Research on mechanism and characteristics of harmonic resonance problem of independent energy storage grid-connected system based on time domain simulation method

Energy storage equipment is useful for stabilizing the fluctuation of new energy power, and is of great significance to help the development of new energy. Energy storage has been developed on a large scale. In recent years, when new energy equipment based on power electronic converters such as wind power, photovoltaic, and flexible direct is connected to the system, harmonic resonance is caused and brought harm to the system. As energy storage is also a grid-connected device based on power electronic converters. Therefore, it is necessary to pay attention to the harmonic characteristics of the energy storage power station after it is connected to the system. This paper studies the harmonic resonance problem of an actual independent energy storage grid-connected system. Firstly, the harmonic resonance simulation calculation model of the actual energy storage system is established in PSCAD/EMTDC. On this basis, the effects of energy storage charge and discharge, the changes of output, the changes of access system and the changes of system strength are analyzed. The research results have certain guiding significance for the design and grid-connected operation of energy storage power stations.