New methods of partial discharge detection and location

A complete partial discharge measurement system has been assembled from two main components, namely, a waveform digitiser linked to a fast processor. With some additional hardware and electronics and the appropriate software for the particular task, this same system can be used for partial discharge mapping on samples ranging from 0.5 m to 3 km in length and for discharge spectrum measurements. The location of partial discharges which is fundamental in drawing discharge maps of cables, switchgear and other samples, is achieved using a double ended method for sample lengths up to 50 m or so and for operational simplicity, a single ended method for longer cables. The replacement of the traditional discharge detector with discharge spectrum measurements, means that a permanent non-subjective, detailed record of the partial discharge activity can now be made. The pulse height spectrum, polarity, phase, voltage at excitation and any result derived from this raw data can now be used to make much more accurate and appropriate discharge measurements