Study On Vibration Energy Harvesting Circuit Based On Piezoelectric Effect

With the rapid development of micro devices and sensors,more and more attention has been paid to the vibration energy harvesting technology.The vibration energy harvesting technology can be widely used in people’s production and life,to overcome the difficulties and problems such as limited life to replace the traditional battery,and the vibration energy is higher than other new energy collection efficiency for micro electromechanical equipment,high risk,high corrosive environment under the energy supply problems,has good application prospects.The contents of this paper are: firstly,introduces the application of piezoelectric materials and energy acquisition based on acquisition circuit of the piezoelectric element of the domestic and foreign research status,and the characteristics of piezoelectric element energy acquisition;secondly,starting from the piezoelectric equations,the basic principle of vibration of the piezoelectric cantilever beam to generate strain,output voltage and charge for the piezoelectric cantilever,equivalent circuit model is discussed;then,the interface circuit is improved and the design,analysis,study a parallel double synchronous switching energy acquisition circuit(P-DSSH),carried out on the circuit simulation and theoretical analysis,and the selection of electronic components,set up energy acquisition circuit.The cantilever piezoelectric vibration energy harvesting scheme.Finally,an experimental platform is built on the piezoelectric energy harvesting circuit,P-DSSH circuit and several common interface circuit designed in this paper are tested,recorded waveform and data,makes a comparative study.The experimental results show that the vibration acceleration of arms is 0.035m/s2,the instantaneous output power P-DSSH circuit for 0.25 mW,than the parallel synchronous switch inductance interface circuit(P-SSHI),full bridge rectifier circuit(SEH)and LTC3588-1 output power circuit is much higher,and the output power does not change with load.At the same time to change the natural frequency of piezoelectric cantilever beam are compared,in the case of constant acceleration,piezoelectric beam placed mass,the measured natural frequencies of the piezoelectric beam becomes small,varying from 38.4Hz to 29.3Hz,at the same time,beam generated mechanical stress becomes large,stuck in the roots the piezoelectric deformation increases.Experiments were carried out under this condition,the experimental results show that compared with the natural frequencies of the beam is low before the experiment,while the output power of P-SSHI circuit and SEH circuit,LTC3588-1 circuit,P-DSSH circuit power acquisition are increased,but the instantaneous output power P-DSSH circuit is 0.264 mW,the output power is still higher than the interface circuit.And the output power does not change with load.Experimental results show that the P-DSSH circuit designed in this paper improves the output power of piezoelectric vibration energy acquisition system,and also solves the problem that the collection efficiency is affected by the change of load.The P-DSSH circuit stabilizes the output 3.6V voltage and realizes the intermittent operation of the 1W small lamp,which can be used for low-power intermittent working micro sensors for energy supply.