An Interleaved High Step-Up DC-DC Converter with Coupled Inductor and Built-in Transformer for Renewable Energy Applications

This paper introduces an interleaved high step-up DC-DC converter with high voltage gain, low voltage stresses on the switches, low current stresses on the components, and continuous input current with low ripple, all of which are beneficial for the renewable energy (RE) applications. The proposed converter is based on the integration of three voltage-boosting (VB) methods: coupled inductor (CI), built-in transformer (BIT), and switched-capacitor (SC) cells. The energies of the leakage inductances of the CIs and BIT are absorbed and recirculated to the output side, which further extends the voltage gain. In addition, the current-falling rates of the diodes are controlled by the leakage inductances, which leads to the reduced reverse-recovery losses of the diodes. The operating stages, steady-state analysis, and a comparison with similar existing topologies are presented in this paper. Furthermore, the performance of the proposed converter is verified through the experimental results of a 200-W prototype with an output voltage of 400 V and a voltage gain of 30.