Table 35:FDPSPDIS Non group settings (basic)Name Values (Range) Unit Step Default DescriptionGlobalBaseSel 1 - 6 - 1 1 Selection of one of the Global Base Valuegroups6.2.6 Operation principleThe basic impedance algorithm for the operation of the phase selection measuringelements is the same as for the distance zone measuring function. Phase selection withload encroachment, quadrilateral characteristic FDPSPDIS (21) includes six impedancemeasuring loops; three intended for phase-to-ground faults, and three intended for phase-to-phase faults as well as for three-phase faults.The difference, compared to the distance zone measuring function, is in the combinationof the measuring quantities (currents and voltages) for different types of faults.A current-based phase selection is also included. The measuring elements continuouslymeasure three phase currents and the residual current, and compare them with the setvalues. The current signals are filtered by Fourier's recursive filter, and separate tripcounter prevents too high overreaching of the measuring elements.The characteristic is basically non-directional, but FDPSPDIS (21) uses information fromthe directional function (ZDNRDIR) to discriminate whether the fault is in forward orreverse direction.The pickup condition STCNDZI is essentially based on the following criteria:1. Residual current criteria, that is, separation of faults with and without groundconnection2. Regular quadrilateral impedance characteristic3. Load encroachment characteristics is always active but can be switched off byselecting a high setting.The current pickup condition DLECND is based on the following criteria:1. Residual current criteria2. No quadrilateral impedance characteristic. The impedance reach outside the load areais theoretically infinite. The practical reach, however, will be determined by theminimum operating current limits.3. Load encroachment characteristic is always active, but can be switched off byselecting a high setting.Section 6 1MRK 506 335-UUS AImpedance protection130Technical manual
