Phase-resolved and time-sequential partial discharge pulse measurements in a metal-void-insulator system using a personal computer

Abstract

We have developed a partial discharge measurement and analysis system using a personal computer, which allows one to obtain reproduced partial discharge pulse data with the phase information in an applied alternating current voltage and the number of cycles. For the CIGRE method II electrode system using 0.1 mm thick polyethylene film, temporal changes of partial discharge characteristics were measured up to breakdown of the sample. The average inception phase theta inc was proposed as a new statistical partial discharge parameter, which was obtained by making use of the capability of the time-sequential partial discharge data acquisition of our system; theta inc is defined as the average of theta inc of the number of cycles in a measurement; theta inc is a phase at which the first partial discharge pulse occurs in the half cycle after the polarity reversal of the previous partial discharge pulses. The experimental results revealed that the partial discharge pulse occurrence phase distribution ( phi -q-n distribution) exhibited a good correlation with ageing time. It was suggested that theta inc is a candidate signal for diagnosis of insulation performance of the system from the initial to middle degradation stage. We also discuss the physics of the temporal change of the phi -q-n distribution and theta inc as the ageing process proceeded.

Critical Agglomerate Size for Electrical Insulation Lifetime Extension of Epoxy/TiO2 Nanocomposite with a Void Defect

“…It should be noted that although the PD current signals were not detected by the measurement system, the PD light emission was detected by a camera observation through the transparent ITO ground electrode. This PD characteristic has been reported in the previous paper as the swarming pulsive micro-discharges (SPMD) [22]. In this SPMD stage, the oxygen in the void was consumed by the continuous PDs, and the internal air pressure decreased, resulting in lowering the PD inception voltage.…”

Partial discharges due to electrical treeing in polymers: phase-resolved and time-sequence observation and analysis

“…Simultaneously, the PD pulses were measured by a computer-aided partial-discharge measurement system of sensitivity about 0.3 pC and maximum time resolution 5 µs. The details of the measurement system were reported elsewhere [24]. The phase angle (φ), the magnitude (q) and the cycle number of PD occurrence of each PD pulse were recorded.…”

Relation between Concentration of Partial Discharge and Surface Degradation and Breakdown

“…7). Just after the voltage application, the PD pattern was so-called turtle-like pattern and then passing so-called rabbitlike pattern pulses became very small (Table 1) [2,3,4]. This drastic change compared with the case of open void should be caused by the change in gas condition.…”

“…Throughout the voltage application time, the PD pattern remained so-called turtle-like pattern [2,3,4] and the pulse number per cycle and the average charge of each pulse remain constant as shown in Table 1. This implies that the gas content remained unchanged and the PD characteristics are determined mostly by the atmospheric condition.…”