Piezoelectric method-based harvested energy evaluation from car suspension system: Simulation and experimental study

The main objective of this work is to build a mathematical model to evaluate the potential of harvesting power from the car suspension system. Quarter- and half-car models with built-in piezoelectric stack were modeled mathematically and simulated using MATLAB/Simulink. The piezoelectric stack was installed in series with the suspension spring to maintain the performance of the original car suspension system in ride quality and comfortability. The harvested voltage and power were tested with respect to time and frequency. From a half car model, the maximum generated voltage and power at the excitation frequency of 1.46 Hz were 33.56 V and 56.35 mW, respectively. By comparing a half-car model with the quarter-car model, the outcomes illustrated that the harvested voltage and power of the half-car model were increased by 75.6% and 53.4%, respectively. Piezoelectric stack parameters (number of stack layers and area to thickness) and the car suspension parameters (sprung and unsprung stiffness, damping coefficients, and masses) were examined for half-car model. Also, the influence of road amplitude unevenness was considered. The simulation results of the quarter-car system were verified with the experimental test under harmonic excitation. The results exhibited good agreement with the simulation results at different excitation frequencies.