A Review of Photovoltaic Inverter Topologies: Addressing Practical Design Constraints

Abstract

The rapid growth of solar photovoltaic (PV) systems has increased the need for efficient, reliable, and sustainable inverter solutions for reduced levelized cost of electricity (LCOE). This article reviews practical design issues associated with central PV inverters, focusing on challenges, such as leakage current, potential induced degradation, power imbalance, and reliability concerns, in medium and high-power inverter configurations. A comprehensive assessment of transformerless and multilevel inverter topologies has been carried out. These include neutral point clamped (NPC), flying capacitor, cascaded H-bridge (CHB), modular multilevel converters (MMC), and hybrid topologies. Their structural characteristics, device count, losses, and power quality are compared under standardized conditions. Special attention is given to asymmetric CHB (ACHB) and level doubling network-based hybrid topologies that can deliver high-resolution output with reduced switching losses and improved efficiency. Simulation results verify that hybrid ACHB and MMC structures offer superior harmonic performance and lower conduction losses. Because of this, they are seen as better options for future PV power plants. The review highlights current research trends and identifies pathways for developing next-generation inverters with improved efficiency, reliability, and reduced LCOE.