Research On The Design And Application Of Nonlinear Harvesting Circuit Based On Piezoelectric Vibration Energy

With the continuous development of science technology and social economy, requirement for power energy becomes more and more frequently in every field, while the traditional electric energy acquisition mode makes traditional energy become less and less. In order to solve the energy crisis, the new energy has become a hotspot in the field of scientific research. At present, the new energy mainly includes solar energy, wind energy, hydropower and nuclear power, whose application is very mature. In the microelectronic system, the problem of energy supply has been paid more and more attention. Because of its energy supply mode has certain specific characteristics, such as the size of energy acquiring device can not be too large, the energy consumption of the system should be very small, in this case, the piezoelectric energy with simple collection, wide application range, no electromagnetic, no pollution and other advantages, has become the ideal choice of microelectronic systems’supply power.The purpose of this paper is to study and construct the piezoelectric energy harvesting circuit based on the piezoelectric effect of piezoelectric ceramic, and transform environmental vibration energy into electrical energy which is stored. At the same time, the stored energy is used by wireless sensor network node, which could validate the feasibility of the energy harvesting system. Based on the above objectives, the research contents are divided into the following sections:The first section is to introduce the research purpose and meaning of piezoelectric power generation, and elaborate the research status of the domestic and international piezoelectric power generation technology. And it does a simple generalization about the basic concepts and theories, such as the piezoelectric effect, piezoelectric material and piezoelectric equation. On the basis of the above, this paper presents a cantilever beam structure used in the piezoelectric power generation, which includes a piezoelectric vibrator.On the basis of the introduction of research status and theories, the second section is to analyze the principle and function of the piezoelectric energy harvesting circuit and do the circuit simulate. Then it compares the efficiency of different piezoelectric energy harvesting circuit and studies how to choose a suitable nonlinear energy harvesting circuit. And the performances of different storage devices are compared in order to choose the suitable electrical energy storage. Finally, the actual circuit is designed according to the working principle of nonlinear energy harvesting circuit.The third section is to construct the piezoelectric vibrator test-bed based on the cantilever beam structure, and study the experiment about energy harvesting circuit. Different forms of piezoelectric vibrator combination is tested in order to determine the optimum vibration frequency and vibration force, and find the energy collection effect because of different piezoelectric vibrator combination modes. Through the contrast test of energy harvesting circuits, the energy harvesting efficiency is analyzed based on the circuit structure.The fourth section is to design the wireless sensor network node experiment platform, and the node power is supplied through the energy harvesting circuit to validate its feasibility. Experimental results show that the nonlinear harvesting circuit designed in this paper enhances the piezoelectric energy collection efficiency, and the collected energy could be stored in the supercapacitor in order to supply the wireless sensor network node.