Partial Discharge Process and Characteristics of Oil-Paper Insulation under Pulsating DC Voltage

Abstract

-Oil-paper insulation of valve-side windings in converter transformers withstand electrical stresses combining with AC, DC and strong harmonic components. This paper presents the physical mechanisms and experimental researches on partial discharge (PD) of oil-paper insulation at pulsating DC voltage. Theoretical analysis showed that the phase-resolved distributions of PDs generated from different insulated models varied as the increase of the applied voltages following a certain rule. Four artificial insulation defect models were designed to generate PD signals at pulsating DC voltages. Theoretical statements and experimental results show that the PD pulses first appear at the maximum value of the applied pulsating DC voltage, and the resolved PD phase distribution became wider as the applied voltage increased. The PD phase-resolved distributions generated from the different discharge models are also different in the phase-resolved distributions and development progress. It implies that the theoretical analysis is suitable for interpretation of PD at pulsating DC voltage.

Study on partial discharge and charge accumulation characteristics of oil‐pressboard insulation under DC superimposed harmonic voltage

“…Fard et al simulated the partial discharge phenomenon of air-gap defect model under pulsating DC voltage, and the results showed that the discharge repetition rate increases with the increase of harmonic frequency and amplitude [4]. Li et al conducted partial discharge experiments on oil-pressboard insulation under pulsating DC voltage and studied the phase distribution of partial discharge [5]. Florkowski et al studied the ageing characteristics of insulating materials under DC superimposed harmonic voltage [6].…”

“…Li et al. conducted partial discharge experiments on oil‐pressboard insulation under pulsating DC voltage and studied the phase distribution of partial discharge [5]. Florkowski et al.…”

The Evolution of Trapping Parameters on Three-Layer Oil-Paper of Partial Discharge Degradation for On-Board Traction Transformers

“…The time lag/recovery model is presented and 3-dimensional histogram is suggested to be used as a base for discharge recognition under DC in [8]. In addition, Li et al [9] have paid much attention to the characteristic and mechanism of PD with combined voltage. They founded that the great difference of PD behavior and mechanisms exists among combined voltage, AC and DC voltage.…”