交流500 kV XLPE绝缘海底电缆户外终端的开发

Development of 500 kV XLPE AC Submarine Cables Outdoor Termination

为满足海底电缆线路设计要求,考虑500 kV电压性能要求及近海高污秽重盐雾的环境特点,对户外终端的结构选型、内外绝缘设计方面进行论证,特别对其抗污秽能力进行优化设计。产品设计定型后开展验证试验,测试产品设计的电气性能,并顺利通过型式试验及预鉴定试验。海底电缆户外终端的电场分布设计应着重考虑近海运行环境的影响,近海盐雾导致套管表面积累的污秽中存在较多导电可溶性物质。通过优化降低套管表面电场强度,可以提高套管表面闪络起始电压。海底电缆户外终端相对内陆用户外终端需保有适量的外绝缘安全裕度。

In order to meet the design requirements of submarine cable lines,considering the 500 kV voltage performance requirements and the characteristics of the offshore environment with high pollution and heavy salt fog,the outdoor termination is studied in structural design,electrical insulation design,and the product's anti⁃pollution capability is optimized.After the product design is finalized,a verification test is performed to test the electrical performance of the product design,and it successfully passes the type test and pre⁃qualification test.The electric field distribution design of the submarine cable termination needs to consider the impact of the offshore operating environment,and there is more conductive soluble matter in the pollution of the insulator surface caused by the offshore salt fog.By reducing the electric field strength on the insulator surface,the insulator flashover voltage can be increased.Submarine cable outdoor terminations need to maintain a proper amount of external insulation safety margin compared to land cable outdoor terminations.