Research On Magnetic Levitation Based Low Frequency Vibration Energy Harvesting Technology

With the continuous progress of microelectronics technology,wireless sensor networks are utilized extensively in structural health monitoring,environmental protection,intelligent agriculture,medical monitoring,and other fields.However,an unavoidable issue is that the chemical batteries used to power wireless sensors have drawbacks such as limited life,low energy storage,and the need for regular replacement,which severely limits the application of wireless sensor networks.Vibration energy harvesting technology converted convert the ambient vibration energy into electrical energy to power low-power electronic devices using electromagnetic,piezoelectric,electrostatic,and triboelectric energy conversion mechanisms,which is an ideal solution to replace chemical batteries and achieve sustainable power supply.Based on the recent research of energy harvesting technology,the research on lowfrequency vibration energy harvesting technology is carried out around magnetic levitation technology,and the magnetic levitation-based electromagnetic vibration energy harvesting technology,the magnetic levitation-based piecewise nonlinear vibration energy harvester and the magnetic levitation-based electromagnetic-triboelectric vibration energy harvesting technology are proposed,which realizes efficient harvesting of low-frequency ambient vibration energy.The main work of this thesis is as follows:(1)A magnetic levitation-based electromagnetic vibration energy harvesting technology is proposed,and the electromechanical coupling model of the energy harvester is constructed,and the principles of electromagnetic induction,magnetic repulsion,and winding coil are elaborated.Magnetic flux and magnetic repulsion force calculations are performed using COMSOL with MATLAB co-simulation method.The dynamic response of the energy harvester is analyzed by using the Simulink simulation model built using system dynamic equations.To investigate the voltage output of the energy harvester under various external excitations,the energy harvester prototype is manufactured,the experimental platform is established,and the correctness of the electromechanical coupling model is verified.(2)A piecewise nonlinear vibration energy harvester based on the magnetic suspension system is proposed,and the electromechanical coupling model is constructed.The dynamic response of the energy harvester is analyzed by using the Simulink simulation model built using system dynamic equations.To investigate the voltage output of the energy harvester under various external excitations and structural characteristics,and the correctness of the electromechanical coupling model is verified,and the possibility of the energy harvester to realize the self-supply of the sensor is tested.(3)An electromagnetic-triboelectric hybrid vibration energy harvester is proposed based on the operational features of piecewise nonlinear vibration energy harvesters.Triboelectric nanogenerator theoretical foundation,operating system,and triboelectric materials are introduced,and a planar spring was designed as the elastic stopper.Experiments were carried out to analyze the effects of various excitation,planar spring stiffness,and initial clearance on the output electrical energy of the energy harvester,and the performance of the energy harvester is also tested by harvesting human motion energy.