压电液压隔振器的能量回收特性分析与测试

Energy Harvesting Performance of a Piezo-Hydraulic Vibration Isolator

为实现高性能的振动主动控制、振动能量回收以及基于能量回收的自供电半主动振动控制,提出一种压电液压隔振器.基于实际流体的可压缩性,建立了压电液压隔振器的能量回收系统模型并进行了模拟仿真分析,获得了相关要素对发电量的影响规律.结果表明,压电液压隔振器的发电能力随系统背压及液压缸振幅的增加而增加,且存在最佳压电振子直径、厚度以及直径-厚度比使发电量最大.采用Ф60×1.6 mm3单晶压电振子及Ф16×100mm3液压缸制作了试验样机,并以水为工作介质进行了不同频率、背压、激振器振幅条件下的试验测试.试验所获得的压电液压隔振器的最佳工作频率仅为6 Hz,可用于低频振动能量回收.在频率为6 Hz、激振器输入电压为9 V、背压为0.4 MPa时,发电量为2.42 mJ;当其他条件相同,背压为0.4 MPa时的发电量约为无背压时的20倍.

A piezo-hydraulic vibration isolator （PHVI） was presented for active vibration control, vibra- tion energy harvesting, and self-powered semi-active vibration control based on energy harvesting. A the- oretical model for the PHVI to harvest vibration energy was established and simulated based on the com- pressibility of actual liquid. The analytical results show that the electrical energy generated from the PHVI depends greatly on system parameters, the obtained electrical energy increases with the increase of back- pressure and vibration amplitude of the cylinder, and there exist the optimal diameter and thickness of pi- ezodise and their ratio for the PHVI to achieve the maximal energy. A PHVI prototype was fabricated with a piezodisc measuring Φ16 × 1.6 mm3 and a cylinder measuring Φ16 × 100mm3. It was tested with water as liquid medium at different frequencies, backpressures, and exciter-amplitudes. The optimal frequency for the PHVI to achieve peak energy is 6 Hz, which is desirable for low-frequency vibration energy har- vesting. When the exciter is driven at 6 Hz, 9 V and .0. 4 MPa, the obtained electrical energy is 2.42 mJ. The electric energy under the backpressure of 0.4 MPa is about 20 times greater than that without baekoressure.