压电-电磁复合式俘能器设计及能量收集测试

Design of Coupled Piezoelectric-Electromagnetic Energy Harvester and Energy Collecting Tests

设计了一种压电-电磁复合式俘能器,利用机电耦合状态方程推导了输出功率表达式。应用试验测试对比分析了压电式、电磁式、复合式俘能器的输出特性,结果表明,复合式俘能器的3dB带宽比压电式、电磁式俘能器分别增大了67%、25%,最大功率提高了38%、118%。设计了压电-电磁复合式俘能器能量收集电路,分别利用LTC3588、LTC3108芯片收集压电俘能单元、电磁俘能单元输出的电能,并用超级电容存储。分别应用3种俘能器进行超级电容充电测试,结果表明,复合式俘能器的充电时间比压电式、电磁式俘能器分别减少了29%和52%。

A coupled piezoelectric-electromagnetic energy harvester was designed, the expression of output power was derived by the electromechanical coup[ingstate equations. The output characteristics of piezoelectric, electromagnetic and coupled piezoelectric-electromagnetic energy harvesters were compared through experimental tests. The results show that the 3 dB bandwidth of the coupled piezoelectric-electromagnetic energy harvester was increased by 67% and 25 % compared with piezoelectric and electromagnetic energy harvesters, respectively, resulting in an increase of 38% and 118% in maximum output power respectively. The energy collecting circuit of coupled piezoelec tric-electromagnetic energy harvester was designed. The electric energy converted from piezoelectric energy harvesting unit and electromagnetic energy-harvesting unit were collected by LTC3588 and LTC3108 chips separately, and then stored in a super-capacitor. The charge tests of super-capacitor were conducted using three energy harvesters separately. It is indicated that the charge time of coupled piezoelectric-electromagnetic energy harvester was decreased by 29% and 52 % compared with piezoelectric and electromagnetic energy harvesters, respectively.