Ultra High Step‐Up Soft Switching Converter Based on the Interleaved Structure

A new interleaved high step‐up DC–DC converter is presented in this paper, providing very high voltage conversion, significantly lowering the voltage stress across semiconductor components, and minimizing conduction losses. In this topology, an active snubber circuit guarantees zero‐voltage switching (ZVS) of the main switches over a wide load range, while the auxiliary switch achieves complete zero‐current switching (ZCS) operation without contributing to additional power losses in the converter. Since the duty cycle of the auxiliary switch is small, the auxiliary circuit remains active in the converter for a short duration. The use of fixed‐frequency PWM control enables an optimized design of the magnetic components while keeping the control implementation relatively simple. In addition, because the input and output terminals share a common ground, the control circuit does not require input‐side isolation, thereby further simplifying the overall system design. The theoretical analysis is validated by a 250 W prototype with 20 V input to 600 V output voltage with a 100 kHz switching frequency.