Design and Development of a Smart Solar PV Fault Detection and Protection System using IoT

Solar photovoltaic (PV) systems can experience abnormal conditions that reduce electrical output and may affect safe operation. Manual inspection is not suitable for continuous monitoring because a fault may remain unnoticed until the system is checked. This work presents a compact IoT-enabled solar PV monitoring and protection system based on an ESP32 microcontroller. An INA219 sensor is used to obtain PV voltage and current, while a DHT11 sensor measures ambient temperature and humidity. An LDR is also installed to sense relative changes in incident light. The controller processes the sensor readings and identifies four conditions considered in the prototype: open circuit, short circuit, over-temperature, and partial shading. When an abnormal condition is identified, the system provides a local indication through a 16 × 2 LCD and buzzer and controls a relay to isolate the affected PV path. A battery-backed supply is included to support the load during the isolation period. The measured parameters and fault status are made available through a Wi-Fi-based remote dashboard. The developed prototype was tested under normal operation and intentionally created fault conditions. The available hardware and dashboard observations demonstrate the integration of PV monitoring, fault indication, isolation, backup supply and remote status reporting in a single small-scale prototype. Quantitative performance claims require additional calibrated and repeated measurements.