The mega white loading on a transmission line is at the
point where the natural MVAR production of the line
matches the lines MVAR usage. This MW loading point is
called the? Correct Answer Serge impedance loading
(SIL)
Load increases or decreases according to the increase or
decrease in frequency. For every 1% change in frequency,
load will change approximately_________percent in the
same direction. Correct Answer 2
A transmission line conductor is rated at 180 MVA, the line
side current transformer is rated at 160 MVA and the bus
is rated at 200 MVA. What is the MVA limit for the
transmission line? Correct Answer 160 MVA
If frequency, voltage, and phase angle difference are too
large to permit breaker closing, a system operator should
first consider? Correct Answer Re-dispatching generation
Station A bus is connected to station B bus by 230 kV
transmission line. All stations have 100 MVAR shunt
capacitor bank off-line. The SOL on this line is 350 MVA.
The system operator is made aware that the line flows are
,345 MW from station A to station B and 100 MVAR From
station B to station A. The system operator should return
the transmission line to its operating limit by? Correct
Answer Placing the capacitor bank online at Station A.A
good way to think of this is that which ever direction is
absorbing or taking in MVAR will need to be turned on.
During extreme low load conditions, what are the primary
system conditions a system operator typically works to
alleviate? Correct Answer High-voltage and over
generation
Which of the following actions is used to prevent a voltage
collapse due to a reactive power deficiency? Correct
Answer Implement load reduction
A reactor is rated at 100 MVAR nominal and is operating
at a voltage of 90% how many MVAR is it absorbing from
the system? Correct Answer (V actual/V nominal) ^2 ) x
MVAR 81 MVAR
Reactive resources are used to Correct Answer Maintain
acceptable voltage levels
When I system is on the verge of voltage collapse and
nothing else can be done to alleviate the problem
operating personnel should? Correct Answer Shed Firm
load
To be effective, reactive resources should be? Correct
Answer Located close to load areas
,If the line is loaded above it's SIL, how does that affect the
line and the voltage? Correct Answer The line becomes
more inductive and the voltage drops
If the line is below it SIL, how does that affect the line
voltage? Correct Answer The line becomes more
capacitive and the voltage raises.
The value of MVAR,MW,MVA,Ampere,Hz, and volts that
satisfies the most limiting of the prescribed operating
criteria for a specified system configuration to ensure
operation within acceptable reliability criteria is called?
Correct Answer System Operating Limit (SOL)
A system operator is attempting to synchronize two
systems together in preparation of supplying customer
load. The synchroscope it not moving. A system operator
should first? Correct Answer Adjust generation to verify
the synchroscope is working
Which condition is likely to lead to potential voltage
collapse Correct Answer Insufficient dynamic reactive
resources
Several SCADA Alarms indicate a disturbance in area B.
They are for transmission lines connecting area A the area
B which have become heavily loaded due to the
disturbance. One of the lines above it's SOL. Reid
dispatching of generation has no effect on line flows. As
the operator, which answer best applies to the situation?
, Correct Answer There is a possible separation or island in
an area B
When reactive resources are woefully inadequate to meet
reactive power demand, A likely ultimate outcome is:
Correct Answer Voltage collapse and separation of the
system
Why is location of transmission system reactive power
reserves important? Correct Answer Reactive power is
difficult to transmit through high impedance
Of the following reactive Reserve sources, which would
fall into the static reactive reserve category Correct
Answer Static VAR compensator in automatic mode
Of the following reactive reserve possibilities, which could
be counted as dynamic reactive reserve from rotating
source? Correct Answer Generator in automatic voltage
regulation
Following a contingency or other even that results in an
IROL violation, the appropriate TOP shall return it
transmission system to within limits as soon as possible
but no longer than: Correct Answer 30 min
Under what circumstances can low voltage occur without
an initiating event? Correct Answer When reactive
resources are deficient
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