Basic Theory And Experimental Study Of Tri-stable Piezoelectric Vibration Harvester

With the concept of green and sustainable development being generally recognized,people are increasingly eager for green energy and new energy.The studies of the utilization of new energy technology have aroused wide attention,which causes a rapidly development in new energy,such as solar energy,tidal energy,nuclear energy and vibrational energy and so on.While vibrational energy is everywhere in nature,how to gather and make effective use of it is currently a hot issue.Traditional energy supply mainly through batteries and power lines,but they have many inconvenience factors,such as large size,heavy quality,environmental pollution,maintenance inconvenience,short life and so on.Although the new type of nuclear battery is small in size and long in energy supply life,it has radioactivity,needs protective equipment,and the high cost.It cannot be widely applied.By contrast,non-polluting energy,vibrational energy,with inexhaustible and abundant features,is called the green new energy of the 21st century,which has wide application foreground.The use of piezoelectric energy harvesting is to collect and convert environmental vibrations into electrical energy through positive piezoelectric effect of piezoelectric ceramics,which has been widely spread in wireless sensor network nodes and other low-power electronic devices in the self-power supply system for its high energy efficiency,simplicity and convenience.Researches focus more on piezoelectric bimorph cantilever structure,when studying piezoelectric energy harvester.For its narrow frequency range and low collecting efficiency,how to widen the frequency range and improve collecting efficiency is of importance in the study.In this paper,a magneto mechanical piezoelectric coupled tri-stable piezoelectric vibration harvester is proposed.Nonlinear magnetic force model,nonlinear electromechanical coupling dynamic model of tri-stable piezoelectric energy harvester and dynamic characteristics of tri-stable piezoelectric energy harvester are studied.And the correctness of the theoretical research is verified by experiments.The main work is as follows:(1)Presents the internal and external state of development and current problems about piezoelectric vibrational energy collector,then proposes main research work and introduce relevant basic theories in this field,including piezoelectric effect,ceramics,piezoelectric equations and the cantilever beam bending vibration theory.(2)Introduces the structure design of the theoretical model of the mono-stable and bi-stable piezoelectric cantilever beam vibration energy collector and the problems existing in its output performance.Subsequently,a magnet mechanical piezoelectric coupling type tri-stable piezoelectric cantilever vibration energy harvester is proposed.The nonlinear magnetic force model and nonlinear lumped parameter dynamic model of the vibration energy tri-stable piezoelectric energy harvester cantilever beam are studied.The influence of system parameters on vibration characteristics and energy acquisition characteristics of the tri-stable piezoelectric energy harvester is simulated and analyzed.The output characteristics of mono-stable,bi-stable and tri-stable piezoelectric cantilever vibration energy harvesters are compared in time domain and frequency domain respectively.It is proved that the tri-stable piezoelectric cantilever vibration energy harvester has a wide operating frequency band and superior output performance.(3)An experimental prototype of tri-stable piezoelectric cantilever vibration energy harvester is developed.The test platform is built,and the correctness of the theoretical model and the simulation result is verified by experimental tests.(4)The research results is summarized,and the future research work is prospected.