A novel carrier based pulse width modulation technique for quasi-z-source inverter with improved voltage gain

This paper proposes a new carrier based pulse width modulation (PWM) strategy for the quasi-z-source inverter (QZSI). The conventional triangular wave carrier used in simple boost control technique is replaced by sine wave, which improves the shoot-through duty ratio for a given modulation index. The technique is to employ sine wave as both carrier and reference signal, with which the simple boost control for the shoot-through states is integrated to obtain an output voltage boost. The proposed strategy gives a significantly high voltage gain compared to the traditional PWM techniques. Detailed analysis of output voltage gain, individual harmonic contributions and THD for various modulation indices is simulated and the results are presented.