Zero-voltage transition H-bridge dc-dc converter with load-side energy recovery

Renewable energy generation systems, based on photovoltaic sources, currently represent the most suitable solution, for low power levels, to reduce the energy consumption produced by oil and gas. Moreover, they are becoming more and more attractive as the price per watt of the photovoltaic modules is decreasing. However, the conversion efficiency of commercial photovoltaic modules is still rather low so it is particularly important to be able to achieve, in every operating situation, the maximum possible energy. The paper focuses on a new zero-voltage transition dc-dc full-bridge converter with recovery of energy on load side. Analysis of its operating modes and a comparison, also of the conversion efficiencies, with conventional ZVT-PWM converters are given. Design example of a 750 W 100 kHz dc-dc converter and PSPICE simulation tests are provided to justify the analysis. Finally, experimental results, carried out on a laboratory prototype, are provided to validate the simulation tests.