Research On Technology Of Environmental Energy Harvesting Based On Cantilever Beam In Low Frequency Environment

The device which picks up energy from environment is called energy harvester.The piezoelectric energy harvester has the best performance among common energy harvesters(electrostatic energy harvesters,electromagnetic energy harvesters and piezoelectric energy harvesters).In this paper,a novel E-type piezoelectric trapping energy structure based on cantilever beam is proposed,and its mathematical model of energy conversion is established to discuss its vibration characteristics,power generation performance and piezoelectric energy collection circuit.Specific performance of the following aspects:In this paper,the principle of power generation of piezoelectric energy harvester is analyzed,and the energy conversion mathematical model of piezoelectric capture energy meter is established by piezoelectric constitutive equation.The effects of load,piezoelectric material,substrate and thickness ratio on the output performance of piezoelectric energy harvester were studied by MATLAB and ANSYS software.The results show that when the piezoelectric material is PZT7,the material of the substrate is copper,the ratio of the thickness of the substrate to the thickness of the piezoelectric sheet is 0.4,piezoelectric energy harvester can get higher output voltage at the lower resonant frequency.When the intrinsic impedance of the piezoelectric energy harvester matches the load impedance,its output power is maximum.A novel E-shaped piezoelectric energy harvester(EPEH)was proposed.The static analysis,modal analysis and harmonic response analysis of EPEH were discussed by using the Finite Element Analysis.When the degree of freedom is 7,the maximum output voltage of E-type piezoelectric actuator is 7.72 V,increased by 33.6%.And the maximum voltage plane density is 1.055V/cm~2,increased by 118.9%.And the 6dB bandwidth which represents capability of broad-band energy harvesting increased 250%.The LTC3588-1 integrates a low-loss full-wave bridge Rectifier with a high efficiency buck converter to form a complete energy harvesting solution optimized for high output impedance energy sources such as piezoelectric.Four output voltages,1.8V,2.5V,3.3V and 3.6V,are pin selectable with up to 100 mA of continuous output current.