Low-voltage renewable sources require substantial step-up conversion for bipolar DC microgrids, while their interfaces must suppress source-current ripple and prevent pole-voltage imbalance caused by parasitics. This paper aims to propose an interleaved coupled-inductor high-gain DC/DC converter with bipolar outputs.
The converter’s operating modes and steady-state characteristics are analyzed. Voltage gain, device stresses, input-current ripple and input-branch power sharing are derived, and a nonideal model incorporating component parasitics is established. A 400 W laboratory prototype verifies the operating principle and steady-state analysis.
Interleaving reduces the input-current ripple. The two main-switch gate signals remain 180° phase-shifted, while their duty cycles can be adjusted independently to regulate the total output voltage and compensate for the bipolar voltage deviation caused by the Mode-VII zero-current interval and component parasitics. The coupled-inductor and voltage-multiplier structure provides high voltage gain with low device voltage stress, and the topology retains a common input–output ground.
The converter combines unequal-duty-cycle interleaving, coupled-inductor high-gain conversion and bipolar output balancing. The independent duty cycles preserve the 180° phase displacement while enabling total-output-voltage regulation and bipolar voltage balancing. Clamp branches recover leakage energy and suppress switch-voltage spikes. In addition, S2 turns on under ZCS, while S3, S4 and S5 turn on and off under ZCS.
