| With the social progress and economic development,the existing energy structure has been unable to meet the needs of mankind,so we need to use new energy to ease the energy crisis.Photovoltaic energy has attracted great attention for its clean,environmental protection,great energy and other advantages.It has become the focus of the study of all countries in the world.However,a single photovoltaic power generation may not be able to meet the user's normal demand in the case of poor weather conditions.At this point,the energy storage system will ensure the normal output of energy and no longer be affected by the sunshine intensity,the length of time and other external environmental factors.Firstly,this paper introduces the main part of the photovoltaic power generation system,and the basic principle and characteristics of P-U,I-U were given the characteristics of photovoltaic cells.And it introduces and analyzes the three basic principle of maximum power maximum power tracking and tracking algorithm:constant voltage method,perturbation method and incremental conductance method.Secondly,the working principle and mathematical model of lead-acid batteries and super capacitors are introduced,and their charging and discharging characteristics are simulated and analyzed.According to the characteristics of battery and super capacitor as well as several different hybrid energy storage system is proposed through the circuit structure and circuit structure of battery current Reversible Chopper in parallel and super capacitor hybrid energy storage,the structure can make the battery and super capacitor capacity configuration is more flexible,and can fully play their respective advantages.Thirdly,the construction of lead-acid battery and super capacitor hybrid energy storage system,and according to the hybrid energy storage system of 4 kinds of operation mode and load demand,the one-way DC/DC converter and bi-directional DC/DC converter flexible switch under different working conditions.Different control methods are adopted for different operation modes of different power converters.An integrated photovoltaic cell,battery and super capacitor charging and discharging characteristics are given,and a hybrid energy storage system energy control strategy is proposed to ensure the reasonable and effective flow of energy in the system.Finally,the paper uses MATLAB to establish model of PV system containing battery super-capacitor hybrid energy storage,by changing tl e intensity of light load and vacancy size,power fluctuation of photovoltaic power generation in the simulation,to verify the proposed hybrid storage can inhibit the power fluctuation of structure. |
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