Design of high-efficiency microinverter for a photovoltaic system with low harmonic distortion

Abstract

This article presents the design of a modular pure sine wave microinverter with a high-efficiency maximum power point tracking (MPPT) regulator for photovoltaic (PV) systems. The design starts with a DC/DC buck-boost chopper regulator, simulated using the perturb and observe (P&O) algorithm. Next, a high-frequency DC/AC conversion stage is implemented using a toroidal transformer to achieve various voltage levels and isolated power sources. Finally, a 27-level multilevel inverter is designed to produce a pure sine wave with minimal total harmonic distortion (THD). Simulation results indicate that the microinverter achieves a total efficiency of 90% and produces a pure wave output with 3% harmonic distortion. Compared to commercial solutions, the proposed design enhances efficiency while integrating key components. Additionally, the system maintains a cost-effectiveness and directly proportional to its energy efficiency, making it a viable and cost-effective solution for PV energy conversion.