ABB RELION REX640 - 4.8.2.5 Operation principle

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.
4.8.2.5 Operation principle
The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off".
The operation of DOPPDPR can be described using a module diagram. All the
modules in the diagram are explained in the next sections.
BLOCK
OPERATE
START
Directional
calculation
U3P
I3P
Power
calculation
Level
detector
t
Timer
U_AB
U_BC
U_CA
I_A
I_B
I_C
U
1
I
1
Figure 593: Functional module diagram
Power calculation
This module calculates the apparent power based on the selected voltages and
currents. The Measurement mode setting determines which voltages and currents
are used. It is also possible to use positive-sequence components for calculating the
apparent power which makes the determination of power insensitive to a possible
asymmetry in currents or voltages and corresponds to the real load on the prime
mover of the generator.
Table 1001: Power calculation
Measurement mode setting Power calculation
PhsA, PhsB, PhsC
S U I U I U I
a a b b c c
+
*
* *
.
.
.
P S=
( )
Re
Arone
S U I U I
ab a bc c
= ⋅ − ⋅
* *
P S=
( )
Re
Table continues on the next page
Protection functions 1MRS759142 F
1064 REX640
Technical Manual