Pressure-Dependent Propagation of Streamers under Step Voltage in a long Point-Plane Gap in Transformer Oil
Peer reviewed, Journal article
Accepted version
Permanent lenke
https://hdl.handle.net/11250/2684857Utgivelsesdato
2020Metadata
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- Publikasjoner fra CRIStin - SINTEF Energi [1633]
- SINTEF Energi [1757]
Originalversjon
IEEE transactions on dielectrics and electrical insulation. 2020, 27 (5), 1595-1603. 10.1109/TDEI.2020.008940Sammendrag
The effect of pressure on positive and negative streamer propagation in a mineral transformer oil is studied in an 80 mm point-plane gap under step voltage. Increased pressure causes reduced stopping length for non-breakdown streamers, higher breakdown voltage, reduced background current, reduced branching in positive streamers and virtually no change in negative streamer shape. The velocities and acceleration voltages are close to being independent of pressure, indicating that the velocity controlling mechanisms take place in the liquid phase. Amplitude and frequency of small current pulses (probably small "reilluminations") during negative 1st mode is reduced with increasing pressure, but the effect on reilluminations during 2nd and 3rd mode is small in both polarities.