Influence of Open Switch Failure on Control and Thermal Performance of CHB Converters

Abstract

Cascaded H-Bridge (CHB) converters have been widely considered in various applications, showing the advantages such as physical modularity, multi-level ac voltage, low dv/dt and so on. However, the CHB converters employ the higher number of power semiconductor device than standard two-level converters. Furthermore, it has been well-known that the power semiconductor device is one of the most prone components to failure, where the failure can be divided into two categories; short-circuit failure and open-circuit failure. In this work, the influences of open-circuit failure on the control performance and loss distribution are analyzed through a simulation model of grid-connected 7-level CHB converter.