RXHK Wins ±800kV/8GW Converter Valve Package on Mengxi–Jing-Jin-Ji Project
Rongxin Huiko Electric Company (RXHK) has emerged as the successful bidder for the ±800kV/8GW converter valve package on the Mengxi–Beijing-Tianjin-Hebei (Jing-Jin-Ji) UHV VSC-HVDC Transmission Project, operated by State Grid Corporation of China (SGCC).
The Mengxi–Jing-Jin-Ji project is a 700-kilometre, ±800kV direct current transmission line with a rated capacity of 8 GW, designed to transmit renewable energy from the western parts of Inner Mongolia to the industrial load centres of Beijing, Tianjin and Hebei province. The total project investment stands at 17.2 billion yuan (approximately USD 2.4 billion), and the line is expected to be put into operation by 2027.
The sending-end converter station, known as the Kubuchi North ±800kV station, is located in Dalate Banner, Ordos, Inner Mongolia, while the receiving-end station is sited in Cangzhou, Hebei province, with a rated converter capacity of 8,000 MW at each end.
The project is the first UHV transmission line in Inner Mongolia to specifically serve the national strategy of exploiting large-scale wind and solar bases in China's sand, Gobi and desert regions. It passes through Inner Mongolia, Shanxi and Hebei — three provinces and autonomous regions — and employs the "double-eight-hundred" UHV hybrid direct current transmission technology for the first time, designed to better accommodate the output characteristics of large-scale renewable energy bases and enhance the security of the broader transmission network.
Construction began in late December 2025. The project forms part of China's broader "14th Five-Year Plan" for power development, with the Mengxi–Jing-Jin-Ji link one of the first UHV VSC schemes to begin construction following the groundbreaking of the Gansu–Zhejiang project — the world's first full-VSC UHV transmission project — in mid-2024.
The Mengxi–Jing-Jin-Ji project applies VSC (Voltage Source Converter) technology at both the sending and receiving ends, representing China's ongoing pivot from conventional LCC-based UHV direct current transmission to flexible direct current architecture. VSC-based converter valves, built around IGBT power modules in a modular multilevel converter (MMC) topology, are regarded as particularly suited to integrating high proportions of renewable energy and eliminating the commutation failure risk inherent in thyristor-based LCC systems.
The converter valve package represents one of the highest-value equipment lots in any UHV HVDC project. In comparable full-VSC ±800kV/8GW schemes, the total converter valve procurement value has been reported at over CNY 40 billion across both converter stations, reflecting the significantly higher unit value of VSC valves relative to conventional LCC equivalents.
RXHK, headquartered in Anshan, China, is one of the leading domestic suppliers of VSC-HVDC converter valve systems. The company holds a VSC converter valve market share of over 25% in China, placing it in the first tier of domestic suppliers alongside NARI Group and XJ Electric.
RXHK's prior UHV VSC-HVDC references include the Wudongde (Kunliulong) hybrid multi-terminal UHVDC project, where RXHK undertook the development and supply of one branch of the ±800kV/5,000MW HVDC converter valve for the Longmen converter station — at the time the largest VSC-HVDC valve in the world. The company also supplied converter valves for the Baihetan–Jiangsu ±800kV UHVDC project, the CSG Guangdong Power Grid back-to-back HVDC project, and international projects including the Saudi Arabia Central-West ±500kV VSC-HVDC scheme. RXHK has built its business on the application of low-loss intrinsically safe press-pack IGBT technology.
The Mengxi–Jing-Jin-Ji award extends RXHK's footprint into China's second-generation UHV VSC programme and its first inland VSC UHV project delivered entirely over an overhead transmission corridor.
