Design & Real-Time Field Implementation of Micro-Inverter for Rural Applications

Need for comprehensive development of photovoltaic (PV) based micro-inverter interface for various rural applications is observed. This paper demonstrates the design, development, and real-time field experimentation of an energy-efficient, PV based single-phase micro-inverter for rural/remote applications. The proposed dual-stage single-phase inverter takes the advantage of interleaved DC/DC boost converter for cancellation of 180 ο phase-shifted harmonics and application of voltage doubler circuit results in a reduction of the transformer turns ratio with low flux leakage and thus endeavoring for better conversion efficiency at a reduced size of magnetics. Further, high-frequency switching at the first leg and low switching frequency at another leg of the full-bridge converter ensures lower switching losses at light load conditions. Experimental results are carried out at field location (latitude: 26.431°, longitude: 74.707°) in Rajasthan, India. The interleaved boost DC/DC converter efficiency is found approximately 91.73% at full load and 77.74% at 10% load. Micro-inverter overall efficiency is observed in between 57.34% to 91.6%.