Relay Settings in the "Overcurrent" Room – Part 4

To perform “Overcurrent Directional” test, first select “Test Object” from the toolbar and then enter “I Primary” and “I Secondary” information which is the Turns ratio of “CT” in the tree diagram in “Device” section. Note that any mismatch between these two sections will result in incorrect responses.

After double-clicking on “Overcurrent” block in “Relay Parameters” page, select “Directional” option in “Relay Behavior” section. Then, specify the directions of “VT” and “CT Start Point” in “VT Connection” and “CT Start Point Connection” respectively. Note that mismatch between this section and the relay setting will result in a 180 degree phase difference between the device and relay settings.

After entering the intended “Stages” in “Element” section, whether the protection direction of relay is “Forward” or “Reverse” should be entered in “Direction” field. Then, enter “Maximum Torque Angle” and “Sector Opening” of the relay in “Define Element Directional Behavior” tab. The calculation method for these parameters will be explained in the videos related to protective functions test. In “Directional” mode, a “Directional Plane” is added to this page where you can view the range of relay protection. In “View Resulting Characteristic” tab, you can view the general characteristic curve and “Directional Plane” diagram.  Note that if you have multiple directional “Stages” with different “Pick Ups” and performance times, each “Stage” is depicted with a different color specified in the table at the top.

To display the “Directional” characteristic curve or “Directional Plane” and add test points, select “Medium Detail View” from the toolbar and specify your test points on the curve.

Another way to make a characteristic curve is to use an “XRio” file. To do this, first, select “Test Object” from the toolbar and check “Import from List” option and specify the relay “Template” type in “Search” section. For example, here, “7UT” relay is selected. Then, select “XRio” format from “File”, “Load Relay Setting”, “Relay Config Type” and import your “XRio” file in “Config File Path”. To make sure that the imported information is correct, you can review the entered parameters from the tree diagram of this section. If necessary, you can examine the parameters effective on every other parameters of the relay by using “Reference Map” and modify it if there is any mismatch with the relay setting.