An investigation on the magnetic interaction for frequency up-converting piezoelectric vibration energy harvesters

This work presents an investigation of different approaches for modelling the magnetic force between permanent magnets for realizing the frequency up-conversion (FuC) in piezoelectric vibration energy harvesters (PVEH). Different analytical models are compared with finite element analyses (FEA). After the investigation, the FuC mechanism is applied on a meso-scale case study and dynamic analyses in the time domain are performed in case of harmonic monochromatic acceleration signal on the device at low-frequency. Both the repulsive and the attractive layouts of the magnets are considered and a larger amount of power is recovered in case of repulsive configuration.