35kV单芯电缆线路配置护层电压限制器选型分析

Selection Analysis of Sheath Voltage Limiter for 35kV Single-Core Cable Line

单芯电缆护层电压限制器(SVL)广泛应用在交叉互联保护箱与电缆终端保护箱上,用来限制电缆金属护层上的感应过电压,确保电缆外护套(护层绝缘)免遭过电压击穿破坏。虽然相关电缆线路设计标准中建议在需要加强护层绝缘保护时进行35 kV及以下单芯电缆线路的SVL配置,但所述不详。为此,展开了35 kV单芯电缆线路配置SVL选型分析。通过对SVL的保护原理与技术参数分析,确立了35 kV单芯电缆线路配置SVL选型原则、选型要求。在具体SVL选型过程中发现目前市售的SVL产品均为高电压等级配备,有些SVL产品虽可用但仍无法切实保护35 kV单芯电缆护层绝缘。为了有利于电缆线路的运维,建议对35 kV及以下单芯电缆线路配置SVL进行专门研制,并制定相应标准加以规范。

The single-core cable sheath voltage limiter(SVL) is widely used in the cross interconnection protection box and cable terminal protection box to limit the induced over-voltage on the cable metal sheath and ensure that the cable outer sheath(sheath insulation) is not damaged by over-voltage breakdown.Although SVL configuration for 35 kV and below single-core cable line is recommended in relevant cable line design standards when it is necessary to strengthen the insulation protection of sheath,the description is unknown.Therefore,SVL selection analysis of 35 kV single-core cable line configuration is carried out.Through the analysis of SVL protection principle and technical parameters,the SVL selection principle and requirements for 35 kV single-core cable line configuration are established.During the specific SVL selection process,it is found that the SVL products currently sold in the market are all equipped with high voltage levels.Although some SVL products are available,they still cannot effectively protect the sheath insulation of 35 kV single-core cables.In order to facilitate the operation and maintenance of cable lines,it is recommended to specially develop SVL for 35 kV and below single-core cable lines,and formulate corresponding standards to regulate it.