—This paper proposes a controlled transition full-bridge (CTFB) hybrid multilevel converter (HMC) for medium and high voltage applications. It employs a full-bridge cell chain-link (FB-CL) between the two legs in each phase to generate multilevel bipolar output voltage. The CTFB-HMC has twice dc voltage utilization or power density of conventional converters due to the bipolar capability of its full-bridge configuration. Hence, for the same power rating and same voltage level number, its total cells per phase are quarter that in modular multilevel converter (MMC), which reduces the hardware installation volume. Also, in the proposed converter, the total device number in the conduction paths is the same as in the half-bridge MMC, leading to low con-duction losses. The FB-CL current of the CTFB converter has no dc component, which offers the potential to enhance the transient response. Comparative studies between the CTFB and other mul-tilevel topologies are carried out to clarify its main features. The modulation strategies and parameter sizing of the proposed con-verter are investigated using a generic case. Simulation and exper-imental results are used to verify the effectiveness of the proposed approach.
- Controlled transition process
- Zero Dc-Chain-Link current
- full-bridge cell chain-link
- hybrid multilevel converter
- improved dc voltage utilization
- low conduction losses