Efficient PV-Based Microinverter With Enhanced ROI for Lower Economic Zone Habitants

Abstract

In this article, the conceptualization, design, development, and real-field validation of a photovoltaic (PV)-based single-phase microinverter (SP $\mu \text{I}$ ) to address three major challenges of rural standalone PV-based electrical systems: 1) to perform efficiently over a wide range of input voltage variations/irradiance; 2) maintains system efficiency within a satisfactory limit even under lightly loaded conditions; and 3) robust and stable operation under harsh/outdoor operating environments has been done. The developed novel dual-stage SP $\mu \text{I}$ adapts the benefits of the interleaved dc–dc boost converter for 180° phase-shifted harmonic cancellation and integration of voltage doubler circuit benefits in lessened transformer’s turn ratio with decreased flux leakage, thus resulting in improved energy conversion efficiency at a reduced magnetic size and Si-GaN. Furthermore, adapted high- and low-frequency switching at the first and second legs of the full-bridge converter, respectively, ensures minimized switching losses even at lightly loaded conditions. Based on a per watt comparison to a 500-W inverter, the proposed SP $\mu \text{I}$ achieves 6.16% and 8.5% higher efficiency at 100% and 10% loading, respectively, at a reduced cost of 9.33% and an increased return on investment (ROI) of 12.23%.