ABB REC 523 Technical Reference Manual

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ABB REC 523 Technical Reference Manual Manual pdf 32 page image

321MRS750881-MUMRemote Monitoring and Control UnitTechnical Reference ManualREC 523The correction parameters/factors are calculated as follows:Current transformersVoltage transformersRogowski coilVoltage divider5.3.3. Calculated analogue channelsREC 523 includes virtual channels to obtain phase-to-phase voltages, residualvoltage and neutral current when sensors are used. Current sensors and voltagedividers are connected to the feeder terminal via coaxial cables. Therefore a phase-to-phase voltage connection, an open-delta connection of phase voltages or aresidual connection of phase currents cannot be made. Both the amplitude and thephase angle are calculated for the virtual channels.The virtual channel voltages and currents are numerically derived from the phasevoltages and phase currents according to Table 5.3.3-1. Though primarily meant tobe used with sensors, the calculated analogue channels can also be used withconventional current and voltage transformers.The virtual channels are numbered according to the priority numbers in the Table5.3.3-1. The virtual channel used first is numbered as 11 and the following as 12, 13and so on. For example, U0s is numbered as 11 and U12s as 12, if these virtualchannels are selected for use.Amplitude error at current In(e = error in per cent)Amplitude correction factor 1= 1 / (1+ e/100)Amplitude error at current 0.01 x In(e = error in per cent)Amplitude correction factor 2= 1 / (1+ e/100)Phase displacement error at current In(e = error in degrees)Phase displacement error 1 = - ePhase displacement error at current 0.01 x In(e = error in degrees)Phase displacement error 2 = - eAmplitude error at voltage Un(e = error in per cent)Amplitude correction factor= 1 / (1+ e/100)Phase displacement error at voltage Un(e = error in degrees)Phase displacement error= - eAmplitude error for the entire measuring range(e = error in per cent)Amplitude correction factor= 1 / (1+ e/100)Phase displacement error for the entire measuringrange (e = error in degrees)Phase displacement error = - eAmplitude error for the entire measuring range(e = error in per cent)Amplitude correction factor= 1 / (1+ e/100)Phase displacement error for the entire measuringrange (e = error in degrees)Phase displacement error = - e