Distance Relay
1. Protection of high voltage power transmission lines, what types of relays are generally used for
protection?
a. Voltage Relay
b. Overcurrent Relay
c. Differential Relay
d. Distance Relay
2. Which of the following is/are the Input signal/signals to the Distance Relay?
a. CT and VT
b. CT
c. VT
d. Meter
3. In Distance Relay Operation Analysis, Which diagram mention below is commonly used for
analysis?
a.
b.
c.
d.
R-X Diagram
V-I Diagram
P.F. Diagram
I-T Diagram
4. Setting for Ground Fault Distance Relay used for protection when Single Line to Ground
Fault (SLG) occurs, we have to take into account during Ground Fault Distance Relay
setting?
a. Power Factor
b. Compensation Factor
c. Full Load Current
5.
a.
b.
c.
d.
Which is the property of the Impedance Relay?
It is a directional distance relay.
Use only the resistance of the transmission line for setting the relay.
If the measured impedance is greater than the set impedance, the relay will operate.
Use the impedance to set the relay.
6.
a.
b.
c.
Which is the property of the Mho Relay?
Most impedances fall into the 1st quadrant on the R-X diagram.
It is a non-directional relay.
The circumference on the R-X diagram goes beyond the Origin point.
d. If the measured impedance is greater than the set impedance, the relay will operate.
7. Setting the Step Distance Protection Relay Zone 1 What kind of working time must be
adjusted?
a. Delay for 0.3 seconds.
b. Delay for 0.5 second.
c. Delay for 1.0 seconds.
d. Set to work immediately. (Instantaneous)
8.
a.
b.
c.
d.
How much distance should I set to protect the transmission line?
40-50% of the transmission line length in the range to be shielded.
50-60% of the transmission line length in the range to be shielded.
80 - 90% of the transmission line length in the protected range.
120% of the transmission line length in the protected range.
9.
a.
b.
c.
d.
How much distance should I set up to protect the transmission line?
90 - 100% of the transmission line length in the range to be shielded.
120-150% of the transmission line length in the range of protection.
180 - 200% of the transmission line length in the protected range.
250 - 300% of the transmission line length in the protected range.
10. Setting the Step Distance Protection Relay Zone 2 How much time must be set to the
time delay relay?
a. Delay for 0.3 seconds.
b. Delay for 0.8 seconds.
c. Delay for 1.0 seconds.
d. The delay is about 1.5 seconds.