Research On Piezoelectric Vibration Energy Harvesting Circuit

With the fast development of wearable electronic devices,MEMS,wireless sensor network and the application of a variety of new low energy consumption electronic components,as the size dimension of traditional power supply system is too large,effective power supplying time is too short,the pollution to surrounding natural environment and the other shortcomings,that can not meet the needs of life and industrial production.With the use of piezoelectric materials to collect the mechanical vibration energy in the environment which is stored as electrical energy to the low power consumption electronic components that have become the current research hotspot.This paper has made an intensive study of piezoelectric vibration energy harvesting interface circuit and proposes a new energy harvesting interface circuit which improves the output power and load adaptability of the energy harvesting system,the main work contents of this paper are as follows:(1)By use of the piezoelectric effect and piezoelectric equation of piezoelectric materials,the electromechanical coupling model of the piezoelectric cantilever beam was established and the energy conversion process of the system was analyzed.(2)According to the theoretical waveform and the energy conversion equation of the electromechanical coupling model,the paper analyzed the detailed working process of SEH,SECE,P-SSHI,S-SSHI,the four typical interface circuits,the interface circuits' mathematical expressions of maximum theoretical harvesting power were derived in detail,and explained the influence of linear load resistance on the harvesting power of system.According to the four typical power harvesting interface circuits' disadvantages of low harvesting power and bad load adaptability,this paper proposed a new energy harvesting interface circuit which was named of parallel-double intermediate capacitor harvesting(P-DICH),and deduced its theory mathematical expression of harvesting power.Through the comparative analysis of the P-DICH interface circuit and four typical interface circuits,it could draw a conclusion that the harvesting power of P-DICH had nothing to do with the load,which was about 6 times the harvesting power of the SEH interface circuit.(3)This paper utilized Multisim simulation software,according to the theoretical assumptions set appropriate parameters of the circuit system,and get the ideal circuit simulation waveform of the five interface circuits,the validity of P-DICH interface circuit was verified on theory.(4)Energy harvesting experiment platform of five kinds of interface circuits were built to test the influence of linear load resistance on the maximum harvesting power,the experimental results were consistent with the results of theoretical analysis,from the perspective of practical application it also verified the correctness of P-DICH interface circuit.