11.1.7.3 Dead line detectionA simplified diagram for the functionality is found in figure 144. A dead phasecondition is indicated if both the voltage and the current in one phase is below theirrespective setting values VDLDPU and IDLDPU. If at least one phase is considered tobe dead the output DLD1PH and the internal signal DeadLineDet1Ph is activated. If allthree phases are considered to be dead the output DLD3PH is activatedIAIBICab aab aab aIDLDPUVAVBVCab aab aab aVDLDPUORANDANDANDANDAND ANDANDAllCurrLowDeadLineDet1PhDLD3PHDLD1PHintBlockDead Line DetectionANSI0000035-1-en.vsdANSI0000035 V1 ENFigure 144: Simplified logic diagram for Dead Line detection part11.1.7.4 Main logicA simplified diagram for the functionality is found in figure 145. The fuse failuresupervision function (SDDRFUF) can be switched on or off by the setting parameterOperation to Enabled or Disabled.For increased flexibility and adaptation to system requirements an operation modeselector, OpModeSel, has been introduced to make it possible to select differentoperating modes for the negative and zero sequence based algorithms. The differentoperation modes are:• Disabled; The negative and zero sequence function is disabled• V2I2; Negative sequence is selected• V0I0; Zero sequence is selectedSection 11 1MRK 502 043-UUS BSecondary system supervision310Technical Manual
