| 摘要 |
Partial discharge events in a multi-phase electrical system can be identified and distinguished from noise by measuring characteristics of a signal from each phase in a common measurement period and comparing the respective characteristics between the phases. If a similar signal is present on all three phases, this indicates a source of noise common to all three phases (figure 1c). A similar signal on two phases indicates a phase to phase partial discharge (figure 1b) and a signal only on one phase indicates a phase to ground partial discharge (figure 1a). The comparison of characteristics may performed using ternary diagrams or triangular plots (figure 2, not shown), which facilitates performance of the method by unskilled persons. The characteristic may be amplitude, rate of change, rise time, power spectral density, peak to peak distance, or frequency composition. |
