Low power interleaved DC-DC converter with high voltage gain for photovoltaic applications

Before being injected into the electric grid, the energy provided by a photovoltaic panel must be conditioned in several stages. In the micro-inverter concept, the low voltage at the output of a panel is elevated using a DC-DC converter, being the power controlled by a maximum power point tracking algorithm in such a way that the panel always works around its maximum power point. The paper presents the design and implementation of a DC-DC converter based on the three-state switching cell and voltage multipliers. The converter can be easily integrated in low-power photovoltaic applications due to its high voltage conversion ratio, high efficiency and power density. The main design parameters are discussed and a precise converter model is presented. Simulation and experimental results for an extended input voltage range show the validity of the design approach and the suitability of the converter for micro-inverter applications.