ABB RELION REX640 Technical Manual page 91

1MRS759142 C
REX640
Technical Manual
Redundant SMV streams are also supported by using the voltage (VMSWI) and
current (CMSWI) function blocks. Automatic switching to the backup SMV stream
can be configured in Application Configuration using SMV quality and/or other logic.
UniGear Digital switchgear concept relies on the process bus together with current
and voltage sensors. The process bus enables several advantages for the UniGear
Digital like simplicity with reduced wiring, flexibility with data availability to all
devices, improved diagnostics and longer maintenance cycles.
With process bus the galvanic interpanel wiring for sharing busbar voltage value can
be replaced with Ethernet communication. Transmitting measurement samples over
process bus brings also higher error detection because the signal transmission is
automatically supervised. Additional contribution to the higher availability is the
possibility to use redundant Ethernet network for transmitting SMV signals.
Station bus (IEC 61850-8-1), process bus (IEC 61850-9-2 LE) and IEEE 1588 v2 time synchronization
GUID-2371EFA7-4369-4F1A-A23F-CF0CE2D474D3 V5 EN
Figure 10: Process bus application of voltage sharing and synchrocheck
REX640 supports IEC 61850 process bus with sampled values of analog currents and
voltages. The measured values are transferred as sampled values using the IEC
61850-9-2 LE protocol which uses the same physical Ethernet network as the IEC
61850-8-1 station bus. One example application is sharing the measured busbar
voltage from one or several REX640 relays with the other REX640 relays. This can be
done even for a double busbar switchgear installation using automatic 9-2 stream
selection based on the bus disconnectors' physical position.
REX640 protection relays with process bus based applications use IEEE 1588 v2
Precision Time Protocol (PTP) according to IEEE C37.238-2011 Power Profile for
high accuracy time synchronization. With IEEE 1588 v2, the cabling infrastructure
requirement is reduced by allowing time synchronization information to be
transported over the same Ethernet network as the data communications.
Common Ethernet
Section 3
Basic functions
85