多因素影响下直流套管胶浸纸绝缘沿面放电特性分析OA

Breakdown discharges and surface flashover caused by internal and external factors in high-voltage direct-current(HVDC)bushings have posed a serious threat to the safe and stable operation of ultra-high-voltage DC trans-mission projects.To investigate the surface discharge characteristics of resin-impregnated paper(RIP)insulation in DC bushings under the combined influence of multiple internal and external factors,a surface discharge test system for RIP insulation specimens was established.The discharge behavior associated with internal insulation defects in HVDC bushings was analyzed,and the influence laws and underlying mechanisms of metallic particle contamina-tion,surface roughness,air pressure,specimen dimensions,and humidity on surface discharge of RIP insulation were systematically examined.Experimental results indicate that the presence of metallic particles,increased sur-face roughness,elevated humidity,and larger specimen dimensions all significantly reduce the surface flashover electric field strength,whereas surface coating and secondary drying can moderately improve insulation perfor-mance.Electric field distortion at the gas-solid interface and surface charge accumulation are identified as key fac-tors governing the surface discharge process.The size and location of metallic particles,moisture ingress into the specimen,increased surface roughness,and reduced air pressure can all cause severe distortion of the surface elec-tric field,thereby accelerating the occurrence of surface flashover.This study provides a useful reference for insula-tion optimization design and fault early warning of HVDC bushings.