Common Mode Interference Modeling and Measurement for Cascaded Photovoltaic Grid-Connected System Module

Modular design and medium voltage grid connection are the mainstream of large-scale photovoltaic power generation system in recent years. Investigation of the electromagnetic interference (EMI) characters of cascaded modular photovoltaic system is the basis for the implementation of electromagnetic compatibility (EMC) design. This paper analyzes the coupling mechanism of common mode interference in the module units of cascaded photovoltaic grid-connected system. On this basis, a common mode coupling model of multi-winding transformer and a high-frequency common mode interference model of module unit are proposed. The measurement results on a prototype verified the proposed model.