压电单晶梁发电机的能量效率

压电发电装置的能量转换效率主要取决于其结构形式、几何参数及材料性能等.为提高压电发电机的机电能量转换效率及其发电能力,利用欧拉一伯努利方法建立了发电装置的能量转换模型,研究了结构及参数等对压电发电机能量转换效率及发电能力的影响规律.结果表明,存在最佳厚度比(基板/总厚)可使发电机获得最大的能量转换效率和发电量;随杨氏模量比(基板/陶瓷)的增加,最佳厚度比降低,但效率提高.钼、铝基板发电机的最佳厚度比和效率分别为(O.4,2.74%)和(O.7,2.25%).此外,压电发电机的发电能力还与激励方式有关,恒力激励时存在的最佳杨氏模量比使产生的电量最多,恒位移激励时产生的电量随杨氏模量比的增加而增加.因此,设计时应根据激励方式确定基板的材料及合理的厚度比.

Energy efficiency of piezoelectric monomorph cantilever generator

The Energy Conversion Efficiency(ECE)of a Piezoelectric Monomorph Cantilever Generator(PMCG)mainly depends on its structural style,geometric parameters and material properties.To enhance ECE and energy-generating capability of a PMCG,the Euler Bernoulli method is utilized to establish a analysis model of energy conversion.The expression for ECE is figured out as a function of the structural parameters and material properties of the PMCG.At the same time.the influencing factors on energy-generating capability are also investigated.Simulation results show that there is an optimal thickness ratio(substrate thickness to overall thickness) for the PMCGs to achieve peak ECE and energy generation.With the increasing of Young's modulus ratio.the optimal thickness ratio decreases and the ECE increases.The optimal thickness ratios and ECEs for the PZT-Molybdenum and PZT-Aluminum generators are(O.4,2.74 oA)and(0.7,2.25%)respectively.Moreover.the energy-generating capability of the PMCG also depends on the type of external excitement for a given Young's modulus ratio.For a constant force excitement,there iS an optimal Young's modulus ratio to generate maximal energy,and under a constant end-deflection,the generated energy increases with the increasing of Young's modulus ratio.Therefore.Young's modulus ratio and thickness ratio should be chosen according to the style of mechanical energy.