The Ministry of Trade, Industry and Energy of South Korea has selected four companies--Hyosung Heavy Industries, HD Hyundai Electric, LS Electric, and Iljin Electric--to lead the development of 500kV-class high-voltage direct current (HVDC) conversion transformers. The announcement, made on September 24, is part of a broader effort to establish the West Sea (Yellow Sea) Energy Highway by 2030.

HVDC technology enables the efficient transmission of large power volumes across long distances and is better suited for integrating renewable energy sources compared to conventional AC systems. Among HVDC systems, voltage-source HVDC is preferred due to its real-time, bidirectional power control and grid stabilization features.

This initiative forms a key part of President Lee Jae-myung's energy policy. The government plans to invest â‚©12 billion (approx. USD 8.8 million) in the project next year, with the goal of completing core transformer development by 2027. The project was included in the July supplementary budget and followed a public call for participation in August.

In parallel, the private sector is developing large-capacity HVDC valves and controllers, which will be integrated into a demonstration transmission line by the end of the decade.

The ministry is also drafting a comprehensive HVDC Industry Fostering Strategy, to be released by year-end, outlining a roadmap for the full-scale rollout of the West Sea Energy Highway.