Theoretical Analysis And Experimental Study Of The Floating Body Power Generator Based On Piezoelectric Effect

In recent years, the energy crisis and the environmental issues caused bygreenhouse effect become increasingly prominent. As a kind of renewable alternativeenergy, the development of wave energy has become increasingly important. Most ofthe wave power generation devices are complex and unreliable, and the cost ofproducing electricity is relatively high, so the commercialization of them is difficult.Although most of the piezoelectric generators by wave are simple and reliable, but theoutput power and the power generating efficiency are limited by wave frequency. Inorder to improve power generation, people have to increase the size of the generator.On the basis of previous research, a new wave powered piezoelectric generator ispresent in this paper to these practical problems. The theoretical analysis andexperimental verification are made in this paper, and they provide a reference for theoptimal design of the wave powered piezoelectric generator.The floating body power generator based on piezoelectric effect comprises afloating body on the surface of the ocean, the cams in the middle and the cantileverpiezoelectric oscillators on the both sides. The cams in the middle are fixed on thefloating body at the bottom of the system. Arrays of cantilever piezoelectric oscillatorsare in interlaced form to reduce the force between the cam and the cantileverpiezoelectric oscillator. Cams fixed on the floating body come up and down withwaves to interact with the cantilever piezoelectric oscillators, and cause engagementand deflection of them to generate electricity. This generator is simple, reliable, easyto implement, and its vibration frequency is high.A mathematical model is established in this paper, in consideration of the firstpiezoelectric equations, the equivalent circuit of the piezoelectric oscillator, as well asthe basics of the mechanics of materials. Then the influence of the external factors andthe size of the piezoelectric oscillator to power generation characteristics are analyzed.Through the analysis, it is concluded that the vibration frequency is the higher thebetter and the amplitude of the piezoelectric oscillator is as big as possible when thefatigue life of the material is taken full account of. In the case of resistance load is notvery large, the parallel electrodes are better than electrodes in series. The system getsthe best output power when the resistance load and the thickness ratio of piezoelectricchip and the shim are both optional. The thickness ratio and the efficiency for systemwith PZT-5H and stainless steel are0.6and5.6%. Some experiments were designedaccording to the results of theoretical analysis, and they verify the correctness oftheoretical analysis and the feasibility of the device. The experimental value is slightlysmaller than the theoretical value due to the energy loss in the test and themeasurement error...