Over the past few days, a record-breaking event in the East China Sea --- ldquo; big action --- rdquo; ended successfully, amazing foreign netizens: China --- ldquo; Jiaolong --- rdquo; went to sea!
On June 2, with the successful landing of the seventh submarine cable in the north-central part of Dapengshan headland, Jintang City, Zhoushan City, Zhejiang Province, China's self-developed 500 kilovolt cross-linked polyethylene submarine cable circuit laying project - mdash; - mdash; Zhoushan 500 kilovolt interconnected transmission and transformation project submarine cable laying completed smoothly.

This & ldquo; Jiaolong & rdquo; also created & ldquo; the world's first & rdquo; it will become the world's first cross-linked polyethylene insulated cable with the highest voltage level actually put into commercial operation. It also sets a world record for the longest single connectionless submarine cable, which is equivalent to eliminating the weakness of electrical breakdown and has higher reliability.
The seven submarine cables (6 cables and 1 communication optical cable) used in this project are all independently developed by China. Each submarine cable is 18.15 km in length, and its power transmission capacity is 3-4 times that of the general interconnection project. They are green and environmentally friendly, and will not pollute the marine environment.

It is worth mentioning that before the success of the project, China had not yet had the capacity to produce 500 kilovolt AC submarine cables, and technology and products depended on imports. The successful entry of this & ldquo; Jiaolong & rdquo; to the sea marks China's breaking the technical barriers to international cables, and represents the highest level of China's marine power transmission technology.
Dongfang Cable has successfully provided two 500 kV (including soft connectors) photoelectric composite cross-linked submarine cables for the first and second transmission lines of the project, totaling 36 kilometers. The 500kV soft joint technology adopted in the project is a recognized technical problem in the industry, which is called China & ldquo; Core & rdquo; Technology.
It is understood that the research, manufacture and engineering application of 500kV XLPE insulated AC submarine cable are the first in the world, which has solved the core problem of ocean power transmission technology. It will promote the localization of key technologies of 500KV submarine cable with large cross-section, and realize the high-end equipment of electric power: ldquo; Made in China; and even - ldquo; China's leader - rdquo;.
It is reported that after laying the submarine cable, after debugging and other procedures, it is expected to be put into operation by the end of June. At that time, Ningbo and Zhoushan will add new electric power channels and inject new impetus into the economic development of the region.

The data show that crosslinked polyethylene (XLPE) insulation uses chemical or physical methods to change the linear molecular structure of polyethylene into three-dimensional network structure, and from thermoplastic material to thermosetting material, which significantly improves the material properties. Crosslinked polyethylene (XLPE) has been used as high voltage, high cycle, heat-resistant insulating material and wire and cable cladding materials for rockets, missiles, motors, transformers, etc. due to its excellent performance. At present, the most widely used areas are wire and cable, pipe and foam plastics.