11.1.7.3 Dead line detectionA simplified diagram for the functionality is found in figure 159. A dead phase conditionis indicated if both the voltage and the current in one phase is below their respective settingvalues VDLDPU and IDLDPU. If at least one phase is considered to be dead the outputDLD1PH and the internal signal DeadLineDet1Ph is activated. If all three phases areconsidered to be dead the output DLD3PH is activatedIAIBICab aab aab aIDLDPUVAVBVCab aab aab aVDLDPUORANDANDANDANDAND ANDANDAllCurrLowDeadLineDet1PhDLD3PHDLD1PHintBlockDead Line DetectionANSI0000035-1-en.vsdANSI0000035 V1 ENFigure 159: Simplified logic diagram for Dead Line detection part11.1.7.4 Main logicA simplified diagram for the functionality is found in figure 160. 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 different operatingmodes for the negative and zero sequence based algorithms. The different operationmodes are:• Disabled. The negative and zero sequence function is disabled.• V2I2. Negative sequence is selected.• V0I0. Zero sequence is selected.Section 11 1MRK 502 048-UUS ASecondary system supervision338Technical manual
