Evaluation of current stresses in nine‐switch energy conversion systems

Converters with reduced‐switch counts usually face some performance tradeoffs, which make them suitable for some applications but not others. The same applies to the nine‐switch converter, which is a reduced‐switch version of the back‐to‐back twelve‐switch converter. The nine‐switch converter has since been shown to experience a higher voltage stress, which can be lowered in some cases. A corresponding evaluation of its current stress is however lacking, and is hence addressed now by computing its switch currents when used for ac–ac, ac–dc, dc–ac and dc–dc energy conversions. Relevant expressions, application requirements and simulation results are presented for identifying cases, where the nine‐switch converter can have an improvement in performance despite its reduced‐switch count. These cases are verified in experiments using a 1.5 kW prototype built in the laboratory.