On September 5, 2023, breakthrough progress was made in submarine cables developed by NBDF Submarine Cable Technology Corporation
The world's first 500 kV three core submarine cable developed by it has passed the on-site withstand voltage test in one go
This marks the successful application of the world's highest voltage level three core submarine cable
Submarine cables are important equipment for offshore wind farms, serving as the "blood vessels" and "nerves" in the entire operating structure of the wind farm. The complex sea conditions of wind farms pose extremely high requirements for the design, manufacturing, construction, and maintenance of submarine cables.
Previously, China's offshore wind farms mainly used 220 kV submarine cables. The Qingzhou I and II projects used 500 kV three core cross-linked polyethylene insulated steel wire armored submarine cables, with a total length of about 60 kilometers. It is the world's first 500 kV three core submarine cable used in engineering, and also the world's highest voltage level and longest single submarine cable. Its production, production, shipping, transportation, installation, and on-site handover testing, For the first time in the world.
As the EPC general contractor of Qingzhou I and II projects, NBDF fully leverages the technological advantages of offshore wind and submarine cables, actively organizes professional backbone forces, and deeply carries out the special research work of 500 kV submarine cables. It has conducted a large number of comprehensive comparison and argumentation on the electrical parameters, current carrying capacity, reactive power allocation, maturity and reliability of single core and three core submarine cables, and has innovatively proposed 2 and 3 circuits × The transmission plan for a 500 kV three core submarine cable with a cross-sectional area of 800 square millimeters.
Compared with single core submarine cables, double circuit and three core submarine cables have significant advantages in terms of smaller sea area, higher reliability, easier implementation of withstand voltage tests, and faster debugging and grid connection time.
To ensure the safety, reliability, and feasibility of submarine cable selection schemes, the NBDF project department has organized 7 different levels of submarine cable selection scheme review meetings, which have conducted comprehensive technical reviews on key links such as design scheme, production and manufacturing, laying difficulty, handover test, selection of ship equipment and construction process, and window period prediction.
In June 2022, the design and manufacturing technology scheme passed the review of the expert group led by Lei Qingquan, an academician of the CAE Member, and was highly praised
In the spring of 2023, 500 kV submarine cables were successfully taken offline, loaded and shipped
In July 2023, submarine cables will be laid offshore
The successful application of 500 kV three core submarine cables in the Qingzhou I and II projects is of milestone significance for promoting the improvement of China's submarine cable design and manufacturing level, as well as driving the development of China's manufacturing industry and offshore wind power industry chain.