pole-slip is usually allowed before the generator-transformer unit is disconnected. Aparameter setting is available to take into account the circuit breaker opening time. Ifthere are several out-of-step relays in the power system, then the one which finds thecenter of oscillation in its zone 1 should operate first.Two current channels I3P1 and I3P2 are available in OOSPPAM function to allow thedirect connection of two groups of three-phase currents; that may be needed for verypowerful generators, with stator windings split into two groups per phase, when eachgroup is equipped with current transformers. The protection function performs a simplesummation of the currents of the two channels I3P1 and I3P2.13.4.5.1 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 is issued ifthe following events happen.• the impedance, seen by the function, enters the lens characteristic from one sideand 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 performed bytaking into account the following key points that are shown in Figure 48:• the point RE (RE = Receiving End)• the intersection between the line segment SE-RE and the X-line, which is definedthrough the setting ReachZ1• the point SE (SE = Sending End)Section 13 1MRK 502 073-UUS ATesting functionality by secondary injection160 Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062Commissioning manual
