Operation Principle - ABB RELION REX640 Technical Manual

Section 5
Protection related functions
5.1.5
1062
See the preprocessing function blocks in this document for the
possible signal sources.
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 INRPHAR can be described using a module diagram. All the
modules in the diagram are explained in the next sections.
I_2H_A
I_2H_A /
I_1H_A
I_1H_A
I3P
I_2H_B
I_2H_B /
I_1H_B
I_1H_B
I_2H_C
I_2H_C /
I_1H_C
I_1H_C
I_1H_A
I_1H_B Level
detector
I_1H_C
BLOCK
GUID-13E1A389-3E3B-46C2-B8AF-A830DFD2FD44 V2 EN
Figure 570: Functional module diagram
I_2H/I_1H
These modules calculate the ratio of the second harmonic (I_2H) and fundamental
frequency (I_1H) of the phase currents. The calculated value is compared to the set
Start value. If the calculated value exceeds the set Start value, the module output is
activated.
Level detector
The output of the phase-specific level detector is activated when the fundamental
frequency current I_1H exceeds the set Min operate current of the nominal current.
Timer
t
AND
Timer
t
AND
Timer
t
AND
1MRS759142 C
Phase
BLK2H
selection
logic
REX640
Technical Manual