Jeju 3 (Wando-Jeju)

The Jeju 3 HVDC project, also known as the Wando-Dongjeju 3 HVDC Converter Station Project, is the third high-voltage direct current transmission system connecting Jeju Island to the South Korean mainland. This project represents South Korea's first point-to-point voltage source converter (VSC) HVDC installation.

Technical Specifications

The Jeju 3 HVDC link has a power transmission capacity of 200 MW and operates at a direct voltage of ±150 kV, in a symmetrical monopole configuration. The two converter stations are located in Wando County on the mainland and the other on Jeju Island.

The transmission system comprises a submarine cable approximately 90 kilometers long, connecting Wando County in South Jeolla Province to Jeju Island. The cable system includes three high-voltage cables and one medium-voltage cable.

Technology

The Jeju 3 HVDC project employs MMC voltage source converter (VSC) technology, which offers several advantages over the other two Jeju HVDC projects, which utilize traditional line-commutated converter (LCC) systems.

Project Timeline and Stakeholders

The project was initiated in 2020, with Korea Electric Power Corporation (KEPCO) as the primary stakeholder. Hitachi Energy was selected to provide the converter stations and related HVDC technology. The project was commissioned in December 2024.

Importance and Benefits

The Jeju 3 HVDC link is an important addition to Jeju Island's power infrastructure. It supplements two existing HVDC connections, bringing the total power transmission capacity to Jeju Island to 900 MW. This increased capacity helps meet the growing electricity demand on the island, which hosts over 13 million tourists annually.

Environmental Considerations

The Jeju 3 HVDC project aligns with South Korea's commitment to reduce carbon dioxide emissions. It supports Jeju Island's goal to become carbon-free and powered entirely by renewable energy by 2030. The VSC technology's ability to efficiently integrate irregular renewable energy sources is particularly valuable in this context.