Patent ID: 8873258

Claim:
A method for inhibiting a converter having at least two phase modules, which each phase module having an upper and a lower valve branch, with each upper and lower valve branch having a plurality of two-pole submodules, which are electrically connected in series and each have a unipolar energy storage capacitor, with a series connection of two turn-off semiconductor switches each being connected in parallel with an antiparallel connected diode, the method comprising the steps of: a) triggering a pulse inhibitor in response to a fault occurring during operation of the converter, b) controlling a switching state of exactly one two-pole submodule in each valve branch to a switching state III after a pulse inhibitor has been set, wherein in the switching state III all semiconductor switches of a corresponding two-pole submodule are in an off state, c) controlling exactly one additional submodule in each valve branch to the switching state III after a predetermined time interval has elapsed, wherein at steps b) and c) all semiconductor switches of an identical number of submodules are in the switching state III, and d) repeating step c) until all two-pole submodules in each valve branch are controlled to the switching state III.