ABB Relion 670 Series Applications Manual page 351

1MRK 511 407-UUS Rev. J
23.5 Sample specification of communication requirements for
the protection and control terminals in digital
telecommunication networks
The communication requirements are based on echo timing.
Bit Error Rate (BER) according to ITU-T G.821, G.826 and G.828
•
<10
Bit Error Rate (BER) for high availability of the differential protection
•
<10
•
<10
During disturbed conditions, the trip security function can cope with high bit error rates up to 10
or even up to 10
differential protection communication supervision, or blocked when COMFAIL is issued after
receive error >100ms. (Default).
Synchronization in SDH systems with G.703 E1 or IEEE C37.94
The G.703 E1, 2 Mbit shall be set according to ITU-T G.803, G.810-13
• One master clock for the actual network
• The actual port Synchronized to the SDH system clock at 2048 kbit
• Synchronization; bit synchronized, synchronized mapping
• Maximum clock deviation <±50 ppm nominal, <±100 ppm operational
• Jitter and Wander according to ITU-T G.823 and G.825
• Buffer memory <250 μs, <100 μs asymmetric difference
• Format.G 704 frame, structured etc.Format.
• No CRC-check
Synchronization in PDH systems connected to SDH systems
• Independent synchronization, asynchronous mapping
• The actual SDH port must be set to allow transmission of the master clock from the PDH-
system via the SDH-system in transparent mode.
• Maximum clock deviation <±50 ppm nominal, <±100 ppm operational
• Jitter and Wander according to ITU-T G.823 and G.825
• Buffer memory <100 μs
• Format: Transparent
• Maximum channel delay
• Loop time <40 ms continuous (2 x 20 ms)
IED with echo synchronization of differential clock (without GPS clock)
• Both channels must have the same route with maximum asymmetry of 0,2-0,5 ms, depending
on set sensitivity of the differential protection.
• A fixed asymmetry can be compensated (setting of asymmetric delay in built in HMI or the
parameter setting tool PST).
IED with GPS clock
Phasor measurement unit RES670
Application manual
-6
according to the standard for data and voice transfer
-8 -9
-10 during normal operation
-6
during disturbed operation
-4
. The trip security can be configured to be independent of COMFAIL from the
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Section 23
Requirements
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