Design And Experimental Research Of Low Frequency Vibration Multiplication Electromagnetic Generator

With the advancement of technology,miniaturization and integration become the development trend of wireless sensor networks(WSNs)and micro-electromechanical systems(MEMS).However,its power supply becomes a major obstacle to its development.Conventional power supply is the use of electrochemical cells,there are many shortcomings,such as short life,limited storage capacity etc..In addition,subject to some working environment restrictions,it is difficult and complex to replace the battery,and some cannot be replaced.Even if you can replace the battery,it will make the cost increase.Scraped batteries,if not be handled effectively,can have a bad effect on soil and water resources.Therefore,how to use new power to replace the traditional battery has become a hot topic in recent years.Compared with other power generation methods,the vibration power generation device which can utilize the vibration energy in the environment has four advantages: long service life,strong practicability,high power density and easy integration.According to the characteristics of the actual work environment,combined with the electromagnetic induction principle and the physical model of electromagnetic energy harvesting device,two kinds of electromagnetic vibration energy collecting devices suitable for working in low frequency environment are designed.It is found that the axial structure of low frequency vibration frequency multiplication electromagnetic generator is superior to the radial structure in power generation efficiency,and so the whole structure of the energy collection system is determined.The device forms a closed magnetic circuit,which significantly improves the energy conversion efficiency.Using two yokes to form a multi-tooth structure,the frequency of change of the magnetic flux in the core is greatly improved,so that the device can be applied to the low-frequency vibration environment.Armature is embedded in upper and lower sides of permanent magnet armature,reducing the leakage flux.The influence of air gap width,permanent magnet radius,core cross-sectional area and armature tooth thickness on the maximum magnetic flux density of the coil was analyzed by numerical simulation,and the structural parameters of the device were determined.Ansoft software was used to simulate the dynamic model,and the characteristic curves of flux linkage and induced voltage were obtained.In order to study the working performance of the device in the application environment,the simulation experiment is carried out after the winding of the finite element model is connected with different adjusting circuit,and the maximum power that can be provided by the device is obtained.And compared with the results of other design methods,it proves that the device has better output performance and can supply power for low power consumption wireless sensor network nodes.Finally,the prototype of low frequency vibration frequency multiplication electromagnetic generator is fabricated and the performance test is carried out.