A Model of a Magnetically Sprung Vibration Generator for Power Harvesting Applications

This paper presents a new topology for a magnetically sprung electromagnetic velocity damped resonant generator for applications in harvesting energy from mechanical vibrations. It is demonstrated that the use of a magnetic suspension can achieve a low compliant spring rate required for optimal operation of a small resonant generator at low excitation frequencies. Similar characteristics can be difficult to achieve using a conventional mechanical spring. A model of the vibration generator is described and is based on an electrical equivalent network. Analytical expressions are used to determine the network components as functions of the generator geometry and material properties. These are validated through experimental measurements taken from a prototype generator. The model is to be used in the design optimization of such generators.