| Solar energy is one of the cleanest new energy sources at present.As a secondary energy source,solar energy with the characteristic of inexhaustible supply does not need the consumption of other energy sources,and has no impact on the environment.Given the vast land area of our country,solar energy is an excellent choice in the development of new energy due to its extreme abundance and the relatively safe power generation process.However,photovoltaic power generation is greatly influenced by the environment.The output of photovoltaic cells will be unstable,intermittent,and change the output power under the influence of different local shadows,different temperatures and other environmental factors.Therefore,it is necessary for the photovoltaic power generation to store discontinuous output electric energy by the energy storage system,and how to make the system work at the maximum power point is always a hot topic of photovoltaic power generation.This paper combined the fuzzy algorithm with the variable step disturbance observation method,and established the photovoltaic energy storage system by using lithium battery as the energy storage battery.The research of improving the maximum power point tracking method was performed on the built dual-battery switching platform of lithium battery and solar lithium battery,to verify whether it could increase the power output of photovoltaic battery,thus prolonging the running time of the system,and to test the feasibility of dual-power switching of photovoltaic lithium battery.The main contents included:Firstly,the simulation model of photovoltaic power generation system was built according to the equivalent circuit of photovoltaic cells.The variation rules of output characteristics of photovoltaic power generation system under different environmental conditions was deeply studied.By analyzing the requirements of the system,a photovoltaic energy storage system based on STC12C5A60S2 as the main chip,relay as the dual power switching element of photovoltaic lithium battery,and lithium battery as the energy storage battery was designed.Secondly,the traditional maximum power point tracking algorithm was illustrated.Their advantages and disadvantages were analyzed respectively.To enhance the tracking performance of the maximum power point of photovoltaic power generation output in the photovoltaic energy storage system,the maximum power point tracking strategy with the combination of the fuzzy algorithm and improved disturbance observation method was selected,and then the simulation model to improve the maximum power point tracking algorithm was established.t is verified that the improved maximum power point tracking algorithm exhibited the effect of enhancing the energy output of photovoltaic power generation via the simulation results under different environmental conditions.Finally,a dual-battery switching platform of lithium battery and solar battery was built.The output power was tested under different environmental conditions,and compared with the output power without MPPT control and the ideal output power under simulation,verifying the applicability of the improved MPPT algorithm to the platform.Moreover,it could also enhance the output performance of photovoltaic power generation effectively.Whether the improved MPPT algorithm could prolong the running time of the system was verified by testing the running time of the car body. |
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