Efficient optimal load and maximum output power determination for linear vibration energy harvesters with a two-measurement characterization method

Abstract

This paper presents a new characterization method allowing to efficiently characterize vibration energy harvesters (VEH). It enables to determine for example the optimal electrical loads at any frequency or the maximum output power; and this with only two measurements (two frequency sweeps on a shaker with two well-chosen electrical loads). This technique, while being timeefficient, greatly simplifies the determination of the maximum output power of VEH without requiring a measurement of the output power with many resistors; it is also compatible with finite element simulations. The proposed methodology has been tested and validated on a piezoelectric VEH.

Non-linear losses study in strongly coupled piezoelectric device for broadband energy harvesting

“…As discussed in [25], the electric field must be considered variable across the patches thicknesses for strongly coupled piezoelectric materials. Then the expression of the transverse electric field is given by (16) where is the flux leakage as introduced in [26] and expressed in (17).…”

“…The linear losses of piezoelectric materials have already been studied in the prior art for various piezoelectric devices [15,16]. As an example, Uchino et al expressed the necessity to consider a piezoelectric loss tangent coefficient especially for actuator applications [17].…”

A new approach to design electromagnetic transducers for wideband electrically-tuned vibration energy harvesting

“…Indeed, as shown in Zhu et al (2012), the addition of a supplementary capacitance C s = 1= L c v 2 ð Þin series with L c allows us to cancel the impedance of both inductance and capacitance, thus making the assumption true regardless of the value of L c . By passing the system (3) into the frequency domain, where v, i, and a are the complex notations of v, i, and a respectively, v can be expressed as a linear combination of i and a, as shown in (4) and in Freychet et al (2020).…”

“…By passing the system (3) into the frequency domain, where v true¯ , i true¯ , and a true¯ are the complex notations of v, i , and a respectively, v true¯ can be expressed as a linear combination of i true¯ and a true¯ , as shown in (4) and in Freychet et al (2020).…”

“…Following the same development as in equations (1)–(7) from Freychet et al (2020), where the maximum harvestable power is expressed in the resistive-reactive case and the purely resistive case, equation (8) gives the maximum harvestable power P ( normalω ) for any VEH with an adjustable resistive-capacitive load. An analytical expression of (8) is given as (17) in Appendix A.…”