North American Electric Reliability Corporation (NERC) Practice Exam

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• What is the immediate effect on voltage when a capacitor bank is removed from service?
• Which type of protection relay utilizes current transformers to ensure a balance between current inflow and outflow?
• What does a system operator need to consider when managing reactive power flow in a transmission system?
• What is the maximum time a reliability coordinator may take to return the transmission system to within its IROL?
• What should a BA's primary objective be during a capacity or energy emergency?
• What should a system operator do if system voltage continues to decline after exhausting all resources?
• What type of HVDC system uses two conductors, one with a positive voltage and one with a negative voltage?
• Why is the acceleration of fault clearance time significant in electrical systems?
• Which protective relay is most likely to operate while adjusting the tap changer on a power transformer?
• What measurement is crucial for a distance relay to function effectively?
• What is the primary reason for favoring a controlled operation switching strategy during recovery from a blackout in extreme cold weather?
• Which of the following activities is not part of standard transmission reliability procedures?
• When the voltage is at 207 kV, how many MVARs does a 230 kV, 50 MVAR capacitor bank provide?
• Which action is most appropriate for a transmission operator when faced with the potential for cascading outages?
• What type of metering must each Balancing Authority have on their tie-line with other BAs?
• During initial restoration conditions, what issue is more likely to occur?
• If a system frequency runs at 60.02 Hz for two hours, what is the total positive time error that would occur?
• Why is the location of transmission system reactive power reserves important?
• What term describes the limiting value for MW, MVAR, amperes, frequency, or volts to ensure operation within acceptable reliability criteria?
• Under what condition would an UFLS load shedding plan be considered ineffective?
• Reactive resources are used primarily to maintain what levels in the power system?
• What corrective actions should a transmission operator take to prevent voltage collapse if reactive resources are insufficient?
• What is the primary function of a series capacitor in a power system?
• What duration must a failure of interpersonal communications capability be communicated for notification to the affected entities?
• Which of the following is a key goal of the Capacity Benefit Margin (CBM)?
• During an all-time summer peak load forecast, which scheduled job should proceed given tight generation and reactive resources?
• After selling 500 MW of non-firm ATC from a total of 1000 MW, what amount remains as firm ATC?
• What must each BA agree on with adjacent BAs regarding their Composite Confirmed Interchanges?
• What should be the first step if a study shows that a single contingency would cause an IROL violation?
• What is a primary concern addressed by high-speed transmission protection?
• After a disturbance, what action should a system operator take if re-dispatching generation has no effect on the transmission line?
• What must be ensured for the interchange schedules between two BAs?
• If frequency, voltage, and phase angle are all too high for breaker closing, what should a system operator consider first?
• Which type of MW load is most affected by an intentional frequency reduction?
• If the phase voltage in a wye-connected load is 277 V, what is the line-to-line voltage?
• What key function does a transmission operator perform during operating emergencies?
• What is a likely ultimate outcome when reactive resources are inadequate to meet reactive power demand?
• A transmission line that is loaded above its surge impedance loading (SIL) acts as what?
• What does Frequency Droop in Hz/Max Generation indicate?
• In a simple power system with three lines, if one line trips while initially loaded at 200 MW, what will the loading on the remaining lines become?
• A 1000 MVA rated generator that produces 800 MW and 100 MVAR is best described as?
• The Maximum Sustainable Steady State Capacity (MSSC) for a BA Area is 850 MW. A defined disturbance for DCS reporting is equivalent to how many MWs?
• A generator experiences a 0.3 Hz drop. If its output increases by 50 MW from 400 MW, what is the % droop of the generator?
• In the context of BA operations, what is a critical response during a frequency drop?
• If an IROL is exceeded longer than Tv, what could be the potential result?
• How is stability typically maintained in a power system?
• Can a synchronous machine have a negative torque angle, and what does it indicate?
• What is critical for ensuring the stability and reliability of the bulk electric system during operations?
• Which factor primarily influences the need for reactive power in a power system?
• What information should be confirmed to ensure accurate transactions between BAs?
• What does MSSC stand for in the context of balancing authorities?
• In microwave telecommunications systems, the transmission media primarily used is:
• If line X absorbs 25% of a generator's output, and line X has a transfer limit of 200 MW, what is the maximum output of that generator?
• What is an advantage of employing a distance relay in a system?
• Which resource can provide operating reserves as required by NERC?
• A dynamic schedule tagged for 25 MW must be updated if the flow changes by what percentage?
• What happens to the system frequency when significant MW load is suddenly reduced?
• What could happen if an IROL is allowed to be exceeded for longer than its Tv?
• What will be sold as a non-firm transmission product during EEA2?
• What must be true about the Composite Confirmed Interchanges between adjacent BAs?
• When facing a voltage collapse situation, what action should operating personnel take first?
• When the voltage across the delta winding is calculated from the line to ground voltage, what factor is used?
• The best prediction of system load comes from which load forecast tool?
• What role does natural capacitance have in power system dynamics?
• What is the purpose of transmission reliability policies established by TOP?
• What two methods does NERC recommend for verifying a system's power restoration plan?
• How do series capacitors influence the overall system capacity in power transmission?
• What outcome does raising VAR output from a generator typically have on grid stability?
• What is the immediate action a BA should take when anticipating a capacity shortage?
• What could happen if an Interconnection Reliability Operating Limit (IROL) is exceeded for longer than the allowable time?
• What signifies that interchange transaction information is comprehensive?
• What aspect of electric system reliability does a voltage control device primarily influence?
• During system disturbances, why is it important to monitor frequency changes?
• If three transmission lines connect the generation area to the load area and Line 1 trips, can Line 2 violate its operating security limit when 1000 MW is flowing?
• In the early stages of a system restoration, why are high transmission voltage issues more prevalent than low voltage issues?
• What is the best method for addressing high MVAR and MVA alarms in a 345 kV system during restoration?
• What happens when the ratio of PT to CT measurements falls below a certain limit?
• What is the expected real power output on the secondary side of a 230/115 kV transformer rated at 100 MVA with 80 MW entering the primary side?
• What is an effect of connecting too much inductive load during system restoration?
• What does "DCS" stand for in the context of Balancing Authorities?
• In the case of low voltage in a portion of an RC, what directive should the RC issue?
• Lightly loaded transmission lines behave essentially like what?
• How many hours of system restoration training is required for field switching personnel according to regulatory standards?
• What is the purpose of including Pseudo-Tie in the balancing authorities tie line bias ACE equation?
• To whom must electric utilities report losses of large amounts of firm system loads?
• What is the maximum time for a Transmission Operator to return the system within limits after an IROL violation?
• To comply with operational standards, what is the minimum alteration to a dynamic schedule flow value that triggers a Tag update?
• Which of the following aspects are balancing authorities required to monitor according to NERC regulations?
• How does reducing angle spread contribute to system reliability?
• What is a common method used to compensate for bilaterally inadvertent interchange?
• How does high-speed transmission protection affect angle stability during faults?
• Why is the location of transmission reactive resource reserves significant?
• Which of the following is NOT typically part of load forecasting?
• What is the conceptual basis for determining the p.u. voltage level in electrical systems?
• What is the short-term thermal limit of the transmission path described?
• When synchronizing two systems, if the synchroscope is not moving, what should the system operator do first?
• What is typically necessary for a power system to maintain its stability during peak load conditions?
• What should a system operator do if the line load is approaching its thermal limit?
• If BA A has multiple import and export schedules, what is the net interaction for BA A?
• What information must be evaluated by the Source BA and Sink BA for Arranged Interchange?
• What role do CT measurements play in the operation of distance relays?
• If a transmission line is loaded above its System Interaction Limit (SIL), what happens to the voltage?
• If a dynamic schedule is tagged for an average flow of 100 MW, what is the minimum change required for the Tag to be updated?
• Which statement best describes how reactive power MVAR power normally flows?
• What could be a consequence of failing to manage reactive power effectively during restoration?
• What net effect would a generator trip external to a BA have on that BA's operations?
• What does maintaining acceptable voltage levels help avoid in the bulk electric system?
• According to NERC standards, what is the primary focus of BAs when managing system reliability?
• TOP must develop, maintain, and implement formal policies to ensure transmission reliability. Which of the following does NOT need to be addressed in these policies?
• If the initial interconnection time error is zero seconds and experiences four hours of 60.02 Hz followed by three hours of 59.98 Hz, what is the total accumulated time error?
• For two identically constructed transmission lines, Line A (150 miles) produces more reactive power than Line B (15 miles). What can be inferred about their loading conditions?
• If an EEA 3 is declared and a deficient Balancing Authority needs additional ATC, from where could the RC potentially obtain this ATC?
• In the event of an IROL or SOL violation, who is responsible for responding?
• What is the main focus for operators in terms of preventing cascading outages?
• What is an example of 'supplementary excitation control' equipment?
• Which Balancing Authority is responsible for initiating each Interchange Transaction as tagged?
• When reactive resources are insufficient, what corrective action is required by the Transmission Operator (TOP) to prevent voltage collapse?
• What phenomenon is a geomagnetic disturbance (GMD) most likely to cause?
• The most severe single contingency for a balancing authority area is defined as 850 MW. How much should a disturbance be reported in MW for DCS reporting?
• What occurs to the low side voltage of a 345/115 kV auto-transformer if the high side tap is decreased by 5%?
• Why is closely monitoring system parameters critical during restoration efforts?
• Which aspect is improved by the reduction of fault duration in high-speed transmission protection?
• Which of the following is true regarding lightly loaded transmission lines?
• Under what circumstance is a transmission operator allowed to disconnect from the interconnection?
• If alternative communications are unavailable during routine testing, how long does the responsible entity have to repair or designate a replacement?
• What is a critical action for transmission operators during sudden changes in system load?
• Which of the following tools is essential for ensuring system reliability during high load demands?
• Which component of a coal-fired steam generator creates the rotational force?
• In the event of SCADA alarms indicating a disturbance, what should the operator consider if one of the lines is above its SOL?
• The loading point on a transmission line where MVAR production equals MVAR usage is known as?
• What factor primarily affects the surge impedance loading (SIL) of a transmission line?
• In a high voltage area with off-peak demand, how can voltage be effectively lowered?
• In a power system, the main function of synchronous condensers is to provide what type of power?
• What type of units will provide the largest adjustments in MW output during frequency disturbances?
• What must operating personnel confirm after issuing burst Operating Instructions?
• All transmission operators shall operate to prevent instability, uncontrolled separation, or cascading outages as a result of which factor?
• Which factor is most important to consider when energizing transmission lines during power system reconstruction?
• What tool is used to ensure that the power system can respond within acceptable limits for N-1 conditions?
• Why are high transmission system voltage problems more likely in the initial stages of system restoration?
• How may inadvertent interchange accumulations be repaid?
• What is the approximate line charging contribution of a 230 kV transmission line that is 100 miles long?
• What does NERC stand for?
• Which AGC mode should a BA operating asynchronously switch to?
• Under what circumstance is a Tag not required for an Interchange Transaction replacing an unexpected generation loss?
• Which variable is NOT required to be controlled when synchronizing two islander power systems?
• When coordinating a scheduled outage for a tie-line substation, which parties must communicate?
• Which measure indicates poor voltage stability when operating beyond limits?
• What benefit does high-speed transmission protection provide to angle stability?
• If a generator raises its VAR output, what should the system operator expect to happen to system voltage?
• What types of information must be included in transaction tags?
• In a transaction where BA A sells 100 MW to another BA, how much energy is actually transferred in the first hour if the ramp begins at the top of the hour and lasts 10 minutes?
• Reactive power reserves are crucial for maintaining what aspect of the power system?
• What characteristic defines the operation of a distance relay?
• To minimize a high over voltage at the open end of a transmission line, which type of load is recommended?
• What is typically the first response when a transmission line goes beyond its operating limits?
• When synchronizing two Islands with different frequencies, what is the preferred action?
• What is the function of the CT and PT in a power system?
• Which is a key consequence of failing to manage reactive power effectively?
• How long does it take for a 60Hz voltage wave to complete 1/4 of its cycle?
• What is the per unit (p.u.) voltage if the actual voltage is 362 kV on a 345 bus?
• What action can be taken to prevent voltage collapse due to a reactive power deficiency?
• If a load has a power factor of 0.9 lagging and draws 100 MVA, what is the MW draw?
• What does a gradual decrease in frequency and erratic net actual interchange typically indicate in a power system?
• What is the normal ramp duration for an interchange Schedule between the Eastern and TRE Interconnections?
• For real-time tags of interchange transactions less than an hour, when must they be submitted?
• What is the minimum amount of MWs that would trigger an event report to NERC if load is shed to maintain continuity of the BES?
• What is one responsibility of a Reliability Sharing Group (RSG) when multiple Balancing Authorities join together?
• During the initial system restoration process, load pick-ups are recommended to be limited to what percentage of total synchronized generation?
• What is one function of the Reliability Coordinator?
• During what condition should a transmission operator primarily focus on preventing voltage collapse?
• How much will load change per 1% change in frequency?
• What is one of the outcomes of using high-speed transmission protection?
• What is the importance of reactive power reserves in the transmission system?
• In a tight generation and reactive resources condition, which scheduled job should proceed?
• Which action is NOT within the responsibilities of operating authorities to ensure reliable system operation?
• What is the main purpose of a contingency analysis tool in electric reliability operations?
• What is the main function of Automatic Generation Control (AGC) in terms of NERC compliance?
• If a generator increases its VAR output, what is the expected effect on system voltage?
• In an interchange transaction replacing an unexpected generation loss, what is the maximum duration for which a Tag is not required?
• What is used to help balance a system after it separates from the interconnection during a disturbance?
• After a disturbance in frequency, what could indicate an automatic governor response?
• What can be affected if a transmission line exceeds its temperature threshold?
• A 5% reduction in customer voltage typically leads to what level of reduction in load magnitude?
• If a generator raises its VAR output, what should the system operator expect the system voltage to do?
• A TOP restoration plan should describe the restoration of the power system up to which point?
• What could indicate that interconnection system loads are higher than on-line generation?
• When can dynamic reactive resources be effectively dispatched?
• What should a system operator prioritize to stabilize high voltage in a lightly loaded area?
• During which level of an Energy Emergency Alert is the entity first identified as an Energy Deficient Entity?
• When facing an islanded condition, what is the first step you should take?
• According to NERC requirements, what happens if reactive resources are insufficient during a voltage collapse situation?
• Overlapping regulation service allows a BA to incorporate what into its AGC/ACE equation?
• If a System Protection Scheme (SPS) or Remedial Action Scheme (RAS) is out for maintenance, what should the transmission operator do?
• What tool is used to ensure the power system can respond within acceptable limits N-1 conditions?
• If two 250 mile long transmission lines are exporting excessive MW and one trips, what is the most likely cause of system collapse?
• When the system is nearing a voltage collapse and other remedies are unfeasible, what should operating personnel do?
• What happens to the voltage profile of a bus with a closed breaker when approaching an open breaker?
• In a region experiencing low voltage, what action can a System Operator take to increase the voltage?
• What is one of the basic uses of transformers in electrical systems?
• During high-load conditions, what is a common challenge operators must address to maintain reliability?
• Which device is primarily designed to assist in damping power system oscillations?
• What is the MVA limit for a transmission line with a conductor rated at 180 MVA and a rated line side current transformer of 160 MVA?
• In a computer simulation showing a 100 MW schedule from Bus A to Bus B, if 63% flows on the scheduled path, what is the distribution factor for the scheduled path?
• If balancing authority A is importing 225 MW while only scheduled to import 200 MW, what does the ACE indicate if frequency is 59.99 Hz?
• What is the submission time for Real-Time Tags for interchange transactions within 1-4 hours from Ramp start time?
• What may not exceed during the net scheduled transfer between two Balancing Authority areas?
• Frequency response from AGC systems helps maintain what aspect of system operation?
• Which voltage level is commonly used to reference the size of reactive power resources?
• For reactive resources to be most effective, where should they be located?
• After an Operating Security Limits violation is resolved, which Interchange Transactions should be re-established?
• If a SPS/RAS system is out of service for maintenance, what action should you take within your balancing area?
• If it becomes necessary to implement voltage reduction during an emergency, which system should be prioritized for the reduction?
• What AGC mode should a BA operating asynchronously switch to?
• What is the approximate MVAR per mile production for a 345kV line?
• When generation or transmission equipment must be removed from service, what must the GOP BA and TOP do?
• If a GDM is predicted to occur tomorrow, which parts of the system are most at risk?
• If the phase angle at an open breaker is equal to 1/10 of a cycle, what is this equivalent to in degrees?
• What type of special operation procedure is used to relieve an overloaded transmission path?
• Which entities must coordinate seasonal planning and operations together?
• What does VAR stand for in electrical terms?
• What is the main disadvantage of a microwave telecommunication relay station that relies solely on a local AC power source?
• If a Balancing Authority (BA) has 500 MW of spinning reserves and 300 MW of that are regulating reserves, what does NERC require for those reserves?
• Who is NOT required to receive the complete interchange Transaction Tag?
• What is a potential consequence of exceeding an Interconnection Reliability Operating Limit (IROL)?
• What is not a basic use of transformers?
• What effect does a negative ACE have on a Balancing Authority's (BA) CPS1 score when frequency is above schedule?
• The initial response to a frequency deviation is attributed to which of the following?
• What is the ramp duration for an interchange Schedule between the Western and TRE Interconnections?
• What is the primary purpose of reactive resources in an electrical system?
• During a switching operation, if you notice a loss indication after opening one end, what should you do?
• What type of relay operates based on the ratio of PT measurements to CT measurements?
• A pseudo-tie is included in which part of a Balancing Authority's tie-line ACE equation?
• Under what condition can low voltage occur without an initiating event?
• A BA changes NIs by +40MW for time error correction. What would their Fs value be if their bias setting is -200MW/0.1Hz?
• Which of the following is the best indicator of voltage collapse-prone conditions?
• What type of stability is described by the ability of a power system to maintain equilibrium after a disturbance?
• How often must a Balancing Authority and Reserve Sharing Group review their probable contingencies?
• What is a consequence of a transmission path operating past its long-term limits?
• In the case of line trip situations, how does the load flow change across other lines connected to the grid?
• During operating emergencies, what plan should be in place to manage fuel supplies?
• What is the main risk associated with ignoring GMD warnings?
• If a generator's turbine is spinning the rotor, what type of energy conversion is taking place?
• What is the approximate MVAR/mile for a 345 kV overhead line?
• The responsibility of evaluating reliability impacts during system outages primarily lies with which parties?
• What average percentage decrease in non-motor load magnitude has been indicated for a voltage reduction of 5%?
• If a utility distribution bus has various customer loads totaling 20 MW, what type of load characteristic does this represent?
• Which entity is NOT typically involved in interpersonal communications in the context provided?
• How does a static VAR compensator function when in automatic mode?
• What are the two categories of emergency outlined in NERC Standard EOP-011?
• What action must the Transmission Operator (TOP) perform to relieve an overloaded radial transmission line?
• What would be the best indicator for voltage collapse prone conditions?
• What action should be taken when the interconnection frequency drops from 60Hz to 59.94Hz and the BA ACE is zero?
• How does the power factor of 0.9 lagging affect the apparent power drawn by a load?
• When the Source BA and Sink BA assess information for Arranged Interchange, what key element must be included?
• In reactive power management, raising VAR output is primarily used for what purpose?
• If an 800 MW generator is loaded at 650 MW and can ramp at 5 MW per minute, what is the available spinning reserve on the unit?
• In a distance relay, what triggers its operation?
• If the phase angle at an open breaker is equal to 1/10 of a cycle, what is this same angle expressed in degrees?
• What happens to ACE limits if replacement generation is not restored within the allowed time frame following a DCS event?
• Which of the following types of data are BA and RC not required to share with one another?
• What documentation must operating personnel possess to ensure stable and reliable operation of the Bulk Electric System (BES)?
• What is the primary role of a synchroscope during system synchronization?
• If a BA's bias setting is -200MW/0.1Hz and NIs changed by +40MW, what is a viable Fs value?
• Who should coordinate seasonal planning and operations with the transmission operator?
• If generator at 180 MW trips off in BA A with a total capacity of 1500 MW, is this a DCS event?
• Which two items are typically powered from an emergency power source in a thermal generator?
• In the context of NERC regulations, what is required for regulating reserves that are part of spinning reserves?
• During low load conditions, what primary system conditions does an operator typically seek to alleviate?
• If a substation operator receives an operating instruction incorrectly, what should they do?
• How much advance notice should emergency assistance for a capacity deficiency be scheduled by the BA?
• Why are pilot relay schemes necessary in the context of transmission line protection?
• If a transmission line carries 400 MW and 300 MVAR, what is the total MVA?
• With an actual voltage of 362 kV on a 345 kV bus, what is the p.u. voltage?
• What happens to the voltage phase angle difference when the receiving end load of a transmission line is suddenly increased?
• NERC requires balancing authorities to carry sufficient operating reserves to ensure adequate what?
• What is the voltage across the delta winding of a transformer connected to a power system with 199 kV L-G high side voltage?
• A decrease in voltage can be expected immediately when which component is taken out of service?
• In a load rejection scheme, what does the term 'load' refer to?
• Which of the following elements can affect the operational security limits in a power system?
• Which of the following is categorized as a static reactive reserve source?
• A transmission operator has clear decision-making authority to do what during emergencies?
• What is a common method used to compensate for unilaterally inadvertent interchange?
• What requirement does NERC have for the percentage of Contingency Reserve that must be frequency responsive?
• In a Balancing Authority, what represents a key responsibility for maintaining system reliability?
• To whom should damage or destruction of a facility caused by actual suspected human action be reported?
• Which Balancing Authority is responsible for implementing each Interchange Transaction as Tagged?
• What is the net integrated schedule of BA A after a generator in BA B trips and they agree to a cut?
• Who has the highest level of authority for the reliable operation of the Bulk Electric System (BES)?
• Which of the following reactive reserve sources falls into the static reactive reserve category?
• Which device provides the best reactive reserve response during a disturbance?
• If your frequency bias is -50 MW/0.1 Hz and a large generator in another BA trips, how should your ACE ideally read?
• What term describes the value that satisfies the most limiting operating criteria for a system configuration?
• How should a system operator handle a transmission line that is experiencing loading above the operating limit?
• What type of certification must operation personnel have to implement real-time actions for reliable system operation?
• What effect does having a line loaded below its SIL have on the line voltage?
• What should a system operator do if a major transmission line is out for maintenance and the load is expected to be greater than anticipated?
• What impact does reconnecting disconnected loads too quickly have during system restoration?
• Which aspect is crucial for a Transmission Service Provider to consider when selling ATC?
• What must all Transmission Operators (TOP) ensure to avoid instability in the power system?
• What does it mean when a line is described as being inductive?
• What concept refers to the maximum flow of power that a line can safely handle?
• What is the approximate line charging contribution of a 230kV transmission line that is 100 miles long?
• What condition is likely to contribute to a potential voltage collapse in a power system?
• For Real-Time Tags for interchange transactions 4 hours or more from Ramp start time, what is the required submission time?
• Which factor accounts for the transfer capability reserved by a Load Serving Entity to ensure access to generation for reliability requirements?
• Why is it important for Automatic Generation Control (AGC) equipment to be operational during normal conditions?
• If the voltage is 207 kV, how many MVAR does a 50 MVAR capacitor bank at 230 kV provide?
• Why is the operating reserve capacity important for balancing authorities?
• What does ATC stand for in the context of energy transmission?
• Which term describes the transmission path used to connect a black start resource to the next generator?
• Which source could be counted as dynamic reactive reserve from a rotating source?
• If a Balancing Authority does not meet the DCS in a given quarter, what type of reserve must be increased for the next quarter?
• What should operating personnel do when a system is on the verge of a voltage collapse and no other solutions are available?
• Cold load pickup can involve current flows of up to what maximum levels?
• Upon receiving an alarm for low oil pressure on an underground transmission cable, what is the first step to protect the line?
• In emergency conditions, where should a voltage reduction take place?
• In terms of fault response, what is a potential benefit of reducing angle spread?
• If a transmission line has a flow of 400 MW and a thermal limit of 600 MVA, what is the MVA loading on the line if it is within its thermal limits?
• What is one disadvantage of microwave systems in telecommunications?
• What is the primary purpose of an UFLS program?
• Under what condition does a Balancing Authority's (BA) Area Control Error (ACE) remain at zero?
• What tool is utilized to ensure the power system can operate within acceptable limits following an N-1 contingency?
• In the event of heavy loading in area B, what is the best conclusion for the operator regarding potential separation or islanding?
• If both manually controlled shunt capacitors and automatically controlled generator MVAR are available, which should be used first?
• A reactor rated at 100 MVAR is operating at 90% voltage. How many MVAR is it absorbing from the system?