针对引信小型物理电源体积与功率矛盾问题,课题组提出了小型气流激振压电发电机结构方案。本文建立了测量小型气流激振压电发电机输出特性的实验系统,对原理样机进行了吹风实验研究,测量了发电机的激振力、输出电压,并分析了其振动频率、输出功率以及能量转换效率。实验数据表明,在所研究的气流速度范围内,激振力曲线呈正弦波形,幅值随入流速度的增大而线性增大,频率较高且稳定,约6 kHz,频率变化在9%以内;压电换能器工作在线性段,输出电压值与激振力幅值成正比,频率一致,符合振动压电发电机的能量转换原理;在负载匹配的情况下(R=3 kΩ),最高能输出85.3 mW的电能,且发电机的转换效率为1.2‰。其输出特性可满足在小口径及低功耗引信的应用。它具有结构简单、体积小、振动频率高且无活动部件等特点,具有作进一步研究的价值。
To solve the problem of the conflict between volume and power of a small fuze physical power supply, the structure of a small airflow vibration piezoelectric generator was presented, and the experimental system was established to study the output performance of the generator. The prototype was tested, the sound pressure and the output voltage were measured, and the vibration frequency, the output power and the energy conversion efficiency were analyzed. The results show that the sound pressure follows a sinusoidal pattern, the amplitude of the pressure increases linearly with the airflow velocity within the interesting range of airflow velocity. The frequency of the pressure is up to 6 kHz and it is stable within 9%. Piezoelectric transducer works in linear segments, the amplitude of output voltage is proportional to that of the pressure, and they have the same frequency, which are consistent with the energy conversion principle of the vibrationbased piezoelectric generator. A maximum power of 85 mW could be attained when the load resistance R is 3 kΩ. The efficiency of conversion from airflow to electric power of the generator is 1.2‰. It has the advantages of simple structure, small volume, high vibration frequency and non moving component, which is worth further studies.