ABB Relion 670 Series Applications Manual page 593

1MRK 511 401-UUS F
24.2 Voltage transformer requirements
The performance of a protection function will depend on the quality of the measured input signal.
Transients caused by capacitive Coupled voltage transformers (CCVTs) can affect some
protection functions.
Magnetic or capacitive voltage transformers can be used.
The capacitive voltage transformers (CCVTs) should fulfill the requirements according to the IEC
61869-5 standard regarding ferro-resonance and transients. The ferro-resonance requirements of
the CCVTs are specified in chapter 6.502 of the standard.
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.
24.3 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.
24.4 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.
24.5 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
Bay control REC670
Application manual
-6
according to the standard for data and voice transfer
-8 -9
-10 during normal operation
-6
during disturbed operation
© Copyright 2017 ABB. All rights reserved
Section 24
Requirements
M11608-3 v5
GUID-588FCD12-C494-445E-8488-8287B34EFD9A v4
GUID-741CC863-D760-49D6-85B2-AFECA222A8C3 v1
GUID-0A9F36AF-3802-42FE-8970-4662798C19D1 v3
587