Design and Implementation of a Microcontroller-Based Solar Inverter for Efficient DC–AC Conversion

Abstract

Solar inverters are critical components in PV systems, converting the DC from solar panels into AC power for loads or grid use. In this work, a 500 W single-phase inverter is designed using a PIC16F877A microcontroller to generate sinusoidal PWM (SPWM) signals for an H-bridge inverter. The microcontroller’s digital control replaces many analog components (comparators, counters, ADCs), simplifying the hardware and enabling advanced control functions. Detailed simulation and experiments demonstrate a peak efficiency of 92.2% and output THD of 4.83% at 230 VAC/50 Hz under full load, meeting typical grid standards (THD<5%). For context, similar advanced inverter designs have reported efficiencies >98% and sub-5% THD, so the results compare favorably. The prototype produces a clean sine wave (see Fig. 3) and maintains stable output voltage (±2% deviation). These results confirm that a compact microcontroller-driven inverter can achieve high efficiency and low distortion, validating the approach for efficient DC–AC conversion in renewable energy systems.