Operation Principle - ABB RELION REX640 Technical Manual

Section 4
Protection functions
4.5.9.5
826
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 VVSPPAM can be described by using a module diagram. All the
modules in the diagram are explained in the next sections.
U_A_AB
U_B_BC
U3P
U_C_CA
BLOCK
GUID-A18588F6-9AEE-4B06-9631-8AC2BA2A8573 V1 EN
Figure 450: Functional module diagram
Vector shift detector
This module measures the duration of each cycle of the voltage signal phase. The
duration of the present cycle is compared to the previous cycle, considered as
reference. When the mains is lost, a sudden change is seen in the cycle length, if
loading of the generator changes suddenly and power mismatch or unbalance
(generation vs. load) in the islanded part of the network is large enough. The cycle
shifts with time, that is, the frequency may not change but a vector shift is seen in phase
as shown in Figure 451.
This step is measured in degrees for each voltage signal defined by the Phase
supervision setting. The Phase supervision setting determines which voltage is used
for detecting vector shift. The available Phase supervision options are "All" and "Pos
sequence". If the calculated value of Δδ exceeds the set Start value setting for all the
defined phases, the module sends an enabling signal to start the Pulse timer.
The Voltage selection setting is used to select whether the available voltage signal is
phase-to-earth or phase-to-phase voltage.
The recommended and the default value for Phase supervision is "Pos
sequence".
If the magnitude of the voltage level of any of the monitored voltage signal, defined
by the Phase supervision setting, drops below Under Volt Blk value or exceeds Over
Volt Blk value, the calculation of vector shift is disabled and the INT_BLKD output is
activated.
Pulse timer
Vector
shift
detector
1MRS759142 C
OPERATE
INT_BLKD
REX640
Technical Manual