Design And Research For Coordinated Operation In Hybrid Energy Storage System In DC System Of Substation

To solve the problems of exiting in DC system of substation such as more impact loads, high battery capacity margin and low reliability, a hybrid energy storage system combined with batteries and super capacitors is put forward to improve the present separate battery energy storage system which makes full use of the advantages of super capacitor high power density and long cycle life. On this basis, the article is intended to design and research how to distribute the output capacity of batteries and super capacitors rationally in the transient process to achieve the coordinated operation of hybrid energy storage DC system.Firstly, hybrid energy storage related element mathematical models, circuit topology and working principle of coordinated operation for DC system are provided. According to the specific load of substation DC system, the capacity of batteries and super capacitors are chosen respectively by calculation and study. The limiting inductor which is used for limiting the current in such system has been then researched according to the length of time of the current caused by impact load. Secondly, the paper establish a simulation model in MATLAB/SIMULINK software, while build the corresponding experimental platform in the laboratory. Simulation analysis and experimental verification are used in the coordinated operation of hybrid energy storage DC system. Super capacitors bear the impact load and batteries undertake the regular load, thus which can distribute reasonably the output capacity of the hybrid energy storage devices. Hybrid energy storage DC system is in coordinated operation state. Finally, considering the limitations of direct parallel hybrid energy storage coordinated operation, a improve circuit topology has been proposed based on super capacitors via DC-DC converter, which has been designed and simulated by software, and a prospect has been made through the research in he last chapter.