非接触式旋转压电发电机建模及仿真分析

Modeling and simulation analysis of non-contact rotary piezoelectric generator

针对传统的机械撞击式旋转压电发电机因机械碰撞压电发电单元导致发电机寿命较短的问题,提出了一种使用永磁铁传动的非接触式旋转发电机结构,并对发电机结构进行了理论建模和仿真分析。研究表明,当阵列的压电双晶梁固有频率相同时,发电机存在一个最佳转动速度,该速度乘以驱动轮阵列永磁铁个数等于压电双晶梁的一阶固有频率。驱动轮半径以及驱动轮到压电双晶梁间距越大,发电机能量输出越少。当阵列压电双晶梁固有频率不同时,以两个压电双晶梁为例,发电机转速在18. 0 rad/s(33. 0～51. 0 rad/s)范围内,输出功率超过1. 5 mW。研究结果为宽频发电机的设计和优化打下了基础。

Aiming at the problem that common rotary piezoelectric generator with mechanical impact,the working time is relatively short due to the mechanical impact,which leads the damage of piezoelectric elements.The noncontact rotary piezoelectric generator with magnets is proposed,and theoretical modeling is built,then simulation analysis is performed.Research shows that when piezoelectric bimorph beams in the array has the same natural frequency,the generator has an optimum rotary speed which multiplies by number of permanent magnets fixed on the drive wheel array equals to first order natural frequency of the piezoelectric bimorph beam.As the radius of the driving wheel and distance from the driving wheel to the piezoelectric bimorph beam increasing,the energy output of the generator is decreasing.When piezoelectric bimorph beams in the array has different natural frequencies,the output power is over 1.5 mW within rotary speed range of 18.0 rad/s(33.0~51.0 rad/s),taking two piezoelectric bimorph beams as example.Research result lay a foundation for design and optimization of the generator with wider frequency band.