AbstractThis article proposes an interleaved high step‐up DC–DC converter topology designed for renewable energy applications, featuring an ultra‐high voltage conversion ratio. The converter employs an interleaved structure, resulting in a low peak‐to‐peak ripple in the input source current, which is particularly advantageous for solar PV sources. To enhance the output voltage, the topology utilizes voltage multiplier cells (VMC) and coupled inductor techniques. Two coupled inductors with three windings are integrated into the proposed topology, with the secondary and tertiary windings combined with VMC. This combination effectively reduces the maximum voltage stress across power switches, enabling the use of low‐rated and cost‐effective power switches for implementation. The article offers comprehensive operation modes and steady‐state analyses to demonstrate the converter's performance. A comparison is made between the suggested structure and other similar converter topologies. To validate the mathematical analysis, a 200‐W prototype is constructed, operating at a frequency of 25 kHz and achieving a voltage conversion range of 20 to 409 V. The experimental results are presented to support the findings.