High voltage power cable

Due to the excellent conductivity of copper conductors, more and more projects are using copper core power cables as the backbone of power supply systems, while the application of aluminum core power cables is relatively rare, especially in higher voltage power systems, where copper core cables are more commonly chosen.

Manufacturer's manufacturing reasons

The manufacturing reasons of manufacturers can be divided into three categories based on different locations: cable body reasons, cable joint reasons, and cable grounding system reasons.

Reasons for manufacturing cable body

The common problems that may occur during cable production include insulation eccentricity, uneven insulation shielding thickness, impurities in the insulation, protrusions in the inner and outer shielding, uneven cross-linking degree, cable moisture, poor sealing of cable metal sheath, etc. In some serious cases, faults may occur during completion testing or shortly after commissioning, and most of them exist in the form of defects in the cable system, posing serious hidden dangers to the long-term safe operation of the cable.

Reasons for manufacturing cable joints

High voltage power cablePreviously, joints were made using wrapped, molded, and molded types, which required a large amount of on-site production work. Due to the limitations of on-site conditions and production processes, there were inevitably air gaps and impurities between the insulation tape layers, making it prone to problems. The commonly used types in China are assembled and prefabricated.

High voltage power cableConnectors are divided into cable terminal connectors and cable intermediate connectors. Regardless of the type of connector, cable connector failures generally occur at the insulation shielding fracture of the cable, because this is the location where electrical stress is concentrated. The reasons for cable connector failures due to manufacturing reasons include defects in the stress cone body, insulation filler problems, and sealing ring oil leakage.

Cable grounding system

The cable grounding system includes cable grounding box, cable grounding protection box (with protective layer protector), cable cross interconnection box, protective layer protector, and other parts. The common problem is mainly due to poor sealing of the box, which leads to water ingress and multiple grounding points, causing excessive induced current in the metal protective layer. In addition, unreasonable parameter selection or poor quality of the protective layer protector can also easily cause damage to the protective layer protector due to unstable zinc oxide crystals.