Experimental investigation of partial discharges activities in palm kernel oil methyl ester and mineral oil by using a Rogowski coil

• Published in: Electric power systems research 2022-12, Vol.213, p.108708, Article 108708
• Main Authors: Mengounou, Ghislain Mengata, Jiosseu, Jean Lambert, Imano, Adolphe Moukengue
• Format: Article
• Language: English
• Subjects: Mineral oil; Palm kernel oil methyl ester; Partial discharges; Rogowski coil; Shunt sensor
• ISSN: 0378-7796; 1873-2046
• DOI: 10.1016/j.epsr.2022.108708

•Phase-resolved partial discharge patterns model and the Weibull distribution.•Detection of internal partial discharges.•Prototype Rogowski coils.•RC integrator module for partial discharge current evaluation.•Shunt detection and Rogowski detection. This paper deals with the influence of the characteristics of a Rogowski coil compared to a shunt sensor in the detection of partial discharges (PDs) in insulating oils. An experimental investigation is conducted on the activity of PDs and their inception voltage in mineral oil (MO) and palm kernel oil methyl ester (PKOME). This is done by using the analysis of the phase-resolved partial discharge patterns model and the Weibull distribution. The experimental set-up consists of a 220 V/50 kV high voltage transformer, a control box and a test cell containing four electrode configurations. The tests are conducted according to the IEC 61,294 for the determination of partial discharge inception voltage. The experimental results show that the characteristics of a Rogowski coil have a considerable effect on the waveform and the number of occurrences of detected discharges. The number of occurrences of discharges detected with the shunt sensor is reduced by almost 50% compared to those of a Rogowski sensor. The parameters obtained from the Weibull distribution show that PKOME has a higher resistance to discharge inception than MO.