Existing low-current-stress high-gain bidirectional converters generally suffer from drawbacks such as discontinuous high-voltage-side (HVS) current
excessive component count
and low conversion efficiency
making them unsuitable for hybrid energy storage systems. To address these issues
this paper proposes an interleaved high-gain bidirectional converter
featuring near-zero current ripple on HVS
zero-voltage-switching (ZVS) operation and reduced component count. The proposed topology is derived by parallel-connecting the low-voltage sides (LVSs) of a Buck/Boost converter and a coupled-inductor Cuk bidirectional converter while series-connecting their HVSs. When the duty cycle satisfies the constraint D2=1/(2−D1)
the converter achieves automatic current sharing in the LVS inductors and achieves a voltage gain of 2/(1−D1)
with the voltage stress on switches equal to or approaching half of the HVS voltage. Operating in triangular current mode
the converter enables ZVS turn-on for all switches across the entire operating range and achieves zero ripple current on HVS through optimized inductance design; therefore
the need for an HVS filter can be eliminated
the volume and losses can be reduced
and the conversion efficiency can be improved. Comprehensive analyses are presented on the operating principles
steady-state characteristics
zero-current-ripple conditions
soft-switching criteria
control strategy
and parameter design methodology. A 500 W prototype with an LVS voltage range of 40~56 V
HVS output of 400 V
and minimum switching frequency of 50 kHz validates the theoretical analysis. Experimental results demonstrate peak and minimum efficiencies of 97.6% and 94.2%