Contingency Analysis & Reliability
What is an Operating Instruction?
- Any conversation between two or more parties related to the reliability of the BES
- A documented procedure or process for addressing an IROL exceedance
- Real-time Operating personnel command to change or preserve the state of an
element of the BES
- Managers command to shed load - answer- Real-time Operating personnel command
to change or preserve the state of an element of the BES
A Generator Operator receives an Operating Instruction from its Transmission Operator
to bring on additional generation to mitigate a low voltage situation. The Generator
Operator must comply with the Operating Instruction unless:
- The Generator Operator disagrees with the Operating Instruction
- It results in safety concerns or environmental violations
- It has serious financial implications
- The operator is in the middle of shift turnover - answer- It results in safety concerns or
environmental violations
TOP 001, R3
The Transmission Operator experiences an unexpected line outage which results in the
subsequent loading of a parallel line at 101% of its SOL, what action should the
Transmission Operator take?
- Inform the Reliability Coordinator
- Wait until load decreases
- Take the appropriate action to return the system to within normal limits
- Open the overloaded line - answer- Inform the Reliability Coordinator
- Take the appropriate action to return the system to within normal limits
Following a contingency or other event resulting in an Interconnection Reliability
Operating Limit (IROL) violation, the Transmission Operator shall return to within the
IROL as soon as possible, but no longer than ______.
- 15 minutesIts
- IROL Tv
- 30 minutes
- 60 minutes - answerIts IROL Tv
,A Transmission Operator performs a Real-time Assessment that identifies a SOL
exceedance. What should the Transmission Operator do next?
- Shed load required to return to the SOL limit
- Contact the Reliability Coordinator and ask for assistance
- Isolate the line with the exceedance
- Initiate its Operating Plan to mitigate the SOL exceedance - answer- Initiate its
Operating Plan to mitigate the SOL exceedance
When another Transmission Operator requests emergency actions to be implemented
in your area, what is the expectation?
- The requesting TOP has also implemented emergency actions
- You assist immediately without asking questions
- The Reliability Coordinator must make the request
- Uncontrolled cascading outages are imminent - answer- The requesting TOP has also
implemented emergency actions
Which of the following actions would a Transmission Operator be expected to take, or
direct others to take, to mitigate SOL and IROL violations? Select all that apply.
- Shed load
- Change limit
- Disconnect from neighbors
- Reduce Interchange
- Change the output of generators - answer- Shed load
- Reduce Interchange
- Change the output of generators
Why is it necessary to report SOL and IROL exceedances to the Reliability
Coordinator?
- The Reliability Coordinator will then evaluate actions being taken and direct additional
corrective actions as needed
- To shift responsibility for fixing the issue to the Reliability Coordinator
- The Reliability Coordinator will then notify neighboring Reliability Coordinators to open
various circuit breakers
- The Reliability Coordinator will then determine consequences and penalties for the
exceedance - answer- The Reliability Coordinator will then evaluate actions being taken
and direct additional corrective actions as needed
Which are the three types of limits to consider when determining system limits?
- Voltage
- Angle stability
- Thermal
, - Impedance - answer- Voltage
- Angle stability
- Thermal
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?
- Failure of the transmission line
- Loss of power to a local area
- Interruption of power to a large part of the BES
- Voltage below its normal Operating range - answer- Interruption of power to a large
part of the BES
A Transmission Operator has scheduled a short, temporary outage of the SCADA
system for a software update at 22:00 tonight. Which of the following actions is required
of the Transmission Operator?
- Request permission from NERC Operating Committee
- Notify the Reliability Coordinator and known impacted entities of the outage
- Fully implement the Backup Control Center
- Request a level 1 Energy Emergency Alert - answer- Notify the Reliability Coordinator
and known impacted entities of the outage
A transmission line trip results in a SOL exceedance and the Transmission Operator
implements the Operating Plan for the SOL. What should the Transmission Operator do
next?
- Update the map board
- Inform the Reliability Coordinator of actions taken
- Make a fresh pot of coffee
- File event report to NERC within 24 hours - answer- Inform the Reliability Coordinator
of actions taken
No IROL can have an IROL TV that exceeds __________?
15 minutes
30 minutes
90 minutes
60 minutes - answer30 minutes
A Transmission Operator notified the Generator Operator to change the MW output of
their hydro plant to relieve an overloaded transmission line. That is an example of which
of the following?
Operating Plan
Operating Instruction
What is an Operating Instruction?
- Any conversation between two or more parties related to the reliability of the BES
- A documented procedure or process for addressing an IROL exceedance
- Real-time Operating personnel command to change or preserve the state of an
element of the BES
- Managers command to shed load - answer- Real-time Operating personnel command
to change or preserve the state of an element of the BES
A Generator Operator receives an Operating Instruction from its Transmission Operator
to bring on additional generation to mitigate a low voltage situation. The Generator
Operator must comply with the Operating Instruction unless:
- The Generator Operator disagrees with the Operating Instruction
- It results in safety concerns or environmental violations
- It has serious financial implications
- The operator is in the middle of shift turnover - answer- It results in safety concerns or
environmental violations
TOP 001, R3
The Transmission Operator experiences an unexpected line outage which results in the
subsequent loading of a parallel line at 101% of its SOL, what action should the
Transmission Operator take?
- Inform the Reliability Coordinator
- Wait until load decreases
- Take the appropriate action to return the system to within normal limits
- Open the overloaded line - answer- Inform the Reliability Coordinator
- Take the appropriate action to return the system to within normal limits
Following a contingency or other event resulting in an Interconnection Reliability
Operating Limit (IROL) violation, the Transmission Operator shall return to within the
IROL as soon as possible, but no longer than ______.
- 15 minutesIts
- IROL Tv
- 30 minutes
- 60 minutes - answerIts IROL Tv
,A Transmission Operator performs a Real-time Assessment that identifies a SOL
exceedance. What should the Transmission Operator do next?
- Shed load required to return to the SOL limit
- Contact the Reliability Coordinator and ask for assistance
- Isolate the line with the exceedance
- Initiate its Operating Plan to mitigate the SOL exceedance - answer- Initiate its
Operating Plan to mitigate the SOL exceedance
When another Transmission Operator requests emergency actions to be implemented
in your area, what is the expectation?
- The requesting TOP has also implemented emergency actions
- You assist immediately without asking questions
- The Reliability Coordinator must make the request
- Uncontrolled cascading outages are imminent - answer- The requesting TOP has also
implemented emergency actions
Which of the following actions would a Transmission Operator be expected to take, or
direct others to take, to mitigate SOL and IROL violations? Select all that apply.
- Shed load
- Change limit
- Disconnect from neighbors
- Reduce Interchange
- Change the output of generators - answer- Shed load
- Reduce Interchange
- Change the output of generators
Why is it necessary to report SOL and IROL exceedances to the Reliability
Coordinator?
- The Reliability Coordinator will then evaluate actions being taken and direct additional
corrective actions as needed
- To shift responsibility for fixing the issue to the Reliability Coordinator
- The Reliability Coordinator will then notify neighboring Reliability Coordinators to open
various circuit breakers
- The Reliability Coordinator will then determine consequences and penalties for the
exceedance - answer- The Reliability Coordinator will then evaluate actions being taken
and direct additional corrective actions as needed
Which are the three types of limits to consider when determining system limits?
- Voltage
- Angle stability
- Thermal
, - Impedance - answer- Voltage
- Angle stability
- Thermal
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?
- Failure of the transmission line
- Loss of power to a local area
- Interruption of power to a large part of the BES
- Voltage below its normal Operating range - answer- Interruption of power to a large
part of the BES
A Transmission Operator has scheduled a short, temporary outage of the SCADA
system for a software update at 22:00 tonight. Which of the following actions is required
of the Transmission Operator?
- Request permission from NERC Operating Committee
- Notify the Reliability Coordinator and known impacted entities of the outage
- Fully implement the Backup Control Center
- Request a level 1 Energy Emergency Alert - answer- Notify the Reliability Coordinator
and known impacted entities of the outage
A transmission line trip results in a SOL exceedance and the Transmission Operator
implements the Operating Plan for the SOL. What should the Transmission Operator do
next?
- Update the map board
- Inform the Reliability Coordinator of actions taken
- Make a fresh pot of coffee
- File event report to NERC within 24 hours - answer- Inform the Reliability Coordinator
of actions taken
No IROL can have an IROL TV that exceeds __________?
15 minutes
30 minutes
90 minutes
60 minutes - answer30 minutes
A Transmission Operator notified the Generator Operator to change the MW output of
their hydro plant to relieve an overloaded transmission line. That is an example of which
of the following?
Operating Plan
Operating Instruction
