Develop energy-saving and environmentally friendly products

 to promote the green and high-quality development of the power grid

SF6 is a potent greenhouse gas. Its greenhouse effect is 23,900 times that of CO2 gas, and it is one of the six greenhouse gases globally regulated as listed in the Kyoto Protocol. General Secretary Xi Jinping has mentioned on multiple occasions at meetings that in order to jointly address the challenges in the field of climate and environment, China will increase its national independent contribution efforts, achieving "carbon peak" by 2030 and "carbon neutrality" by 2060. Reducing the use and emission of SF6 gas is a powerful guarantee for achieving this goal and promoting the green and high-quality development of the power grid. Since 2023, State Grid Corporation of China has comprehensively promoted the application of mixed gases, and all newly built stations have adopted mixed gas equipment. It has been promoting the renovation of mixed gas equipment in operating stations in an orderly manner, aiming to achieve "all eligible renovations" in operating stations by the end of 2028. China Southern Power Grid Company is also actively promoting the research, development, and application of low-carbon and environmentally friendly equipment. In response to this call, our company has actively carried out research on mixed environmentally friendly products to reduce the use and emission of SF6 gas.

This project includes two major categories of products: environmentally friendly gas voltage transformers and surge arresters, using SF6+N2 mixed environmentally friendly gas as the main insulation medium. During the research and development process of the project, through the application of information technologies such as the PLM system, the project progress has been comprehensively controlled, shortening the R&D cycle. The mixed environmentally friendly gas voltage transformer adopts a low-power consumption design. The maximum winding temperature rise is 22K, which is better than the national standard requirement of 75K. The water content in the gas is 89μL/L, better than the national standard requirement of 250μL/L. By optimizing the design of the sealing structure and selecting high-quality sealing materials, the annual gas leakage rate is less than 0.1%, better than the national standard requirement of 0.5%. With a fully shielded structure design, the partial discharge amount is less than 2pC, better than the national standard requirement of 5pC.

The mixed environmentally friendly gas surge arrester adopts an integrated internal shielding structure. The uneven coefficient of potential distribution is 6%, better than the requirement of State Grid Corporation of China, which is 15%. By using high-gradient high-quality varistor discs, the volume is reduced by 40%. The repeated charge transfer is 1.2C, better than the national standard requirement of 1.0C. The rated thermal energy meets 6kJ/kV, better than the national standard requirement of 4kJ/kV. The partial discharge amount is less than 3pC, better than the national standard requirement of 5pC.

Through the joint efforts of the project team members, four types of products passed all type tests at one time in July and November 2021 at the Wuhan Branch of China Electric Power Research Institute (Quality Inspection and Testing Center for Electrical Equipment of the Electric Power Industry) and Suzhou Electrical Apparatus Research Institute Co., Ltd. (Quality Inspection and Testing Center for Electrical Equipment of the Electric Power Industry), making our company the first manufacturer in China to pass type tests in accordance with the mixed environmentally friendly gas standards of State Grid Corporation of China.

On the premise that the insulation level of the mixed environmentally friendly gas transformers and surge arresters is the same as that of the original models, the use of SF6 gas can be reduced by more than 50%, and the use of raw materials can be reduced by more than 20%. The effects of energy conservation and environmental protection are obvious, which is in line with the national strategic decision of "carbon peak and carbon neutrality". The successful development of this project demonstrates the product quality strength of Shandong Taikai Instrument Transformer Co., Ltd., enhances the brand and popularity, and strengthens the market competitiveness of the products. It is also a powerful guarantee for promoting the green and high-quality development of the power grid. In the future, we will continue to support national policies and jointly build a green homeland.