A Dumbbell Type (D-Type) multilevel inverter based on switched capacitor concept

Abstract

<p>In this paper, a new single-phase seven level inverter with reduced device count is introduced. The structure can boost the input voltage by synthesising the capacitors’ voltages in predetermined current paths. A single DC voltage source is utilised to generate the output AC staircase waveform, which is facilitated via Nearest Level Control. Self-voltage balancing ability, less number of semiconductor devices, high efficiency and control simplicity are the most significant inherent attributes of the proposed circuit. It is also noticeable that in this configuration neither bulky transformer/inductor nor filters are applied. Power loss calculation and required capacitance of the proposed inverter are investigated and theoretical efficiency of 93.31% was reached. Moreover, the proposed converter operates under various load conditions with lower Total Harmonic Distortion compared to recent topologies. Ultimately, operating principles of the proposed D-Type seven-level Inverter and simulation results in MATLAB SIMULINK environment are validated by experimental ones obtained from the laboratory prototype.</p>