Evaluation of the impact of grid-connected energy storage on short-circuit current in systems with a high proportion of renewable energy

Energy storage technology breaks the asynchrony between energy production and consumption, makes energy convertible in time and space, and realizes the premise of energy complementarity and sharing. In modern power grid, energy storage, especially electrochemical battery energy storage technology, has become an important support for the access and utilization of large-scale centralized and distributed renewable energy generation. In the context of the development of energy Internet, the role and status of energy storage will change significantly. Based on the application of energy storage in power system, the function of energy storage will be further expanded, and energy storage technology will obtain new development opportunities. With the rapid development of the application of battery energy storage technology, its impact on the power grid is far-reaching. However, the research on the short-circuit current contributed by battery energy storage after AC short-circuit and its influence on power grid stability is still blank at home and abroad. In addition, the existing short-circuit current calculation standards and methods do not involve the influence of energy storage system on short-circuit current in case of AC short-circuit fault. At present, the International Electrotechnical Commission IEC 60909 and American National Standards Association short-circuit current calculation standards do not involve the contribution of battery energy storage to the short-circuit current of AC system during short circuit. Circuit and connected to the grid. In the planning, design and operation control of power system, the selection of system equipment capacity parameters, the setting of protection devices and the arrangement of operation mode all need to calculate the short-circuit current. With the increasing proportion of energy storage system capacity, the impact on AC system short-circuit current can not be ignored.