ABB RELION REX640 Technical Manual page 876

Protection functions
4.5.5.4 Analog channel configuration
NSPTOV has one analog group input which must be properly configured.
Table 821: Analog inputs
Input
U3P
There are a few special conditions which must be noted with the configuration.
Table 822: Special conditions
Condition
U3P connected to 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.
4.5.5.5 Operation principle
The function can be enabled and disabled with the
corresponding parameter values are "On" and "Off".
The operation of NSPTOV can be described using a module diagram. All the modules
in the diagram are explained in the next sections.
Figure 491: Functional module diagram
Level detector
The calculated negative-sequence voltage is compared to the set
If the value exceeds the set
876
See the preprocessing function blocks in this document for the possible
signal sources.
U
U3P
BLOCK
Description
Three-phase voltages
Description
The function requires that any two voltage
channels are connected.
Timer
Level
2
detector
Blocking
logic
Start value , the level detector enables the timer.
1MRS759142 F
Operation setting. The
OPERATE
t
START
Start value setting.
Technical Manual
REX640