Digital partial discharge measuring system with interference recognition

This paper deals with a digital PD measuring system especially designed for reliable high-speed testing of large numbers of test specimens. The measuring process is based on a broadband measurement (f/sub c//spl ap/100 MHz) of PD in the time domain followed by a high speed A/D converter (f=1 GHz). Then the signal is transformed to the frequency domain by FFT and the frequency characteristics of the measured pulses are compared with a "standard-PD-spectrum" that has been generated before. So the automatic distinction between interference pulses and PD-signals is possible. The measuring system is described and typical examples of measurements given. The capability of the system to distinguish between PD and interference pulses is shown.