旋磁激励式圆形压电振子发电机

为满足旋转机构监测系统自供电需求,设计旋磁激励式圆形压电振子发电机,并着重研究磁铁尺寸、磁铁间距、压电振子厚度等对压电振子一次受激产生的最大输出电压及总能量的影响规律。结果表明,其它条件确定时,增加磁铁尺度或减小磁铁间距均可有效提高发电机输出电压及有效速带宽度。试验获得输出电压大于12 V的转速范围为100~2 850 r/min。压电振子厚度对输出电压及总发电量均有较大影响,低转速时采用薄压电振子、高转速时采用厚压电振子有助于提高发、供电能力。0.2 mm、0.4 mm、0.6 mm厚压电振子最佳转速分别为707.5 r/min、1 301.8 r/min、2 490.4r/min,0.2 mm厚压电振子一次受激产生的电能/功率分别为0.4 mm、0.6 mm压电振子的3.1/1.7倍、6.4/2.0倍。以输出5 V供电电压为例,912 r/min时0.4 mm厚压电振子输出电能为0.6 mm厚压电振子的5倍,1710 r/min时0.6 mm厚压电振子的输出电能为0.4 mm压电振子的1.7倍。

Piezodisc energy generator excited by rotary magnets

To meet the demands of rotating machine for self-powered monitoring system, a novel piezodisc generator excited by the coupling effect between rotating magnets and those fixed on the piezodisc was presented. The influence of system factors on the maximal voltage and total energy generated from the piezodisc at one excitation was investigated mainly. The research results show that both the output voltage and effective speed-band can be enhanced with increasing magnet size or decreasing the distance between the magnets. In this way, output voltage beyond 12 V was obtained at rotating speed range of 100-2850 r/min. Besides, the thickness of the piezodisc exerts also great influence on the generated voltage and electric energy. Both the maximal voltage and total electric energy can be enhanced with using a thin piezodisc at low speed or a thick piezodisc at high speed. The optimal speeds for the piezodiscs of 0.2/0.4/0.6 mm in thickness to obtain maximal energy are 707.5 r/min，1301.8 r/min，2490.4 r/min respectively. At the optimal speed and one excitation, the obtained energy/power from the 0.2mm-thickness piezodisc are 3.1/1.7 and 6.4/2.0 times those from the 0.4mm and 0.6mm thickness piezodiscs. Taking 5V output voltage for example, the usable energy generated from the 0.4mm-thickness piezodisc is 5 times that from the 0.6mm thickness piezodisc at 912 r/min. While, the usable energy from the 0.6 mm-thickness piezodisc is 1.7 times that from the 0.4mm thickness piezodisc at 1710 r/min.