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WorksheetsSYSTEM OPERATION — STUDY GUIDE KEY
Total questions: 70
Worksheet time: 35mins
Fill in the blank: Jurisdiction is utilized to confirm the _______ for an operations center and typically confirms two factors: the physical description of the elements of the system and the geographical area in which the system is located.
area of responsibility
chain of command
scope of authority
level of security
Fill in the blank: NERC certification establishes standards of _______ for system operators who operate the interconnected transmission grids.
competency
attendance
equipment
location
Fill in the blank: The central point from which operation of the system is conducted is called the _______.
operations center
control room
command post
headquarters
Fill in the blank: Operating errors are incidents in which an _______ occurred when the system was being operated.
error
accident
delay
shutdown
Fill in the blank: Regional transmission organizations are independent regional organizations formed to better operate the _______.
transmission system
distribution network
power plants
energy market
Fill in the blank: SCADA stands for _______ and provides system operators the ability to monitor and control the flow of power.
supervisory control and data acquisition
system control and data analysis
secure communication and data automation
signal control and device administration
Fill in the blank: Switching orders refer to a planned sequence of _______ or steps that are followed to accomplish some operation of the system.
actions
devices
signals
locations
Fill in the blank: The system operator is a highly skilled and knowledgeable individual who _______ and _______ the operation of the power system.
monitors; directs
designs; builds
ignores; disrupts
repairs; dismantles
The jurisdiction of an operating center refers to:
The area or scope over which the operating center has authority or control.
The number of employees working at the operating center.
The type of equipment used in the operating center.
The financial budget allocated to the operating center.
The system operator uses the wall maps to:
monitor and control the flow of electricity across the grid.
decorate the control room.
track employee attendance.
display weather forecasts.
List six items that might be logged by a system operator in the operations center log.
Clearances that were issued or released, power interchanges, load transfers, system outages, abnormal conditions such as low system voltage, equipment failures, and visitors to the center.
Only visitor names, weather reports, and lunch schedules.
System operator's personal notes, unrelated emails, and social media activity.
Routine cleaning schedules, cafeteria menu updates, and holiday decorations.
What does NERC stand for, and how might this organization affect a system operator?
North American Reliability Council; it establishes standards of competency for system operators who operate the interconnected transmission grids.
National Energy Resource Commission; it manages fuel supply for power plants.
Network Emergency Response Center; it coordinates disaster recovery for utilities.
National Electrical Regulation Committee; it enforces safety codes for electrical installations.
List five key responsibilities of the system operator.
Safe and efficient operation of the system, direct switching, monitor and operate the system, transfer load, monitor system conditions, respond to alarms, isolate problems and restore service, maintain proper flow of power, communicate and coordinate, restore lines and equipment, dispatch generation resources, ensure operating reserves adhere to requirements.
System operator is responsible for only monitoring weather conditions and reporting them to the local authorities.
System operator's main duty is to maintain office supplies and schedule meetings for the management team.
System operator is tasked with organizing company events and handling employee payroll.
What typical procedures are followed to ensure switching orders are fully understood by the switchman?
Switchman has a copy of the switching order and executes steps upon direction from the system operator; operator dispatches steps verbally for emergency switching.
Switchman relies solely on verbal instructions from the system operator for all switching procedures.
Switchman performs switching steps based on personal judgment without consulting the system operator.
Switchman receives written orders but does not require confirmation from the system operator before executing steps.
During emergency operations, what are the restoration priorities for the system operator?
Restoring critical loads and essential services first
Restoring all loads simultaneously
Restoring non-essential loads first
Restoring only residential areas
Some common errors that can occur on equipment include:
Overheating
Perfect operation
Unlimited lifespan
Self-repairing capability
Study the following term and identify where it is first mentioned in the text: Automated switch – Typically mechanically operated with either a motor, which drives a gear mechanism, or a stored energy operator, which uses a motor to wind a spring that operates the switch when released by the control. (For more information, refer to section 2.8 of the manual) Fill in the blank: An automated switch is typically operated with either a ________, which drives a gear mechanism, or a ________ operator, which uses a motor to wind a spring that operates the switch when released by the control.
motor; stored energy
spring; manual
lever; hydraulic
battery; pneumatic
Study the following term and identify where it is first mentioned in the text: Clearance – A formally recognized condition of a line, line section, or equipment that has been de-energized from all potential sources of energy by opening devices in the path or the potential flow of power. (For more information, refer to section 2.3 of the manual) Fill in the blank: Clearance is a formally recognized condition of a ________, ________, or ________ that has been de-energized from all potential sources of energy by opening devices in the path or the potential flow of power.
line; line section; equipment
circuit; transformer; relay
panel; switch; generator
bus; fuse; conductor
Study the following term and identify where it is first mentioned in the text: Clearance point – Any device, connector, or open that is used to isolate the line or piece of equipment from a potential source of energy. (For more information, refer to section 2.3 of the manual) Fill in the blank: A clearance point is any ________, ________, or ________ that is used to isolate the line or piece of equipment from a potential source of energy.
device; connector; open
switch; wire; fuse
panel; circuit; relay
valve; pump; motor
Study the following term and identify where it is first mentioned in the text: Energy sources – Specific sources of energy that potentially could energize a line, line section, or piece of equipment that needs to be cleared and worked on. (For more information, refer to section 2.5 of the manual) Fill in the blank: Energy sources are specific sources of energy that potentially could energize a ________, ________, or ________ that needs to be cleared and worked on.
line; line section; piece of equipment
transformer; substation; generator
circuit; relay; switch
panel; fuse; wire
Fill in the blank: A foreign generator is any generator connected to the system that is not known by the ________ or the ________ in the field.
system operator; line crews
maintenance team; engineers
control room; supervisors
dispatchers; technicians
The three main objectives that apply to clearing lines and equipment are:
Safety, reliability, and efficiency
Speed, cost, and convenience
Profit, growth, and expansion
Flexibility, adaptability, and innovation
The difference between a clearance point and a visual clearance point is:
A clearance point is a designated location for train separation, while a visual clearance point is identified by sight for safe passage.
A clearance point is only used in airports, while a visual clearance point is used in railways.
A clearance point is always marked with a sign, while a visual clearance point is never marked.
A clearance point and a visual clearance point are the same and used interchangeably.
Energy sources considered when clearing lines and equipment include power flow from the same circuit or line, power flow from a different circuit or line, and power flow from a foreign generator. Which of the following is NOT typically considered a potential source of energy to be isolated?
Power flow from a foreign generator
Power flow from the same circuit or line
Power flow from a different circuit or line
Power flow from a battery backup system
Procedures associated with using automated switches as clearance points include which of the following?
Ensuring the switch is locked and tagged out before clearance is given.
Allowing clearance without verifying switch position.
Ignoring automated switch status during clearance.
Providing clearance only after manual inspection.
What type of information would typically be found on a hold tag?
The reason for holding the item
The price of the item
The manufacturer of the item
The expiration date of the item
An operating center may need three days to process a line clearance because:
it requires coordination and safety checks
it is a routine task with no checks
it can be done instantly without review
it is always delayed due to lack of staff
To switch around an outage using a map from your system, what would you do?
Identify the affected area, locate alternate supply routes, operate switches to reroute power, and confirm restoration.
Ignore the map and wait for the outage to resolve itself.
Call customers to inform them about the outage without taking any action.
Replace all equipment in the affected area before checking the map.
What is the definition of 'Cold-load inrush'?
The amount of load that will be connected when the system or portions of the system are energized after being out of service for an extended period of time. It can be as high as 10 times the normal system load.
The sudden drop in voltage when a generator is started under no load conditions.
The process of gradually increasing the load on a transformer to avoid overheating.
The maximum current a circuit can handle before tripping due to overload.
What is 'Distributed generation'?
Generating units typically utilized to supply power to the customer's load and provide excess power to the utility's distribution system.
A method of centralizing all power generation at a single location.
A process of distributing electricity only through transmission lines.
A technique for storing energy in large batteries for future use.
What is meant by 'Load transfer/load shift'? (For more information, refer to section 3.4 of the manual)
The process of taking a portion or all of the load being supplied by a given circuit or system and transferring it to another circuit or system by opening and closing circuit breakers or switches.
The process of increasing the voltage in a circuit to improve efficiency.
The method of reducing the current in a system to prevent overheating.
The technique of balancing loads by adding more generators to the system.
What does 'Looping' refer to in electrical systems? (For more information, refer to section 3.4 of the manual)
Defines an operation where two branches of the same circuit are connected together.
Refers to the process of grounding electrical equipment.
Describes the method of increasing voltage in a circuit.
Indicates the use of a fuse to protect a circuit.
What is a 'Non-reclose condition'? (For more information, refer to section 3.7 of the manual)
The temporary disabling of a reclosing feature of a circuit breaker or recloser.
A condition where a circuit breaker is permanently closed.
A situation where a recloser operates continuously without interruption.
The automatic restoration of power after a fault without any delay.
What is a 'Null point' in electrical circuits?
When two circuits are tied together in parallel, the flow of power is from the source of each circuit out to a 'null point,' where no current is flowing.
A point in a circuit where the voltage is maximum and current is minimum.
A location in a circuit where all resistances are connected in series.
A point in a circuit where the current is always zero regardless of the voltage applied.
What is 'Paralleling' in electrical systems?
An operation in which two separate circuits emanating from the same or different transformer source are physically connected together so that there is a current flow from each source that meets at some point along the path of the wire.
A method of increasing voltage by connecting batteries in series.
A process of grounding electrical circuits to prevent short circuits.
A technique for reducing resistance by using thicker wires.
What is a 'Reclosing relay'? (For more information, refer to section 3.2 of the manual)
A relay that controls how a breaker reacts during a fault. This relay can be preset to allow the breaker to open and reclose for a set number of times. It can be disabled to prevent any reclosing, if desired.
A relay that measures the current in a circuit and trips the breaker if it exceeds a set value.
A relay used to synchronize two generators before connecting them to the grid.
A relay that provides time delay before tripping the breaker during overload conditions.
What is an 'RTU' in electrical systems? (For more information, refer to section 3.3 of the manual)
Remote terminal unit, that receives a signal from a sensing device such as a line post insulator sensor, which senses the current and voltage flow in the line.
Resistor transformer unit, used to step down voltage in transmission lines.
Rotary transfer unit, which switches electrical loads between circuits.
Relay timing unit, that controls the timing of relay operations in substations.
State the procedural steps for clearing lines and equipment. (For more information, refer to section 2.10 of the manual)
1. Identify, plan, and confirm clearance details 2. Request clearance in writing 3. Approve clearance 4. Isolate, lock, and tag all potential sources of energy 5. Establish and issue the clearance 6. Test and apply personal protective grounds 7. Releasing the clearance 8. Return the system to normal
1. Request clearance in writing 2. Approve clearance 3. Isolate, lock, and tag all potential sources of energy 4. Establish and issue the clearance 5. Test and apply personal protective grounds 6. Releasing the clearance 7. Return the system to normal
1. Confirm clearance details 2. Request clearance verbally 3. Approve clearance 4. Isolate, lock, and tag all sources of energy 5. Issue the clearance 6. Test and apply grounds 7. Release the clearance 8. Return system to normal
1. Identify clearance details 2. Request clearance in writing 3. Approve clearance 4. Isolate, lock, and tag all potential sources of energy 5. Establish and issue the clearance 6. Test and apply grounds 7. Release the clearance
To restore service after a long rural circuit has relayed to lockout and the cause of the trouble is unknown, you should:
Patrol the line to locate and correct the fault before re-energizing.
Immediately re-energize the circuit without investigation.
Ignore the lockout and wait for automatic reset.
Replace all relays before restoring service.
List three reasons for paralleling distribution circuits.
1. Distribute load as needed 2. Clear a piece of equipment in a substation 3. Transfer load in conjunction with clearing a section of line
1. Increase transmission losses 2. Reduce system reliability 3. Cause voltage instability
1. Limit the number of connected loads 2. Prevent load transfer 3. Isolate all substations
1. Increase the complexity of circuit design 2. Restrict maintenance operations 3. Eliminate backup power sources
When paralleling circuits, should the ground relays be enabled or disabled? Also explain the reason for your answer.
Ground relays should be disabled to prevent false tripping during paralleling.
Ground relays should be enabled to ensure maximum protection.
Ground relays should be alternately enabled and disabled for balance.
Ground relays should be set to manual mode during paralleling.
List four requirements that are needed to parallel distribution circuits.
1. Line-to-ground and phase-to-phase voltages must be the same 2. Angular displacement of transformer banks must be identical 3. Phases must match across paralleling point 4. Frequency of each system must be the same
1. Only the voltage levels need to match 2. Transformer banks can have different angular displacement 3. Phases do not need to match 4. Frequency can be different for each system
1. Only the frequency needs to be the same 2. Voltage and phase matching are not required 3. Transformer banks can be different 4. Any angular displacement is acceptable
1. Distribution circuits can be paralleled without matching any parameters 2. Only the transformer type matters 3. Frequency and voltage are irrelevant 4. Phases can be mismatched
List the steps for clearing a line regulator.
1. Place on manual position 2. Adjust to neutral position 3. Verify on neutral position 4. Set control to off 5. Close bypassing regulator 6. Open install hold tag 7. Open install hold tag
1. Set control to off 2. Open bypassing regulator 3. Place on manual position 4. Adjust to neutral position 5. Verify on neutral position 6. Close install hold tag 7. Open install hold tag
1. Adjust to neutral position 2. Place on manual position 3. Verify on neutral position 4. Set control to off 5. Open bypassing regulator 6. Close install hold tag 7. Open install hold tag
1. Place on manual position 2. Adjust to neutral position 3. Set control to off 4. Verify on neutral position 5. Close bypassing regulator 6. Open install hold tag 7. Close install hold tag
Distributed generation refers to electricity generation from sources that are often located close to the point of use. Which of the following lists at least four operating concerns associated with distributed generation?
Voltage regulation, protection coordination, islanding, and power quality
Fuel cost, water supply, land acquisition, and labor unions
Marketing strategy, customer service, advertising, and branding
Internet connectivity, software updates, hardware compatibility, and user interface
Which of the following is the correct switching order to clear a capacitor bank?
Open the circuit breaker, discharge the capacitors, isolate the bank, and ground the terminals.
Ground the terminals, discharge the capacitors, open the circuit breaker, and isolate the bank.
Discharge the capacitors, open the circuit breaker, isolate the bank, and ground the terminals.
Isolate the bank, open the circuit breaker, discharge the capacitors, and ground the terminals.
Which of the following is the correct switching order to clear a recloser?
Open the upstream breaker, isolate the recloser, test for absence of voltage, and apply grounds.
Close the recloser, then open the downstream breaker, and apply grounds.
Open the recloser, then immediately close it to reset.
Apply grounds first, then open the upstream breaker and recloser.
A type of switchgear that houses the circuit breaker in a metal cubicle inside a metal clad building is called a _________?
Metal clad switchgear
Air insulated switchgear
Gas insulated switchgear
Vacuum switchgear
When would you be likely to refer to the single-line diagram in a substation?
When performing operations in the substation. (For more information, refer to section 4.2 of the manual)
When conducting routine cleaning of the substation equipment.
When preparing a financial report for the substation.
When organizing a staff meeting in the substation.
Which equipment in substations is routinely cleared for maintenance?
Circuit breakers, regulators, capacitor banks, and transformer banks. (For more information, refer to section 4.3 of the manual)
Only lighting systems and control panels.
Communication towers and fencing.
Office furniture and landscaping equipment.
Explain the purpose of the transfer or auxiliary bus in a substation.
If it is a newly installed bus ready for energizing; if an existing bus has been cleared to perform maintenance, modification, or extension; if it is a bus that is normally de-energized and needs to be energized. (For more information, refer to section 4.4 of the manual)
To increase the voltage level of the substation during peak hours.
To provide backup power to residential areas during outages.
To control the frequency of the electrical grid in real time.
List the steps that are commonly followed to test an existing transformer bank in a substation.
See the listed steps in the question text.
Check the oil level only and restart the transformer.
Disconnect all wiring and leave the transformer idle for 24 hours.
Replace the transformer with a new one without any testing.
What guidelines should be followed when operating hook-type disconnects in substations?
See the listed guidelines in the question text.
Always operate disconnects without any safety gear.
Ignore manufacturer instructions when using hook-type disconnects.
Operate disconnects only during thunderstorms.
When testing a substation bus, would you enable or disable the reclosing relay on the breaker being used to test the bus?
Disable the reclosing feature in case a fault occurs. (For more information, refer to section 4.4 of the manual)
Enable the reclosing feature to ensure automatic restoration.
Leave the reclosing relay in its default state.
Adjust the reclosing relay based on the manufacturer's recommendation.
What is the correct switching order to clear a regulator?
Open bypass, close inlet, open outlet, close bypass
Close inlet, open bypass, close outlet, open bypass
Open outlet, close bypass, open inlet, close bypass
Close bypass, open inlet, open outlet, close inlet
What are the steps to clear a circuit breaker? Write out a switching order.
1. Open the trip coil circuit, check for faults, reset the breaker, and close the breaker.
2. Close the trip coil circuit, ignore faults, and leave the breaker open.
3. Open the breaker without checking for faults, then immediately close it.
4. Reset the breaker without inspecting the trip coil circuit or checking for faults.
Where do the losses occur in a typical system?
VAR flow
Power generation
Energy storage
Load consumption
What is the typical temperature range for a power arc?
5,000 to 25,000 degrees Celsius
500 to 2,000 degrees Celsius
100 to 500 degrees Celsius
25,000 to 50,000 degrees Celsius
When de-energizing a line with no load connected, the operator will typically experience what two conditions?
High voltage and lower amperage
Low voltage and higher amperage
High voltage and higher amperage
Low voltage and lower amperage
Explain the purpose of a ground switch.
To mitigate large arcs when personal protective grounds are applied, grounding switches are installed at terminal ends and interlocked with regular switches.
To increase the voltage in a circuit for better efficiency.
To provide lighting in emergency situations.
To measure the current flowing through a conductor.
Why is it important to take load readings during loop switching?
To ensure switching devices can interrupt current and to locate abnormal conditions.
To reduce the overall system voltage.
To increase the temperature of the switching device.
To minimize the number of switching operations required.
List five common indicators of potential voltage or VAR flow problems on the system.
Voltage oscillations at high loads, abnormally high or low voltage at key substations, higher than normal VAR flow, VAR flow in an abnormal direction, load tap changers or voltage regulators on an extreme high or low tap position.
Frequent transformer failures, excessive line losses, unusually high frequency, persistent circuit breaker tripping, low power factor at all substations.
Sudden increase in system frequency, continuous operation of backup generators, high temperature in transmission lines, low current readings, random relay operations.
Constant voltage at all substations, zero VAR flow, balanced load at all times, no tap changer movement, stable system frequency.
Define the term: Ferranti effect.
The capacitance that can result in a large voltage rise occurring when a long transmission line is opened at one end, and no load is on the line.
The phenomenon where the resistance of a transmission line increases with load.
The effect of inductance causing current lag in short transmission lines.
The voltage drop that occurs due to heavy loading on a transmission line.
Define the term: Loop switching.
This type of switching involves the connecting and disconnecting of transmission lines supplied from different sources of power.
This type of switching is used to increase the frequency of alternating current in a circuit.
Loop switching refers to the process of converting direct current to alternating current.
Loop switching is the method of measuring the resistance in a closed circuit.
Define the term: Oscillograph.
An instrument that can record one or more rapidly varying electrical quantities such as voltage or current.
A device used to measure temperature changes in a circuit.
A tool for amplifying weak electrical signals.
An instrument for measuring the resistance of a conductor.
Define the term: Re-strike.
The phenomenon that can occur when an arc is being interrupted.
A method of increasing voltage in a circuit.
A process of cooling electrical conductors.
A technique for measuring resistance in a wire.
Define the term: Single pole relaying.
Clears only the phase that is affected and has relayed, allowing power to continue being carried on the other phases; clears temporary faults.
Disconnects all phases simultaneously during any fault.
Monitors voltage levels without interrupting power flow.
Is used only for permanent faults in three-phase systems.
Define the term: VAR flow.
Volt-ampere reactive flow or non-working flow of power in a system. This term goes hand in hand with the voltage of the system.
Voltage and current flow in the same direction in a system.
The total power consumed by all loads in a system.
The flow of real power in a system.
What does the term “restrike” mean?
The phenomena that can occur when an arc is being interrupted. As the switch contacts are being opened, and the arc is interrupted at the current zero, a high level of voltage tries to continue to force power across the gap. If the level of the voltage is greater than the strength of the dielectric between the contacts, the arc can be re-established (restrike).
A process of reapplying insulation to electrical wires after damage.
The act of switching off a circuit breaker manually.
A method of grounding electrical equipment to prevent surges.
How would you clear a transmission line when poles need replacing? Write out a switching order.
Open isolators, then circuit breakers, apply earths, and issue permit to work.
Close circuit breakers, then open isolators, and apply earths.
Apply earths first, then open circuit breakers and isolators.
Open circuit breakers only and issue permit to work.
How would you transfer the load from one transmission line to another? Write out a switching order.
By opening the isolator, then the circuit breaker, and closing the isolator on the new line.
By closing the circuit breaker first, then opening the isolator.
By opening the circuit breaker, then closing the isolator on the old line.
By closing both isolators simultaneously without operating the circuit breaker.
