Capacity Optimization Method Of Hybrid Energy Storage In Wind/solar Microgrid

With the development of society, the situation of environmental pollution and energy shortage is becoming more and more urgent. Therefore, people begin to pay more attention to the research and utilization of renewable energy such as wind energy and solar energy. However, their output power is intermittent and fluctuating,it is difficult to guarantee the power quality. The energy storage system is needed. It is widely used in the new energy generation system, especially in the micro-grid because of its fast power regulation. Considering its high cost, in order to improve the economy of micro-grid operation,thesis studies the optimization of hybrid energy storage capacity.Firstly, the mathematical models of each component are given, including the photovoltaic and wind power supply, storage battery and super capacitor. In practical application, battery excessive charge and discharge affect its life, we use digital filtering algorithm to achieve energy storage charge and discharge control, and the rain flow counting method for assessment of battery life. Then we use storage life cycle net present value as the objective function. The general model and optimization model considering demand response (DR) of the micro-grid hybrid energy storage capacity are given. The DR model is solved by particle swarm optimization algorithm. It can make the load and distributed generation closer to each other, and reduce the storage capacity. The introduction of hybrid energy storage and DR is helpful to improve the flexibility of micro-grid and reduce the impact of distributed generation on the grid. The stability of differential evolution algorithm is combined with the reliability of simulated annealing algorithm to solve the problem of hybrid energy storage capacity optimization.Finally, taking an actual micro-grid as an example, the simulation is given by comparing the four schemes can verify the hybrid energy storage can improve the effect of distributed generation on micro-grid; DR can effectively reduce the hybrid energy storage capacity, improve the economic benefit of micro-grid.