GE Renewable Energy’s Grid Solutions business recently completed an upgrade to one of two high-voltage direct current (HVDC) links between the South Korean mainland and Jeju Island, allowing for more efficient bi-directional transfer of power, including renewable energy.

South Korea’s first HVDC upgrade ever includes the first commercial application of Grid Solution’s most advanced Line Commutated Converter (LCC) valve technology, the H450, as well as an upgrade to the control system and cooling system. Thanks to the upgraded control system, both the refurbished 300-MW link and the second 400-MW link are now using GE’s latest algorithms for maintaining grid frequency, providing higher reliability and more robust operational control.

The HVDC refurbishment was done exceptionally fast, in accordance with Korea’s largest electric utility Korea Electric Power Corporation’s (KEPCO’s) 24-month deadline. Within this timeframe, the link continued to operate except for an amazingly small window of about three months.

The innovative H450 valve technology was developed by GE’s Grid Integration Solutions, a division of GE’s Grid Solutions, at its HVDC Center of Excellence in Stafford, UK. Thanks to its smaller physical footprint compared with the previous valve technology, GE was able to install it within the existing valve hall.

“The reinforcement of the grid to accompany the renewable energy generation objective of the Korean government is critical. HVDC transmission, and specifically this upgrade project for Jeju Island, is a critical enabler of this energy transition in Korea,” said Kim Sung-Arm, Member of the Board of Directors and Senior Executive Vice President for Power Grid, KEPCO.

Jeju Island, located 100 km south of the peninsula mainland, is the center of smart grid investments and energy efficiency projects in the country. KEPCO is supporting the Jeju Special Self-Governing Province as it moves toward the goal of a 2030 Carbon Neutral Island. Wind and solar farms generate power for the island, and the bi-directional HVDC link now enables any excess power to be transmitted back to the mainland.

South Korea imports 98% of its fossil fuel consumption. This has prompted its government to develop a number of new energy policies to help the country become more energy independent, meet its growing demand, and increase its energy efficiency.

“This vital HVDC upgrade significantly improves the bi-directional flow of energy on the two HVDC links between mainland Korea and Jeju Island by allowing them to work together in a more coordinated fashion,” said Rajendra Iyer, Global Business Leader for GE’s Grid Integration Solutions.

“This project came with the added challenge of a very tight 24-month timeline to meet summer peak demand on Jeju Island in 2020. The most important factor in the success of the project was the regular and transparent communication between GE, KAPES and KEPCO to successfully complete this upgrade.”

“The successful completion of this project demonstrates the great partnership with GE to localize and equip KAPES in the field of HVDC projects. Seven years after its creation, KAPES is very proud to have successfully completed its first reference project in Korea,” said Park Jin-Hong, KAPES CEO.
In 1994, GE successfully delivered the first 300-MW HVDC link between Haenam on the mainland and Jeju Island. On average, 150 MW of power was transmitted from the mainland to Jeju, corresponding to approximately 40% of the total demand on the island.

However, as booming tourism increased the island’s energy demand, the South Korean government decided to install another submarine line. In 2013, GE delivered a second link from Jindo on the mainland to Jeju Island that adds an additional 400 MW of power transfer capability. In June 2017, the consortium GE/KAPES was selected to upgrade the initial link with our most advanced H450 LCC valve and cooling system and to upgrade the control system.

GE’s Grid Integration Solutions division, comprised of HVDC and FACTS technologies, designs and integrates transmission solutions that help meet the world’s ever-evolving power needs.