| The scale of renewable energy is growing. Energy storage, as the core unit of energy management system and micro-network system, as while as the main mean of intelligent adjustment, is increasingly valued and strong supported around the world. However, economically viable large-scale energy storage is still a technical difficulty.Because efficiency,charge and discharge times, capacity, cost and other issues remain to be resolved. In addition, with the growing popularity of household optical storage systems and the maturity of the electricity trading market, it is imperative to have an intelligent energy storage management system adapting to the future electricity market environment,which can facilitate the use of the public and help users to demand the side response in order to save electricity, while achieving the ideal of power load demand. The research on the management of energy storage system in microgrid is aimed at solving the above problems.(1) The main storage method of power and power density, energy density, the number of cycles, the use of the environment, the use of cost and so on are dissertated. Examples are given to analyze the application cases of energy storage system in microgrids all over the world, and the attitude of countries in the world for the development of energy storage.The research status and existing problems of energy storage system management in microgrid are analyzed.(2) The charge and discharge characteristics of the battery, and influences to battery caused by temperature, the number of charge and discharge, self-discharge, and the overcharge or overdischarge are analyzed. The basic control algorithm of the converter is studied, and the effect of battery charge and discharge efficiency and converter AC/DC conversion efficiency on the energy efficiency of energy storage system is analyzed through the actual energy storage system operation data.(3) For large-scale hybrid energy storage unit independent microgrid,select the appropriate energy storage unit considering the battery characteristics and economy to meet the requirements of microgrid's power and energy, and plan its capacity. The energy storage unit is used to coordinate the management of the mixed energy storage unit and the rules of power efficiency allocation are established.(4) A energy storage management method based on fuzzy logic control(FLC) energy distribution is put forward for the complex energy scheduling caused by strong randomness of real-time electricity price and renewable energy power generation, as well as the flexibility of energy storage battery charge and discharge. The method is that real-time price,state of charge (SOC) of the energy storage battery and the difference value of load power and photovoltaic power these three parameters are put into the fuzzy logic controller, while the economic operation of the power system is taken as target considering the cost of battery storage depreciation and its safety performance, then establish the simulation model.In this paper, the intelligent management method of energy storage system in microgrid is presented by numerical analysis and Matlab simulation. The method can effectively utilize the battery under the condition of ensuring the safety performance of the battery, and reduce the total converter running loss,resulting in improving the operating efficiency of the microgrid. The fuzzy logic control energy distribution strategy has strong robustness, high universality, and can obviously reduce electricity charge. |
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