Modeling and Analysis of Multi-source Spectrum in PV Inverter Considering EMI Accumulation Effect

High voltage, high-power PV inverters contain multiple power electronic converters, all of which emit EMI. Multi-source coupled EMI has accumulation effects and may exceed EMC limits. The existing EMI modeling methods do not take into account the accumulation effect of EMI emitted by different sources. This will cause significant errors in the prediction. In this paper, the CM frequency domain models of multiple converters in PV inverters are first investigated. A multi-source coupled EMI spectrum is predicted. Second, based on the EMI receiver model, the accumulation effect of multi-source EMI is explained, and the effect of the EMI source phase on the accumulation is discussed. Finally, the multi-source EMI model and analysis of the accumulation effect are verified on a commercial PV inverter.