The insulators sprayed with PRTV coatings have better pollution tolerance and can effectively prevent pollution flashover.But in HVDC power system

PRTV coatings will aggravate the surface charge accumulation

resulting in the distortion of the synthetic electric field on insulator surface.In order to obtain insulator sprayed PRTV coating surface electrostatic potential variation law under negative polar corona

the surface potential of ceramic

glass and sprayed with PRTV coated insulators was measured by electrostatic probe method

and the surface potential of two insulators under corona was measured.The results show that the surface potential of glass and ceramics insulators are almost zero after corona

while the insulators coated with PRTV coatings are easy to accumulate charges

and the absolute value of surface potential is larger.When the surface charge of insulators coated with PRTV coatings accumulates saturated

the electrostatic potential is about-700 V

and the attenuation trend of surface potential is approximately exponential.When two insulators are suspended

the absolute value of upper insulators surface potential is higher

and the potential decay rate of upper and lower insulators is equal.