Systematic Implementation and Performance Evaluation of Multiphase Power Converter in Medium Voltage Drive System

Investigation of power converters for use in industrial drive applications finds that these converters are used low reliable components. To overcome this issue, in this paper, advanced power converters (multi-pulse AC–DC and multilevel DC–AC converter) are developed and implemented to feed vector-controlled induction motor drive (VCIMD), which enhance power quality of medium voltage drive system. Multi-winding transformers with multiphase conversion as well as phase displacement technique for multi-pulse AC–DC converters are designed. Hence, to attain high power quality at grid side, while drive system is designed with the few numbers of DC sources, a multiphase conversion and phase displacement techniques-based 50-pulse rectification system is designed and developed here. For it, circuit structure of five multi winding transformers (T₁, T₂, T₃, T₄, T₅) is developed through phase displacement and multiphase conversion (3- phase to 5-phase) technique instead utilising low reliability components. Apart from this, to overcome the challenges at the drive side, a six-level cascaded multilevel inverter is developed with a low number of components. The rigorous design of a 50-pulse AC–DC converter and six-level cascaded inverter-based medium voltage drive system is made and responses of this system are analysed through experiments (7.5 kW IM) at various operating conditions. In verification processes, operation principle and impact of converters utilisation are clearly analysed. More importantly, using proposed circuitry, the input current is almost sinusoidal; its input current total harmonic distortion is less than 5%. Hence, the presented drive system addresses power quality standard IEEE 519 in the system.