Investigation of vibrations energy harvesting from vehicle suspension system and modeling using electrical equivalent circuits

The objective of this paper is to investigate the vibrations’ energy harvesting from car’s suspensions using piezoelectric harvesters connected in parallel or in series with the suspension’s spring. A quarter car model is utilized to study the suspension’s dynamics and evaluate the energy harvesting capabilities. The novelty of this research work consists in utilizing lumped electrical equivalent circuits for both suspension system and piezoelectric harvester. The complete equivalent circuit is implemented in LTspice simulator. The simulations done for a piezoelectric stack connected in series with the suspension’s spring indicated that, the maximum harvested voltage and power are obtained at the suspension’s first natural frequency 1.45 Hz. At this frequency, when the suspension is excited by a harmonic acceleration of 1g (9.8 m / s
²
) the harvested voltage and power are 25.74 V and 66.2 mW respectively. Also, it is observed that, the connection of the harvester in series does not affect the suspension’s dynamics. Finally, it is shown that, the effect of the harvester’s dissipation (mechanical, piezoelectric, and dielectric losses) is negligeable: about 0.7 % and 1.15 % of voltage and power difference respectively.