Fan-structure wind energy harvester using circular array of polyvinylidene fluoride cantilevers

Abstract

A fan-structure piezoelectric energy harvester was proposed and tested in order to collect wind energy. Polyvinylidene fluoride was chosen due to its flexibility and longevity when compared to lead zirconate titanate. The impact-induced piezoelectric energy harvester consists of a stator and a rotor and a circular array of four cantilevers, utilize the rotor blades’ periodic impact on the free end of the cantilevers to generate oscillatory motion of cantilevers. A circular array of polyvinylidene fluoride cantilevers was fixed around the rotor in order to increase output power, save space at the same time. Static and transient characteristics of different cantilevers were investigated using finite element method and the result showed that polyvinylidene fluoride triangular cantilever performs the best in output voltage and power. Under the condition of optimal impedance and optimal overlap distance, a sum AC output power of four cantilevers without connection to each other approach to 0.75 mW was measured at the wind speed of 7 m/s when the blade number of rotor is 7 or 9. Two branches 0.27 mW DC output power was obtained when each two cantilevers in parallel connection in the case of full-wave rectification of each cantilever at the wind speed of 7 m/s.

Gerador Rotacional Piezoelétrico Baseado No Conceito De Colheita De Energia

“…Dentre eles, o PZT (Titanato Zirconato de Chumbo) possui propriedades intermediárias em relação à fadiga mecânica e às propriedades piezoelétricas. (AVIRIVOK e KISHORE, 2015) (FU, 2018) (CHEN, LAW, et al, 2017) (YANG, ZHOU, et al, 2018) (BAI, SONG, et al, 2016 (MADHU P, 2016) (CHENG, LIU, et al, 2018) (FU e YEATMAN, 2017).…”

Design and experimental study of a rotational piezoelectric energy harvester

“…Regarding piezoelectric materials, the type of application defines the material whose mechanical and electrical properties are most suitable. The PZT (Lead Zirconate Titanate) has intermediate properties in relation to mechanical stress, and piezoelectric properties, however, it cannot capture considerable mechanical energy if they are directly coupled to the vibration structure, therefore, a common configuration is attached the piezoelectric element to a flexible sheet/surface, creating a piezoelectric beam [5][6][7][8][9][10][11][12][13][14][15][16].…”

Experimental Analysis of the Arrays of Macro Fiber Composite Patches for Rotational Piezoelectric Energy Harvesting from a Shaft

“…Energy harvesting can be also realized by the use of a patch of piezoelectric material, which is directly glued onto the rotating element, e.g., a Macro Fiber Composite (MFC) glued onto a shaft [7]. The second category includes harvester structures based on an array of elements containing piezoelectric material, also most often a cantilever beam, e.g., two cantilevers [8], two clamped-clamped beams [9,10], three cantilevers [11][12][13], four cantilevers [14][15][16], six cantilevers [17], eight cantilevers [18,19], nine cantilevers [20] or twelve cantilevers [21,22]. The greater number of elements with piezoelectric material, the larger amount of electric energy can be harvested.…”

“…Several piezoelectric elements, which are not equipped by a full-bridge rectifier, may be parallel or series, connected only when they generate the same or opposite voltage [14]. Piezoelectric elements, each of which is equipped by a full-bridge rectifier, may be parallel [8,9,15] or series [9], connected independently from generated waveforms of voltage. It can be noticed that the number of used full-bridge rectifiers is equal to the number of piezoelectric elements.…”

“…MFC patches were connected by the use of a star circuit (similar to [12,13]) and a delta circuit, which is a second way to connect three electrical sources with a three-phase rectifier. The star and delta circuits were compared with three full-bridge rectifiers connected in parallel and in series, a practice which is often reported in the literature, e.g., [8,9,15]. In contrast to what is presented in the results of the literature, MFC patches were connected by the use of a delta circuit and electrical responses for energy harvesters, with the delta circuit of MFC patches compared with both the electrical responses of energy harvesters with star circuits, and with the electrical responses of energy harvesters with three full-bridge rectifiers connected in parallel and in series.…”