Design And Experimental Research Of An Energy Harvesting Device With Serial-connected Piezodiscs

The piezoelectric energy harvesting device is used to convert mechanical energyto electrical energy by piezoelectric effect. The energy conversion process of thisdevice is easy to achieve, and its structure is simple and various such as the cantileverpiezoelectric energy harvester, the discal piezoelectric energy harvester. Moreover, thepiezoelectric energy harvesters also have the advantages of anti-electromagneticinterference, high stability, high energy density, no pollution, etc. Compared to thecantilever piezoelectric energy harvester, the discal piezoelectric energy harvester hasthe traits of high strength, high resonance frequency and low power, so in this paper,an energy harvesting device with serial-connected piezodiscs will be presented tolower the resonance frequency and increase the total generating capacity. Thereinto,the foundation vibration energy harvesting device with serial-connected piezodiscs isput forward to harvest the environmental vibration energy, and the energy harvestingdevice with serial-connected piezodiscs drived by magnetic force is presented tosupply power to the sensor detection system of the rotator, such as the helicopterpropeller, TPMS, Oil and gas drilling spindle, etc. The main content of this paper is asfollows:1. IntroductionThis paper firstly introduced the working principle, research significance,overseas and domestic research status of the piezoelectric energy harvesting device,and then some application example are showed to analyze their merit and demerit. Inview of the demerits of the previous study, an energy harvesting device withserial-connected piezodiscs which has low resonance frequency, high strength andhigh power is proposed.2. Structural Optimization and Analysis of PiezodiscThe piezodisc is the fundamental work unit of the energy harvesting device withserial-connected piezodiscs, and its working performance directly determines theworking performance of the total system. When the boundary conditions, loadingforms are given, the working performance of the piezodisc is determined by itselfstructure and material parameters, etc. In this paper, the mathematical model of the piezodisc which is under the condition of clamped boundary and centre-line load isestablished. Then, the influence of the thickness ratio, radius ratio and Young’smodulus ratio to working performance is researched by Numerical simulationanalysis and ANSYS emulation analysis. When the total diameter is32mm, the totalthickness is0.55mm, and the baseplate material is Aluminum or beryllium bronze, thebest thickness ratio and radius ratio of the piezodisc are achieved.3. The Mathematical Model Establishment and Simulation of the EnergyHarvesting Device with Serial-connected PiezodiscsAccording to different work situations, two kinds of energy harvesting devicewith serial-connected piezodiscs are proposed. Then their working principle isintroduced and their mathematical model is established. The influence rule of drivingfrequency, mass and the number of the piezoelectric drum transducer to thefoundation vibration energy harvesting device with serial-connected piezodiscs arefound by numerical simulation analysis. And then, the influence rule of the magneticpole gap, the size of the magnet, rotor speed, and the number of the piezoelectricdrum transducer to the energy harvesting device with serial-connected piezodiscsdrived by magnetic force are also found by numerical simulation analysis.4. The Manufacture and Experimental Measurement of the EnergyHarvesting Device with Serial-connected PiezodiscsTwo kinds of energy harvesting device with serial-connected piezodiscs aredesigned and manufactured respectively, and then according to their workingsituations, different test systems are established. By experimental measurement, theinfluence rule of driving frequency, mass, the number of the piezoelectric drumtransducer, the connection types electrically to the foundation vibration energyharvesting device with serial-connected piezodiscs, and the magnetic pole gap, thesize of the magnet, rotor speed, and the number of the piezoelectric drum transducerto the energy harvesting device with serial-connected piezodiscs drived by magneticforce are found.