Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2018
Date : August 28, 2018 - August 31, 2018
In this paper, we report the damping force generated from nonlinear circuit in a piezoelectric vibration energy harvester, which is drawing attention as a small power source for IoT wireless sensor module. In recent years, much work has been done on improving the output power of harvester to oparate IoT wireless sensor module. To improve the harvested energy, nonlinear circuit called SSHI was developed and showed excellent porformance. However, the early stage SSHI requires extarnal power source. Subsequently, self-powered nonlinear circuits which require no external power source was developed from the specialty of electronics. However, for a harvester with a high electromechanical coupling coefficient k, the damping force from nonlinear circuits, which enhances by the SSHI's voltage increase, is likely to reduce the harvester's displacement and thus lower the output power. In this paper, we investigated experimentally the performance for self-powered SSHI circuit and for standard circuit considering damping force generated from nonlinear circuit for a harvester with a high electromechanical coupling coefficient. It is shown experimentally that the output power of self-powered SSHI circuit is lower than that of standard circuit due to the effect of the damping force. Additionally, the result of experiment showed intriguing phenomena that is a rate of increase of the output power decreases above a specific acceleration.
