A new high step-down soft-switched DC–DC converter based on coupled inductor

ABSTRACT

This study introduces a new non-isolated DC–DC converter capable of achieving a high step-down conversion ratio. The design reduces switching losses through soft-switching, allowing switches to operate under Zero Voltage Switching (ZVS), which enhances efficiency. The converter employs a single coupled inductor without additional inductors in the power path, achieving low voltage gain and an extended duty cycle, resulting in reduced losses, lower costs, and optimal efficiency compared to similar topologies. Voltage stress on semiconductors is minimised by recycling leakage inductance energy to the output. The proposed converter achieves a greater step-down voltage gain per component compared to similar designs. Different operational modes and design aspects are examined. A prototype was constructed, and experimental results confirmed the theoretical analysis.

Highlights

• A high step-down DC–DC converter with a significant reduction ratio is introduced, featuring a non-isolated design.

• The switching losses have been reduced by converter operation under soft-switching conditions.

• The switches in the proposed converter can function under Zero Voltage Switching (ZVS) conditions, enhancing efficiency.

• Additionally, the voltage stress on the semiconductors can be minimised by redirecting the leakage inductance energy to the output port.

• A converter prototype is implemented, and the theoretical analysis is confirmed by the experimental results.

Graphical abstract

Schematic of the power circuit of the proposed topology.

KEYWORDS:

• Non-isolated high step-down DC–DC converter
• switching losses
• soft-switching conditions
• optimal efficiency
• coupled inductor

Disclosure statement

No potential conflict of interest was reported by the author(s).