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Advanced Distance provides advanced functionality in addition to the base functionality of Distance:
- Search and Check tests
- Test settings relative to zone reaches and line angle ("relative shots")
- Testing multiple fault loops
Shot tests, Search tests, and Check test
At a Shot test (the only mode provided in the Distance module), test points in the test point table are automatically processed.
At a Search test, zone reaches are determined automatically. Zone transitions are searched along search lines specified in the impedance plane, using an optimized algorithm. It is possible to define a series of search lines in a single step. All defined search lines are stored in a table for automatic processing.
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At a Search test, zone reaches are determined automatically. Zone transitions are searched along search lines specified in the impedance plane, using an optimized algorithm. It is possible to define a series of search lines in a single step. All defined search lines are stored in a table for automatic processing.
At a Check test, test points are automatically set at the tolerance boundaries of zones. The setup is done with test lines (check lines) similar to a search test, but test points are only set at the intersections of the check lines with the zone tolerances. The Check test is an efficient overall test of the relay with minimum testing time. This gives a quick verification of whether the specifications are met, particularly for routine tests.
Adding test points and test lines to the tables is possible in a variety of ways. Parameters can be precisely defined by numerical inputs, or specified by pointing to certain locations in the characteristic diagram. A magnetic cursor supports the choosing of useful values. Mouse commands, context menus and keyboard shortcuts facilitate data input.
A test in Advanced Distance can have any combination of Shot, Search, or Check tests. At test execution, the whole test settings are processed sequentially.
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Relative Test Definitions
A revolutionary feature is that the test settings can be made relative to the characteristic of the distance relay. Test points are not entered in absolute R, X, Z, or angle values, but are instead referred to zone reaches and the line angle. The relative settings can be applied to reaches and to angles, either combined or individually.
Test points defined relative to zone reaches (e.g. 90 % of zone 1, 110 % of zone 1, 90 % of zone 2, …) have the magnitude of the impedance automatically adjusted to the actual values defined in the test object data.
Test points and test (search/check) lines defined relative to the line angle are twisted according to the setting of the line angle in the XRIO test object file.
With this feature, re-usable test templates that adopt themselves to the actual relay settings can be created.
Constant Source Impedance Model
In addition to the constant test current and constant test voltage models from Distance, Advanced Distance provides the constant source impedance test model which is useful in special cases where parameters such as SIR (Source Impedance Ratio) are important.
Load Current
To verify special behavior of certain relays which occurs only when a prefault (load) current is present (e.g. accelerated tripping performance), a load current can be superimposed.
Testing multiple fault loops in one test module
Advanced Distance provides special support by performing the tests for multiple fault loops within one test module. For all test modes (shot, search, check) multiple tabs are provided with a separate test point table for every fault type. For every fault type, individual test settings can be made, but for the common case of equal settings in related fault types, there are functions to make the same settings in multiple fault types simultaneously.
Multi-windows user interface
The user interface can be configured individually, using the following elements:
Test View
This view holds the test point tables for the Shot, Search, and Check tests and the impedance plane. Test definitions are made in this view. During and after the test execution, this view displays the results numerically in the tables and graphically in the impedance plane.
Z/t Diagram
This view shows the graded trip time curve over the impedance along a certain line. The actual line is determined by pointing in the impedance plane or by a selection in one of the test tables. It is also possible to define test points and view the assessments in the diagram.
Vector Diagram
The vector diagram shows the phasors of the voltages and currents, both for the phase quantities and the sequence components. The corresponding numerical values are displayed in the attached table.
Time Signal View
The voltages, currents, and binary signals after a completed shot are shown in this view. This is useful to perform more detailed investigations (e.g. time measurements using cursors).