How can the wind in the Hexi Corridor, the light on the Gobi Desert, cross over two thousand kilometers of mountains and rivers, and light up the lights of thousands of households in the water towns of Jiangnan? This grand proposition concerning the national energy layout has now found its key answer in a factory located in Hengyang, Hunan.

Recently, the last high-end converter transformer of Yuezhou Station in the Gansu Zhejiang ± 800 kV high-voltage flexible DC transmission project, manufactured by TBEA Hengyang Transformer Co., Ltd., successfully passed all factory tests in one go. This behemoth with a rated capacity of 750 megavolt amperes meets or exceeds industry design specifications, technical requirements of the State Grid, and user acceptance standards in all performance indicators. Its successful offline not only means that all the core converter transformers required for the Gan Dian Zhejiang project are ready for delivery, but also signifies that Hengbian Company has successfully passed 108 consecutive tests of ultra-high voltage products.

The super artery that delivers electricity for thousands of miles

The Gansu Zhejiang Ultra High Voltage Flexible DC Transmission Project is a key project in the 14th Five Year Plan for power development. The project starts in Wuwei, Gansu and ends in Shaoxing, Zhejiang, with a total length of about 2370 kilometers, like an east-west energy artery. Its mission is to transport the abundant clean energy from the Gansu desert, Gobi desert, and desert areas to the Zhejiang load center on a large scale and with high efficiency.

The strategic significance of this major artery is self-evident. After the project is put into operation, it can deliver 36 billion kilowatt hours of electricity to Zhejiang every year, of which clean electricity accounts for more than 50%.

This will not only significantly enhance the energy interdependence between the east and the west, inject strong momentum into the green transformation of Zhejiang's energy structure, but also strongly support the high-quality development of the regional economy. The ± 800 kV high-end converter transformer at Yuezhou Station is the core hub equipment on this major artery, which can be regarded as the power valve of the entire ultra-high voltage direct current transmission channel, shouldering the responsibility of cross regional large capacity power transmission.

Technological breakthrough in extreme capacity

As the largest capacity flexible DC converter transformer in the current industry, this equipment has a rated capacity of 750 megavolt amperes, which is more than 80% higher than conventional DC equipment. A single device can meet the peak electricity demand of a medium-sized city. However, as the capacity increases, the technological challenges climb exponentially. Compared to conventional power transmission and transformation products, the operating conditions of this equipment are extremely strict, and the fault tolerance rate of various technical indicators is extremely low - any small process defects, environmental disturbances, or assembly deviations may cause the test to be obstructed or even the previous efforts to be in vain.

Faced with this technological peak, the R&D team of Hengbian Company adheres to the concept of independent innovation and has achieved key technological breakthroughs in multiple dimensions such as product structure design, manufacturing processes, and key quality control. On June 17, 2026, the product successfully passed the national authoritative technical appraisal, and its comprehensive performance indicators reached the international leading level. This achievement fully demonstrates Hengbian Company's top-notch research and development and manufacturing capabilities in ultra-high voltage equipment, further consolidating its leading position in the global field of major equipment manufacturing for ultra-high voltage transmission and transformation.

Six months of hardcore battles

From technological breakthroughs to product implementation, it tests the ultimate execution capability of the manufacturing end. To ensure that all 5 devices in the project pass the test in one go, the Hengbian company team will embed strict standards into every process. They repeatedly improved and optimized the experimental plan, comprehensively cleaned the test busbar, accurately calibrated the sensing equipment, and even fine tuned the power supply frequency to avoid external environmental interference, building a comprehensive defense line for the test.

Under such high standards of quality control, the team completed the development of all 5 converter transformers in less than 6 months. The pursuit of excellence in every process and the perfection of every test have ultimately converged into an industry record of 108 consecutive ultra-high voltage products passing a single test.

At present, all the core converter transformers required for the Gan Dian project in Zhejiang are ready for delivery. Hengbian Company will seize the opportunity and fully cooperate with the on-site installation and commissioning of the Yuezhou Station project, continuously empowering the stable operation of this cross regional energy corridor. The construction of this green energy corridor, from the wind turbine blades on the Gobi Desert to the dazzling night scenery of Jiangnan cities, will be another solid footnote to China's new power system construction and the implementation of its dual carbon goals.Editor/Yang Meiling