Unidirectional Step-Up DC–DC Converter Based on Interleaved Phases, Coupled Inductors, Built-In Transformer, and Voltage Multiplier Cells

This article proposes a unidirectional high step-up dc–dc converter. The study approaches principle of operation, analysis, guide design, and experimental validation. The high-voltage gain is reached using coupled inductors and voltage multiplier cells (VMC). An interleaved structure of two phases is employed to provide a low-current ripple in the input side. The current balance between the phases occurs due to the insertion of a built-in transformer, which also contributes to increasing the voltage gain. The energy from the leakage inductances is reused, reducing voltage spikes across the semiconductors. Additionally, the proposed converter provides an input–output common ground, which is a requirement for many applications. To verify the proposed converter, a 1-kW prototype, 48–800 V, and 16.67 of voltage gain, was designed and tested. The maximum peak efficiency reached was 94.89% and the rated power efficiency was 93.86%.