Power transformer protection with distance relays
Power transformer protection with distance relays
(OP)
Distance relays have been proposed as backup relays for transformer protection, primary protection being Differential relays. Any thoughts on
1. what zones / logic should be used.
2. Some have recommended using POTT schemes. Anybody using this?
3. Ways to mitigate inrush
Thx
1. what zones / logic should be used.
2. Some have recommended using POTT schemes. Anybody using this?
3. Ways to mitigate inrush
Thx






RE: Power transformer protection with distance relays
Why use distance relay as back up for transformer protection? Why not 50/51 and distance relays for your transmission lines?
RE: Power transformer protection with distance relays
a. High speed protection with POTT
b. Breaker Failure
c. Bus backup with either reverse zone or far looking forward
opmgr1,
By mitigating inrush, i meant logic/ways etc. in a relay to inhibit it from tripping on an inrush, but still keeping the protection on for any failures on energization etc.
Thanks
RE: Power transformer protection with distance relays
Usually 21 function used as back-up protection for the generator-trafo units.
We hade here some thread on the topic.
But with "zero" time it protect only 75% of trafo, second zone not so fast, you need selectivity with other protection.
for the transmission or distribution trafos, 21 is unusuall protection, but maybe you have block: trafo-line?
Best Regards.
Slava
RE: Power transformer protection with distance relays
RE: Power transformer protection with distance relays