Surface Potential Decay on Silicon Rubber Samples at Reduced Gas Pressure
Paper i proceeding, 2013

Accumulation of interfacial charges is an inherent feature of HVDC insulation based on solid and gaseous media. The collected surface charges can alter the geometrical electric field leading to undesirable phenomena such as partial discharges and even unexpected flashovers. In the present paper, surface potential decay on silicone rubber samples is analyzed at reduced pressures of ambient air that allows for elimination of surface charge neutralization by gas ions. Thus, influences imposed by bulk and surface conduction in the solid material are studied by means of computer simulations and experimental measurements. The results allow for identifying levels of bulk and surface conductivities above which the corresponding charge decay mechanism becomes dominant. It is shown that with a negligible space charge effect and significant surface leakage, there exists a notable spread of charge along gas-solid interface yielding visible crossover phenomenon in charge decay characteristics. It is also demonstrated that the effect of space charge in the material bulk on surface potential decay can only be significant within layers of material finer than ~100 µm.

Surface charging

surface potential

potential decay

electrical conductivity.

HVDC systems

charge transport


Shahid Alam

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

Yuriy Serdyuk

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

Stanislaw Gubanski

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

Proceedings of the 23rd NORDIC INSULATION SYMPOSIUM, June 9-12, 2013 Trondheim, Norway



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