Impact Based Piezoelectric Wind Energy Harvester With Hinged Splitter Plate

The nodes of the wireless sensor network have the characteristics of huge number,wide distribution, poor working conditions and long working cycle, which make thetraditional batteries not applicable for them. The micro harvester which can convert theambient energy into electrical energy has become the ideal power supply for thewireless sensor network. Wind energy is a widely present green renewable energy innature, to meet the power requirement of the wireless sensor network, studying microwind energy harvester which can work in low wind speed has great significance.Based on the theoretical model of piezoelectric vibration energy harvesters, thisdissertation studied the modeling method of impact based piezoelectric energy harvesterby using lumped parameter model. A new structure of impact based wind energyharvester with splitter plate was proposed, and the prototypes of the wind energyharvester were assembled. The characteristic of the prototype were tested in a smallwind tunnel. The specific contents of the dissertation are as following:(1) Summarized and analyzed the research status and development trend ofvibration and wind energy harvester, and determined the main research direction of thisdissertation;(2) Established the differential equation of motion and coupling circuit equation ofpiezoelectric cantilever beam subjected to transverse impact of a ball by utilizinglumped parameter modeling method, and compared the results of the simulation and theexperiment;(3) Inspired by researches on inhibiting wind-induced-vibration of a cylinder by ahinged splitter, two new structures of impact based wind energy harvester with hingedsplitter plate were proposed, and their working principle were described;(4) Prototypes of impact based wind energy harvester were assembled, and theircharacteristics were tested in a small wind tunnel. The experimental results showed thatthe smaller the initial distance between the splitter plate and the piezoelectric cantileverbeam, the lower the critical wind speed; the proof mass on the free ends of the splitterplate or the piezoelectric cantilever can improve the output power of the harvester in thelow wind speed segment;(5) The maximum output power of the prototype in which the splitter plate impactswith piezoelectric cantilever beam was64μW when the wind speed was15m/s; The maximum output power of the prototype in which the splitter plate impacts withpiezoelectric MEMS harvester was227.5nW when the wind speed was13m/s; theprototype in which the splitter plate on which mounted the piezoelectric MEMSharvester impacts with the rigid stop was65.5nW when the wind speed was15m/s.