Symmetrical switching patterns and an adaptive modulator for three-phase quasi-Z-source inverters

In this paper, four symmetrical switching patterns for high-frequency three-phase quasi-Z-source inverters are proposed. Each pattern results in different values of currents during semiconductor switching processes. Therefore, an adaptive pulse width modulator is introduced to perform operation at minimum switching losses, related especially to shoot-through states. On the other hand, changes in pulse width modulation patterns (PWM) impact input current ripples and the quality of the output waveforms. In order to verify new PWM techniques, an experimental study was conducted using a 100 kHz/6 kVA SiC-based inverter. Proposed PWM patterns and the adaptive modulator were implemented and compared to the Discontinuous Maximum Constant Boost Control method.