间接激励压电发电机的建模仿真与试验研究

为满足旋转机械监测系统的自供电需求、解决现有压电发电机可靠性低及有效带宽窄等问题,提出一种基于移动凸轮间接激励并限幅的旋转式压电发电机(简称间接激励压电发电机).介绍了发电机的结构原理并进行了建模仿真与试验测试,获得了激励磁铁数量比、凸轮升程及升角对激振力形式/幅值、压电振子变形量/输出电压及发电机带宽等的影响规律.结...

Performance analysis and test of a piezoelectric energy harvester based on indirect excitation

To meet the demands of self-powered monitoring system for rotating machine and improve the reliability and effective working frequency band for existing piezoelectric energy harvesters,a Rotary Piezoelectric Energy Harvester(PEH)is introduced,which is based on a moving cam with indirect and limited excitation.The system structure and working principle of the energy harvester are introduced and its dynamic response model is established.In this way,the influence of the excitation magnets ratio,the cam lift and angle to the excitation force form/magnitude,the deformation of the piezoelectric vibrator/output voltage and the harvester bandwidth are obtained by simulation and experiment.The research results show that the indirect excitation of the cam can effectively limit the amplitude/output voltage and avoid the obvious resonance peak of the amplitude-frequency characteristic curve;When other conditions are given,the effective bandwidth of the piezoelectric vibrator deformation/output voltage increases as the excitation magnet ratio decreases and the cam angle increases(30°-45°).As the cam lift increases,the piezoelectric vibrator deformation amount/output voltage increases,and the effective bandwidth decreases.When magnet ratio is 0.25,lift angle is40°,excitation distance are 2/3/4/5 mm,the effective speed range is 212.8/67.2/67.2/44.8 r/min for the output voltage is 20/40/60/70 V;In addition,there is an optimal load of 70 kΩto maximize harvester output power(9.66 mW).