Dynamics of surface charge and electric field distributions on basin‐type insulator in GIS/GIL due to voltage polarity reversal

Abstract

In this study, a simulation model of surface charge accumulation has been established. The model considers three accumulation ways, i.e. electrical conduction within the gas, through insulator volume and along the insulator surface. The generation, diffusion, drift and recombination of charge carriers are also taken into account. Based on it, the influence of polarity reversal, reversal time on surface charge and electric field distribution on a basin-type insulator are studied. The polarity of the surface charges and the direction of the electric field change after the voltage polarity reversal. When the preload voltage is equal to reversal voltage, the surface charge and the electric field distributions at steady state before and after voltage polarity reversal are all the same with opposite sign, and not affected by the reversal time. However, the time to reach the steady state varies with different reversal time. The steady-state surface charge and electric field increased with the rise of reversal voltage. The transient normal and tangential electric field would not exceed the value of the steady state, which means voltage polarity reversal has no additional influence on insulation performance. This research can provide guidance to the design and manufacture of DC GIS/GIL.

Surface Charge Properties of Epoxy Composites under DC Voltage Affected by Surface and Bulk Conductivity

“…The gap between the probe and sample was set at 2 mm. The measuring error can be limited within 2% when the gap distance is no more than 3 mm, beyond which the measuring error becomes dramatically higher [13]. The gap distance of not less than 2 mm could effectively avoid discharges between the sample surface and the probe [14].…”

“…Cone-shaped insulators made of Al 2 O 3 -filled epoxy resin composites have been used to investigate the surface charge properties [4,5,10] and demonstrate the distortion of electric field distribution and the process of surface flashover [4]. Apart from the bulk effect of insulating materials, surface modification is utilized to generate more surface traps and suppress the charge accumulation [5,[10][11][12][13][14][15][16][17][18][19][20].…”

“…Energies 2021, 14,370 Apart from the bulk effect of insulating materials, surface modification is utiliz ate more surface traps and suppress the charge accumulation [5,[10][11][12][13][14][15][16][17][18][19][20]. In ad material properties, the influence of voltage type on charge accumulation is als [11].…”

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