generation load balance in the interconnection. Each
Balancing Authority must ensure generation-load and interchange balancing within their
area.
\At what power angle does the next transfer across a transmission path equal 1/2 of the
max?
A) 15 degrees
B) 20 degrees
C) 30 degrees
D) 45 degrees - ANS C) 30 degrees
\Automatic Generation Control automatically and ____________ adjusts a Balancing
Authority's generation in response to changes in the Balancing Authority's ACE.
a) positively
b) economically
c) precisely
