5-198 D30 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUALGROUPED ELEMENTS CHAPTER 5: SETTINGS5Figure 5-104: Quadrilateral distance characteristic sample shapesPHS DIST Z1 XFMR VOL CONNECTION — The phase distance elements can be applied to look through a three-phase delta-wyeor wye-delta power transformer. In addition, VTs and CTs can be located independently from one another at differentwindings of the transformer. If the potential source is located at the correct side of the transformer, set this setting to“None.”This setting specifies the location of the voltage source with respect to the involved power transformer in the direction ofthe zone. The following figure illustrates the usage of this setting. In section (a), zone 1 is looking through a transformerfrom the delta into the wye winding. Therefore, the Z1 setting is set to “Dy11.” In section (b), Zone 3 is looking through atransformer from the wye into the delta winding. Therefore, the Z3 setting is set to “Yd1.” The zone is restricted by thepotential point (location of the VTs) as illustrated in (e).PHS DIST Z1 XFMR CUR CONNECTION — This setting specifies the location of the current source with respect to the involvedpower transformer in the direction of the zone. In section (a) of the following figure, zone 1 is looking through a transformerfrom the delta into the wye winding. Therefore, the Z1 setting is set to “Dy11.” In section (b), the CTs are located at the sameside as the read point. Therefore, the Z3 setting is set to “None.”See the Application of Settings chapter for information on calculating distance reach settings in applications involvingpower transformers.
