Renewable energy generation systems, based on photovoltaic modules, 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 predictive current control for quasi-resonant Zero Current Switch (ZCS) DC-DC boost converters suitable for photovoltaic (PV) conversion systems based on transformerless multi-string topology.