| With the development of science and technology, implementing wireless sensor networks(WSNs) has become a new hot research topic.The research is focused on how to make wirelesssensors in some special application fields harvest the energy around the working environment,which can replace the battery or charge the battery to power themselves. This paper established anequivalent circuit model of the bimorph piezoelectric cantilever beam, through the analysis of itscircuit model, designed a vibration energy harvesting system in a low frequency environment.In this paper, the concrete research content is as follows: first, we set up the equivalent circuitmodel of the bimorph piezoelectric cantilever beam, and analyzed the electromechanical couplingcoefficient and quality factor of influence on energy conversion efficiency.Then the basic bridgerectifier circuit and improved synchronization charge circuit were analyzed theoretically, simulatedwith LTspice software. Through the calculation of simulation data, we verified the energy extractionefficiency of the improved circuit is200%higher than that of basic bridge rectifier circuit.Then westudied the piezoelectric energy storage technology and DC-DC transducer circuit, and designed apractical circuit of energy management. Finally, we made the bimorph piezoelectric cantilever beamusing the PZT5H4E material, designed a vibration energy harvesting system, and set up a testplatform to test the system. The experimental results showed that at resonance condition, the systemcan harvest vibration energy into electrical energy to store in an ultracapacitor, and power wirelesssensor node every once in a certain period, which can collect and sent a set of temperature data tothe master node.This paper designed a vibration energy harvesting system that can harvest vibration energy topower wireless sensors under the low frequency environment, which made certain and basicresearch for intelligent power supply of wireless sensor network. |
PDF Full Text Request