Following the approval and establishment of the national standard “Integrated Gate Commutated Thyristor (IGCT) Valve for Flexible DC” in 2024, two national standards jointly led by Tsinghua University and Huairou Laboratory and overseen by Professor Zeng Rong, titled “Integrated Gate Commutated Thyristor (IGCT) High Voltage DC Converter Valve Part 1: Technical Requirements” and “Integrated Gate Commutated Thyristor (IGCT) High Voltage DC Converter Valve Part 2: Test Methods,” have recently been approved for establishment. These three standards are the first national standards in the IGCT converter valve field and will respectively regulate the terminology and definitions, symbols and abbreviations, operating environment conditions, basic parameter ratings, technical requirements, test methods, nameplate, packaging, transportation, and storage of IGCT converter valves used in flexible DC transmission and high voltage DC transmission.

High voltage direct current (HVDC) transmission is a core technology supporting new energy delivery and the construction of a new power system. Conventional HVDC transmission systems use thyristor converter valves, which inherently suffer from commutation failure due to the inability of thyristors to turn off actively. The IGCT HVDC converter valve — a hybrid commutation converter valve (HCC) based on reverse blocking IGCT devices — is a novel DC conversion technology independently proposed and led by China. While inheriting the high reliability, low cost, and high efficiency advantages of conventional DC converter valves, it uses IGCTs with bidirectional blocking and active turn-off capabilities in the bridge arms, enabling the converter valve to perform forced commutation by active turn-off in the event of commutation failure, eliminating the risk of commutation failure present in conventional DC transmission systems.

Tsinghua University and Huairou Laboratory, in collaboration with several leading domestic enterprises, have successfully developed the world’s first hybrid commutation converter valve (120kV/360MW) and passed all tests and product evaluations. This technology has been adopted in the Lingbao Converter Station renovation project of the “Central China–Northwest” interconnected project.

IGCT High Voltage DC Converter Valve

With rapid engineering progress, the advantages of IGCT HVDC converter valves—low cost, low loss, and no commutation failure—are becoming increasingly prominent. However, existing DC converter valve standards mainly target traditional thyristor converter valves and IGBT converter valves, which cannot meet the design, testing, and operation requirements of IGCT high-voltage converter valves. The formulation of this series of standards will fill the gap in standards related to IGCT HVDC converter valves, further improve the DC transmission technical standard system, facilitate consensus among enterprises across the entire “design-manufacture-test-application” industrial chain, form a healthy industrial ecosystem, and enhance China’s independent innovation capability in the field of IGCT HVDC converter valves.