Two new transformer-based isolated seven-level inverters

In this paper, two various transformer-based inverters are proposed. The proposed inverters consist of one center-tap transformer, two bidirectional switches and three unidirectional switches. The proposed inverters are capable of increasing the input voltage according to the winding turn-ratio of the transformers and isolating input DC sources with the load, resulting in enhanced reliability. The performance of the proposed inverter has been compared to some of the commonly used transformer-based inverters from the literature in terms of the number of components and the overall performance. The proposed multilevel inverters have reduced number of IGBTs and gate drivers and subsequently require a relatively simple control strategy for generating the desired output voltage. Finally, the performance of the proposed inverter has been simulated utilizing PSCAD/EMTDC software package.