Investigation on the partial discharge behaviour in GFRP under AC and combined AC/DC field stress

Inhalt:
This paper deals with the study of internal partial discharge in voids inside glass-fiber reinforced polymer (GFRP) materials at different temperatures under AC and combined AC/DC field stress. To investigate the partial discharge activities of GFRP materials, a special high voltage circuit have been developed, which could provide AC and combined AC/DC voltage up to 100 kV with different AC to DC ratios. Partial discharge activities in GFRP dielectric under AC and combined AC/DC field stress at 20˚C, 40˚C, 60˚C and 80˚C have been investigated, leading to an equivalent circuit and mathematical model of partial discharges at combined AC/DC field stress. The results show the dependency of partial discharge parameters to the temperature at combined AC/DC and AC field stress, which could be helpful to material selection and environmental condition consideration to utilization of insulation components.