As the head of the submarine cable test team, Zheng Xinlong has been working in the research, development and application of offshore transmission engineering technology for nearly 10 years since he joined the State Grid Zhoushan Power Supply Company in 2009.
During the period of 10, Zheng Xinlong participated in the establishment of a scientific research team for offshore transmission engineering, which was responsible for the first submarine cable test in China, which changed the lack of systematic research in related fields in China and filled many gaps in the design of cross-sea transmission engineering, high voltage test research, operation and maintenance monitoring and standardization system construction in China.
With scientific research achievements in the field of marine power transmission, Zheng Xinlong has successively won many awards, such as China Electric Power Science and Technology Progress Award and Zhejiang Science and Technology Progress Award, been authorized to invent 7 patents, published more than 40 papers, and was selected as the "National Model of Young Professionals" on 20 16-20 17.
Energy supply is a very important project on the road of building a maritime power. Zhoushan City, Zhejiang Province is adjacent to the East China Sea in the east and Hangzhou Bay in the west, with many islands and abundant offshore wind resources. However, offshore wind power generation depends on natural wind, which can not only provide stable electric energy, but also how to transport it to land and access the power grid.
"In fact, Europe began the research and practice of light DC in the 1990 s, which is now a popular flexible DC in China." Zheng Xinlong said, "On 20 10, together with the DC team of China Electric Power Research Institute at that time, we carried out the preliminary research work on the feasibility of implementing flexible DC in island areas, which laid the foundation for the construction of Zhoushan flexible DC transmission demonstration project."
The construction of flexible DC transmission project must first have corresponding submarine cables. Zheng Xinlong recalled: "At that time, there was a flexible DC project in Shanghai, which used a 30 kV DC cable. The products of this voltage level are different from the 200 kV flexible DC high-voltage submarine cable we need. "
At the beginning of 20 12, when the State Grid Corporation of China was ready to start the construction of multi-terminal flexible DC transmission project, only Shanghai Cable Research Institute cooperated with cable manufacturers to carry out 160 kV DC cable related tests. "From design, production and putting into use, ultra-high voltage submarine cables need long-term type tests and pre-qualification tests to determine their performance and service life. At that time, our position was 500 kV. Of course, we first ensure that 200 kV is the development, engineering construction and test service of 500 kV AC /DC submarine cable in China. "
With the persistence and efforts of Zheng Xinlong's team, State Grid Corporation of China has built a flexible direct connection supporting test capability in Zhoushan, which is also the only test base in China specializing in offshore transmission engineering technology research.
After the completion of the offshore transmission experimental base, the first challenge that Zheng Xinlong and his team faced was the pre-certification test of submarine cables used in the world's first five-terminal flexible DC transmission project.
This is extremely important as a pre-qualification test to evaluate the long-term performance of cables. In the absence of domestic standards, Zheng Xinlong organized the establishment of a flexible DC cable test site, compiled a DC cable test plan, and carried out the pre-qualification test of 200 kV DC cable for the first time in China.
"More than 50 kilometers of cables were tested on site. In fact, we have never done it, but it was quite successful for the first time. " Recalling this special experiment, Zheng Xinlong's tone was very relaxed. However, the DC withstand voltage test of such a large capacity cable is the first time in China, and only they know the hardships.
After more than 50 kilometers of cable field test, the energy stored in the insulation of the whole cable is still very large. In order to safely discharge these charges in a short time, Zheng Xinlong came up with a step-by-step discharge scheme: "We replaced the resistor for it many times, and when the voltage finally became very small, the discharge was successful."
After the successful test, DC cable has been put into use, connecting Dinghai, Daishan, Qushan, Yangshan and Sijiaowu islands in Zhoushan, ensuring the efficient and stable power supply of all islands.
Recently, Zheng Xinlong and his team have just completed the pre-qualification test of the first batch of 500 kV XLPE submarine cables in the world, which means that this type of submarine cable can be put into use.