Magnetic field optimization of an axial flux permanent magnet energy harvester

A self-sufficient power supply is a key challenge for sustainable and low-maintenance systems in various applications, such as IoT devices and wireless sensor networks. This paper presents an electromagnetic energy harvester based on a directly driven axial flux machine that converts ambient kinetic energy into electrical energy. The focus is on optimizing the magnetic circuit to maximize energy efficiency. Through targeted dimensioning and optimization of the magnetic circuit, a sufficient voltage for efficient operation was achieved. The developed design guidelines were validated through 3D-FEM simulations and experimentally verified. Measurements show a generator efficiency of 0.70, enabling efficient energy conditioning for a wide range of applications. The results indicate the potential of the proposed electrical machine for scalable and application-optimized energy harvesting solutions.