Influence of Grid Structure Change on Resonance Frequency of Distributed Photovoltaic Cluster Grid-Connected System

Abstract

As the number of distributed photovoltaics in the power grid continues to increase, the inherent resonance points of distributed photovoltaic cluster grid-connected systems become more complex. This paper firstly analyzes the grid structure of the distributed photovoltaic cluster grid-connected system. Then, the grid structure and resonance coupling relationship of single inverter, and the grid structure and resonance coupling relationship of cluster grid-connected inverters are analyzed. Based on the above analysis, the resonant frequency distribution of the distributed photovoltaic cluster grid-connected system is obtained. Then, the influence mechanism of the grid structure on the resonance is analyzed. Finally, it is verified by simulation that the change of the grid structure will cause the change of the resonant frequency distribution of the distributed photovoltaic cluster grid-connected system.