North American Electric Reliability
Corporation Test Questions and
Answers Study Guide
A transmission line is operating with a voltage phase angle different of 30 degrees
between the sending Vs and the receiving bus Vr. If the receiving end load is
suddenly increased, the voltage phase angle difference will be? - ANSWER>>The
phase angle will increase. When load is increased phase angle will increase.
A load has a power factor of 0.9 lagging. If the load draws 100 MVA, what is the
MW draw? - ANSWER>>90 pf= mw/mva
The high side of a delta-wye connection transformer is connected to a power
system with 199 kV L-G high side voltage. What is the voltage across the delta
winding of the transformer? - ANSWER>>Vl-l= square root of 3 times Vl-g
1.73x191= 345kV
,If a transmission line is carrying 400 MW and 300 MVAR what is the MVA? -
ANSWER>>3-4-5 triangle 500 MVA
The prime mover is the component of the generator that creates the rotational
force. In a typical coal fired steam generator what component spins the rotor? -
ANSWER>>Turbine
Reactive reserve response during a disturbance is best obtained from which
devise? - ANSWER>>Synchronous condensers
For two identically constructed transmission lines where Line A is 150 miles long
and line B is 15 miles long, if both lines are lightly loaded? - ANSWER>>A produces
more reactive power than B.
Lightly loaded transmission lines essentially behave like? - ANSWER>>Shunt
Capacitors
You receive an alarm that indicates low oil pressure on an underground
transmission cable. SCADA shows the pressure is continuing to drop. What is the
first step you take to protect the line? - ANSWER>>Isolate the line
Computer simulations show that for a 100 MW schedule from Bus A to Bus B, 63%
of the schedule will flow on the scheduled path and the remainder will flow on
other parallel paths. What is the distribution factor for the scheduled path? -
ANSWER>>63%
Which statement best describes how reactive power MVAR power normally
flows? - ANSWER>>High Voltage to Low Voltage
Which of the following types of data are BA and RC not required to share with one
another? - ANSWER>>Generator start up cost
, TOP must develop, maintain, and implement formal policies and procedures to
provide for transmission reliability. Which of the following DOES NOT need to be
addressed in these policies and procedures? - ANSWER>>Planned outages of
generation units
A 1000 MVA rated generator that produces 800 MW and 100 MVAR is best
described as? - ANSWER>>Operating in a lagging mode. Inductive system
Which of the following types of MW load is the most impacted by an intentional
frequency reduction? - ANSWER>>Motor
Assume there are two 250 mile long transmission lines exporting an excessive
amount of MW from a generation area to a load area. One of the lines suddenly
trips and the area power system collapses within a few seconds. The most likely
cause of the collapse? - ANSWER>>Angle Instability
The phase voltage in a wye-connected load is 277 V. What is the line to line
voltage? - ANSWER>>480 V
A simple power system is composed of three lines connecting generation to load.
Each lines the same impedance, is initially loaded at 200 MW, and has a thermal
limit of 400 MW. If one line trips, what the loading on the shortest remaining line
be and will the thermal limit either remaining line be violated? - ANSWER>>300
MW and No
The best prediction of system load is the load forecast tool that uses? -
ANSWER>>Forecasted Weather
If the phase angel at an open breaker is equal to 1/10 of a cycle, this is the the
same angle as? - ANSWER>>1/10 of 360 so 36
A ___________ tool is used to ensure the power system can respond within
acceptable limits of N-1 - ANSWER>>Contingency Analysis
Corporation Test Questions and
Answers Study Guide
A transmission line is operating with a voltage phase angle different of 30 degrees
between the sending Vs and the receiving bus Vr. If the receiving end load is
suddenly increased, the voltage phase angle difference will be? - ANSWER>>The
phase angle will increase. When load is increased phase angle will increase.
A load has a power factor of 0.9 lagging. If the load draws 100 MVA, what is the
MW draw? - ANSWER>>90 pf= mw/mva
The high side of a delta-wye connection transformer is connected to a power
system with 199 kV L-G high side voltage. What is the voltage across the delta
winding of the transformer? - ANSWER>>Vl-l= square root of 3 times Vl-g
1.73x191= 345kV
,If a transmission line is carrying 400 MW and 300 MVAR what is the MVA? -
ANSWER>>3-4-5 triangle 500 MVA
The prime mover is the component of the generator that creates the rotational
force. In a typical coal fired steam generator what component spins the rotor? -
ANSWER>>Turbine
Reactive reserve response during a disturbance is best obtained from which
devise? - ANSWER>>Synchronous condensers
For two identically constructed transmission lines where Line A is 150 miles long
and line B is 15 miles long, if both lines are lightly loaded? - ANSWER>>A produces
more reactive power than B.
Lightly loaded transmission lines essentially behave like? - ANSWER>>Shunt
Capacitors
You receive an alarm that indicates low oil pressure on an underground
transmission cable. SCADA shows the pressure is continuing to drop. What is the
first step you take to protect the line? - ANSWER>>Isolate the line
Computer simulations show that for a 100 MW schedule from Bus A to Bus B, 63%
of the schedule will flow on the scheduled path and the remainder will flow on
other parallel paths. What is the distribution factor for the scheduled path? -
ANSWER>>63%
Which statement best describes how reactive power MVAR power normally
flows? - ANSWER>>High Voltage to Low Voltage
Which of the following types of data are BA and RC not required to share with one
another? - ANSWER>>Generator start up cost
, TOP must develop, maintain, and implement formal policies and procedures to
provide for transmission reliability. Which of the following DOES NOT need to be
addressed in these policies and procedures? - ANSWER>>Planned outages of
generation units
A 1000 MVA rated generator that produces 800 MW and 100 MVAR is best
described as? - ANSWER>>Operating in a lagging mode. Inductive system
Which of the following types of MW load is the most impacted by an intentional
frequency reduction? - ANSWER>>Motor
Assume there are two 250 mile long transmission lines exporting an excessive
amount of MW from a generation area to a load area. One of the lines suddenly
trips and the area power system collapses within a few seconds. The most likely
cause of the collapse? - ANSWER>>Angle Instability
The phase voltage in a wye-connected load is 277 V. What is the line to line
voltage? - ANSWER>>480 V
A simple power system is composed of three lines connecting generation to load.
Each lines the same impedance, is initially loaded at 200 MW, and has a thermal
limit of 400 MW. If one line trips, what the loading on the shortest remaining line
be and will the thermal limit either remaining line be violated? - ANSWER>>300
MW and No
The best prediction of system load is the load forecast tool that uses? -
ANSWER>>Forecasted Weather
If the phase angel at an open breaker is equal to 1/10 of a cycle, this is the the
same angle as? - ANSWER>>1/10 of 360 so 36
A ___________ tool is used to ensure the power system can respond within
acceptable limits of N-1 - ANSWER>>Contingency Analysis
