Investigation of states recognition of motion conducting particles under DC voltages using the pulse current method

Abstract

Gas insulated switchgear (GIS) is widely used in the power system, due to its high reliability and great insulation characteristics. However, partial discharge (PD) caused by particle contamination in GIS threatens the stability and reliability of power system. Experiments have been carried out to observe the motion trials of single macroscopic conducting particle under DC voltages. Simultaneously, the pulse current signals have been measured. The result shows that the dominant frequency of PD signals for conducting particle under DC voltage is in the range of 0~7 MHz. In this paper, a method that recognized the particle states is proposed based on pulse characteristic parameter maps which consist of time intervals between pulses (Δt), discharge numbers (n) and discharge charges (q). The result indicates that pulse characteristic parameter maps can be used to recognize the motion states of metallic particle.

Relationship between PD magnitude distribution and pulse burst for positive coronas

“…Moreover, no phase angles under DC voltages make the diagnosis of insulation states difficult since it is no longer possible to use phase-resolved-partial-discharge patterns under AC voltage. Currently, many researchers used discharge magnitude (q) and time intervals between PDs (Δt) to establish time-resolved-partialdischarge (TRPD) patterns and made a progress in diagnosis of insulation state under DC voltage [11][12][13]. For example, some researchers used q and Δt and their deduced quantities, such as mean magnitude to the preceding or successive discharge (q pre or q suc ) and mean time intervals to the preceding or successive discharge (Δt pre or Δt suc ), to construct TRPD patterns like the discharge magnitude distribution, (q pre (q) and Δt suc (q)) and [6].…”