Abstract: Test system and test method for testing the operability of test samples (7). A selection can be made in a user-specific manner from a plurality of test modules (2a-2c) which are made available, which can be assembled together to a desired test specification. A control module (1) carries out the overall test corresponding to the user-specific test specification, and controls individual selected test modules (2a-2c) in the desired sequence in correspondence to this test specification. Advantageously, there is produced automatically a test report on the test results of the individual selected test modules (2a-2c), which reports in particular embedded in the user-specific test specification.

Abstract: A relay test apparatus useful for the testing of three-phase differential protection relay systems with up to three windings including the corresponding current transformers (Cts). Especially for differential protection relays, which protect a three phase transformer, the transformer with its vector group (delta and wye windings including phase shift) is simulated within the test software. From the simulation the injected test currents are calculated and applied to the relay (via current signal generators), and the reaction of the relay is measured back (via a trip contact). This is a common technique for relay text apparatus. Normally the magnitude of the injected signals has to be specified. The characteristics are differential projection relays are specified as operating characteristics in an IDiff/IStab two-dimensional plane and as trip time characteristics in the t over IDiff plane.