NERC SOS /356 EXAM QUESTIONS AND CORRECT ANSWERS
(VERIFIED ANSWERS ) ARATED.
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?
Generator Reactive Output
Transformer Underload Tap Changers
All answers are correct
Shunt Capacitor Banks - ANSWER-NERC Standard VAR-001 states,
"Each Transmission Operator shall operate or direct the operation of
capacitive and inductive reactive resources within its area - including
reactive generation scheduling; transmission line and reactive
resource switching; and, if necessary, load shedding - to maintain
system and Interconnection voltages within established limits."
- NERC Standard VAR-001
All answers are correct
One of the functions of underfrequency load shedding is to
______________ within an electrical island that may have been
created by a system disturbance.
,establish balance between load and interchange balance
generation and load
stabilize balance between generators
stabilize the Interconnection - ANSWER-EPRI 4.8 Underfrequency
Load Shedding (UFLS) When disturbances result in power system
islands, there is no guarantee that the islands that form will have the
proper match between generation and load. In fact, there will usually
be a mismatch. The frequency in the island increases or decreases
until the correct balance exists between generation and load. PRC008,
Underfrequency Load Shedding Equipment - Provide last resort
system preservation measures by implementing an Under Frequency
Load Shedding (UFLS) program.
A Balancing Authority that is operating asynchronously (separated
from the Interconnection) should switch its AGC to which mode
__________.
flat frequency control tie line bias control manual control
flat tie-line control - ANSWER-Automatic Generation Control
flat frequency control
A System Operator is in the process of restoring load after a system
collapse. The system currently has three generators online with a
combined capacity of 1200 MWs. Current load on the system is 500
MWs. What is the maximum load that the System Operator can restore
at one time without risking the re-collapse of the system.
,80 MWs
35 MWs
60 MWs
25 MWs - ANSWER-The thumb rule is to restore blocks of load not to
exceed 5% of online generation capacity, which is 1200 MWs in this
scenario.
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 ____________.
Shedding load prior to generation tripping
Shedding all load to arrest frequency
Voltage reduction on the distribution system.
Tripping generation first - ANSWER-Shedding load prior to generation
tripping
Once a deficient Balancing Authority informs the Reliability
Coordinator of future or current Capacity and Energy Emergencies, it
is the responsibility of the __________________ to mitigate the
emergency condition?
Reliability Coordinator
Transmission Operator
Transmission Owner
Deficient Balancing Authority - ANSWER-Deficient Balancing
Authority
, The responsibilities for BAs and RCs are in attachment 1 to EOP-011.
The RCs main responsibility is to notify other entities of the
deficiency situation. The Balancing Authority still has responsibility
of ensuring reliability by taking actions up to, and including shedding
firm load (EEA3).
You are a Reliability Coordinator experiencing a flow gate that has
become overloaded because a parallel 345 kV line has relayed out
causing an SOL violation and possible IROL violation.
What would you do to relieve this violation?
Implement the appropriate transmission loading relief procedures
Notify the affected Reliability Coordinator and ask them to resolve
this issue
Issue a warning to the Transmission Operators that lost the 345 kV
line.
Order the line be placed back in service within 30 minutes. -
ANSWER-Megawatts flow on the path of lowest impedance. When the
345 kV line relayed out, the path of lowest impedance is the flow gate
that has now become in violation of an SOL and IROL. The Reliability
Coordinator has the authority to relieve any transmission facility that
is an actual or potential reliability concern. One of the options
available is to use transmission loading relief procedures which
curtails interchange that contribute to the line overload.
A Balancing Authority anticipating a capacity or energy deficiency
emergency shall perform which of the actions?
(VERIFIED ANSWERS ) ARATED.
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?
Generator Reactive Output
Transformer Underload Tap Changers
All answers are correct
Shunt Capacitor Banks - ANSWER-NERC Standard VAR-001 states,
"Each Transmission Operator shall operate or direct the operation of
capacitive and inductive reactive resources within its area - including
reactive generation scheduling; transmission line and reactive
resource switching; and, if necessary, load shedding - to maintain
system and Interconnection voltages within established limits."
- NERC Standard VAR-001
All answers are correct
One of the functions of underfrequency load shedding is to
______________ within an electrical island that may have been
created by a system disturbance.
,establish balance between load and interchange balance
generation and load
stabilize balance between generators
stabilize the Interconnection - ANSWER-EPRI 4.8 Underfrequency
Load Shedding (UFLS) When disturbances result in power system
islands, there is no guarantee that the islands that form will have the
proper match between generation and load. In fact, there will usually
be a mismatch. The frequency in the island increases or decreases
until the correct balance exists between generation and load. PRC008,
Underfrequency Load Shedding Equipment - Provide last resort
system preservation measures by implementing an Under Frequency
Load Shedding (UFLS) program.
A Balancing Authority that is operating asynchronously (separated
from the Interconnection) should switch its AGC to which mode
__________.
flat frequency control tie line bias control manual control
flat tie-line control - ANSWER-Automatic Generation Control
flat frequency control
A System Operator is in the process of restoring load after a system
collapse. The system currently has three generators online with a
combined capacity of 1200 MWs. Current load on the system is 500
MWs. What is the maximum load that the System Operator can restore
at one time without risking the re-collapse of the system.
,80 MWs
35 MWs
60 MWs
25 MWs - ANSWER-The thumb rule is to restore blocks of load not to
exceed 5% of online generation capacity, which is 1200 MWs in this
scenario.
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 ____________.
Shedding load prior to generation tripping
Shedding all load to arrest frequency
Voltage reduction on the distribution system.
Tripping generation first - ANSWER-Shedding load prior to generation
tripping
Once a deficient Balancing Authority informs the Reliability
Coordinator of future or current Capacity and Energy Emergencies, it
is the responsibility of the __________________ to mitigate the
emergency condition?
Reliability Coordinator
Transmission Operator
Transmission Owner
Deficient Balancing Authority - ANSWER-Deficient Balancing
Authority
, The responsibilities for BAs and RCs are in attachment 1 to EOP-011.
The RCs main responsibility is to notify other entities of the
deficiency situation. The Balancing Authority still has responsibility
of ensuring reliability by taking actions up to, and including shedding
firm load (EEA3).
You are a Reliability Coordinator experiencing a flow gate that has
become overloaded because a parallel 345 kV line has relayed out
causing an SOL violation and possible IROL violation.
What would you do to relieve this violation?
Implement the appropriate transmission loading relief procedures
Notify the affected Reliability Coordinator and ask them to resolve
this issue
Issue a warning to the Transmission Operators that lost the 345 kV
line.
Order the line be placed back in service within 30 minutes. -
ANSWER-Megawatts flow on the path of lowest impedance. When the
345 kV line relayed out, the path of lowest impedance is the flow gate
that has now become in violation of an SOL and IROL. The Reliability
Coordinator has the authority to relieve any transmission facility that
is an actual or potential reliability concern. One of the options
available is to use transmission loading relief procedures which
curtails interchange that contribute to the line overload.
A Balancing Authority anticipating a capacity or energy deficiency
emergency shall perform which of the actions?
