CHINA - Hitachi Energy has developed and supplied the Vacuum-Cast-Coil (VCC) dry-type transformer for China's first floating wind turbine called 'Sanxia Yinling Hao' (Three Gorges Lead).

The 5.5 MW wind turbine has been successfully put into operation in December 2021 at the Yangjiang wind farm off the coast of south China's Guangdong Province. It was developed by China Three Gorges and Mingyang Smart Energy, a leading wind turbine manufacturer in China.

China is accelerating the transition to a low-carbon energy to meet the country's carbon neutral targets. The construction of more than 1.2 GW of solar and wind power is planned by 2030, nearly 2 times the current size, Hitachi Energy said in a press release.

Currently, the majority of potential offshore wind resources are in water bodies that are more than 60 m (196.8 ft) deep. This is beyond the reach of traditional offshore wind platforms. The solution are floating wind turbines, which have more flexible and cost-effective design, Hitachi Energy said in a press release.

However, the harsh environments around floating wind turbines, including 10 times more vibrations compared to fixed wind turbines, pose huge challenges to the operation of the transformer inside a wind turbine generator.

The VCC dry-type transformer designed by Hitachi Energy is designed to operate with heavy and frequent vibrations and withstand the extreme environments on the floating platform, such as typhoons and extreme waves in the South China Sea. The transformer also reduces the risk of oil leakages, the manufacturer said in a press release.

This floating offshore wind turbine adopts semi-submersible foundation and can withstand typhoons up to level 17. It is capable of generating up to 40 million kWh of electricity per year at its full capacity, equivalent to providing green and clean electricity for up to 11,000 households in China.

Source: Hitachi Energy