Generator optimization for roadway energy harvesting system

Road infrastructure energy harvesting, which utilizes energy harvesters installed under speed bumps, is an emerging area of research. While many researchers have focused on electromagnetic energy harvesters, a gap remains in the methodology for selecting generators and exploring new technologies. This study presents a step-by-step approach to choosing the optimal generator for a speed bump energy harvester, particularly under low-displacement and low-frequency conditions. It examines advanced generator technologies, including the Brushed DC generator, Reluctance generator (RG), and a combination of Brushless DC (BLDC) and RG generators. Experiments conducted both in the lab and in the field using an MTS system, with human and vehicle loads, show that the combined configuration performs best, producing 500 mJ at 1 Ω for a 65 kg human step load. Additional tests in the field demonstrate that the same setup generated 1.1 J with a 1500 kg car load, with an average power density of 392 W/m³. Overall, the combined configuration proves effective in identifying suitable generators for low-displacement and low-frequency energy harvesting applications, offering a viable solution for real-world use.