nerc mix question miss
A Balancing Authority informs the Reliability Coordinator that the projected load in a
Balancing Area for the next four hours (over the morning peak) is trending above the
available generation that had been committed for the day. Operating Reserves will be
required to be converted into energy to cover the shortfall. Which Energy Emergency
Alert (EEA) level should the RC declare?
No EEA should be declared until load shed is expected.
EEA 3
EEA 2
EEA 1 - ANS EOP-011 Emergency Operations, Attachment 1, Energy Emergency Alerts -
Level 1 is when the Balancing Authority is experiencing conditions where all available
generation resources are committed to meet firm Load, firm transactions, and reserve
commitments, and is concerned about sustaining its required Contingency Reserves.
\A Balancing Authority with several units offline anticipates a capacity shortage during
the afternoon peak due to unseasonal temperature forecast. What should the BA
consider first?
Implement voltage reduction procedures
Postpone or cancel unit maintenance
Drop load
Curtail interruptible customers - ANS Postpone or cancel unit maintenance
\A basement fire forces the evacuation of a Reliability Coordinator's primary control
center. How long does the Reliability Coordinator have to transition to and fully
implement backup functionality?
Within 30 minutes
Within 1 hour
By the next shift
Within 2 hours - ANS Backup functionality must be implemented within 2 hours.
Reliability Coordinators are required to have a backup control center.
\A car on a city street hit a 13kV power pole causing A and B phases to wrap around each
other. The 13kV line relays at the substation fail to trip the 13kV circuit breaker feeding
the troubled line. Which relay will likely pick up and trip the 138/13kV transformer feeding
the 13kV system off line to protect it from damage.
Differential
Phase Comparison
Timed Overcurrent
Ground - ANS Due to the failure of the circuit feeder breaker operating and clearing the
fault, an increase in current will be imposed on the transformer feeding the bus. Since
,the differential relay 87T only looks at current entering and leaving the transformer the
ratio will remain the same. The increase in current on both sides of the transformer will
indicate a fault downstream of the transformer and a resulting trip of the overcurrent
relay. Timed Overcurrent
\A contingency results in the exceedance of an IROL. What could be the result if the IROL
is allowed to be exceeded longer than its TV?
The transmission line could fail
Protective relays could fail
Interruption of power to a large part of the BES
Loss of power to a local area - ANS Interruption of power to a large part of the BES
\A contingency results in the exceedance of an IROL. What could be the result if the IROL
is allowed to be exceeded longer than its TV? 1.The transmission line could fail
2.Interruption of power to a large part of the BES
3.Protective relays could fail
4.Loss of power to a local area - ANS Interconnection Reliability Operating Limit TV: The
maximum time that an Interconnection Reliability Operating Limit can be violated before
the risk to the interconnection or other Reliability Coordinator Area(s) becomes greater
than acceptable. Each Interconnection Reliability Operating Limit's Tv shall be less than
or equal to 30 minutes.
\A dynamic schedule is running with a MW profile of 285 MW. Last hour the actual hourly
integrated energy was 310 MW's. What will be the schedule for the next available
scheduling hour?
313.5
310
320
285 - ANS 285
There is no change. The deviation had to be more than +/- 10% to require a change in the
RFI. -
\A Generator Operator has some vibration problems with a 500MW coal fired steam
generator. As the result of the vibration problems the Generator Operator has to set the
maximum reactive power production for that unit at 25 Megavar instead of the normal 200
Megavar. Who should the generator operator notify as the result of this problem?
System Coordinator
Transmission Operator
Regional Reliability Organization
Department of Energy (DOE - ANS It is vital for the Transmission Operator to know how
much reactive power is available. The Transmission Operator must have sufficient
reactive reserves in case of an emergency such as the loss of a major transmission line
or generating unit. NERC specifically says that the Generator Operator shall inform the
Transmission Operator when reactive resources are limited or unavailable as the result of
mechanical or electrical problems. - NERC Standard VAR-001
, \A line is operating at 125% (25% above its SOL) following several parallel line outages
caused by a severe storm. The flow on this line is from Bus A, which is north, to Bus B,
which is south. As a System Operator, you decide to use generation redispatch to relieve
the line loading problem. What should your course of action be?
1.Increase generation on the north side of Bus A and decrease generation on the south
side of Bus B.
2.Decrease generation on the north side of Bus A and increase the generation on the
south side of Bus B.
3.Decrease generation on the north side of Bus A and decrease generation on the south
side of Bus B.
4.Increase generation on the north side of Bus A and increase generation on the south
side of Bus B - ANS answer 2. Power is flowing from the north to the south by way of
Line A-B. This means the demand is south of Bus B. The corrective action would be to
increase the generation south of Bus B to serve the demand with increased generation in
that area, at the same time decreasing the generation north of Bus A. These actions will
relieve some of the loading problems on line A-B.
\A major transmission line has become overloaded and the transmission operator has
taken actions to unload the line. However, the overload persists, and the equipment is
now in imminent danger of damage. What is the next action to take?
Request a Transmission loading relief procedure
Disconnect the overloaded line and notify the RC and affected Transmission Operators.
Request permission from the RC to open the line.
Separate from the Interconnection - ANS Disconnect the overloaded line and notify the
RC and affected Transmission Operators
\A power system with long transmission lines that connect remote generation to load
centers is more likely to have System Operating Limits or Interconnection Operating
Limits determined by:
Angle stability limitations
Generator thermal limitations
Generator voltage limitation
Transmission thermal limitations - ANS Angle stability limitations
\A radial transmission line is overloaded. Which action must a Transmission Operator do
to unload the line?
Shed load at the end of the radial line.
Lower interchange schedule.
Raise interchange schedule.
Notify Balancing Authority to increase generation - ANS A radial line carries power in one
direction to serve the load demands at the end of that line. When a radial line is
overloaded, the system operator will have to shed load to relieve the overload condition
A Balancing Authority informs the Reliability Coordinator that the projected load in a
Balancing Area for the next four hours (over the morning peak) is trending above the
available generation that had been committed for the day. Operating Reserves will be
required to be converted into energy to cover the shortfall. Which Energy Emergency
Alert (EEA) level should the RC declare?
No EEA should be declared until load shed is expected.
EEA 3
EEA 2
EEA 1 - ANS EOP-011 Emergency Operations, Attachment 1, Energy Emergency Alerts -
Level 1 is when the Balancing Authority is experiencing conditions where all available
generation resources are committed to meet firm Load, firm transactions, and reserve
commitments, and is concerned about sustaining its required Contingency Reserves.
\A Balancing Authority with several units offline anticipates a capacity shortage during
the afternoon peak due to unseasonal temperature forecast. What should the BA
consider first?
Implement voltage reduction procedures
Postpone or cancel unit maintenance
Drop load
Curtail interruptible customers - ANS Postpone or cancel unit maintenance
\A basement fire forces the evacuation of a Reliability Coordinator's primary control
center. How long does the Reliability Coordinator have to transition to and fully
implement backup functionality?
Within 30 minutes
Within 1 hour
By the next shift
Within 2 hours - ANS Backup functionality must be implemented within 2 hours.
Reliability Coordinators are required to have a backup control center.
\A car on a city street hit a 13kV power pole causing A and B phases to wrap around each
other. The 13kV line relays at the substation fail to trip the 13kV circuit breaker feeding
the troubled line. Which relay will likely pick up and trip the 138/13kV transformer feeding
the 13kV system off line to protect it from damage.
Differential
Phase Comparison
Timed Overcurrent
Ground - ANS Due to the failure of the circuit feeder breaker operating and clearing the
fault, an increase in current will be imposed on the transformer feeding the bus. Since
,the differential relay 87T only looks at current entering and leaving the transformer the
ratio will remain the same. The increase in current on both sides of the transformer will
indicate a fault downstream of the transformer and a resulting trip of the overcurrent
relay. Timed Overcurrent
\A contingency results in the exceedance of an IROL. What could be the result if the IROL
is allowed to be exceeded longer than its TV?
The transmission line could fail
Protective relays could fail
Interruption of power to a large part of the BES
Loss of power to a local area - ANS Interruption of power to a large part of the BES
\A contingency results in the exceedance of an IROL. What could be the result if the IROL
is allowed to be exceeded longer than its TV? 1.The transmission line could fail
2.Interruption of power to a large part of the BES
3.Protective relays could fail
4.Loss of power to a local area - ANS Interconnection Reliability Operating Limit TV: The
maximum time that an Interconnection Reliability Operating Limit can be violated before
the risk to the interconnection or other Reliability Coordinator Area(s) becomes greater
than acceptable. Each Interconnection Reliability Operating Limit's Tv shall be less than
or equal to 30 minutes.
\A dynamic schedule is running with a MW profile of 285 MW. Last hour the actual hourly
integrated energy was 310 MW's. What will be the schedule for the next available
scheduling hour?
313.5
310
320
285 - ANS 285
There is no change. The deviation had to be more than +/- 10% to require a change in the
RFI. -
\A Generator Operator has some vibration problems with a 500MW coal fired steam
generator. As the result of the vibration problems the Generator Operator has to set the
maximum reactive power production for that unit at 25 Megavar instead of the normal 200
Megavar. Who should the generator operator notify as the result of this problem?
System Coordinator
Transmission Operator
Regional Reliability Organization
Department of Energy (DOE - ANS It is vital for the Transmission Operator to know how
much reactive power is available. The Transmission Operator must have sufficient
reactive reserves in case of an emergency such as the loss of a major transmission line
or generating unit. NERC specifically says that the Generator Operator shall inform the
Transmission Operator when reactive resources are limited or unavailable as the result of
mechanical or electrical problems. - NERC Standard VAR-001
, \A line is operating at 125% (25% above its SOL) following several parallel line outages
caused by a severe storm. The flow on this line is from Bus A, which is north, to Bus B,
which is south. As a System Operator, you decide to use generation redispatch to relieve
the line loading problem. What should your course of action be?
1.Increase generation on the north side of Bus A and decrease generation on the south
side of Bus B.
2.Decrease generation on the north side of Bus A and increase the generation on the
south side of Bus B.
3.Decrease generation on the north side of Bus A and decrease generation on the south
side of Bus B.
4.Increase generation on the north side of Bus A and increase generation on the south
side of Bus B - ANS answer 2. Power is flowing from the north to the south by way of
Line A-B. This means the demand is south of Bus B. The corrective action would be to
increase the generation south of Bus B to serve the demand with increased generation in
that area, at the same time decreasing the generation north of Bus A. These actions will
relieve some of the loading problems on line A-B.
\A major transmission line has become overloaded and the transmission operator has
taken actions to unload the line. However, the overload persists, and the equipment is
now in imminent danger of damage. What is the next action to take?
Request a Transmission loading relief procedure
Disconnect the overloaded line and notify the RC and affected Transmission Operators.
Request permission from the RC to open the line.
Separate from the Interconnection - ANS Disconnect the overloaded line and notify the
RC and affected Transmission Operators
\A power system with long transmission lines that connect remote generation to load
centers is more likely to have System Operating Limits or Interconnection Operating
Limits determined by:
Angle stability limitations
Generator thermal limitations
Generator voltage limitation
Transmission thermal limitations - ANS Angle stability limitations
\A radial transmission line is overloaded. Which action must a Transmission Operator do
to unload the line?
Shed load at the end of the radial line.
Lower interchange schedule.
Raise interchange schedule.
Notify Balancing Authority to increase generation - ANS A radial line carries power in one
direction to serve the load demands at the end of that line. When a radial line is
overloaded, the system operator will have to shed load to relieve the overload condition
