Introduction of Haenam-Jeju HVDC system

Jeju´s main industry being tourism, the addition of more diesel generation on the island to meet demand was thought to be environmentally detrimental and alternatives were examined. Since power was available from larger and more efficient generator units on the mainland, a submarine connection was desirable, but with a 100 km route length, an HVAC connection was not technically feasible because of the large charging current for the HVAC cable. An HVDC connection was chosen, both to overcome this technical difficulty and additionally because of economic considerations. After testing, KEPCO begun to operate the scheme in 1998. The HVDC scheme is a 300 MW bipolar link between Jeju and the Korean mainland. The scheme is intended to be the principal source of electrical power of the island of Jeju but it is also required to operate in parallel with local generation and, if necessary, export power to the mainland. To permit the importing of power into the island when there is no local generation, two synchronous compensaters are to be installed near to the island converter station