Alstom MiCOM P545 - 2.1.4 Direct optical fiber link, 1550 nm single-mode fiber; 2.1.5 IEEE C37.94 interface to multiplexer; 2.1.6 Switched communication networks

P54x/EN OP/La4 Operation
(OP) 5-104 MiCOM P543, P544, P545 & P546
OP
2.1.4 Direct optical fiber link, 1550 nm single-mode fiber
The relays are connected directly using two 1550 nm single-mode fibers, type 9/125 m for
each signaling channel. BFOC/2.5 type fiber optic connectors are used.
P540
1550nm
P540
1550nm
Optical fibre
This is typically suitable for connection up to approximately 130 km (from April 2008).
Pre-April 2008 relays were suitable for connection up to approximately 80 km.
The list of all available fiber channel options is:
820 nm dual channel
1300 nm single-mode/single channel
1300 nm single-mode/dual channel
1300 nm multi-mode/single channel
1300 nm multi-mode/dual channel
1550 nm single-mode/single channel
1550 nm single-mode/dual channel
Ch 1 850nm multi-mode + Ch 2 1300nm single-mode
Ch 1 850nm multi-mode + Ch 2 1550nm single-mode
Ch 1 1300nm single-mode + Ch 2 850nm multi-mode
Ch 1 1300nm multi-mode + Ch 2 850nm multi-mode
Ch 1 1550nm single-mode + Ch 2 850nm multi-mode
2.1.5 IEEE C37.94 interface to multiplexer
A P54x rel
ay with 850 nm short haul optical interface is connected directly to the multiplexer
by 850 nm multi-mode optical fiber. Multi-mode fiber type 50/125 m or 62.5/125 m is
suitable. BFOC/2.5 type fiber optic connectors are used.
The setting Comms Mode should be set to IEEE C37.94. Note the relay must be powered off
and on before this setting change becomes effective.
The IEEE C37.94 standard defines an N*64kbits/s standard where N can be 1 – 12. N can
be selected on the P54x or alternatively set to Auto in which case the relay will configure
itself to match the multiplexer.
2.1.6 Switched communication networks
The P5
4x relays make use of digital communication signaling channels for the differential
protection. For correct operation of this protection element, it is essential that the integrity of
this link is continuously checked. For P54x relays, when GPS is not used it is also a
requirement of this link that ‘go’ (tp1) and ‘return’ (tp2) times are similar (a difference of up to
1 ms can be tolerated). Times greater than this can result in relay instability.
Where switched communications networks are used, it is possible that during switching, a
transient time period may exist with different ‘go’ and ‘return’ times. All P54x relays include a
facility to ensure protection stability during this transient period.