Theoretical And Experimental Research On A Compact Wind-Induced Galloping Piezoelectric-Electromagnetic Hybird Energy Harvester

In recent years,with the rapid development of Io T,physical perception layer of Io T requires a large number of microelectronic devices(MEMS)such as sensors.The energy supply problem of MEMS has become a key issue of Io T.There are some drawbacks to traditional battery power.The environmental energy harvester derived from the environmental energy harvesting technology can solve the defects of the traditional battery power supply method.However,most of the environmental energy harvesters all have the problems of insufficient output power and narrow operating frequency band,and some of them occupy a large space.In this paper,a compact galloping piezoelectric-electromagnetic hybrid energy harvester(GPEEH)is designed which is aroused by wind and has higher output power,wider working frequency band,and saves working space to a certain extent.Firstly,GPEEH is designed.The electromagnetic energy harvester(EEH)is embedded in the hollow bluff body through springs and guide rods.When the wind speed reaches the start-up wind speed of GPEEH,the bluff body swings with a large displacement,the cantilever beam bends,and then the inertial magnet performs the motion of cutting the magnetic field line.The coupling model is a two-degree-offreedom motion model(2DOF),which has better output characteristics than ordinary galloping single-degree-of-freedom energy harvesters.Then,the electromechanical coupling equation of the GPEEH is deduced in detail by using Hamilton’s principle,Newton’s mechanics theory,Galerkin’s discrete method,Ohm’s theorem and other methods and tools.And the electromechanical coupled differential equations are solved by MATLAB software to obtain the vibration displacement and voltage,which are compared with the output results of the classical galloping vibration energy harvester(CGPEH).Moreover,the effects of wind speed,load resistance and key parameters on the output performance of GPEEH are also analyzed.Afterwards,an adaptive switching synchronous inductance energy extraction circuit(SP-SSHI)is designed,which modulates,filters,and converts the output power to direct current for use in direct current microelectronic devices.The feasibility and effectiveness of this interface circuit are verified through circuit simulation and debugging platform and wind tunnel experiments.Finally,a wind tunnel experimental platform was built to conduct a series of verification experiments on the GPEEH.The experimental results show that when the wind speed is 9 m/s,the effective output power of the CGPEH is 1.68 m W,and the effective output power of the GPEEH is 3.57 m W.Compared with the former,the output power increase rate η of the latter is 112.5%,and the deviation from the simulation result 118.5% is smaller.The excellent output characteristics of the GPEEH are verified.