Current Harmonics Suppression of a Grid-Connected PV-Integrated with Energy Storage System

As the penetration rate of photovoltaic (PV) power generation increases, significant challenges arise concerning the power quality of the power system. The uncertainty of PV output can result in issues such as high levels of harmonic components and waveform distortion. This paper presents a novel approach to mitigate current harmonics in a grid-connected PV system (PVs), which utilizes a voltage and current double closed-loop PI (VCPI) control. Subsequently, the stability of system is confirmed through an examination of the Bode and Pole-Zero diagrams of both the proportional resonant (PR) and PI controller, and the efficacy of the control strategy in suppressing current harmonics with varying light intensities is investigated. Furthermore, a grid-connected PV-integrated with energy storage system (PV-ESs) is utilized to mitigate current harmonics, examining the influence of PV and energy storage system (ESs) output on the harmonic characteristics of the grid current of PVs. The simulation model of grid-connected PVs and P -ESs are fabricated, respectively, validating that the current harmonic characteristics of the grid-connected PV-ESs are 0.37% lower than those of the grid-connected PVs.