PWM Techniques for a 13-Level Asymmetrical Dual Inverter Configuration Without the Overcharging of Floating Capacitor

Abstract

This paper presents a PWM technique for an asymmetrical dual inverter with a floating capacitor bridge fed an open-end ac load. This technique is to prevent the inrush current during charging into the floating capacitor by using buck-mode operation and to regulate the dc-link voltage its capacitor employing the space-vector PWM strategy for the dual inverter. This is desirable as it leads to avoiding the overcharging of the floating capacitor. These methods help in generating the 13-level voltage waveform of each phase at the output terminal of open-end ac loads in the full range of the modulation index from 0 to 1. Simulation results are illustrated and discussed to validate the effectiveness of the proposed method, which are compared with the existing dual inverters under the same PWM technique in terms of the total harmonic distortion of output phase voltages and so on.