High-level number multilevel single-phase current-source inverter with reduced switching device count

Abstract

This paper proposes an advanced technique in generating a pure sinusoidal output current waveform for the high number multilevel lsingle-phase current-source inverter (CSI) with reduced switching device count. Previous multilevel CSI development proposed a new technique in generating pure sinusoidal output by compensating the staircase current with a linear current. This linear current compensation intends to reduce the output filter capacitor size without sacrificing inverter efficiency. However, this hybrid multilevel CSI would give higher efficiency and performance if applie in high number of levels. Consequently, the system needs high switching device count. Too many switching devices utilization will decrease the performance and the power density of the CSI as well. Therefore, this technique is introduced and only possible to be realized if the number of levels is higher than 5-level. By applying multilayer stagemethod while managing the DC current module activation sequences, the high number of levels CSI can be constructed with only using few DC current modules. As a result, according to the computer comparison simulation, the implementation of the proposed technique delivers relatively equal results compared to the conventional one just by utilizing fewers witching devices.