Investigation On Piezoelectric Vibration Energy Harvesting And Semi-active Vibration Control

Vibration is one of the most common natural phenomenons, but it is usually harmful to structures, so vibration control is a problem which cannot be ignored. Compared to conventional active vibration control, where many bulky electronic devices and a power supply for operation are required, and passive vibration control systems are sensitive to the variation parameters of the system, the semi-active control becomes the preferred solution on many occasions. The semi-active vibration control is combined with vibration energy harvesting technology in this paper which can not only control the vibration effectively, but also can harvest vibration energy.Based on the mechanical-electrical coupling characteristics of the piezoelectric materials, the theoretical model of the nonlinear synchronized switch damping(SSD) of the semi-active control system has been established. And then the working principles of SSD(including SSDI, SSDS, SSDV and improved SSDS)have been analysed, and the electromechanical energy conversion expressions of the various control methods within a vibration cycle have been derived. As for the key technology of SSD is switch design, a passive switch circuit is adopted to realize its functions, and it has been proved that the passive switch circuit can fulfill different switching times with SSDI, SSDS. Secondly, the realization circuit of the semi-active control system is improved in this paper, and charge generated in the vibration process will be stored or output. Then on the basis of the working principles, the output power and voltage have been established. Finally, the semi-active vibration control has been combined with energy harvesting technology in this paper. Based on the experimental results, voltage regulator circuit and the appropriate control strategy have been designed for SSDV, so as to achieve optimal control voltage 2.5v and to be self-powered.Semi-active control system has the advantages of simple structure and easy to implement. Since the switching method consumes ultralow power of that harvested, the semi-active control system can be self-powered. Experiments show that the effect of vibration suppression of SSDS, improved SSDS, SSDI and SSDV gradually increases, consistent with the theoretical results. Among them, SSDV with vibration energy harvesting voltage 2.5v achieves better control effect.