Leakage Current Suppression Strategies for Non-Isolated Photovoltaic Inverters: Topology Improvements and Performance Analysis

Non-isolated photovoltaic inverters are widely utilized in small- and medium-scale distributed photovoltaic power generation systems. However, the issue of leakage current remains a significant challenge, impeding their further development and application. This paper presented a detailed circuit model to describe the leakage current phenomenon in non-isolated photovoltaic inverters. Additionally, an analysis was provided to identify the key factors contributing to leakage current. Following this, the paper reviewed and evaluated recent advancements in leakage current suppression strategies, particularly those involving improvements in circuit topology. The analysis covered two innovative single-phase inverters and three advanced three-phase inverters. Finally, this paper discussed the challenges associated with emerging non-isolated photovoltaic inverters and offered insights and recommendations for future research aimed at improving leakage current suppression.