At a depth of 100 meters underground in Guangning County, Zhaoqing, Guangdong Province, the air is so heavy that it can twist water out. On May 16, 2026, a massive structure with a height of 5.8 meters, a diameter of about 5 meters, and a weight of 380 tons - the stator of a variable speed pumped storage unit - slowly suspended under the traction of a giant bridge crane. The scene was completely silent, with only intermittent commands coming from the walkie talkie. This "giant" made up of more than 500 wire rods and 120000 0.5mm silicon steel sheets stacked together is the core component of China's first fully independently developed large-scale transmission unit. Its precise positioning marks the official entry of China's pumped storage equipment into the era of "flexible variable speed", breaking the long-term dependence on imports in this field.

Switching from 7% speed to 50% flexible

The core breakthrough of this domestically produced transmission unit lies in its flexibility. Traditional fixed speed units, like old-fashioned fixed frequency air conditioners, can only operate at a fixed speed; And the new unit is like a variable frequency air conditioner, which can adjust speed infinitely according to the needs of the power grid. The project leader introduced that the unit can achieve up to 50% power regulation range by only changing the speed by about 7%. This means that under pumping conditions, it can act like a "smart sponge" to accurately absorb the surplus fluctuating energy such as wind power and photovoltaics in the power grid, and convert it into water energy storage. Every hour, it can convert about 300000 kWh of green electricity into 280000 cubic meters of water energy, which can be generated in reverse when needed, greatly improving energy utilization efficiency.keywords:Infrastructure News

Equip new energy with stabilizers

With the surge in wind and photovoltaic installed capacity, the volatility of the power grid has become the biggest challenge. The value of a gearbox lies in its ability to respond quickly. Compared to the response speed of fixed speed units in seconds, variable speed units can quickly adjust power within 0.2 seconds through AC excitation technology, effectively smoothing out frequency fluctuations in the power grid. As the first project in the Guangdong Hong Kong Macao Greater Bay Area to apply this technology, the Zhaoqing Langjiang Power Station is expected to be put into operation in 2027. At that time, it will become an important "power stabilizer" in the Greater Bay Area, supporting more green electricity to be safely connected to the grid and assisting in the green transformation of the energy structure.Editor/Yang Meiling