Probing Leakage Current Suppression Techniques for Non-Isolated Photovoltaic Inverters

Abstract

The evolution of photovoltaic (PV) inverters has witnessed distinct trade-offs between isolated and non-isolated configurations. While isolated PV inverters grapple with challenges such as increased volume and suboptimal system efficiency due to transformer inclusions, their non-isolated counterparts offer a solution by eliminating these transformers. However, this lack of electrical isolation in non-isolated inverters engenders a distinct predicament: significant leakage currents. Such currents not only impede system operation but also curtail operational efficiency. Recognizing this, the suppression of leakage current has catapulted to the forefront of contemporary research. This manuscript elucidates the operational intricacies of non-isolated PV inverters. It then embarks on a panoramic review of prevailing leakage current suppression techniques, both domestic and international, contextualizing them with state-of-the-art inverter topologies such as the H7, H10, three-level neutral point clamped (NPC) and three-phase four-bridge arm configurations. The paper culminates with a prospective glance at future research trajectories in leakage current suppression, proffering seminal recommendations for academic and industry fraternities.