Novel SVPWM technique for three-level T-type Z-source inverters

In this paper, a new SVPWM switching technique, named ZSVM_1TI, has been proposed for a three-level (3L) T-type Z-source inverter (ZSI). ZSVM_1TI is based on three main modifications of the existing PWM techniques for 3L inverters. First, the existing SVPWM of a 3L ZSI has been modified to double the frequency of the null interval. After that, an improved version of the maximum boost control (MBC) has been proposed based on modified SVPWM to eliminate the problem of the sixth frequency ripple components of inductor current with the existing MBC technique of ZSIs. Finally, a new switching pattern of a reduced common-mode voltage (CMV) PWM technique has been proposed to increase the switching frequency of the impedance network so that the size of the passive elements can be reduced. The proposed ZSVM_1TI has been compared with the existing PWM technique in terms of the size of the impedance network, the dc-link utilization, and the inductor current ripple profile. The above-mentioned findings have been successfully validated using theoretical analysis, simulations, and experimental results.