微型压电振动发电机谐振频率调节技术的研究

摘要

具有高能量密度的微型压电振动发电机可以无限、持续地为无线传感器网络提供能量。为了适应环境振源频率的变化，提高压电振动发电机的能量转换效率，采用理论建模和数值分析的方法，研究了旁路电容调节振动发电机固有频率的关键技术。建立压电电容与压电层杨氏模量的力学模型，分析压电电容对压电发电机固有频率的影响规律，提出了单晶片和双晶片压电梁的电容频率调节配置方案；分别研究厚度比、长度和宽度对开路、闭路刚度比及固有频率比的影响特性，对结构参数进行了优化配置。%Piezoelectric vibration generator made in MEMS can infinite and continue to supply energy for low power electric device. For adapting change of vibration source frequency,theoretical modeling and numerical analysis are adopted,and key technology of shunt capacity regulating inherent frequency is studied to enhance energy conver⁃sion efficiency of vibration generator. Mechanical model between piezoelectric capacitance and Young modulus of piezoelectric layer is established to analyze influence rule of piezoelectric capacitance to inherent frequency of piezoelectric generator,and capacitance frequency adjustment allocation plan of unimorph and bimorph beam are put forward;influencing characteristic of thickness ratio,length,width and material parameter to open circuit, closed circuit stiffness ratio and inherent frequency ratio is studied respectively,and optimal configuration of struc⁃tural and material parameter is conducted.