Mechanistic Study Of A Non-contact Piezoelectric Energy Harvesting Device For Wind Energy Harvesting

In order to reduce the loss of fossil fuels such as oil,carbon neutrality was achieved early,and many clean,pollution-free green energy sources were developed.Including solar,ocean,wind,etc.Wind energy is widely used as a traditional green energy source.Many large wind harvesters have been manufactured and have become an important part of the population’s electricity supply.However,micro wind harvesters have been slow to develop,and despite the small amount of power generated,there is a huge market potential for their integration in micro-electronics such as mobile electronics,wireless sensor networks and structural health monitoring.There are many technologies that can be used to create micro-wind harvesters such as electrostatic,frictional and piezoelectric technologies.The piezoelectric wind energy harvester made of piezoelectric material has become a hot spot nowadays due to its high energy density,low cost and high voltage output characteristics.This paper realizes the effective harvesting of wind energy through magnetic coupling and special cantilever beam structure,which solves to some extent the problems of poor output performance,high starting wind speed and poor reliability of the piezoelectric wind energy capture device at low frequency,and can be used as a stable power source to make the micro and small electronic devices operate normally.Firstly,we classify micro and small piezoelectric wind energy harvesters,summarize the current status of eddy-excited vibration type and rotary type piezoelectric wind energy harvesters at home and abroad,analyze the characteristics of these two types of harvesters and their shortcomings,so as to provide design ideas for non-contact piezoelectric energy harvesters for wind energy harvesting.For the design idea of non-contact piezoelectric energy harvester for wind energy harvest,the mirror image piezoelectric wind energy harvester and the nonlinear isometric L-shaped cantilever beam piezoelectric wind energy harvester based on magnetic coupling are designed respectively,and the structural parameters affecting their output performance are explored based on theory and simulation to lay the foundation for the subsequent experiments.According to the two proposed piezoelectric wind energy harvesters,the corresponding experimental platform is built to test the output voltage as well as the power under different structural parameters,and the performance of the mirror image piezoelectric wind energy harvester and the nonlinear isometric L-shaped cantilever beam piezoelectric wind energy harvester based on magnetic coupling are demonstrated respectively.For the mirror image piezoelectric wind harvester,when the distance between the magnet on the piezoelectric oscillator and the magnet on the rotating bracket is 15 mm,the twisting angle of the blade is 15°,the height of the blade is 50 mm,and the number of blades is 3,the output power of the prototype can reach 12.5 m W under 8 kΩ load resistance,and the prototype can be used as a stable power source to make a scientific calculator operate normally.For the nonlinear isometric L-shaped cantilever beam type piezoelectric wind harvester based on magnetic coupling,when the rotation angle of the isometric Lshaped cantilever beam is 90°,the height of the excitation magnet is 12 mm,the number is 5,the wire diameter of the additional spring is 1mm,and the load resistance is 2MΩ,the output power of the piezoelectric oscillator in parallel is maximum,reaching142.3μW,and the wind speed at this time is around 8m/s.At this wind speed,the prototype can make nearly 100 LEDs operate normally,providing a valuable solution for the power supply of low-power wireless network system.