Usability of Three-Level ANPC Converters after Short-Circuit Failure

A short-circuit failure of a semiconductor in a multilevel converter causes challenging problems. However, the aftermath can also be troublesome. If a primary fault will cause a secondary loss of a switch, a three-level Active-Neutral-Point-Clamped converter can be impacted in several ways: discharge of one DC-link capacitor, the occurrence of surge current, or limitation in further usage. The appearance of a secondary loss of a semiconductor depends on which short-circuit case is present. Out of this, it can be determined which of these three possibilities will affect the converter afterward.