多振子串联压电俘能器性能分析与测试

Performance analysis and test of an energy harvester with serial-connected piezodiscs

为实现低频、大振幅、高强度振动能量回收,提出多振子串联压电振动俘能器,在理论、试验两方面研究压电振子数量/电学连接方式、集中质量及激励频率等对其性能影响规律。结果表明,增加集中质量及压电振子数量均可有效降低俘能器基频、提高发电量/输出功率;压电振子电学串/并联时输出电压及使输出功率最大的最佳负载不同,但产生的电能及在最佳负载下的输出功率相同。制作1/2/4组压电振子构成的俘能器,进行不同集中质量、频率、压电振子电学连接方式及负载的对比试验。单组压电振子在集中质量292 g时的最佳频率及发电量分别为集中质量36.5 g的0.6倍及1.92倍;4组压电振子电学并联时的最佳频率及发电量分别为单组的0.58倍、2.2倍;两组压电振子电学串/并联的最佳负载及最大输出功率分别为42.3/10.6 kΩ及232.8/202.7 mW。

To harvest low-frequency and high-level vibration energy, a piezoelectric vibration energy harvester （PVEH） with serial-connected piezodiscs was presented. The influence of number and circuit-connection styles of piezodiscs, lumped mass, and driving frequency on the output performance of the harvester was studied theoretically and experimentally. The research results showed that the increase in number of piezodiscs and lumped mass is helpful for reducing the 1 st natural frequency and rising the energy generation as well as the output power of a PVEH ; in the case of piezodiscs connected in serial and parallel, the open circuit voltage and the optimal resistance load for the PVEH to obtain maximum power are different, but the generated electric energy and the maximum power under the optimal loads are equal to each other; PVEHs with 1/2/4 pairs of piezodiscs are fabricated and tested; for a pair piezodiscs, the optimal frequency and generated energy of the PVEH with lumped mass of 292 g are 0.6 times and 1.92 times of those of the one with lumped mass of 36. 5 g; for 4 pairs of pizoediscs connected with parallel circuits, the optimal frequency anti generated energy of the PVEH are 0.58 times and 2.2 times of those of the one with a single pair of pizoediscs; the optimal loads and the maximum power for the PVEH with 2 pairs of piezodiscs connected in serial/parallel are 42.3/10. 6 kΩ and 232.8/202.7 mW, respectively.