Design And Analysis Of Piezoelectric Vibration Energy Harvester Conversion System

With the rapid development of networking technology, microelectronic devices have been widely applied to various areas of life, such as smart city, resource monitoring, environmental monitoring, building structural health monitoring, medical care, home automation, building automation and other fields. According to relevant survey report shows that in2020, the world is expected to have50to300billion Small Things equipment. If using the conventional battery-powered mode, we need to replace the batteries frequently; it would cost huge human and financial resources for maintenance, so the use of conventional batteries had a serious impact on microelectronic devices. Get energy directly from the environment is the so called energy harvesting technology, which allows these devices completely maintenance-free within a period of several years. This technology is gaining great attention currently.Based on piezoelectric vibration energy harvesting technology, the main studied focus on the electromechanical model of a piezoelectric energy harvester, the impact of AC-DC converter circuit in the structure, the application of Cuk-type DC-DC converter circuit when the intensity of the vibration source is unstable and self-powered switching technology in SSHI technology. The concrete work shows as follows:(1) An equivalent model of piezoelectric vibration energy harvesting system is designed, an AC-DC rectifier is connected to the output. According to the structural design and circuit theory, analytical expressions are derived as the output energy under steady-state operation. As the main goal is to maximum the output power, the expression of the average power is normalized, then get the optimized load resistance, vibration displacement, output voltage and output power when the system operate under open-circuit and short-circuit resonant state. Then analyze the output performance of the piezoelectric vibration generator after simulation, and the results were compared to verify the feasibility of this optimization method.(2) In order to ensure energy harvester is still working properly when the intensity of the vibration source is instable, the technology of parallel synchronous switching harvesting on inductive technology with Cuk-type DC-DC converter systems is studied. By adjusting the DC-DC converter’s duty cycle, the energy can efficiently supplied to the load. The simulation is taken when the circuit is built in OrCAD Capture software, then study the influence of relevant parameters for the largest gathering power. Secondly, for the synchronous switching harvesting on inductive technology, considering the need of an additional power for the switching, the self-powered synchronous switching inductive energy technology is studied, it’s working principle and process is analyzed. The circuit is built in OrCAD Capture software, the simulation is performed by PSpice, and then analyzes the impactions on energy harvesting power just like the value of capacitance, the value of associated resistance and the excitation levels.(3) Based on INV-1601B-type vibration teaching equipment, the circuit is built on the experimental platform, the measurement of open circuit voltage, open circuit voltage versus frequency, voltage rectified by the rectifier, the voltage through the filter capacitor processed are taken. And the comparison between the measurement results and the theoretical results were taken in SP-SSHI circuit.