Two current channels I3P1 and I3P2 are available in OOSPPAM function to allowthe direct connection of two groups of three-phase currents; that may be needed forvery powerful generators, with stator windings split into two groups per phase,when each group is equipped with current transformers. The protection functionperforms a simple summation of the currents of the two channels I3P1 and I3P2.11.4.12.1 Verifying the settings GUID-708C4033-3111-481F-9868-FF207C18C9F9 v1The test of the out-of-step protection function is made to verify that the trip isissued if the following events happen.• the impedance, seen by the function, enters the lens characteristic from oneside and leaves it from the opposite side• the trip is issued according to the settings TripAngle and tBreakerThe tripping zone needs to be detected and confirmed. The test may be performedby taking into account the following key points that are shown in Figure 40:• the point RE (RE = Receiving End)• the intersection between the line segment SE-RE and the X-line, which isdefined through the setting ReachZ1• the point SE (SE = Sending End)I = I(50 Hz) + I(49.5 Hz)IEC10000141 V2 EN-USFigure 40: Trajectory of the impedance Z(R, X) for the injected current withtwo components: a 50 Hz component and a 49.5 Hz currentcomponentThe test of the out-of-step protection function requires the injection of the analogquantities for a quite long time. The rating of the analogue channels is consideredin order to avoid any hardware damage. The test current is lower than thecontinuous permissive overload current Iovrl of the protection current channels ofthe transformer module.Section 11 1MRK 505 378-UEN ATesting functionality by secondary injection150 Line differential protection RED670 2.2 IECCommissioning manual
