Recent advances in partial discharge measurement capabilities at NIST

Three techniques for measuring the properties of partial discharges (PDs) are described. The first is concerned with an advanced, real-time PD measurement system that allows a complete characterization of the stochastic properties of PD. With this system it is possible to measure a set of conditional PD pulse-amplitude and pulse-time separation distributions from which memory effects characteristic of the discharge phenomena can be quantified and interpreted. Results for pulsating negative corona discharges in gases are shown. The second technique allows PD location in cables using time-domain reflectometry with appropriate statistical analysis. With the third technique, simultaneous measurements are made of the optical and electrical characteristics of PD in liquid dielectrics using fast photography combined with broadband. low-noise pulse current measurements.<
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