ABB RELION 620 Series Technical Manual page 682

Section 8
Power quality measurement functions
8.3
8.3.1
8.3.2
8.3.3
676
Name Type
DMD_THD_B FLOAT32
3SMHTHD_C FLOAT32
DMD_THD_C FLOAT32
Voltage variation PQSS
Identification
Function description
Voltage variation
Function block
GUID-9AA7CE99-C11C-4312-89B4-1C015476A165-ANSI V1 EN
Figure 340: Function block
Functionality
The voltage variation measurement function PQSS is used for measuring the short-
duration voltage variations in distribution networks.
Power quality in the voltage waveform is evaluated by measuring voltage swells, dips and
interruptions. PQSS includes single-phase and three-phase voltage variation modes.
Typically, short-duration voltage variations are defined to last more than half of the
nominal frequency period and less than one minute. The maximum magnitude (in the case
of a voltage swell) or depth (in the case of a voltage dip or interruption) and the duration
of the variation can be obtained by measuring the RMS value of the voltage for each phase.
International standard 61000-4-30 defines the voltage variation to be implemented using
the RMS value of the voltage. IEEE standard 1159-1995 provides recommendations for
monitoring the electric power quality of the single-phase and polyphase ac power systems.
Values (Range) Unit
0.00...500.00 %
0.00...500.00 %
0.00...500.00 %
IEC 61850 IEC 60617
identification identification
PHQVVR PQ 3U<>
1MAC504801-IB E
Description
Demand value for THD for
phase B
3 second mean value of THD
for phase C
Demand value for THD for
phase C
ANSI/IEEE C37.2
device number
PQSS
620 series ANSI
Technical Manual