This is the first webinar in a series on power system protection webinar series. This video is the first module for Transmission Line protection. Speaker has covered the following topics under transmission line distance protection :
1. Protection Functions used in Transmission Line Protection.
2. Theory of Distance Protection and its advantages over other forms of protection.
3. Understanding RX Plane and its relation to VI Plane and PQ Plane.
4. Infeed / Outfeed. Under-reach / Over-reach effects.
5. Theory behind Zone Reach calculation – typically Zone 2 & 3. Use of Zone 4 for BB Prot.
6. Theory behind Zone Time delays – Z2 & Z3 and Zone 1 sometimes.
7. Typical reach and time setting problems:
a. Zone 2 overlap: Long line followed by short line.
b. Zone 2 encroaching into next voltage level.
c. Zone 3: Non coverage of longest line due to infeed.
d. Zone 3: Encroachment into next Voltage Level with infeed.
e. Zone 4 for short lines not covering local busbar.
8. Concept of fault loop and how apparent Z is calculated.
9. Concept of Zero Sequence Compensation. How does it actually expand the ground fault reach compared to phase fault reach.
10. Resistive reach components, its calculations, reach coverage for LL & LG loops, typical limits.
11. Load Encroachment – Concept and reach calculations.
12. The other configuration settings in modern numerical distance relay which needs to be understood eg. Distance starter reaches, RCA, Directional angles, Memory voltage validity etc.
13. Maybe some examples of bit complicated setting calculations.
14. Protection Philosophy of Eastern region – ERPC document.
15. Some simple Case Studies on mal-operation of Distance Protection.
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