10.3.2 Function blockGUID-9AA7CE99-C11C-4312-89B4-1C015476A165 V1 ENFigure 360: Function block10.3.3 FunctionalityThe voltage variation function PHQVVR is used for measuring the short-durationvoltage variations in distribution networks.Power quality in the voltage waveform is evaluated by measuring voltage swells, dipsand interruptions. PHQVVR includes single-phase and three-phase voltage variationmodes.Typically, short-duration voltage variations are defined to last more than half of thenominal frequency period and less than one minute. The maximum magnitude (in thecase of a voltage swell) or depth (in the case of a voltage dip or interruption) and theduration of the variation can be obtained by measuring the RMS value of the voltagefor each phase. International standard 61000-4-30 defines the voltage variation to beimplemented using the RMS value of the voltage. IEEE standard 1159-1995 providesrecommendations for monitoring the electric power quality of the single-phase andpolyphase ac power systems.PHQVVR contains a blocking functionality. It is possible to block a set of functionoutputs or the function itself, if desired.10.3.4 Operation principleThe function can be enabled and disabled with the Operation setting. Thecorresponding parameter values are "On" and "Off".The operation of PHQVVR can be described with a module diagram. All the modulesin the diagram are explained in the next sections.Section 10 1MRS758755 APower quality measurement functions680 REC615 and RER615Technical Manual
