time：2026-03-27
At 11:00 on March 20, the China Southern Power Grid's 220kV Weizhou Island Cross-Sea Grid Connection Project was officially put into operation! This 44.8-kilometer-long 220kV submarine cable has achieved a stable cross-sea connection between Weizhou Island and the main grid of China Southern Power Grid, completely ending the island's “isolated grid operation”. It represents another significant breakthrough in China's submarine cable construction field.
This project has achieved the application of the first domestically developed and independently controllable 220kV submarine cable insulation material. Its core EHV insulation material was jointly developed by the CSG EPRI and Zhejiang Wanma Macromolecule, with targeted adaptation for the submarine environment. Compared with conventional high-voltage insulation materials, it possesses superior electrical and physical properties, as well as stronger long-term operational stability. It is well-suited for the requirements of cross-sea power transmission involving deep sea, ultra-long distance, and high-voltage level. With its robust product quality, it safeguards this critical submarine energy channel in the Beibu Gulf.
Submarine cables are buried deep underwater for years on end, operating in an environment far more demanding than that of land cables. They must not only withstand harsh conditions over the long term, but also ensure the stability and safety of ultra-long-distance cross-sea power transmission. This imposes stringent requirements on the performance indicators of the core insulation material. In particular, for the large-scale production of long-length submarine cables, the stability of continuous extrusion of the insulation material directly determines cable quality. Once there is an extrusion interruption or performance fluctuation, it will affect the service life and transmission safety of the entire submarine cable, which is also the core technical challenge in the production of long-length submarine cables in the industry.
To ensure the high-quality completion of the Weizhou Island Cross-Sea Grid Connection Project, Wanma Macromolecule partnered with the CSG EPRI. Leveraging the technical accumulation of both parties in EHV insulation material R&D and power grid engineering applications, they carried out in-depth industry-university-research cooperation and specialized technical breakthroughs targeting the 220kV insulation material developed specifically for this submarine cable project. By optimizing the production process, they successfully overcame the industry's key technical challenge of long-length continuous extrusion. During the cable production process for this project, the material demonstrated exceptional process adaptability and stability, setting a domestic record by enabling the continuous extrusion of 105 tons of domestically produced insulation material over 16 days for a single 22.9-kilometer 220kV submarine cable, all while ensuring the performance of the cable's insulation layer. This laid a solid foundation for the successful installation and operation of this cross-sea energy artery.
As a leading enterprise in China's high-end electrical material sector, Wanma Macromolecule has long been dedicated to the R&D, production, and application of materials for EHV and submarine cables. With a strong focus on technological breakthroughs, the company has worked tirelessly to break the long-term technological monopoly of foreign manufacturers in high-end materials, steadily advancing the domestic substitution and iterative upgrading of domestically produced EHV materials. The successful support of the Weizhou Island 220kV Cross-Sea Grid Connection Project represents a landmark achievement of the in-depth industry-university-research cooperation between Wanma Macromolecule and the CSG EPRI, and serves as another classic application case of the company's EHV insulation material in a key island cross-sea grid connection project.
From Weizhou Island to the broader deep-sea frontier, Wanma Macromolecule will continue to adhere to its original intention of innovation, steadily increase investment in the R&D of high-end materials, develop more high-performance, high-reliability domestically produced electrical materials, and provide superior material solutions. In doing so, the company strives to support the high-quality development of China's electric power industry and safeguard the security of the national power and energy industry chain and supply chain.
