Dual Target Design Of Energy Harvesting And Vibration Suppression Of Piezoelectric Energy Harvester

Piezoelectric vibration energy harvester scavenges vibration energy in the environment and converts it to electrical energy through the piezoelectric effect,which is of great significance to sensor networks with small energy consumption,large quantity and wide distribution.In this paper,we improve the power extracting performance of the galloping piezoelectric energy harvester by adjusting the circuits.Two kinds of simple resistive-inductive-capacitive(RLC)circuits which can improve the energy collection efficiency are introduced.For the new energy harvesting systems,the electromechanical coupled distributed parameter models are proposed.Using the Galerkin procedure considering the first mode to simplify the electromechanical coupled models.Then using the method of equivalent structure to decouple the electromechanical coupled models,and validate the decouple model through the numerical results of the distributed parameter model.The analytical solutions including the modified frequency,electrical damping and harvested power are derived during the decoupled process.The analytical solutions of the electrical damping for galloping,optimal electric damping and beam displacement are derived based on the decoupled model.The optimal energy acquisition efficiency is obtained when the electrical damping equal to the optimal electrical damping.The combination of resistance,inductance and capacitance satisfying the optimal electric damping is determined by using the decouple model.The relationship between the optimal energy acquisition efficiency and the maximum energy acquisition efficiency with the change of resistance,inductance and capacitance under different wind speeds is determined.The analytical expressions of critical resistance and maximum electric damping corresponding to two simple circuits are given.These results show that the power acquisition efficiency can be greatlyimproved by adjusting the circuit parameters,and the inductance can be reduced to the applicable range.Based on the study of the galloping piezoelectric energy harvester,piezoelectric energy harvester is a kind of energy dissipation mechanism,so it can be used as a damping factor in the dynamic vibration absorber.In this paper,a dynamic vibration absorption device is designed based on piezoelectric energy harvester.Two kinds of electromechanical coupling Hamilton’s equation are given based on the Hamilton’s equation of dynamics and electricity.The electromechanical coupling control equation of this structure is given by the electromechanical coupling Hamilton’s equation,then the equation is simplified by Gaussian law and so on.The simplified method is verified by comparing the parameters before and after simplification of the control equation.By using the simplified control equation,the numerical solution of vibration suppression and energy collection of the structure is given.Research shows that the dynamic vibration absorber based on a piezoelectric energy harvester can not only effectively reduce the vibration of the main vibration system,but also convert the vibration energy into electrical energy through the piezoelectric effect,achieved the purpose of double target design.The time history,phase portraits,power spectrum and Poincaré sections at different frequencies are presented.Based on these nonlinear analysis methods,the nonlinear characteristics of the dynamic vibration absorption device are analyzed.According to these photos,superharmonic,quasi-periodic motion,period-3 motion and two different forms of chaos are found.Finally,the nonlinear phenomenon of the dynamic vibration absorption device is proved by experimental data.