Introduction of 110kV Cable Accessories

High voltage cable accessories are developed from low and medium voltage accessories. Therefore, the varieties of XLPE insulated cable terminations kit and straight through joints kit for 110kV and above are similar to those for 35kV and below.

Termination kits

The main types of 110kV and above crosslinked polyethylene cable termination are outdoor termination, GIS termination (installed in the fully enclosed combined electrical appliances, also known as SF6 gas terminal) and transformer termination (installed in the transformer tank, also known as oil terminal).

At present, the 110-345kV voltage grade crosslinked cable termination used in most countries are mainly prefabricated rubber stress cone termination (referred to as prefabricated termination), and higher voltage grade cable termination use silicon oil impregnated film capacitor cone termination (referred to as capacitor cone termination). Other types of termination, such as the wrapped type, which was used in the early 110kV voltage class, are now rarely used.

Straight Through Joint Kits

110kV and above cross-linked cable intermediate connector, according to its function, to the cable metal sheath, grounding shield and insulation shield on the electrical disconnect or continuous into insulation connector and straight connector. Whether it is an insulated joint or a straight through joint, according to its insulation joint is divided into wrapped type joint (TJ), coated molded type joint (TMJ), extruded molded type joint (EMJ), prefabricated type joint (PJ) and other types. Prefabricated rubber stress cone terminals and prefabricated intermediate joints are the main types of high voltage crosslinked cable accessories used in China at present.

High voltage accessories product quality

The factors to judge the quality of cable accessories are multiple, in principle, there are the following aspects. 

The quality of electrical performance. It mainly considers whether the electric field distribution of cable accessories is reasonable, whether the measures to improve the electric field distribution are appropriate, the electrical strength of the material, the dielectric loss and the insulation margin of the product.

Stability of electrical properties. Including the chemical, physical properties and structural stability of cable accessories, such as whether the properties of stress control materials are stable, whether the stress cone is easy to deform, the effect of cable insulation retraction on the electric field distribution of cable accessories and prevention measures, the compatibility of various materials, the stability of interface properties, etc.

Thermal performance of cable accessories. Such as dielectric loss, contact resistance and stability of conductor connection, heat conduction and release, thermal expansion and cold contraction on the electrical and mechanical properties of each component.