Integration Technologies for a Fully Modular and Hot-Swappable MV Multi-Level Concept Converter

In order to fully exploit the benefits of modular converters, dedicated hard- and software integration technologies have been developed to complement modular multi-level circuit topologies. The technologies investigated include a wireless auxiliary power supply, a two-phase cooling, solid insulation, wireless optical communication, redundant EtherCAT networking and advanced IGBT junction temperature diagnostics. Emphasis was set on three key aspects of modularity: scalability, configurability and pluggability. To validate the technologies and to demonstrate their benefits, a medium voltage concept converter was built and operated. The combination of these technologies finally also enabled a 'hot swap' functionality, where power modules can be replaced during converter operation. Hot swap has successfully been tested for a DC-link voltage of 3.3 kV and output power of 550 kW.