Thermal and efficiency analysis of five-level multi-level clamped multilevel converter considering grid codes

Abstract

In this paper a five-level Multi-Clamped Multilevel Converter (5L-MLC2) topology is analyzed based on a typical grid integration application for renewable energy generation system. The loss and thermal distribution of the power devices in different switching legs are investigated and illustrated under rated operation. Afterwards, a loss and efficiency evaluation method is proposed and applied which takes into account various reactive power operation boundaries regulated by the grid codes. It is concluded that the 5L-MLC2 multilevel topology shows a good and consistent efficiency characteristic under different output active powers when complying with the active/reactive power operation range regulated by e.g. the German grid codesPostprint (published version

A Traction Three-Phase to Single-Phase Cascade Converter Substation in an Advanced Traction Power Supply System

“…Theoretically, any level of the output voltage could be obtained by cascading multiple converter modules. The output transformer in a traction substation of ATPSS can be canceled to enlarge the system capacity by means of cascading multilevel converters if the interface voltage level were higher than the output voltage level [11,12]. At the same time, if the number of cascade modules or the levels of multi-converter module were too large, it will cause difficulties in the design of the control system.…”