Research On Magnetic Coupling Piezoelectric Vibration Energy Harvester With Auxiliary Beam Indirect Excitation

Combining with the national natural science foundation of " Study on a vibration energy generator based on composite piezoelectric transducer and auxiliary excitation of magnetic coupling" research target,in order to improve the reliability and environmental adaptability of energy harvesters,two magnetic coupling piezoelectric vibration energy harvesters with auxiliary beam indirect excitation were proposed,which use auxiliary beam unidirectional and indirect excitation piezoelectric vibrators to generate electricity.The influences of the auxiliary beam structure parameters,magnet configuration parameters and load resistance on the output characteristics of the energy harvester were analyzed.The characteristics of power generation are studied theoretically and experimentally.The main contents are summarized as follows:1.The COMSOL finite element model of pre-bent piezoelectric vibrator and combined transducer were established,and the influences of structural parameters of piezoelectric vibrator(length,width,pre-bending radius and thickness ratio)on its structural stress,natural frequency and equivalent stiffness were studied.The influences of the auxiliary beam’s structural parameters(length,width and thickness),piezoelectric vibrator stiffness,additional mass and clamping length on the natural frequency of the combined transducer were analyzed.The correctness of the model was verified through experiments.Provide reference basis for the optimization of piezoelectric vibrator and auxiliary beam;2.The structure and working principle of the indirect excitation magnetic coupling energy harvester are introduced.The dynamic model of the magnetic coupling system was established,and the model was numerically solved using COMSOL and MATLAB.The influence of the magnet configuration parameters(spacing and angle),excitation parameters(amplitude and frequency)and initial conditions on the potential energy and output characteristics of two magnetic coupling piezoelectric vibration energy harvester with auxiliary beam indirect excitation were analyzed.Provide a theoretical reference for subsequent experiments;3.Designed and produced single-magnet coupling and dual-magnet coupling prototypes,and built a test and test platform.The influence of the Structural parameters of two types of auxiliary beams(length and thickness,etc.),magnet configuration parameters(spacing and angle)and excitation parameters(amplitude,frequency and excitation method)on the output voltage of two magnetic coupling piezoelectric vibration energy harvester with auxiliary beam indirect excitation were analyzed.The optimal parameters were selected for power test,and the influence law of load resistance on the output performance of the energy harvester was obtained.From the experimental point of view,it is proved that the proposed auxiliary beam indirectly excited magnetically coupled piezoelectric vibration energy harvester can simultaneously improve its reliability and environmental frequency adaptability(natural frequency and effective bandwidth of the energy harvester).