The Trip value recorder calculates the values of all selected analog input signalsconnected to the Disturbance recorder function. The result is magnitude and phaseangle before and during the fault for each analog input signal.The trip value recorder information is available for the disturbances locally in the IED.The trip value recorder information is an integrated part of the disturbance record(Comtrade file).14.8.2 Function blockThe Trip value recorder has no function block of it’s own.14.8.3 Signals14.8.3.1 Input signalsThe trip value recorder function uses analog input signals connected to A1RADR toA3RADR (not A4RADR).14.8.4 Operation principleTrip value recorder calculates and presents both fault and pre-fault amplitudes as wellas the phase angles of all the selected analog input signals. The parameterZeroAngleRef points out which input signal is used as the angle reference.When the disturbance report function is triggered the sample for the fault interceptionis searched for, by checking the non-periodic changes in the analog input signals. Thechannel search order is consecutive, starting with the analog input with the lowestnumber.When a starting point is found, the Fourier estimation of the pre-fault values of thecomplex values of the analog signals starts 1.5 cycle before the fault sample. Theestimation uses samples during one period. The post-fault values are calculated usingthe Recursive Least Squares (RLS) method. The calculation starts a few samples afterthe fault sample and uses samples during 1/2 - 2 cycles depending on the shape of thesignals.If no starting point is found in the recording, the disturbance report trig sample is usedas the start sample for the Fourier estimation. The estimation uses samples during onecycle before the trig sample. In this case the calculated values are used both as pre-fault and fault values.The name of the analog signal that appears in the Trip value recorder function is theuser-defined name assigned when the IED is configured. The same name is used in theDisturbance recorder function .Section 14 1MRK 504 135-UEN AMonitoring478Technical manual
