Experimental Study on Power Generation Performance of Bending Piezoelectric-electromagnetic Coupling Energy Harvester
The bending beam has nonlinear and other mechanical properties.Combining the bending beam with piezoelectric theory can better solve the problems of low output power,large required excitation acceleration and narrow energy scavenge frequency band of a single linear energy scavenge system.Therefore,a bending piezoelectric electromagnetic coupling energy harvester is proposed.The device consists of three bending beams,magnets and coils.The power generation performance of the energy harvester is tested by building an experimental prototype to explore the influence of various factors on the system output power.The results show that the output performance of the system is better when the piezoelectric chip is located on the bent lower beam than on the bent upper beam.The optimal matching resistance of the device maximizes the output power of the system.The optimal electromagnetic and piezoelectric resistances are about 150 Ω and 80 kΩ,respectively.The introduction of magnetic repulsion force increases the output voltage and output power of the energy scavenge system.The electromagnetic output power with magnetic repulsion is 123.1%higher than that without magnetic repulsion,and the piezoelectric output power with magnetic repulsion is 41.8%higher than that without magnetic repulsion.The maximum output power of the system is 0.46 mW when the excitation acceleration is 0.1g,and 1.36 mW when the excitation acceleration is 0.3g.The increase of the excitation acceleration significantly increases the output power of the system,broadens the energy scavenge band of the system,and improves the power generation performance of the harvester.