4.2.1 Setting of the phase reference channel SEMOD55055-5 v3All phase angles are calculated in relation to a defined reference. An appropriateanalog input channel is selected and used as phase reference. The parameterPhaseAngleRef defines the analog channel that is used as phase angle reference.4.2.1.1 Example SEMOD55055-11 v54.2.2 Setting of current channels SEMOD55055-16 v6The direction of a current to the IED is depending on the connection of the CT.Unless indicated otherwise, the main CTs are supposed to be star connected andcan be connected with the earthing point to the object or from the object. Thisinformation must be set in the IED. The convention of the directionality is definedas follows: A positive value of current, power, and so on means that the quantityhas the direction into the object and a negative value means direction out from theobject. For directional functions the direction into the object is defined as Forwardand the direction out from the object is defined as Reverse. See Figure 3A positive value of current, power, and so on (forward) means that the quantityflows towards the object. A negative value of current, power, and so on (reverse)means that the quantity flows away from the object. See Figure 3.Protected ObjectLine, transformer, etcForwardReverseDefinition of directionfor directional functionsMeasured quantity ispositive when flowingtowards the objecte.g. P, Q, IReverseForwardDefinition of directionfor directional functionse.g. P, Q, IMeasured quantity ispositive when flowingtowards the objectSet parameterCTStarPointCorrect Setting is"ToObject"Set parameterCTStarPointCorrect Setting is"FromObject"en05000456.vsdIEC05000456 V1 EN-USFigure 3: Internal convention of the directionality in the IEDWith correct setting of the primary CT direction, CTStarPoint set to FromObject orToObject, a positive quantities always flowing towards the protected object and adirection defined as Forward always is looking towards the protected object. Thefollowing examples show the principle.4.2.2.1 Example 1 SEMOD55055-23 v6Two IEDs used for protection of two objects.Section 4 1MRK 505 393-UEN BAnalog inputs40 Line differential protection RED650 2.2 IECApplication manual
