The Study Of Piezoelectric MEMS Energy Collector Used For Sensor Of Hydropower Station

Hydropower station is a typical industrial environment,there are a variety of sensors in the hydropower.Because of the complex work environment,providing power to sensors is one challenging work.Mechanical vibration and noise are widespread in hydropower station.On the one hand,the mechanical noise and vibration of hydropower station have some negative effects on the safe operation of the hydropower station system;on the other hand,it can also be used as a kind of waste energy.Eliminate or make reasonable use of the vibration energy of the hydropower station system and convert the vibration energy into electric energy.This electrical energy is used to power the sensors which are in complex environments such as near vibration sources.This idea provides a new direction for the study of vibration energy collection.The traditional piezoelectric energy harvester can only work under a single frequency band.But the vibrational environment of hydropower station is complex and changeful.In order to adapt to the actual environment of hydropower station,a new type of piezoelectric energy collector with two-degrees-of-freedom is presented.In order to further improve the performance of the device and reduce the volume of the device,we use the MEMS process for processing and preparation.So that the miniature piezoelectric energy collector has higher energy density and better integration.For which we did the following:(1)Firstly,we analyzed the parameters of various sensors in hydropower station.The energy supply mode and power consumption of various sensors were investigated.Finally,the specific application site of the energy collector is determined.On the other hand,the research status of piezoelectric energy collector at home and abroad is introduced.In particular,the cantilever beam piezoelectric energy collector is analyzed.This paper summarizes the specific ways of optimizing the output performance of piezoelectric energy collector.(2)We introduced the working mode of piezoelectric energy collector,piezoelectric material and piezoelectric energy collector.The theoretical model of piezoelectric cantilever beam is established by theoretical analysis.Based on the single-degree-of-freedom theory model,the two-degree-of-freedom cantilever beam theory model is established.The motion characteristics and output performance of the piezoelectric cantilever beam are analyzed according to the theoretical model(3)We introduced the theoretical basis of finite element simulation.We used ANSYS finite element simulation software to optimize the dimensions of each part of the singledegree-of-freedom cantilever beam,and optimized the dimensions of each part of the two-degree-of-freedom cantilever beam.Finally,the geometric parametersof the cantilever beam with two degrees of freedom are obtained.(4)We introduced the processing technology of MEMS,which include Thinning process,polishing process,bonding process,lithography process,and sputtering process.The preparation procedure of the two-degree-freedom piezoelectric energy collector is introduced in detail.Finally,the two-degree-freedom piezoelectric energy collector is assembled.(5)We introduced the testing platform used to test the piezoelectric energy collector.We tested the two-degree-of-freedom piezoelectric energy collector,including output voltage,output power,energy density,performance change under varying load,and impedance and phase Angle characteristics of the device.The performance of the device was tested under the simulated hydropower station.(6)We summarized the research content and find out the next research direction.