LS Electric and Hyosung Heavy Industries, representing Korea's power equipment sector, squared off at ELEX Korea 2026, declaring side by side that they would complete localization of voltage source HVDC (high-voltage direct current) technology by next year. Competition has intensified to win orders and secure an early lead in the West Coast Energy Expressway project, a massive $11 trillion won state-backed initiative.
◇ LS Electric fronts transformers, Hyosung Heavy Industries fronts valves
At ELEX Korea 2026, the country's largest power and energy exhibition that opened on the 4th at COEX in Gangnam District, Seoul, LS Electric highlighted its in-house capabilities by placing at the front of its booth a model of a 500-megawatt (MW) HVDC converter transformer slated for delivery within the year to the Sin-Bupyeong substation in Incheon. Converter transformers for HVDC precisely control voltage during conversion where AC and DC intersect, boosting transmission efficiency and grid stability.
Hyosung Heavy Industries likewise showcased a model of the operating 200 MW-class HVDC Yangju converter station and a real STATCOM valve (a device that keeps voltage constant) incorporating its own device technology.
The converter transformer and STATCOM valve each company presented are the two core devices that make up an ultra-high-voltage HVDC system. If the valve acts as the brain, converting AC and DC and controlling the overall flow of the system, the transformer serves as the heart of the grid, adjusting voltage levels to match the system. By putting forward devices they have already commercialized, they moved to underscore that they are the right fit for the West Coast Energy Expressway project.
◇ An uncharted path… stressing zero-defect stability
The West Coast Energy Expressway project, on which they have staked everything, is a national grid initiative to supply power generated from coastal nuclear plants, offshore wind and solar on the west coast to major demand centers such as the Seoul metropolitan semiconductor cluster and AI data centers. To improve local acceptance, the project adopts HVDC using subsea cables to raise transmission efficiency.
In particular, voltage source HVDC, the core of the project, unlike the conventional current source method, can send power bidirectionally in real time, emerging as a next-generation grid technology to stably supply renewable energy with highly variable output.
The issue is that the project's transmission capacity is 8 gigawatts (GW), a massive scale equivalent to operating eight large nuclear reactors simultaneously. It is an uncharted path that domestic corporations have not yet traveled, and even a single accident could paralyze the nation's entire industry, making stability the top priority.
Accordingly, at the exhibition that day LS Electric and Hyosung Heavy Industries both emphasized "zero-defect stability." LS Electric highlighted its field experience, having supplied key equipment to the 3 GW Bukdangjin–Godeok project and the 4 GW East Coast–Seoul metropolitan area HVDC project—the only domestic corporation to do so—amassing over 1 trillion won in orders.
Building on this, the strategy is to secure validated design capabilities through collaboration with GE Vernova, one of the world's top three HVDC corporations, and manufacture the equipment directly at its HVDC-dedicated plant in Busan.
Kang Min-chan, Head of Team, Grid Solution Sales at LS Electric, said, "We have already secured a substantial portion of HVDC technology and are at the stage of advancing system-level engineering," adding, "We judged that combining LS Electric's know-how built over more than 20 years in HVDC grids with global leading technologies is the most stable path to localization, which is why we are seeking to work with GE."
◇ Hyosung touts "purely domestically developed" tech… next year is the watershed
Hyosung Heavy Industries is aiming to seize the advantage of "pure domestic development" with proprietary technology that handles everything from system design to manufacturing in-house. On this day as well, Hyosung Heavy Industries highlighted that it is operating without a hitch the country's first voltage source 200 MW-class HVDC Yangju substation. However, there is a large technological gap between megawatt-class and gigawatt-class HVDC in terms such as control complexity, making additional technology development essential to secure large-capacity operation capabilities.
An official at Hyosung Heavy Industries said, "Based on the control technology verified through commercial operation of the Yangju substation, we are accelerating efforts to scale up the capacity of voltage source HVDC facilities and enhance operational stability," adding, "In recent months, overseas power authorities have repeatedly visited the Yangju substation to inspect the facilities and explore large-scale power supply options."
An official in the power industry said, "The key to the 8 GW-class project is engineering capability to stably operate super-large facilities," adding, "Domestic corporations are racing ahead from the design stage at a scale they have never attempted before, and next year competition for leadership to prove full-fledged field capabilities will grow even fiercer."