REDUNDANCY CONTROL METHOD OF MMC FOR HVDC

摘要

The present invention relates to a method of lowering an output voltage of each submodule, which has not broken down, of converter arms, in a MMC for HVDC where redundancy modules for enhancing a rate of operation are applied, when a breakdown of a submodule of the MMC occurs in a case where there is no more redundancy module to be applied, whereby a system may continuously operate. According to the present invention, there is provided a redundancy control method of an MMC for HVDC, wherein the MMC includes multiple converter arms each has multiple submodules in operation and redundancy modules for spares, the method including: checking whether a breakdown of a submodule in operation of a first converter arm among the multiple converter arms occurs in a case where the all redundancy modules of the first converter arm are applied in operation; and lowering an output voltage of each submodule of other converter arms in such a manner that a DC link voltage of each of the other converter arms is controlled to be equal to a DC link voltage of the first converter arm when the breakdown of the submodule of the first converter arm occurs.