Abstract: Method and device for measuring a dielectric response of an electrical insulating system, wherein a first measurement result is determined by a frequency domain method and a second measurement result is determined by a time domain method, whereupon the first measurement result and the second measurement result are combined to form an overall measurement result as the dielectric response. Standard types of measurement methods, for example the FDS and PDC methods, may be used as measurement methods for the frequency domain and the time domain.

Abstract: Method and device for measuring a dielectric response of an electrical insulating system, wherein a first measurement result is determined by a frequency domain method and a second measurement result is determined by a time domain method, whereupon the first measurement result and the second measurement result are combined to form an overall measurement result as the dielectric response. Standard types of measurement methods, for example the FDS and PDC methods, may be used as measurement methods for the frequency domain and the time domain.

Abstract: Testing a transformer by applying to the transformer a test signal, the frequency of which may be lower than the nominal frequency of the transformer. The voltage of the test signal may also be lower than the nominal voltage of the transformer. A number of frequency-dependent parameters are measured, particularly the eddy current resistance and the hysteresis curve of the transformer, in order to derive a simulation model which simulates the behavior of the transformer at different frequencies. Using this simulation model, it is possible to predict operating parameters of the transformer, such as the terminal voltage on the secondary and the terminal current in the secondary, during operation with a frequency deviating from the frequency of the test signal, particularly during operation with the nominal frequency of the transformer.

Abstract: Testing a transformer by applying to the transformer a test signal, the frequency of which may be lower than the nominal frequency of the transformer. The voltage of the test signal may also be lower than the nominal voltage of the transformer. A number of frequency-dependent parameters are measured, particularly the eddy current resistance and the hysteresis curve of the transformer, in order to derive a simulation model which simulates the behavior of the transformer at different frequencies. Using this simulation model, it is possible to predict operating parameters of the transformer, such as the terminal voltage on the secondary and the terminal current in the secondary, during operation with a frequency deviating from the frequency of the test signal, particularly during operation with the nominal frequency of the transformer.

Abstract: There is described a fully automatic portable testing device which can be used generally for testing test-pieces to be operated at high voltages and/or high currents, such as current or voltage transducers or transformers for example. For this purpose, the portable testing device comprises a switched-mode power amplifier (3) whose output is connected to a matching transformer (4-7) having a plurality of secondary windings (5-7), which can be changed over. The test-piece on which measurements are to be made is in each case removably connected to the secondary windings (5-7) of the matching transformer. The portable testing device also comprises a control which in particular may have a digital signal processor (8) and/or a controller or computer (9) and which on the one hand controls the power amplifier (3) in a purposive way and preferably also performs an automatic changeover of the secondary windings (5-7) of the matching transformer, in order to generate a desired testing signal.

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.