Efficient high step-up topology for renewable energy source interfacing

The paper presents the complete analysis and design procedure for an interleaved, isolated resonant boost converter. The topology is inherently capable of high step-ratios and soft-switching operation in a wide input voltage and load range. Thanks to resonant operation, the performance level is further improved with respect to similar, non resonant topologies, achieving higher conversion efficiency and lower switch current stress. Overall, the converter represents an excellent solution to interface low voltage, high current renewable energy sources with the distribution grid through a high voltage DC bus. Topology characteristic equations in different operating modes are provided, based on which a design procedure for the power stage components is derived. A single photovoltaic module interface converter, rated for 300 W output power, is considered as a case study to validate the analysis and the design procedure. Both are fully validated by measurements taken on the laboratory prototype.