ZVZCS Full-Bridge Three-Level DC/DC Converter With Reduced Device Count

Abstract

This paper proposes a new zero-voltage and zerocurrent switching (ZVZCS) full-bridge (FB) three-level DC/DC converter (TLDC) with the reduced device count (RDC). The merits of the proposed converter with the corresponding modulation strategy are concluded as follows. In comparison with the zero-voltage-switching (ZVS) FB TLDC, 1) only one blocking capacitor is added to realize the ZVZCS strategy, 2) the primary circulating current and duty cycle loss can be effectively reduced. Also, the wide input voltage range can be satisfied because of having two working patterns. More significantly, the proposed converter with the corresponding modulation strategy can reduce the device count by removing the primary blocking diodes in comparison with other ZVZCS FB TLDCs, which would reduce the conduction losses of primary power devices and thus increase the converter's efficiency. Finally, experimental results are presented to verify the proposed converter with the corresponding modulation strategy. Index Terms-Full-bridge (FB), three-level DC/DC converter (TLDC), wide input voltage range, reduced device count (RDC), zero-voltage and zero-current switching (ZVZCS).

A T‐type three‐level converter for wide‐range voltage application

“…The output inductance in the proposed converter decreases to half of that in conventional FB converter because of two operation modes in the proposed converter. Number of switches is reduced and the control method is simple in the proposed converter compared with the topologies in References 19,20. No current flows through body diodes of switches in T‐type cell in the proposed converter compared to the topology in Reference 21.…”

“…Output filter can be reduced. However, number of switches in References 19,20 is still high, which is eight. In addition, control methods in References 19,20 are also complex.…”

“…However, number of switches in References 19,20 is still high, which is eight. In addition, control methods in References 19,20 are also complex. Therefore, a hybrid T‐type zero‐voltage switching (ZVS) DC‐DC converter was presented to reduce the number of switches 21 .…”

“…In addition, control method is complex. A three‐level FB converter with reduced device count 19 and a T‐type FB converter 20 were presented to reduce the number of switches. Voltage stress of diodes in the converters in References 19,20 is only half of that in the traditional FB converter.…”

Boost and full‐bridge integrated converter for wide input‐voltage range application

“…Since the voltage stress of output rectifier diodes varies proportionally with input voltage in them, it is high in high step‐up and large input‐voltage range applications. Thus, three‐level DC‐DC converters were presented to reduce the voltage stress of rectifier diodes 24‐26 . However, the voltage gain of the converters is low.…”