Answer / brd ganesh

Pilet wire method

Answer / william lobo

Line distance protection relay Siemens Energy
The SIPROTEC 4 7SA522 is a distance protection relay for
transmission lines. This relay provides full-scheme
distance protection and incorporates all functions usually
required for the protection of a power line. The relay is
designed to provide fast and selective fault clearance on
transmission and subtransmission cables and overhead lines
with or without series capacitor compensation. The power
system star point can be solid or resistance grounded
(earthed), resonant-earthed via Peterson coil or isolated.
The 7SA522 is suitable for single-pole and three-pole
tripping applications with and without tele (pilot)
protection schemes.

The 7SA522 incorporates several protective functions
usually required for transmission line protection.
• High-speed tripping time
• Suitable for cables and overhead lines with or without
series capacitor compensation
• Self-setting power swing detection for frequencies up to
7 Hz
• Digital relay-to-relay communication for two and three
terminal topologies
• Adaptive auto-reclosure (ADT)

One of the communication interfaces is system interface for
connecting to a control system via IEC 61850 Ethernet
protocol.

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