CONTROL OF A MODULAR MULTILEVEL CONVERTER OF A FULL BRIDGE OR MIXED ARM TYPE IN CASE OF A DC LINE DISTURBANCE

摘要

A method (100) of controlling a modular multilevel converter, MMC, of a full-bridge or mixed arm type in case of a DC line disturbance is provided. The method includes determining (102, 104) whether a magnitude of a DC voltage (Udp) of the MMC has fallen below an upper voltage threshold (Ud_max_lim), and, if determining that the magnitude of the DC voltage has fallen below the upper voltage threshold, reducing (106) both a magnitude of an AC active current reference (IVD_ORD) and a magnitude of a DC voltage reference (UDC_REF) for the MMC based on the DC pole voltage. An MMC with a controller implementing the method, a converter station including at least one such MMC, and a power transfer system including at least one such converter station, are also provided.