A Switched-Capacitors-Based 13-Level Inverter

The merit of switched-capacitors based multilevel inverters (SCMLIs) is generally quantified in terms of a ‘cost function’ (CF) which incorporates parameters such as: voltage gain, component count, total standing voltage (TSV) and number of levels. In this work, a 13-level inverter is proposed with the aim of achieving a low value of CF. The proposed single-stage SCMLI uses one input source and three capacitors to attain a voltage gain of three. It requires thirteen power switches, of which the peak-inverse-voltage (PIV) of nine switches is restricted to the source voltage. The remaining four switches have PIV equal to twice the source voltage and they operate at low frequency. Thus, for all switches, the PIV is less than the amplitude of the output voltage. Moreover, the capacitors are self-balanced at all regions of modulation index values. The proposed inverter is validated through simulation and experimental results. A comparison of the proposed topology with other contemporary SCMLIs shows that it is highly competent in terms of CF, PIV and TSV requirements, waveform resolution and capability to achieve voltage balancing of capacitors at low values of modulation index.

Index Terms—Multilevel inverter, peak-inverse-voltage, switched-capacitors, topology, single-stage.