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NERC SOS Exam | Actual Questions and Answers Latest Updated 202 5 /202 6
(Graded A+)
If a Balancing Authority does not comply with the Control Performance Standard, the Balancing Authority is not permitted to provide which of the following for any other Balancing Authority entities? - ✔✔Regulation of other services related to control performance
- It is the obligation of each Balancing Authority to fulfill its commitment to the Interconnection and not the other balancing Authorities in the Interconnection - ✔✔Burden A Balancing Authority is performing Overlap Regulation Service for another Balancing Authority. Which of the following statements applies to the Balancing Authority providing this service? - ✔✔The Balancing Authority's Frequency Bias Setting shall be modified to reflect the combined Frequency Bias Setting of both Balancing Areas. Balancing Authority A is currently reading a system frequency of 59.95 Hz. Its Net Actual Interchange is +100 MW and its Net Scheduled Interchange is +200 MW. If Balancing Authority A's frequency bias setting is 100 MW/0.1 Hz, Balancing Authority A's AGC is pulsing its generators to do what? - ✔✔Increase MW output Which of the following is a Real-time measurement of a Balancing Authority's control performance - ✔✔BAAL Each Balancing Authority shall monitor which of the following against two standards: CPS1 and BAAL? - ✔✔Control performance In the calculating of CPS1, which of the below conditions would contribute to ta favorable score? - ✔✔Negative ACE when frequency is high, positive ACE when frequency is low.
If the frequency bias setting is a higher value than the frequency response of a Balancing Authority and a frequency decline is caused by a sudden loss of generation is an external balancing area, what will be the result? - ✔✔A- The ACE will be a negative value and AGC will increase generation Which statement best describes the CPS1 requirement? - ✔✔The Responsible Entity shall operate such that its CPS1 is greater than or equal to 100% for the preceding 12 month period. To be in compliance with the BAL-001 requirements, a Balancing Authority must have which of the following? - ✔✔CPS1 greater than or equal to 100% and ACE does not exceed the BAAL more than 30 consecutive minutes Actual System Frequency (FA) is 60.03 Hz, a Balancing Authority is under-generating slightly to prepare for an upcoming interchange transaction. What is the Balancing Authority doing? - ✔✔The BA is helping the Interconnection Frequency. You are a Balancing Authority Operator. A neighboring Balancing Authority in the Interconnection suddenly had a 500 MW generator to trip off line by generator differential. What part of the ACE equation, ACE = (NIA-NIS) - 10B (FA-FS) - IME, allows you and other Balancing Authorities in the Interconnection to contribute to the stabilization of the Interconnection frequency error? - ✔✔10B (FA-FS) In your Interconnection, a generator tripped that was large enough to reduce the frequency from 60. Hz to 59.940 Hz. Your Balancing Authority's Frequency Bias is 200 MW/0.1 Hz. How many MW would your system initially contribute to frequency support? - ✔✔120 MW Which of the following would be a use of the IME portion of the ACE equation? - ✔✔Represent flow of a tie line with an out of service meter. What happens to the Balancing Authority ACE Limit (BAAL) when frequency moves farther away from scheduled frequency? - ✔✔The limit gets more restrictive. How is the Frequency Response Obligation (FRO) of a Frequency Response Sharing Group determined? - ✔✔By adding the individual FRO's of each member.
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 DCS evaluation based on the NERC DCS criteria? - ✔✔The loss of a 950 MW generating unit at 100%. If a Reserve Sharing Group member has experienced a Reportable Disturbance condition but does not call for reserve activation from other members, the entire group shall still be considered to be in a disturbance condition. - ✔✔False Which of the following is a potential source of Contingency Reserve?
- Offline generation that takes 10 minutes to start at full output.
- Online generation at 100% capacity
- Controllable load resources.
- Voltage reductions. - ✔✔ 1 and 3 The minimum compliance for NERC DCS is? - ✔✔100% for all reportable disturbances. How is the Frequency Response Measure (FRM) of a Balancing Authority determined? - ✔✔It is the median of the BA's frequency response for the frequency deviation events identified by NERC for the previous year. In order to achieve sufficient Frequency Response, the Frequency Response Measure (FRM) of a Balancing Authority or Frequency Response Sharing Group must be: - ✔✔Equal to or more negative than the Frequency Response Obligation (FRO) A Balancing Authority is performing Overlap Regulation Service for another Balancing Authority. Which of the following statements applies to the Balancing Authority providing this service? - ✔✔The Balancing Authority's Frequency Bias Setting shall be modified to reflect the combined Frequency Bias Setting of both Balancing Areas. Balancing Authority A is currently reading a system frequency of 59.95 Hz. Its Net Actual Interchange is +100 MW and its Net Scheduled Interchange is +200 MW. If Balancing Authority A's frequency bias
setting is 100 MW/0.1 Hz, Balancing Authority A's AGC is pulsing its generators to do what? - ✔✔Increase MW output In order to achieve sufficient Frequency Response, the Frequency Response Measure (FRM) of a Balancing Authority or Frequency Response Sharing Group must be: - ✔✔Equal to or more negative than the Frequency Response Obligation (FRO) If the frequency bias setting is a higher value than the frequency response of a Balancing Authority and a frequency decline is caused by a sudden loss of generation is an external balancing area, what will be the result? - ✔✔The ACE will be a negative value and AGC will increase generation What is the primary purpose of governor dead band? - ✔✔It prevents governors from operating when slight variations occur in the system's frequency. How is the Frequency Response Obligation (FRO) of a Frequency Response Sharing Group determined? - ✔✔By adding the individual FRO's of each member. A portion of a Balancing Authority's EMS has gone down and the EMS can no longer calculate ACE. According to NERC, how long can a Balancing Authority operate without the ability to calculate ACE before notifying its Reliability Coordinator? - ✔✔30 minutes What type of service is a method of providing regulation in which the providing Balancing Authority incorporates all of the other Balancing Authorities tie lines, frequency response, and schedules into its own AGC/ACE equation? - ✔✔Overlap regulation service According to NERC, by the end of the business day following the actual operation, two adjacent Balancing Authorities must agree upon what values with regard to inadvertent interchange? 1.) The hourly values of Net Interchange Schedule 2.) The hourly values of each Interchange Transaction 3.) The hourly integrated megawatt-hour values of individual interconnecting tie lines 4.) The hourly integrated megawatt-hour values of Net Actual Interchange - ✔✔ 1 and 4 only
Which part of the ACE equation reflects dynamic schedules? - ✔✔The scheduled interchange component, NIS NERC requires that Balancing Authority operators be provided with sufficient instrumentation. For ACE Calculation, which of the following are the minimum required real time values that must be available to the Balancing Authority operator? - ✔✔Real-Time values for ACE, Interconnection Frequency and Net Actual Interchange with each adjacent Balancing Authority Area Which entities may determine if a deviation of a Dynamic Schedule constitutes a reliability concern? What entity must they notify of that determination? - ✔✔A Reliability Coordinator or Transmission Operator makes the determination and must notify the Purchasing-Selling Entity What is the purpose of NERC Standard INT-004? - ✔✔Purchasing-Selling Entity What is the difference between a Dynamic Schedule and a Pseudo-tie? - ✔✔A Dynamic Schedule is a time-varying energy transfer that is updated in Real-time and included in the Net Interchange Scheduled term of the ACE equation, while a Pseudo-tie is included in the Net Interchange Actual term. The Confirmed Interchange associated with a Dynamic Schedule is 370 MWs. Assuming the deviation is expected to persist, how much must the actual hourly integrated energy deviate from the Confirmed Interchange to require an update to be submitted for future hours? - ✔✔More than +/- 37 MWs Some inadvertent interchange is unavoidable. Which of the following would help keep inadvertent interchange down to a minimum? - ✔✔Have correct interchange schedules and accurate tie line metering. Each Balancing Authority shall ensure all of its Balancing Authority Area interconnection points are equipped with? - ✔✔common megawatt-hour meters providing readings to the control centers both adjacent Balancing Authorities. What are the two types of Inadvertent Interchange? - ✔✔Primary and Secondary
Each Balancing Authority shall, through daily schedule verification, and the use of , accurately account for inadvertent interchange. - ✔✔reliable metering equipment In order to implement a bilateral payback for inadvertent interchange with another Balancing Authority, what two conditions must be satisfied? - ✔✔The other Balancing Authority must have inadvertent accumulation in the opposite directions. The amount schedules shall be agreed upon by all involved Balancing Authorities and Transmission Providers. Two marketers arranged a transaction but neglected to tell the appropriate Balancing Authorities about it until it had been in effect for two hours. The marketers ask the Balancing Authorities to adjust the inadvertent interchange accounts for the month to account for the energy for those two missed hours. Should the affected Balancing Authorities agree to this request? - ✔✔No, this is not a proper use of inadvertent accounting 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? - ✔✔Decrease transactions into their system Decrease generation Which of the following entities is responsible for approving or denying an Arranged Interchange? Select all that apply. - ✔✔Involved Transmission Service Providers Involved Balancing authorities Which of the following best describes Available Transfer Capability (ATC)? - ✔✔The amount of transfer capability in the transmission network remaining for further commercial activity over and above already committed uses Entities have limited amount of time to evaluate the potential impact of a Request for Interchange. Where would entities find the timing requirements? - ✔✔Attachment 1 in Standard INT- 006 What is the definition of Confirmed Interchange? - ✔✔The state where no party has denied, and all required parties have approved the Arranged Interchange
As a result of high MW flows, a transmission line sags significantly and current flashes over to a tree growing directly below it. This causes the protective relays to take the transmission line out of service. How would you classify this type of fault? - ✔✔Ground fault A transformer differential zone has Circuit Breakers 624 and 634 protecting the transformer. Breaker 624 receives 1500 MVA and Breaker 634 sends 1200 MVA to the bus. Based on these conditions, determine which of the following statements is true. - ✔✔All of the above What type of relays would you most likely find on each end of a 75 mile 230 kV transmission line? - ✔✔ 21 Distance or 67 Directional Overcurrent A protective relay may send transfer trip signals to a remote location in order to trip a circuit via a communication channel. Transfer trip signals may either trip a circuit breaker directly or initiate operation of an auxiliary tripping relay. The use of transfer trip signals, however, is limited because they can only be sent via a power line carrier. - ✔✔False A Generator Operator shall coordinate installation of all new protective systems and changes to existing protective system with its. - ✔✔Transmission Operator and Host Balancing Authority A storm blows the A phase and B phase conductors of a 138 kV transmission line together, creating a phase-to-phase fault. The magnitude of the current and voltage on the line immediately change, causing the distance relays at each end of the line to operate. How did the current and voltage on the line change causing the relay to indicate a fault? - ✔✔The voltage decreased and current increased. When a high voltage transmission line circuit breaker trips open as a result of a fault, a synchronous check relay will monitor certain values on both the line side and the bus side of the open circuit breaker. Before the synchronous check relay re-closes the open circuit breaker, which of the following values has to be within a certain limit before the circuit breaker will close automatically? - ✔✔Frequency Voltage magnitudes Phase Angle between the voltages What type of relay uses a combination of current transformer (CT) measurements and potential transformer (PT) measurements and operates when the ratio of the PT measurements to CT measurements is below a certain limit for a given period of time? - ✔✔Distance Relay (Device 21)
A Generator Operator is planning to increase the capacity of an existing 500 MW generator to support the addition of new equipment. Which entity must be notified of the changes in generation capacity? - ✔✔Its Transmission Operator and others that may require changes in their protection system Protective relays used on transmission and distribution systems are designed to... - ✔✔minimize damage and isolate problems on the system. an entire bus at a substation was cleared instantaneously. A substation maintenance employee calls the control room to inform them the relayed target displays indicate operation of a relay 87 on its bus relay panel. What type of relay has operated? - ✔✔Differential Relay A relay controlling circuit breaker A detects a zone 2 fault outside its line section. Normally, under this condition, the relay is designed to trip circuit breaker A only it its zone 2 timer times out. However, in this case, circuit breaker A trips at high speed. The tripping of circuit breaker A would be classified as a
. - ✔✔misoperation Which of the following situations would require an analysis and corrective action plan be submitted to the local Regional Reliability Organization (RRO)? - ✔✔A 161/69/13 kV transformer was de-energized due to a transformer differential relay operation at exactly the same time that a 161 kV line ground fault occurred on one of the 161 kV lines that feed from the station's 161 kV bus. The Transmission Operator you work for is installing relays with new technology on some of their major transmission tie lines. Who should your company notify before it begins installation of these new relays?
- ✔✔Neighboring Transmission Operators and Balancing Authorities. Examples of reactive resources include generators and static VAR compensators. - ✔✔dynamic The voltage on the power system is starting to drop due to the normal load pick-up during the morning hours. As a Transmission Operator, where should you increase the reactive power on the transmission and distribution systems? - ✔✔As close to the heaviest inductive load areas as possible.
Why must the Generator Operator use an alternative method to control the generator voltage and reactive output when the Automatic Voltage Regulator is out of service? - ✔✔To meet the voltage or Reactive Power Schedule. The Transmission Operator and Transmission Planner have requested the tap settings, available fixed tap ranges, and impedance data for several generator step-up transformers. How long does the Generator Owner(s) have to provide this information? - ✔✔30 Calendar Days The Transmission Operator has determined the tap settings of a generators step-up transformer must change. Which entity is required to ensure the requested changes are implemented? - ✔✔Generator Owner Who is responsible for providing the Transmission Operator and Transmission Planner with requested information about generator step-up transformers and auxiliary transformers with primary voltages equal to or greater than the generator terminal voltage? - ✔✔Generator Owner When power flow is expected to reach or exceed System Operating Limits, the System Operator must: - ✔✔Redistribute power flow to relieve the overloaded transmission line. Which procedure utilizes Power Transfer Distribution Factors to curtail transactions and reduce power flows? - ✔✔Transmission Loading Relief. Outage Transfer Distribution Factors help System Operators. (select best answer) - ✔✔estimate the effect of an outaged transmission elements Generation Shift Factors help System Operators determine which. (select best answer) - ✔✔generators could be adjusted to relieve the loading on the transmission lines. System load is continuing to increase when a transmission line becomes overloaded by 100 MWs. Both St. Clair and Grand River generators affect the overloaded line; the St. Clair generator has a GSF of +0. and the Grand River generator has a GSF of - 0.4. Which of the following options is best for the System Operator to perform? - ✔✔Increase the Grand River generator by 250 MWs.
How does a negative Generation Shift Factor affect line loading? - ✔✔When a generator with a negative shift factor increases its output, it relieves line loading. Which type of tools use Line Outage Distribution Factors to predict the loading on transmission elements in the event of a transmission line outage? - ✔✔Contingency analysis tools. How does a positive Generation Shift Factor affect line loading? - ✔✔When a generator with a positive shift factor increases its output, it contributes to loading on the transmission line. A transmission line is overloaded by 100 MWs. The Harbor and Greenwood generators affect the overloaded line; the Harbor generator has a GSF of 0.25 and the Greenwood generator has a GSF of - 0.5. Which of the following dispatch scenarios will provide adequate relief for the line? - ✔✔Increase the Greenwood generator 200 MWs. Which of the following is a method(s) Reliability Coordinators and Transmission Operators may use to manage transmission outages? - ✔✔Verify voltage control equipment are on automatic to supply the required support. Optimize the use of Load Tap Changer transformer, capacitor, and reactors. Coordinate and adhere to voltage schedules to minimize reactive power flow. Choose the answer that best describes the operation of a rotor. - ✔✔The excited (energized) field winding that rotates inside the stator to induce voltage into the stator winding and allows current to flow out of the stator when the generator is connected to the power grid. n a system that is more capacitive than inductive, the current sine wave will the voltage sine wave which tends to voltage. - ✔✔lead; raise Generator ratings specify the and at which they can operate safely. - ✔✔voltage; frequency Sustained operation with a power angle or torque angle above can lead to system instability. - ✔✔ 90 degrees
Why do power companies choose to operate a three-phase power system? - ✔✔Distribution of power at a more constant rate, increased efficiency and more economical Station configurations vary, balancing the economics of building a station with additional breakers and lines. The most expensive and reliable station bus scheme is which of the following? - ✔✔Double bus, double breaker What is the MVAR output of a 50 MVAR shunt capacitor energized when a 100 kV bus is at 90 kV (or 90% of its nominal voltage)? - ✔✔40. Transmission lines, transformers, and other equipment have System Operating Limits or SOLs. What is a SOL? - ✔✔A MW, MVAR, amp, voltage value that satisfies the most limiting of the prescribed operating criteria for a specified system configuration. Transmission line transfer capability is determined by which characteristics? - ✔✔System loading, voltage, impedance Which of the following communications methodologies would be considered an alternative Interpersonal communications system for a telephone based Interpersonal communications system? - ✔✔Cell phone based system VOIP (Voice Over Internet Protocol) based system Satellite telephone based system If a Reliability Coordinator is testing the Alternative Interpersonal Communications system, and after the test determines the system is not functioning in accordance with requirements, what must the Reliability Coordinator do to address this issue? - ✔✔Initiate action to repair or designate a replacement Alternative Interpersonal Communication system capability within 2 hours. What does NERC's concern with communications systems center mostly on? - ✔✔Reliability Where applicable, telecommunications facilities shall utilize different infrastructure. Which of the following is also required of these facilities? - ✔✔Redundancy
Vital telecommunications facilities shall be managed and alarmed in addition to what other action? - ✔✔Tested and/or actively monitored Each control room should test its telecommunications facilities. Special attention should be given to emergency telecommunications facilities as well as what other equipment? - ✔✔Equipment not used for routine communications Which of the following actions would be required in accordance with COM- 002 - 4 when communicating an Operating Instruction? - ✔✔A Reliability Coordinator confirms the Balancing Authority understood what is to be done. A Reliability Coordinator corrects the response if it is not repeated back correctly. A Reliability Coordinator clearly states the Operating Instruction. A Balancing Authority repeats the operating instruction back to the Reliability Coordinator. A Transmission Operator who issues an oral single-party to multiple-party burst All Call Operating Instruction during an emergency is. - ✔✔Required to confirm or verify that the Operating Instruction was received by at least one receiver of the all call Operating Instruction. NERC COM- 002 - 4 requires initial training for which operating personnel who either issue and/or receive Operating Instructions? - ✔✔Reliability Coordinators Generator Operators Distribution Providers Balancing Authorities and Transmission Operators An operating Instruction is defined as: - ✔✔A command by operating personnel responsible for the Real-time operation of the interconnected Bulk Electric System to change or preserve the state, status, output, or input of an Element of the Bulk Electric System or Facility of Bulk Electric System. Per NERC COM- 002 - 4, which of the following elements MUST be included in the documented communication protocols for operating personnel that issue and receive Operating Instructions? - ✔✔Specify nomenclature for transmission interface Elements and Facilities. Use the English language unless agreed to otherwise.
Transmission Operator Outages have a significant impact on which of the following? - ✔✔The direction of power flow. The distance of power flow. Real and reactive power supply. Which of the following Bulk Electric System facilities does the Reliability Coordinator monitor to evaluate the reliability of the Bulk Electric System? - ✔✔Generators Transmission lines Which function(s) shall have documented specification for data and information to support its reliability- related tasks. - ✔✔Reliability Coordinator In order to ensure primary functional obligations are met, System Operators shall have an Operating Plan including procedures to be exercised if the main monitoring system is unavailable?. The contingency plan for continued real-time monitoring and assessment is which of the following? - ✔✔Relocate to a tested backup control room facility Which of the following information is required to be provided to Reliability Coordinators: - ✔✔Current status of BES elements Real and Reactive power reserves What is the responsibility of the Reliability Coordinator whenever a Remedial Action Scheme/Special Protection System (RAS/SPS) that may have inter-Balancing Authority, or inter-Transmission Operator impact (e.g., could potentially affect transmission flows resulting in SOL or IROL violations) is armed? - ✔✔to be aware of the impact of the operation of that RAS/SPS on inter-area flows. Reliability Coordinators must have monitoring systems that provide needed information for monitoring and assessing their area. These monitoring systems must meet which of the following criteria? - ✔✔Must be over a redundant infrastructure.
What is the value that satisfies the most limiting of the prescribed operating criteria for a specified system configuration to ensure operation within acceptable reliability criteria? - ✔✔System Operating Limit The Reliability Coordinator shall have real-time monitoring capability in addition to Operational Planning Analysis of its area to ensure what? - ✔✔SOL and IROL exceedances are identified. Responsible Entities must report certain events as defined in Attachment 2 of EOP-004. Which of the following is required of the Responsible Entities in accordance with EOP-004? - ✔✔Transmission Operators Must have an Operating Plan for event reporting that includes protocols for reporting events to NERC and other organizations. Reliability Coordinators A Transmission Operator has experienced a loss of its ICCP communication, resulting in the inability to perform reliability analysis on its system. While in the process of implementing its Loss of Control Center Functionality plan, ICCP is restored. Which of the following statements is true? - ✔✔If analysis capability was unavailable for more than 30 minutes, an event report must be submitted. Which of the following events would require submitting an event report? - ✔✔A Balancing Authority making a public appeal for load reduction due to abnormally hot temperatures and expected Energy Emergency. A Reliability Coordinator experiences an event requiring evacuation of the primary control center from 2100 to 2215 on Friday night. How long does the Reliability Coordinator have to report the event? - ✔✔Until the end of business the following Monday. Which of the following is/are reasons that Bulk Electric System disturbances should be analyzed? - ✔✔To help eliminate similar occurrences. To implement corrective actions. To ensure "lessons learned" are documented.
