CONVERTER CELL FOR CASCADED CONVERTERS, CONTROL SYSTEM AND METHOD FOR BYPASSING A FAULTY CONVERTER CELL

摘要

A cascaded electric power converter and a method of operating a cascaded electric power converter are disclosed. The cascaded converter comprises: a converter cell including a cell capacitor and at least one phase leg having at least two electric valves, the at least one phase leg being connected in parallel to the cell capacitor; and a control system for controlling the switching of the electric valves of the at least one phase leg. The control system is configured to, upon detection of a need to by-pass the converter cell, control the switching of the electric valves in a manner so that the cell capacitor is short circuited via a phase leg, so as to obtain a current surge through the phase leg, thereby creating a permanent current path through the converter cell.