Study On Interface Circuit Characteristics For Piezoelectric Galloping Wind Energy Harvesting

Energy harvesting technology is one of the alternative ways to solve the power supply problem of wireless sensor networks.Using clean energy to generate electricity in the environment can not only protect the ecological environment,but also solve the maintenance problems caused by battery replacement.Wind energy is regarded as a valuable environmental energy source because of its wide distribution,clean and renewable.In the technologies of wind energy harvesting,the cantilever beam structure based on galloping effect is used to convert wind energy to mechanical energy because of its low starting wind speed and wide range of wind speed.Piezoelectric material is widely used to convert mechanical energy to electrical energy because of its simple structure and high output power.The energy harvesting interface circuit is very important to improve the efficiency of energy harvesting.In this thesis,L-type piezoelectric cantilever wind energy harvesting device based on galloping effect is taken as the research object,and the characteristics of wind energy harvesting under different types of energy harvesting interface circuits are compared and analyzed.The main work and innovations includes:(1)The structure and working principle of the piezoelectric cantilever beam wind energy harvesting device are analyzed.The electromechanical coupling theory and equivalent circuit model of the L-type piezoelectric cantilever beam are established.Modal,static,and fluid-solid coupling simulations are used to analyze the galloping characteristics of the L-type piezoelectric cantilever beam.(2)The theoretical characteristics of four classical piezoelectric energy harvesting interface circuits are analyzed.Four interface circuits are designed and their circuit simulation models are established.The waveforms of working voltages and characteristics of load outputs of the four interface circuits are simulated and compared.(3)The L-type piezoelectric cantilever wind energy harvesting devices are made and the energy harvesting interface circuits are built.The vibration and harvesting circuit characteristics of the wind energy harvesting device are analyzed experimentally.The L-type piezoelectric cantilever beam galloping wind energy harvesting characteristics under four interface circuits are compared and analyzed.The L-type piezoelectric cantilever wind energy harvesting system proposed in this paper has excellent performances.The output power is greatly improved under the specific interface circuit.It is expected to become an effective power supply for the wild wireless sensor network system.