Operation Principle - ABB RELION REX640 Technical Manual

Section 4
Protection functions
4.4.2.5
742
See the preprocessing function blocks in this document for the
possible signal sources. The GRPOFF signal is available in the
function block called Protection.
There are a few special conditions which must be noted with the configuration.
Table 670: Special conditions
Condition
U3P connected real measurements
Improper analog channel configuration causes a validation error if the analog
channels are not completely configured or they do not match with certain settings. For
troubleshooting, check the contents of this chapter and also the preprocessing blocks
in this document. The configuration can be written to the protection relay once the
mismatch is corrected.

Operation principle

The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "on" and "off".
The operation of DNSPDOC can be described with a module diagram. All the
modules in the diagram are explained in the next sections.
I
I3P
2
Io
IRES
U
U3P
BLOCK
GUID-CBA9A547-A69D-481E-8F54-2EC57DF7E348 V1 EN
Figure 409: Functional module diagram
Level detector
The operating signal is compared to the set Start value. If the operating signal exceeds
the set Start value, Level detector sends an enabling signal to the Timer module. Timer
starts when it is enabled and the directional criterion is fulfilled. A suitable operating
quantity can be selected with the Operating quantity setting. The options are
"Negative seq" or "Residual". The value of operating quantity I_OPER is also
available in the Monitored data view.
Description
The function requires that at least two voltage
channels are connected.
Timer
Level
t
detector
2
Directional
calculation
Blocking
logic
1MRS759142 C
OPERATE
START
REX640
Technical Manual