Cymbal压电发电换能器有限元分析

Finite element analysis on energy harvesting with cymbal transducer

通过建立Cymbal压电发电换能器的机电耦合有限元分析模型,计算分析了换能器结构参数对输出电压和谐振频率的影响以及外接负载对Cymbal换能器输出电压和输出功率的影响。研究表明,为了降低换能器的工作频率和提高换能器的输出电压,应增大换能器的空腔底部直径和减小换能器的空腔高度;在选择金属端帽和压电陶瓷厚度等参数时,应综合考虑换能器系统的刚度和外界振动源的频率特性和加速度特性;在任意一个频率点上,Cymbal换能器均存在一个最佳的外接负载,使得换能器的输出功率最大,而这个最佳的负载阻抗就等于Cymbal换能器在这个工作频率点上的输出阻抗。提出并分析了基于外加预应力的多振子级联方式Cymbal压电发电换能器系统的结构。

A finite element analysis model of energy harvesting with Cymbal transducer was established. The influence of structural parameters of the transducer on the output voltage and resonance frequency was analyzed. The results show that, in order to reduce the operating frequency and increase the output voltage of the transducer, the bottom diameter of the cavity should be increased and the height of the cavity should be reduced. When choosing the thickness of metal end cap and the thickness of PZT, the stiffness of Cymbal transducer and the characteristics of frequency and acceleration of the external vibration source must be synthetically taken into consideration. A pre-stress and multi-layer structure of Cymbal energy harvesting system was proposed and analyzed. The effect of the external resistance load on the output voltage and output power of Cymbal transducer was identified. The results show that, at a specific frequency there is always an optimal external resistance load which makes the transducer generate the maximum output power. The optimal resistance of the load matches with the output impedance of Cymbal transducer at this specific frequency.