| The application of collecting vibration energy and its conversion into electrical energy has entered people’s field of vision more than before.Piezoelectric materials and technologies provide strong support for the development of new energy sources,and vibration energy capture device can recover waste vibration energy from environment and convert it into electric energy.Therefore,it is of great social significance to develop piezoelectric vibration energy capture devices and related research.However,how to combine the characteristics of piezoelectric materials and the matching of piezoelectric oscillator frequency and vibration source to improve power generation,and how to design a reasonable piezoelectric energy capture device to pick up vibration energy in all directions is an urgent problem to be solved.This paper focuses on designing and optimizing the vibration energy harvesting structure.Aiming at the problems of different types of pickup piezoelectric structure and vibration source frequency mismatch,a combination of theoretical research,simulation and experimental analysis is used to carry out research on multi-frequency vibration pick-up device.Vibration and piezoelectric characteristics of single piezoelectric vibrator and multi-frequency energy capture device are analyzed.The vibration characteristics of the XYZ three-way planar single-frequency and multi-frequency pickup structure,the spatial single-frequency single-vibrator,the singlefrequency multi-vibrator,the multi-frequency single-vibrator and the multi-frequency multivibrator pickup structure are analyzed,and the vibration modes of different types of pick-up structures and their natural frequencies are explored.Finally,a test bench was set up to verify the power generation characteristics of various forms of pick-up structures at different external vibration frequencies.The vibration analysis shows that the natural frequencies of piezoelectric vibrators with different structures and forms are different.It is concluded that the spatial multi-frequency oscillators have the advantage of picking up other types of structures and better pick-up sensitivity.Furthermore,it is possible to obtain a better pick-up capability of the structure in the actual working process.Experimental analysis shows that the peak-to-peak voltage of all pick-up structures in the vibration frequency range firstly increases with the vibration frequency,reaching the maximum value of the piezoelectric when the natural frequency of the piezoelectric oscillator is adjacent.It then decreases as the vibration frequency increases.Under the premise of ensuring the same natural frequency of the piezoelectric vibrator,the maximum value of the piezoelectric of the planar piezoelectric structure is increased by 26.13%~72.97% compared with that of the single piezoelectric vibrator.The piezoelectric peak-to-peak value of the planar single-frequency pickup structure is reached only when the external vibration frequency is around 15 Hz.Compared with it,the piezoelectric peak-to-peak value of the planar multi-frequency pickup structure is extended to the range of 15 Hz to 20 Hz.The maximum value of the piezoelectric of the spatial single-frequency single-vibrator pick-up piezoelectric is increased by 69.37% compared with that of a single piezoelectric vibrator.The maximum value of the spatial single-frequency multivibrator pick-up piezoelectric is increased by 2.1%~38.57% compared with that of the planar piezoelectric vibrator with XYZ directions.The maximum value of the spatial multi-frequency pick-up piezoelectric is increased by 14.55%~65.79% compared with that of the planar multifrequency oscillator pick-up due to the common pickup of the piezoelectric vibrator in space.Therefore,it can be concluded that the spatial multi-frequency pickup structure has a higher conversion rate for vibration and electric energy,which has certain guidance for the development of the pick-up and capture energy technology and structure.The paper has 78 figures,20 tables and 80 references. |
