Performance Evaluation of a Micro-Inverter System using Localized Pulse Width Modulation (PWM) Control for Rural Off-Grid Application

Rural electrification in Sub-Saharan Africa, especially Nigeria, is still running into persistent issues, with high infrastructure cost, efficiency losses that come from shading, particularly when string inverters are used. And imported equipment often struggles with thermal instability once it is exposed to tropical climates. In this study the design, prototyping, and performance evaluation of a 300 W localized micro-inverter, built around adaptive Pulse Width Modulation (PWM) control for rural off-grid settings was carried out. The inverter architecture leans on locally available components like ATmega328P microcontrollers and IRF3205 MOSFETs, while the control logic actively tunes switching frequency (15–25 kHz) and duty cycle based on both load and thermal feedback. In laboratory testing, the Total Harmonic Distortion (THD) stayed around 2.8–4.6%, conversion efficiency remaint at 87.5–93.2%, and the designed unit remained stable in 35–40 °C ambient temperature. When benchmarked against imported modified sine wave inverter, the prototype showed better harmonic quality, efficiency, and appliance friendliness, in other words it performs efficiently. Overall, the results suggest local adaptive PWM micro-inverters can meet IEEE 519, thrive well in tropical stress, and remain a cost-effective route for sustainable rural power.

Keywords: Rural electrification, Micro-inverter, Localized PWM, Harmonic distortion, Thermal stability, Nigeria.