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WorksheetsOHM Exam 3 & 4
Total questions: 100
Worksheet time: 25hrs 0mins
Governor droop is used to:
Arrest Frequency Variations
Maintain Voltage
Restore Frequency to normal
Represent energy lost due to inefficiencies in generation
A Balancing Authority has a normal generation capacity of approximately 9400 MW and its most severe single contingency is an 800 MW coal-fired steam unit. At 1430, with an ACE value of 20 MW, a 600-MW generator trips off-line as the result of a generator differential. This resulted in a large negative ACE for the Balancing Authority. What value must the ACE return to and in what time frame to avoid a DCS violation?
Must return ACE to 0 MW in 10 minutes.
Must return ACE to 20 MW in 15 minutes.
This does not constitute a reportable disturbance.
Must return ACE to 0 MW in 15 minutes.
A Balancing Authority’s inadvertent accumulation reflects over-generation during on-peak hours. When system load is decreasing, what actions could a Balancing Authority system operator take to limit additional on peak inadvertent accumulation?
1. Decrease transactions into their system
2. Increase transactions into their system
3. Decrease generation
4. Increase generation
1 and 4
1 and 3
2 and 4
2 and 3
A 700 MW generator in Balancing Authority A’s area trips off line. Which control system on the remaining generators would respond to the drop in system frequency resulting from the loss of generation?
Differential relay systems
Special protection systems
Generator governor control systems
Automatic Voltage Regulators
A Balancing Authority has twenty units on governor control. The units have different capacities that range from 200 MW to 1000 MW and droop settings from 2% to 5%. The biggest adjustments in megawatt output in response to a frequency disturbance will be provided by units that have _______________.
large capacity and small droop setting
large capacity and large droop setting
small capacity and small droop setting
small capacity and large droop setting
When a high voltage transmission line’s circuit breaker has tripped open as the result of a fault, a synchronous check type relay will monitor certain values on the line side of the open circuit breaker, and the bus side of the open circuit breaker. Before the synchronous check relay will close the open circuit breaker back, which of the following values must be within a certain limit before the circuit breaker will close automatically?
Phase Angle between the voltages
Frequency of the voltages, Voltage magnitudes, Phase Angle between the voltages
Voltage magnitudes
Frequency of the voltages
An 800 MW generator trips in a Balancing Authority external to your Balancing Authority Area. Which of the following indications would you expect to see in your area?
Frequency would drop, and ACE would increase significantly.
Net Actual Interchange would decrease significantly.
Frequency would drop, and ACE would remain relatively unchanged.
ACE would drop to approximately -800 MW.
If a Balancing Authority is unable to purchase capacity or energy to meet its demand and reserve requirements on a day-ahead or hour-by-hour basis, which entity (or entities), is it expected to notify?
All Reliability Coordinators.
All Reliability Coordinators and marketers
Its Reliability Coordinator and other Balancing Authorities
Transmission Operators
The Disturbance Control Standard measures a Balancing Authority’s response to a rapid loss of _____________.
interchange.
ACE.
supply of energy.
demand for energy.
Which of the following is considered to be a reliability event?
1) Low voltage
2) Loss of a small generator
3) SOL or IROL exceeded
4) Loss of Energy Management System
3 and 4
1 and 2
2 and 3
1 and 3
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.
Notify Balancing Authority to increase generation
Raise interchange schedule.
Lower interchange schedule.
A Balancing Authority is experiencing a potential capacity or energy emergency and communicates its current and expected future system conditions to its Reliability Coordinator. What would likely be the Reliability Coordinator first action?
Notify all Reliability Coordinators
Order Load Shed
Notify other Balancing Authorities and Transmission Operators in its Reliability Coordinator Area
Notify the deficient BA marketers
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 ____________.
Tripping generation first
Shedding all load to arrest frequency
Voltage reduction on the distribution system.
Shedding load prior to generation tripping
A Transmission line is loaded 25% above its SOL. A parallel line is out for routine maintenance and can be placed in service in 10 minutes. What is the first step the Operator should take to reduce the line loading?
Open the line.
Shed load at the downstream bus.
Initiate the restoration of the parallel line.
Re-Dispatch Generation.
If firm Load shed is imminent or in progress, what level Energy Emergency Alert is required?
EEA 3
EEA 0
EEA 1
EEA 2
It is the responsibility of which entity/entities to develop, maintain, and implement load shedding plans?
Reliability Coordinator
Load Serving Entities
Transmission Operators and Balancing Authorities
Balancing Authority
A Balancing Authority foresees or is experiencing conditions where all available resources are committed to meet firm load, and firm transactions. The BA should request which level of the Energy Emergency Alerts?
Energy Emergency Alert Level 3
Energy Emergency Alert Level 2
Energy Emergency Alert Level 4
Energy Emergency Alert Level 1
Which entity makes the determination of a Capacity or Energy deficiency and notifies the Reliability Coordinator?
Transmission Operator
NERC
Balancing Authority
Distribution Owner
The coordination of the emergency operating plans the Transmission Operator and Balancing Authority shall include which of the following?
Process to prepare for and mitigate Emergencies
All the answers provided are correct.
Roles and responsibilities for activating operating plan
Cancellation of transmission or generator outages
If multiple lines trip resulting in parallel lines overloading and voltage decreasing, the system operator should first consider which mitigating actions?
Re-dispatch or bring on additional generation
Re-dispatch or bring on additional generation
Curtail Interchange Scheduled to the low voltage area
Shed load to reduce the powerflow on the overloaded lines
Open the line breakers to the overloaded lines.
What is the most important consideration in load forecasting?
Energy Profile
Historic load
Generator outages
Weather
Substation transformer 100/44 rated at 50 MVA has 30 MW entering the primary side. What is the power output at the secondary side?
300 MW
300 MW
40 MVAR
44 MW
30 MW
Balancing Authority personnel are preparing the operating plan for tomorrow. Because of several generator forced outages, it will be difficult to meet the capacity and energy requirements for the system. Heavy purchases are needed for all high load hours and for three hours across the peak; prearranged purchases barely cover the load projections. There is not enough capacity available to maintain the required operating reserves across those three hours. Which of the following possible actions is the most correct?
Do nothing unusual. There will be sufficient capacity and energy to meet the load and there will be only three hours of shortfall in reserves.
Do nothing at present, but be ready to notify the Reliability Coordinator, other Balancing Authorities and Transmission Operators if unable to obtain sufficient capacity in real time to cover the load and reserve requirements.
Continue to establish the plan as it is. There will probably be enough energy available in real time to cover the shortage in reserve.
Notify, through predetermined communication paths, the Reliability Coordinator and all other potentially affected Balancing Authorities and Transmission Operators of the problem.
Interconnection frequency is 60.20 Hz. Your ACE is a large positive value and your AGC is pulsing your units down. What should you do?
Suspend AGC and investigate.
Place AGC in constant frequency control.
Place AGC in flat tie line control.
Leave AGC in operation as your units respond.
A 230 kV transmission line makes contact with a tree as a result of heavy transfers and flashes over to the tree causing the transmission line to relay out. What type of fault is this classified as?
Positive Sequence Fault
Overvoltage Fault
Ground Fault
Differential Fault
What is a Power Transfer Distribution Factor (PTDF)?
A measure of the responsiveness or change in electrical loading used for pre-contingency analysis
Congestion management solutions to the most severe single contingency
Outage results that measures the electrical loading of transmission area based on system loading and generation
Post contingency results and configuration of a system under study
Which of the following are dynamic reactive resources?
1. Synchronous Condenser
2. Capacitor Bank
3. Reactor Bank
4. Generator
1 and 4
2 and 3
1 and 3
2 and 4
What is a System Operating Limit?
The maximum generation allowable in your local system
The value that when exceeded will cause automatic tripping and cascading outages or uncontrolled separation.
The point where irreversible damage occurs in a transmission element
The MW, MVAR, Amperes, Frequency or Volts values that satisfies the most limiting of the prescribed operating criteria for a specified system configuration.
Transmission line AB has a SOL of 375 is currently loaded at 450. Generator A has a shift factor of (- .50) and Generator B has a shift factor of (.25) related to this line. If these are the only units available to relieve the overload, what would be the re-dispatch order to relieve the overloaded line?
Increase Gen B by 25 and decrease Gen A 50.
Decrease Gen A 100 and increase Gen B 100.
Decrease Gen B 100 and increase Gen A 100.
Decrease Gen A 50 and decrease Gen B 25.
A System Operator must operate the transmission system so that instability, uncontrolled separation, or cascading outages will not occur as a result of _________.
Normal operations
External disturbances
The most severe single contingency
Any unplanned outage
The largest single contingency for Balancing Authority A is a unit rated at 900 MW. Which of the following disturbances would constitute a reportable disturbance for DCS evaluation based on the NERC DCS criteria?
The loss of the 900 MW generating unit at 60% output.
The loss of two 400 MW units 30 seconds apart.
The loss of 750 MW of firm load.
The loss of a 700 MW generating unit at 100% output.
On a mild spring day, a transmission line trips. The line then trips again when energized. Which of the following is least likely to be the problem?
Overload
Equipment failure
Vandalism
Sabotage
Which value is a Balancing Authorities approximate response to Interconnection frequency errors and has unit of MW/0.1 Hz?
Net Interchange Actual
AGC
Frequency Bias
ACE
Balancing Authority A (BA A) has two tie-lines with BA B with MW readings of +100 MW and –50 MW respectively. BA C has two tie-lines with BA B with actual MW readings of +60 MW and +90 MW respectively. If these are the only tie-lines for BA B, what is the net actual interchange for BA B?
150
-200
-150
200
Balancing Authority ABC is a member of a Reserve Sharing Group (RSG). At 0605 Balancing Authority ABC loses a 500 megawatt generator. At 0610 it calls on its RSG to replace the lost generation until Balancing Authority ABC can get more generation, such as gas turbines on line and loaded. What time must Balancing Authority ABC stop using RSG power to avoid having to submit a Request for Interchange?
0650
0705
0750
0710
Who must approve a Reliability Adjustment Arranged Interchange before it becomes Confirmed Interchange?
The Reliability Coordinator approves all Reliability Adjustment Arranged Interchange
All Balancing Authorities involved in the Interchange
Only the Source and Sink Balancing Authorities associated with the Interchange
Each Balancing Authority and Transmission Service Provider associated with the Interchange
Which of the following is an assessment criterion for Transmission Service Providers with respect to an interchange transaction request?
Valid transmission path
Transaction start and end time
Sufficient ramp capability
Interchange Magnitude
While assessing a proposed Interchange Transaction, the Source Balancing Authority of the Schedule notes that the schedule will exceed available generation to meet the schedule. What should the System Operator do?
Approve the Interchange Transaction, knowing that within ten minutes after the hour, the generation will catch up.
Change the ramp duration to 20 minutes and approve the Interchange Transaction.
Reduce the MW amount to a level the generators can reach in ten minutes and approve the Interchange Transaction.
Deny the proposed Interchange Transaction and provide the reason for doing so.
Which information should be available to the Reliability Coordinators to have adequate analylsis tools to perform their responsibilities?
Pre-and post-contingency analysis capabilities (thermal, stability and voltage).
State Estimation.
Wide-area overview displays.
All the above
A 345 kV line has a MW flow of 400 and a MVAR flow of 300. The thermal limit of the line is 600 MVA. Assuming the line voltage is 352 kV, what is the MVA loading on the line and is the line within its thermal limits?
500 MVA/No
500 MVA/Yes
700 MVA/No
700 MVA/Yes
The transmission line has a net VAR flow of 25 MVAR’s into or absorbed by the line. Which of the statements is true under this condition?
The line is nearing voltage collapse.
The line is inductive.
The line is capacitive.
The line is transferring the optimum load.
The Transmission Operator must inform which entity when an SOL has been exceeded and the actions being taken to return the system to within limits?
Its Reliability Coordinator
Its Supervisor
Neighboring Transmission Operators
Its Balancing Authority
A Generator Operator shall comply with the Operating Instructions of which entities?
Marketers
Other Generator Operators
Reliability Coordinators
Transmission Operators and Balancing Authorities
Two Balancing Authorities have arranged a schedule of 500 MW between them, well within their transfer capability. Before the ramp has begun, the Reliability Coordinator informs them that implementing the schedule will result in overloading a transmission line in a neighboring system. What action should the two Balancing Authorities take?
Reduce the schedule to a level that will not cause a problem in the neighboring system.
Promise to reduce the schedule in the next scheduling hour, since it is too late to make changes now.
Implement the schedule and rely on the Reliability Coordinator to initiate transmission loading relief procedures if a problem actually occurs.
Inform the Reliability Coordinator that they are well below their allowed schedule magnitude and will not make any changes.
The maintenance and relay testing organization wants to take a 161 kV shunt capacitor bank out of service to replace some capacitor cans and change out an insulator. Since this is not emergency work, when would be the best time to schedule the shunt capacitor outage?
During a winter morning
During projected light loading times
Anytime shunt reactors are also in outage
During the summer when peak loading is at its highest
One purpose for special protection system or remedial action schemes is to ___________.
balance load and generation after a loss of resources
ensure proper breaker tripping and reclosing
isolate electrical faults
provide additional load information to the operator
What type of relays would you most likely find on each end of a 75 mile 230KV transmission line?
49 Thermals
21 Distance and a 64 Ground or 67 Directional Overcurrent
27 Voltage or 25 Synchronous check
87 Differentials
If reactive resources are limited, a Transmission Operator should:
1) Keep voltage schedules as low as the voltage schedules allow
2) Consider reducing real (MW) power to increase reactive (MVAR) availability
3) Ensure sufficient dynamic reserves are available
4) Increase loading on the transmission system
2 and 4
2 and 3
1 and 2
3 and 4
A system operator is anticipating a heavy load day. Which of the following would alert a system operator to a potential voltage collapse?
System voltages are low
ULTC adjustments fail to change the voltage
Reactive power outputs approaching maximum
All the Above
Transient instability occurs when a disturbance on the system causes power angles to exceed_________ .
120 degrees
90 degrees
10 degrees
180 degrees
A 50 MVAR shunt capacitor is available at a 230 kV bus. The bus voltage is well below nominal when the capacitor is placed in service and after it is placed in service, the bus voltage steadies out at 207 kV. What is the approximate MVAR output of the capacitor bank?
40 MVAR
45 MVAR
55 MVAR
50 MVAR
Which entity is the key point of contact when emergencies occur or are expected to occur?
Balancing Authority
Transmission Operators
Reliability Coordinator
Interchange Authority
A firm transaction that started at the top of the hour has caused an overload on a transmission line by 40 MWs over its identified SOL. There are currently non-firm transactions in place that have Power Transfer Distribution Factors (PTDF) of 0.40 on the overloaded line. How much of the non-firm will have to be cut to reduce flow on the overloaded line to within its SOL?
80 MWs
20 MWs
40 MWs
100 MWs
Balancing Authority A is importing 400 MWs of power from Balancing Authority B due to generation outages in BA A's area. This is causing the transmission path between the two BAs to approach its SOL. What should the system operators do?
The BAs should both act according to their best interest.
The BAs and the Reliability Coordinator should discuss and solve the potential SOL.
Balancing Authority B should monitor the path.
Balancing Authority A should purchase from someone else.
Some inadvertent interchange is unavoidable. Which of the following would help keep inadvertent interchange down to a minimum?
Increase the frequency bias setting in the ACE equation.
Run one generator on AGC and the rest on manual so all the AGC signals strength can be used.
Have correct interchange schedules and accurate tie line metering.
Schedule small blocks of megawatts across three consecutive hours.
Which entity shall initiate an Energy Emergency Alert and act to mitigate the emergency condition?
Transmission Operator
Transmission Owner
Reliability Coordinator
Balancing Authority
In performing its reliability analysis, a RC identifies a potential reliability problem. What action should the RC take?
Initiate a conference call with all TOP's in the interconnection.
Initiate a conference call with impacted entities.
Reduce Voltage.
Drop Load.
A 700 MW generator trips in your Balancing Authority Area. Which of the following indications would you not expect to see in your Area?
A large negative ACE
AGC pulsing units down
A drop in frequency
Net Actual Interchange would be less than Scheduled Interchange
Balancing Authority A is currently reading a system frequency of 59.98 Hz. Its Net Actual Interchange is +100 MW and its Net Scheduled Interchange is +100 MW. If Balancing Authority A's frequency bias setting is 100 MW/0.1 HZ, what is ACE?
0
20
-20
2
The Balancing Authority selling power to an end user entered the wrong schedule for the upcoming hour. Which part of the ACE equation [ACE = (NIA – NIS) – 10B (FA – FS) – IME], will cause Inadvertent Interchange to occur as the result of the incorrect schedule?
Both the Interchange portion and frequency portion of the ACE equation (NIA - NIS) will contribute.
The only thing that contributes to Inadvertent Interchange are generating units that trip off line unexpectedly.
Only the frequency portion –10B (FA - FS) will contribute.
Only the interchange portion (NIA - NIS) will contribute.
Governor droop is expressed as:
A percentage of the load change required for a governor to move a unit from a 0 HZ to 60 HZ.
A percentage of the frequency change required for a governor to move a unit from a dead stop to rated RPM.
A percentage of the frequency change required for a governor to move a unit from no voltage at the generator terminals to full voltage at the generator terminals.
A percentage of the frequency change required for a governor to move a unit from no load to full load, or full load to no load.
Balancing Authority A is currently reading a system frequency of 60.06 Hz. Its Net Actual Interchange is +100 MW and its Net Scheduled Interchange is +160 MW. If Balancing Authority A's frequency bias setting is -100 MW/0.1 Hz, Balancing Authority A's AGC should be pulsing its generators to __________.
Increase MW output
Remain at current MW output level
Increase excitation on the field windings
Decrease MW output
When a system is in an island, how much load needs to be shed to compensate for a 1 Hz deviation in frequency?
1 to 2 %
10 to 12 %
3 to 5 %
6 to 10 %
In system restoration, priority should be given to:
Restoring power to critical facilities.
Restoring customer load as quickly as possible.
Restoring auxiliary power to off-line generators.
Reporting disturbance to NERC and DOE.
In the event a Balancing Area experiences multiple contingencies occurring within _________ of each other, it shall be treated as a single contingency.
two minutes
five minutes
fifteen minutes
one minute or less
In an island, what is the most appropriate AGC mode of operation?
Tie-line bias control
Constant Interchange or Flat Tie
Constant or Flat Frequency
Off
Your system is on the verge of a voltage collapse and all reactive resources are at maximum output. You have determined that shedding firm load will alleviate the problem. Before shedding the load, with whom must you confirm the action?
No one
The Reliability Coordinator
Other affected Transmission Operators
The Load Serving Entity
If a Transmission Operator enters an unknown operating state (no valid operating limits have been determined), then the Transmission Operator must restore operations to respect proven reliable power system limits within which time limit?
45 minutes
60 minutes
30 minutes
15 minutes
A Balancing Authority’s largest single contingency is a unit rated at 1,000 MW. Which of the following disturbances would constitute a reportable disturbance for Disturbance Control Performance evaluation based on the NERC DCS criteria?
The loss of a 950 MW generating unit at 100% output.
The loss of 715 MW of firm load.
The loss of 3 generating units totaling 1,300 MW over a period of 3 hours.
The loss of a 750 MW generating unit at 100% output.
Preparations are being made to tie two islands together during restoration. Island “A” has a frequency of 58.95 Hz and Island “B” has a frequency of 59.97 Hz. What action should be taken to synchronize the two islands?
Shed load in Island "A".
Increase generation in Island "B".
Disable the Synch Check Relay.
Shed load in Island "B"
If a Transmission Operator or Balancing Authority is unable to restore Real and Reactive Power Balance, and corrective action or emergency assistance is not adequate, they shall:
Reduce voltage on the distribution system.
Direct the RC to provide assistance.
Reduce voltage on the transmission system.
Implement manual load shedding.
Which entity would make the original determination that it is in an EEA event?
Balancing Authority
Distribution Owner
NERC
Transmission Operator
Voltage is dropping on a 345 kV transmission system. Which of the following devices can be used to increase voltage in the 345 kV system?
1. Shunt Capacitor
2. Generator
3. Under-load tap changer increases to raise distribution voltage
4. Shunt Reactor
1 and 3
1, 2 and 3
2 and 4
1 and 2
Interconnection frequency is remaining around 59.88 Hz, your Balancing Area’s ACE is 0 and there is 300 MW of extra generation available. What should the system operator do?
Let the Marketer know so they can sell power to deficient entity
Offer assistance to entities needing it
Curtail Interchange
Increase Generation
Which equipment should be used first for maintaining or increasing system voltages?
Transmission Breakers
Shedding unnecessary load
Generator Reactive maximum output
Shunt Capacitor Banks
What does governor droop accomplish?
It is a graphical method of representing the efficiency of a governor.
It protects the generator from frequency excursions.
It maintains frequency at 60.00 Hz at all times.
Enable all governors to share in frequency regulation and ensure the bulk system does not enter into power oscillations.
Reliability Coordinator's communicate and coordinate changes in system conditions to its member organizations and directs specific steps so that
Operators can complete their shift
System reliability is not adversely impacted
Interconnection remains in current condition
Actual conditions match forecasted conditions
Intentional human actions, previously known as acts of sabotage must be reported to government agencies, law enforcement and regulatory bodies. Which events are considered reportable?
Damage or destruction of a Facility
Threats to a control center
Physical threat of a Facility
All the above
150 MW is flowing into the high side of a 200 MVA transformer. If the transformer windings have a 2 to 1 ratio what MW value is flowing out of the low side winding of the transformer?
250 MW
150 MW
75 MW
200 MW
Which of the following describes Power Factor?
Difference between real and reactive power
Factors of magnetic strength
The ratio of real power and apparent power
Equation to determine real power
What is the role of the Sink Balancing Authority when directed by the Reliability Coordinator to modify a Confirmed Interchange or Implemented Interchange for reliability-related reasons?
Submit a Reliability Adjustment Arranged Interchange within 30 minutes, then implement the change
Implement the change then submit a Reliability Adjustment Arranged Interchange within 60 minutes.
Submit a Request for Interchange Adjustment and once all approvals are received, implement the change
Contact all Balancing Authorities on the path to ensure the change can be implemented
When a Dynamic Schedule varies enough to require updating the tag, whose responsibility is it to ensure the update is accomplished?
Transmission Service Provider
The Purchasing-Selling Entity responsible for tagging the schedule
Sink Balancing Authority
Source Balancing Authority
When a Dynamic Schedule of 150 MW is completed, the actual integrated value received is 180 MW. Which of the following actions is required?
None of these answers are correct.
No action is necessary because the deviation was not large enough for a schedule of less than 250 MW.
The PSE should update the tag for future hours but leave the next scheduling hour alone.
The PSE should provide an updated tag for the next available scheduling hour and future hours.
The only time the tag for a Dynamic Interchange Schedule must be updated is when the actual hourly integrated energy deviates from the tagged energy profile by a sufficient amount or the RC or TOP determines any deviation is a reliability concern. What is the amount of change which would require an updated tag if the original schedule was 250 MW?
+/-10%
+/- 25 MWhrs
25 MWhrs
more than +/- 25 MWhrs
Balancing Authorities must provide information regarding operating reserves to their Reliability Coordinators. What type of information must be provided?
Spinning and synchronized reserve only
Regulating and Contingency Reserves
Generator Output commitments
Forecast Peak
A System Operator identifies a transmission line that is operating at 100% of its SOL. What should be done?
Immediately reduce the loading.
Monitor for necessary action.
Reduce line voltage.
De-energize the line.
Which of the following would not be considered in determining ratings on transmission facilities?
Thermal limits
Power Transfer Distribution Factor
Voltage limits
Short-term loading limits
A 50 MVA transformer has 30 MW's of load. How many MVARs can flow through the transformer?
40 MVAR
0 MVAR
50 MVAR
30 MVAR
A generator is connected to the Bulk Electric System through three transmission lines (A, B & C) all rated at 340 MVA. Line A is loaded to 300 MVA, Line B is loaded at 200 MVA and Line C is loaded at 100 MVA. Following the loss of Line C, 40% of the flow will shift to Line A. Field personnel request an emergency outage on Line C for repair. Which of the following is the best course of action?
Delay the request until system conditions are more favorable.
Deny the outage request.
Grant the outage request and redispatch generation as necessary.
Grant the outage request.
Each Transmission Operator, and Balancing Authority shall have Interpersonal Communication capability with at least which of the following?
The Department of Energy Operations Center.
All Reliability Coordinators in NERC
Its RC and the respective adjacent TOP or BA
Only TOP's operating within the Reliability Area boundaries.
The Transmission Operator should consider which of the following when reactive resources are limited?
1. Re-dispatch even if that means going outside of economic dispatch
2. Unload heavily loaded lines through reconfiguration
3. Request reactive power support from lightly loaded systems
4. Direct neighboring area to shed load also
1 and 4
1 and 2
2 and 3
3 and 4
You discover that Bus A is de-energized. Each of the feeder breakers off the bus are closed. However, the breakers at the other end of each line from the bus are open. What is the most likely cause for this arrangement?
Inadvertent operation of a ground relay.
Failure of a differential relay.
Failure of a distance relay.
Breaker failure relay operation.
Refer to the figure above; both lines A to B and C to D are protected by Permissive Under Reach Transfer Trip (PUTT) schemes. The over reach relays for Circuit Breaker A detects the fault in the line section between C and D. What keeps Circuit Breaker A from tripping high speed at the same time that Circuit Breaker C and Circuit Breaker D operated at?
Circuit Breaker A relays did not receive a Transfer Trip signal from the relays for Circuit Breaker B.
Circuit Breaker C relays sent a Transfer Trip signal telling A not to trip.
Circuit Breaker A over reach relay settings, will not look past circuit B.
The relays for Circuit Breaker B sent a Transfer Trip signal to the relays for Circuit Breaker A telling it not to trip.
Balancing Authority A is experiencing voltages of 0.9 per unit (pu). Neighboring Balancing Authority B requests emergency energy assistance from BA A. What should BA A do?
Balancing Authority B should increase generation
Balancing Authority A should implement voltage reduction
Balancing Authority A should start generation
Balancing Authority B should increase voltage
Under Voltage Load Shed (UVLS) schemes are designed to drop load in__________.
industrial load areas
pre-selected blocks
low load areas
high load areas
Each Reliability Coordinator shall pay particular attention to ____________________ to ensure an unacceptable or undue burden is not placed on an adjacent Reliability Coordinator Area.
parallel flows
data retention
generation stability
load stability
If the power flow on the transmission system causes transmission equipment to exceed established limits, which corrective actions can the Reliability Coordinator direct to change the power flow?
Change generation or re-dispatch
Reduce Interchange Schedules
Shed Firm Load
All the above
A transmission line has a System Operating Limit (SOL) of 650 MWs. A firm transaction is scheduled to start at the top of the hour that will result the line being loaded to 665 MWs. There are currently non-firm transactions in place that have Power Transfer Distribution Factors (PTDF) of 0.2 on the overloaded line. How much of the non-firm will have to be cut to prevent exceeding the SOL?
None. The firm transaction will not flow since the non-firm transactions were in place first.
15 MWs
75 MWs
30 MWs
Transmission Operator A has a local procedure that requires opening one end of the 161 kV line to relieve a constrained facility. Opening the 161 kV line forces the megawatt flow to take alternate paths. The Reliability Coordinator should use this Operating Procedure___________________?
if it has been agreed to by all affected entities
It is approved by the other Reliability Coordinators
It is approved by NERC
if it will work
When a Reliability Coordinator refers to a GMD, what is being referred to?
Generation Monitoring Device
Ground Modeled Distribution
Geo-Magnetic Disturbance
General Modeling Display
