旋磁激励式圆形压电振子发电机

Piezodisc energy generator excited by rotary magnets

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100~2850 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。0．2mm、0．4mm、0．6mm 厚压电振子最佳转速分别为707．5 r／min、1301．8 r／min、2490．4 r／min，0．2mm 厚压电振子一次受激产生的电能／功率分别为0．4mm、0．6mm 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0．4mm 厚压电振子输出电能为0．6mm 厚压电振子的5倍，1710 r／min 时0．6mm 厚压电振子的输出电能为0．4mm 压电振子的1．7倍。

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