Inspection of interharmonic emissions from a grid-tied PV inverter in North Sweden

Abstract

The main objective of the paper is to investigate the existence of interharmonic emissions from an MPPT driven grid-connected PV inverter, identify their severity and persistence. The presence of interharmonics in the measured current from a PV installation is linked to direct and diffused solar irradiation as well as a high ramping rate of the irradiation causing variations in both active and reactive power. The paper sets forth a set of observations and inferences, which is an appendage to the ongoing research on the power quality aspects of solar power. Three different case studies are evaluated in detail using signal processing tools like STFT and FFT.