Abstract: Floating photovoltaic power plants are generally applied in shallow and calm water areas.In order to expand the application range of floating photovoltaic power plants, a protective system which can adapt to the change of water level is invented. It mainly includes a protective steel structure and an adaptive winding chain system.The working principle of the system is introduced, and the strength calculation of the protective steel structure has considered water flow,wind and wave loads in type selection for the winding chain system.The adaptive chain winding system can make the protective steel structure and photovoltaic power plant automatically adapt to the change of water level,which ensures the safety of floating photovoltaic power plants.

Key words: floating photovoltaic power plant, adaptive protection system, winding chain mechanism, mode selection； water flow load