Vibration Characteristics And Efficiency Analysis Of Adjustable Piezoelectric Energy Capture Systems

Vibration energy collection has been widely welcomed by researchers because of its green pollution-free,renewable,and capabilities of collecting very small energy.It has become a hot issue in recent years.Researchers mainly use piezoelectric cantilever devices to convert mechanical energy into electrical energy for vibration energy harvesting.Compared to traditional energy harvesting methods,piezoelectric energy capture has the advantage of collecting small,variable,and unpredictable energies.In this paper,the energy harvesting characteristics of the nonlinear cantilever beam system under random excitation are studied.In the cantilever beam system,the movable electromagnet is innovatively added,and the mathematical model is established by the method of decomposition of beam force and finite element.In terms of random excitation,this paper considers the effects of Gaussian white noise excitation,band-limited white noise excitation,exponential colored noise excitation and narrow-band random excitation on the cantilever beam system.Subsequently,this paper uses the FPK equation to analyze the mathematical model.It is concluded that the output voltage is only related to the load resistance,the electromechanical coupling coefficient,the intensity of the noise and the magnitude of the damping when the capacitance is small enough,which is independent of other quantities.Finally,the model is numerically simulated using MATLAB.Firstly,we analyze the dynamic behavior of the system under periodic excitation.Then we use two methods to simulate white noise and colored noise,and study the output voltage and time under random excitation.In the end,we studied the energy collection efficiency of the movable electromagnet at different positions,and obtained the highest energy harvesting efficiency.