interrupt fault currents. All these actions result in a sudden reduction of voltages on all
voltage phases.
Due to the nature of voltage variations, the power quality standards do not specify any
acceptance limits. There are only indicative values for, for example, voltage dips in
the European standard EN 50160. However, the power quality standards like the
international standard IEC 61000-4-30 specify that the voltage variation event is
characterized by its duration and magnitude. Furthermore, IEEE Std 1159-1995 gives
the recommended practice for monitoring the electric power quality.
Voltage variation measurement can be done to the phase-to-earth and phase-to-phase
voltages. The power quality standards do not specify whether the measurement should
be done to phase or phase-to-phase voltages. However, in some cases it is preferable
to use phase-to-earth voltages for measurement. The measurement mode is always
TRMS.
10.3.7 Signals
Table 693: PHQVVR Input signals
Name Type Default Description
I_A SIGNAL 0 Phase A current magnitude
I_B SIGNAL 0 Phase B current magnitude
I_C SIGNAL 0 Phase C current magnitude
U_A SIGNAL 0 Phase-to-earth voltage A
U_B SIGNAL 0 Phase-to-earth voltage B
U_C SIGNAL 0 Phase-to-earth voltage C
BLOCK BOOLEAN 0=False Block signal for activating the blocking mode
Table 694: PHQVVR Output signals
Name
Type Description
OPERATE BOOLEAN Voltage variation detected
START BOOLEAN Voltage variation present
SWELLST BOOLEAN Voltage swell active
DIPST BOOLEAN Voltage dip active
INTST BOOLEAN Voltage interruption active
1MRS758755 A Section 10
Power quality measurement functions
REC615 and RER615 693
Technical Manual
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