Energy harvesting using piezoelectric transducers for suspension systems

Energy harvesting by using functional materials in suspension systems bear potential to win-back certain (even if low) amounts of vibrational energy, otherwise dissipated via the conventional (passive) dampers. Piezoelectric (PE) ceramics are functional materials that can be used for transforming mechanical energy into electrical and vice versa. In this paper, we study the capabilities and efficiency of energy harvesting (EH) with PE transducers under two different kinds of external excitation: i) Periodic and ii) stochastic. An appropriate nonlinear lumped parameter electromechanical model (LPEM) is brought into the two-port network notation. Laboratory experiments were conducted under periodic external force-controlled excitation performed on a universal test machine (UTM). The two-port model parameters were identified and the model was validated by comparing results of numerical simulations and experiments. Extended simulations have been conducted to investigate the EH capabilities of PE transducers in automotive applications, i.e. EH in suspension systems under the standardized road conditions. The analysis results of the power conversion and EH efficiency are presented and discussed.