Sntp Server Requirements - ABB RELION RET670 Applications Manual

Section 25
Requirements
25.3
25.4
25.5
996
The transient responses for three different standard transient response classes, T1, T2
and T3 are specified in chapter 6.503 of the standard. CCVTs according to all classes
can be used.
The protection IED has effective filters for these transients, which gives secure and
correct operation with CCVTs.

SNTP server requirements

The SNTP server to be used is connected to the local network, that is not more than 4-5
switches or routers away from the IED. The SNTP server is dedicated for its task, or at
least equipped with a real-time operating system, that is not a PC with SNTP server
software. The SNTP server should be stable, that is, either synchronized from a stable
source like GPS, or local without synchronization. Using a local SNTP server without
synchronization as primary or secondary server in a redundant configuration is not
recommended.
PTP requirements
For PTP to perform properly, the Ethernet equipment that is used needs to be compliant
with IEEE1588. The clocks used must follow the IEEE1588 standard BMC (Best
Master Algorithm) and shall, for instance, not claim class 7 for a longer time than it
can guarantee 1us absolute accuracy.
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
•
-6
<10 according to the standard for data and voice transfer
Bit Error Rate (BER) for high availability of the differential protection
• -8 -9
<10 -10 during normal operation
• -6
<10 during disturbed operation
1MRK 504 163-UUS A
GUID-588FCD12-C494-445E-8488-8287B34EFD9A v4
GUID-741CC863-D760-49D6-85B2-AFECA222A8C3 v1
GUID-0A9F36AF-3802-42FE-8970-4662798C19D1 v2
Transformer protection RET670 2.2 ANSI
Application manual