Voltage and Reactive - B Flashcards
What is the most effective equipment for reactive reserve response to a contingency?
A. Shunt reactors
B. HVDC
C. Synchronouse condensers
D. Series capacitors
C. Synchronous condensers
Your system voltages are extremely high during a light load midnight period. All of your capacitors are off, all of your reactors are on and a 500 kv transmission line is loaded below its surge impedance loading. What can be done to reduce the impact of the transmission line on system voltages?
(Two answers)
A. Reduce the loading on the line some more
B. Remove the line from service if it has been pre-studied
C. Load the line above its SIL
D. Open-end the line
B. Remove the line from service if it has been Pre-studied
&
C. Load the line above its SIL
The phase voltage in a wye-connected load is 277V. What is the line-to-line voltage?
A. 277 V
B. 160 V
C. 320 V
D. 480 V
D. 480 V
What is the approximate MVAR/mile production for a 345kv overhead line?
A. 5
B. 0.75
C. 2
D. 0.33
B. 0.75
Transmission Operators shall _____ and _____ reactive resources so that they can be applied effectively and quickly when contingencies occur.
A. Schedule and control
B. Concentrate and locate
C. Control and monitor
D. Disperse and locate
D. Disperse and locate
The MW loading on a transmission line is that the point where the natural MVAR production of the line matches the line’s MVAR usage. This MW loading point is called the
A. Characteristic impedance (CI)
B. Transmission line loading relief (TLR)
C. Surge impedance loading (SIL)
D. Natural loading (NL)
C. Surge impedance loading (SIL)
Which of the following situation would lead to the highest Ferranti Rise?
A. A short open-ended line with a weak closed-end bus
B. A short open-ended line with a strong closed-end bus
C. A long open-ended line with a weak closed-end bus
D. A long open-ended line with a strong closed-end bus
C. A long open-ended line with a weak closed-end bus
The excitation current of a generator should be adjusted…
A. To the maximize the rotor angle stability
B. Manually by the plant operator as directed by the system operator
C. By the local automatic voltage regulator
D. To minimize the MVAR losses
C. By the local automatic voltage regulator
Reactance in a shunt reactor will increase with the _____
A. Magnetic constant of the material that surrounds the coil
B. Number of turns in the coil
C. Diameter of the coil
D. Distance of the plates
B. Number of turns in the coil
Voltage in the system should be kept within _____
A. +/- 5%
B. +/- 1%
C. +/- 10%
D. +/- 8%
A. +/- 5%
The actual voltage is 253kv on a 230kv line. What is the P.U. Voltage?
A. 0.95
B. 0.1
C. 1.05
D. 1.1
D. 1.1
Transmission Operators shall direct corrective action including ______ necessary to prevent voltage collapse when reactive resources are insufficient
A. Load reduction
B. Capacitor switching.
C. Generation scheduling
D. Reactor switching
A. Load reduction
To ensure a generator’s reactive reserve is available to respond to system voltage deviations, the generator’s voltage regulator should be placed in what mode of operation?
A. Manual
B. Automatic
C. Synchronous
D. induction
B. Automatic
Three transmission lines connect a generation source to a load area. Line#1 has an impedance of 40 ohms, line #2, 60 ohms and line #3, 40 ohms. Total power flow is initially 2000 MW, line #1 drops. Assuming no generation or load changes and neglecting losses, what will be the MW flow on line #2
A. 1000 MW
B. 2000 MW
C. 1200 MW
D. 800 MW
D. 800 MW
Reactive sources should be used for ________
A. Normal operating conditions
B. Peak loading
C. Energy Alerts only
D. Normal and first contingency conditions
D. Normal and first contingency conditions
