Power quality in the voltage waveform is evaluated by measuring voltage swells,
dips and interruptions. PHQVVR 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.
PHQVVR contains a blocking functionality. It is possible to block a set of function
outputs or the function itself.
10.3.4 Analog channel configuration
PHQVVR has two analog group inputs which must be properly configured.
Table 1630: Analog inputs
Input Description
I3P
1
Three-phase currents
U3P Three-phase voltages
See the preprocessing function blocks in this document for the possible
signal sources. The GRPOFF signal is available in the function block called
Protection.
There are a few special conditions which must be noted with the configuration.
Table 1631: Special conditions
Condition Description
U3P connected to real meas-
urements
The function can work with one voltage channel connected
(A, B or C depending on the
Phase supervision
setting "Ph A",
"Ph B" or "Ph C") if
Phase mode
is set to "Single Phase".
The function can work with two voltage channel connected
(A-B, B-C or C-A depending on the
Phase supervision
setting
"Ph A+B", "Ph B+C" or "Ph A+C") if
Phase mode
is set to
"Three Phase".
The function requires that all three voltage channels are con-
nected if
Phase supervision
is set to "Ph A+B+C" and
Phase
mode
setting is set to "Three Phase".
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.
1
Can be connected to GRPOFF
Power quality measurement functions 1MRS759142 F
1830 REX640
Technical Manual
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