Analysis of piezoelectric energy harvesting system with tunable SECE interface

Abstract

Numerous interface circuits have been proposed over the past years to improve the performances of piezoelectric energy harvesting devices. The so-called synchronous electric charge extraction interface (SECE) brought the advantage of harvesting power independently of the load voltage. In counterpart, its performances exhibited sensitivity to the electromechanical coupling. It was shown, in particular, that harvested power was significantly decreased at high coupling. To overcome this drawback, the so-called tunable SECE interface has recently been proposed. Instead of the total charge extraction performed by the original SECE, the tuning method consists in extracting only a portion of the electric charge. This paper presents the analytical modeling of an energy harvesting system composed of a linear piezoelectric resonator associated to the tunable SECE interface. Contrary to previous model limited to describe the system behavior at resonance, this model enables to extend the analysis off-resonance. The presented theoretical analysis and experimental results clearly show the possibility to increase both the power and the frequency bandwidth by adequate control of the tunable SECE interface.

A unified N-SECE strategy for highly coupled piezoelectric energy scavengers

“…Moreover, as it will be shown in the experimental part, the N-SECE allows to have good performances with only a few values. Our PEH (Table 2) [2Nf %&' , 0,0] ^W_`= 2`d e ^W_`= 0 = 0 (22) Figure 18 summarizes the power responses of our harvester with state of the art interfaces (SECE [4], tunable SECE [9], phase-shifted SECE [16]), the proposed N-SECE, and the standard electrical harvesting interface SEH whose diode bridge's output voltage has been optimized for every point of Figure 18. Due to the high coupling and low damping of our harvester ( / ( / = 16), the SECE overdamps the system, as explained previously.…”

“…The piezoelectric harvester is fixed on the shaker, and its speed, displacement, and voltage waveforms are recorded for any couple of parameters ( , ). A N-SECE interface circuit made of off-the-shelf discrete components has been realized in order to FoM N-SECE (this paper) Standard interface (SEH) [2] SECE [4][5][6][7] Tunable SECE [9][10] Phase-shift SECE [16] Our PEH ( The highly coupled PEH is composed of two 10×5×0.5 mm 3 single crystal PZN-PT plates deposited on a cantilever beam. This PEH characteristics are summarized in Table 2.…”

“…single crystal, piezoelectric harvesters may now exhibit much higher electromechanical coupling associated with low mechanical damping. For this particular kind of PEH, SECE strategy is not well adapted since it overdamps the mechanical resonator, leading to low displacements and harvested energy [7,8].Some research has been conducted to investigate new efficient strategies that could be used for highly coupled PEH, in order to optimize the damping induced by the electrical interface [8][9][10]. Indeed, in [8], we proposed to wait a certain number of semi-period before harvesting the accumulated energy in order to reduce the damping induced by the electrical interface.…”

Development of Piezoelectric Harvesters with Integrated Trimming Devices

“…On the other hand, some preliminary results [35] showed that the second mode of the harvester has a natural frequency much higher than the first and a very small effect on low frequency dynamics. For these reasons, only the first mode of vibration (i = 1) is considered in Equations (10)- (12). The FRFs of the prototype can be calculated considering the harmonic base excitation:…”

“…Several technical solutions have been developed to cope with these working conditions. Some researchers have proposed dynamically tunable harvesters, in which tuning can be achieved both by means of the interface circuit [11,12] and by mini-actuators that modify the mechanical system [13]. Other researchers have developed wideband harvesters.…”