Capacitor-assisted active-switched quasi-Z-source inverters with high voltage gain.

This paper presents a novel topology called the capacitor-assisted active-switched quasi Z-source inverter (CA/AS-qZSI). The proposed CA/AS-qZSI topology has a high ac voltage gain and low voltage and current stresses on the diodes and extra switch in the Z-network. The design guide of the passive elements used in the proposed topology and a comparative study of the proposed CA/AS-qZSI and four other topologies with an active-switched impedance network are addressed. A new pulse-width modulation (PWM) technique using a sawtooth carrier signal is also suggested to reduce the switching losses of the diodes and switches. Compared with the traditional simple boost control method, the efficiency of CA/AS-qZSI using the new PWM technique is improved by 4–4.6%. The experimental results utilizing a prototype made in the laboratory demonstrate the performance of the proposed CA/AS-qZSI and PWM technique. [ABSTRACT FROM AUTHOR]