THE INFLUENCE OF THE TOPOLOGY OF TEST CIRCUITS ON THE INTERRUPTING PERFORMANCE OF CIRCUIT-BREAKERS

High-voltage circuit breakers are tested in the High Power Laboratory where transient recovery voltages (TRVs) are generated by networks consisting of lumped elements. In the DEC and ANSI standards the TRV waveforms are described, but not the topology of the test circuits. This paper compares different direct TRV test circuits which generate the same initial part of the TRV waveform. It is demonstrated that the surge impedance of the TRV test circuit is an important parameter. The difference in interrupting performance of the TB in the test circuits with the different surge impedances is caused by the influence of the are-circuit interaction.