China's development of large-scale variable-speed pumped storage units enters the stage of engineering application. On 12 June, the procurement and manufacturing contract for China's first 300-megawatt and 400-megawatt domestic variable-speed pumped storage units was signed in Guangzhou, indicating that the development of China's large-scale variable-speed pumped storage units has officially entered a new stage of engineering application. The variable speed pumped storage unit can change the rotor speed, adjust the power flexibly, and make the fluctuating new energy such as wind power and photovoltaic more stably connected to the power grid. With the continuous increase of the installed proportion of wind power photovoltaic in the power system in our country, the speed of variable speed pumped storage unit is increased synchronously. At the end of 2022, the localization of 300 MW variable speed pumped storage units relies on the project, Zhaoqing Langjiang pumped storage power station, and Huizhou Zhongdong pumped storage power station, the first super large capacity variable speed pumped storage project in China. The two variable speed pumped storage units purchased and manufactured this time will be installed in the two pumped storage power stations respectively, and all of them are expected to be delivered by the end of December 2025.