DC FAULT CURRENT REDUCING APPARATUS OF MODULAR MULTI-LEVEL CONVERTER

摘要

The present invention relates to a DC fault current reducing apparatus for constituting a sub module (SM) for reducing a DC fault current inside an arm of a modular multi-level converter. The DC fault current reducing apparatus includes a normal circuit which includes four switching elements of first to fourth switching elements in which two pairs of serially connected switching elements are connected in parallel, a bypass circuit which provides a fault reduction detour bypass path by including one first capacitor (Cc) connected in parallel with the normal circuit, and a discharge circuit blocking the discharge of a voltage by including one capacitor serially connected with the bypass circuit. Accordingly, the present invention can reduce a fault current and a switching loss.;COPYRIGHT KIPO 2017