Multi-level Inverters Application Features for Medium Voltage Electric Drives

the article analyzes the energy characteristics of a medium voltage electric drive with multilevel converters. The research relevance is confirmed by the diverse requirements for energy converters such as insuring high efficiency and power factor, and maximum reliability and stability. The study objective: the frequency-controlled electric drive’s dynamic characteristics analysis with using a multi-level voltage converter based on H-bridges structures. Research methods: the electric machines theory, power electronics, operational calculation, harmonic analysis, numerical simulation. The transient processes of the medium voltage induction motor during start-up are considered. To simulate the characteristics of the electric drive, the model of an asynchronous machine in a fixed coordinate system was used. A comparison is made of the electric drive characteristics as a whole with a multilevel inverter and with a three-phase inverter according to the bridge circuit. The multilevel medium voltage inverters efficiency, as well as the ways of further development, is shown.