A New Asymmetric 49-levels Cascaded MPUC Multilevel Inverter Fed by a Single DC-Source

This work proposes a new multilevel inverter topology composed of two MPUCs cascaded connected and fed by a single dc-source. This topology can provide 49-levels voltage by using four asymmetrical dc-links, and only twelve power switches. Its smaller dc-links are supplied by a single dc-source via high-frequency transformer (HFT) dealing with 33% of total load power when operating at nominal voltage. Besides that, HFT are smaller and lighter compared with line frequency transformers. This transformer is responsible to balance all dc-links providing required power flow. A Nearest Level Modulation (NLM) and analysis of power distribution among converter modules are presented in details. Besides comparisons with other multilevel topologies using HFT. Simulation and experimental results are presented to validate theoretical studies.