铜包铝复合材料用于特高压携带型短路接地线的轻型化方案研究

针对现有携带型短路接地线(简称接地线)在特高压线路上挂接时存在质量重、不便于携带安装的问题,该文提出使用铜包铝复合材料用作特高压接地线导体的轻型化方案。对铜及铜包铝材料在短时间下的熔断电流进行理论计算及试验,并对典型1000 kV同塔双回线路接地线短路电热耦合暂态过程进行仿真分析。研究结果表明:当导线截面大于4 mm2、熔断时间小于1.5 s时,接地线导体材料熔断电流试验值与理论计算值基本一致。采用CCA-10铜包铝接地线相比铜接地线截面积增大71.1%,但质量减轻36.2%。对于1000 kV同塔双回线路单回停电检修的情况,可选择50 mm2的铜接地线或95 mm2的CCA-10铜包铝接地线,且铜包铝接地线安全裕度更大。

Research on lightweight scheme of copper-clad aluminum composites in UHV portable earthing and short-circuiting wires

Aiming at the heavy weight and inconvenience when carrying and installing copper earthing wires on the UHV transmission lines,this paper proposes a lightweight method for UHV earthing wire conductor by using the copper clad aluminum(CCA)as composite materials.Firstly,theoretical calculations and experiments of the fusing current in a short time for copper and CCA material are performed.Then,the transient electro thermal coupling process of the earthing wire short-circuit of typical 1000 kV double-circuit line is simulated.The results show that the theoretical value of the earthing wire conductor's fusing current corresponds with the test value on condition of the conductor cross section greater than 4 mm2 as well as melting time less than 1.5 s.The CCA-10 earthing wires present 71%cross section increase and 36.2%weight reduction compared with copper wires.In the case of single-circuit power-off maintenance of 1000 kV double-circuit line,it is suggested to select 50 mm2 copper wire or 95 mm2 CCA-10 wire,and the CCA earthing wire has greater safety margin.