ABB RELION 620 Series Technical Manual page 686

Section 8
Power quality measurement functions
8.3.4.3
680
Variation validation
The validation criterion for voltage variation is that the measured total variation duration
is between the set minimum and maximum durations (Either one of VVa dip time 1, VVa
swell time 1 or VVa Int time 1, depending on the variation type, and VVa Dur Max). The
maximum variation duration setting is the same for all variation types.
Figure 343 shows voltage dip operational regions. In
swell/Int set is drawn, whereas in this figure there are three sub-limits for the dip
operation. When Voltage dip set 3 is undershot, the corresponding PICKUP_x and also
the DIPST outputs are activated. When the TRMS voltage magnitude remains between
Voltage dip set 2 and Voltage dip set 1 for a period longer than VVa dip time 2 (shorter time
than VVa dip time 3), a momentary dip event is detected. Furthermore, if the signal
magnitude stays between the limits longer than VVa dip time 3 (shorter time than VVa Dur
max), a temporary dip event is detected. If the voltage remains below Voltage dip set 1 for
a period longer than VVa dip time 1 but a shorter time than VVa dip time 2, an
instantaneous dip event is detected.
For an event detection, the TRIP output is always activated for one task cycle. The
corresponding counter and only one of them (INSTDIPCNT, MOMDIPCNT or
TEMPDIPCNT) is increased by one. If the dip limit undershooting duration is shorter than
VVa dip time 1, VVa swell time 1 or VVa Int time 1, the event is not detected at all, and if
the duration is longer than VVa Dur Max, MAXDURDIPCNT is increased by one but no
event detection resulting in the activation of the TRIP output and recording data update
takes place. These counters are available through the monitored data view on the LHMI
or through tools via communications. There are no phase-segregated counters but all the
variation detections are registered to a common time/magnitude-classified counter type.
Consequently, a simultaneous multiphase event, that is, the variation-type event detection
time moment is exactly the same for two or more phases, is counted only once also for
single-phase power systems.
GUID-0D3F6D81-F905-4D8D-A579-836EF7BB6773-ANSI V1 EN
Figure 343: Voltage dip operational regions
1MAC504801-IB E
Figure 342, only one voltage dip/
620 series ANSI
Technical Manual