2008 Yunnan – Guangdong | China

The 1st ±800 kV UHVDC transmission project in the world

Challenge: overcoming technical and design challenges for the 1st 800kV UHDVC project

The system, with a transmission voltage of ±800 kV DC, set a new dimension in the development of HVDC systems. With a length of 1,400 km, Yunnan-Guangong was the 1st system in the world to transmit electricity at a DC voltage of ±800kV, connecting the ten-gigawatt hydropower plant from Yunnan province to Guangdong province, including cities of Guangzhou and Shenzhen, with a capacity of 5 000 MW, beating up the former record of ±600kV voltage and capacity of 3 150 MW. The transmission line is operated by China Southern Power Grid (CSG). The project involved major technical challenges and required specific developments of new products, new characteristics and new functionalities from the different manufacturers.

What we delivered: custom development and unrivalled shattering rate of HRTG insulators

Sediver developed a tailored 550 kN HVDC High Resistivity Toughened Glass insulator (a combination of the most advanced electric glass performance with the highest mechanical strength rating) to meet the specific needs of CSG. Sediver also implemented specific control processes to ensure a shattering rate of less than 1/10 000 per year, a performance unrivalled in the industry.

In 2008, CSG chose the reliability of toughened glass insulators by ordering 85% of cap and pin insulators to Sediver for this critical project. We delivered nearly 200,000 Sediver toughened glass insulators and received several performance certificates from the customer attesting of the exceptional quality of the insulators since the line started operations.