ABB REB670 Series, Applications Manual

Page: 463 / 476

The capacitive voltage transformers (CVTs) should fulfill the requirements according to the IEC
61869-5 standard regarding ferro-resonance and transients. The ferro-resonance
requirements of the CVTs 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. CVTs according to all classes can be used.
The protection IED has effective filters for these transients, which gives secure and correct
operation with CVTs.
21.3 SNTP server requirements
GUID-588FCD12-C494-445E-8488-8287B34EFD9A v4
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.
21.4 PTP requirements
GUID-741CC863-D760-49D6-85B2-AFECA222A8C3 v1
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.
21.5 Sample specification of communication requirements
for the protection and control terminals in digital
telecommunication networks
GUID-0A9F36AF-3802-42FE-8970-4662798C19D1 v3
The communication requirements are based on echo timing.
Bit Error Rate (BER) according to ITU-T G.821, G.826 and G.828
•
<10
-6
according to the standard for data and voice transfer
Bit Error Rate (BER) for high availability of the differential protection
•
<10
-8
-10
-9
during normal operation
•
<10
-6
during disturbed operation
During disturbed conditions, the trip security function can cope with high bit error rates up to
10
-5
or even up to 10
-4
. The trip security can be configured to be independent of COMFAIL from
the 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
1MRK 505 370-UEN D Section 21
Requirements
Busbar protection REB670 457
Application manual