Power Line Coupling Power Supply for Early Wildfire Detection Sensor

In this project, a power supply was designed to detect wildfires with the use of distributed sensors across power lines. The purpose of the power supply is to provide 15W of power to a microcontroller, which controls the sensor nodes. The power supply hangs from power lines and draws energy by inductively coupling to these lines. The design starts with a current transformer that steps down the current from the power line, which is fed into a shunting mechanism as a safety precaution when the load is absent, then to the power supply itself. The power supply design uses a full wave bridge rectifier, SEPIC DC-DC converter, and filters to output the desired power while maintaining a set output voltage with as little ripple as possible. Based on the simulation results, our design had an output voltage peak to peak ripple of 36mV, was able to successfully supply a load of 15W at 5V and had less than 3% load and line regulations. However, the highest overall efficiency did not exceed 66%, and so recommendations are provided to further improve this design.