Buck-boost reduced switch-count converters based on three-phase six-switch dual-terminal inverter

Recently, three-phase six-switch dual-terminal inverter (SSDTI) has been proposed as a reduced switch count converter which employs less number of semiconductor devices compared with former dual-terminal inverters proposed so far in the literature. In SSDTI, the sum of upper and lower modulation indices must be less or equal to one. Therefore, the voltage amplitude of the outputs is small compared to two separate inverters. To remedy this problem, this paper proposes three new buck-boost DC/AC converters based on SSDTI: CUK-SSDTI, SEPIC-SSDTI and Diode-Assisted SSDTI. The performance of the proposed step-up DC/AC converters is verified by simulation and experimental results.