Research Of Control Strategy And Capacity Configuration Method About Hybrid Energy Storage System

Distributed generation into the power system will result in some deteriorative influences, such as poor power quality and stability issues. With the increasing share of distributed generation in the power system, the impact of its integration is becoming more widespread. To reduce the detrimental effect of the distributed generation on the grid, energy storage system has been widely used. In order to increase the economic efficiency of microgrid, the control strategy and capacity configuration method of the hybrid energy storage system are investigated in this paper, The main content of study covers the following:A battery-supercapacitor hybrid energy storage system(HESS) is established for the distributed generation system. HESS takes advantage of different energy storage technologies to provide satisfying compensation capability with high energy density. In order to ensure the load reliability of hybrid energy storage system, a fuzzy control strategy is proposed. The control strategy considering state of charge and the active power compensation of hybrid energy storage system, so as to correct power reference value, optimize the charge/discharge process of the storage system. The simulations result shows that the hybrid energy storage system can effectively streamline the active power of distributed generation and therefore increase the service life of the energy storage system. The proposed method provides an alternative strategy to enhance existing energy storage devices due to the control strategy of this model.The capacity configuration of microgrid is directly related to the power quality and economy. A chance-constrained programming based capacity configuration method of hybrid energy storage system is proposed. Considering the constraints of output power of a HESS and state of charge, aimed to minimize cost of the HESS, this method gets a relationship between the output of the hybrid energy storage and the best configuration of wind power with fluctuations containing in a certain confidence interval. The method quantitatively analyzes the configuration of a hybrid storage capacity, considering an appropriate compromise between power quality and cost. Simulation results illustrate this method can avoid the cost increase of HESS which is caused by short-term wind power fluctuation. Compared to traditional capacity configuration, the method is more flexibility and practical.