Wu Liao, Wang Xinhui, Xie Minghua
School of Electronic Information and Electrical Engineering, Changsha University, Changsha 410022, China.
Micromachines (Basel). 2023 Aug 20;14(8):1639. doi: 10.3390/mi14081639.
This paper presents a piezoelectric (PE) energy harvesting circuit based on the DSSH (double synchronized switch harvesting) principle. The circuit consisted of a rectifier and a DC-DC circuit, which achieves double synchronized switch operation for the PE transducer in each vibration half-cycle. One of the main challenges of the DSSH scheme was precisely controlling the switch timing in the second loop of the resonant loops. The proposed circuit included a MOS transistor in the second loop to address this challenge. It utilized its threshold voltage to manage the stored energy in the intermediate capacitor per vibration half-cycle to simplify the controller for the DSSH circuit. The circuit can operate under either the DSSH scheme or the ESSH (enhanced synchronized switch harvesting) scheme, depending on the value of the intermediate capacitor. In the DSSH scheme, the following DC-DC circuit reused the rectifier's two diodes for a short period. The prototype circuit was implemented using 16 discrete components. The proposed circuit can be self-powered and started up without a battery. The experimental results showed that the proposed circuit increased the power harvested from the PE transducer compared to the full-bridge (FB) rectifier. With two different intermediate capacitors of 100 nF and 320 nF, the proposed circuit achieved power increases of 3.2 and 2.7 times, respectively. The charging efficiency of the proposed circuit was improved by a factor of 5.1 compared to the typical DSSH circuit.
本文提出了一种基于双同步开关采集（DSSH）原理的压电（PE）能量采集电路。该电路由一个整流器和一个DC-DC电路组成，在每个振动半周期内实现对PE换能器的双同步开关操作。DSSH方案的主要挑战之一是精确控制谐振回路第二个回路中的开关定时。所提出的电路在第二个回路中包含一个MOS晶体管来应对这一挑战。它利用其阈值电压来管理每个振动半周期中间电容器中存储的能量，以简化DSSH电路的控制器。根据中间电容器的值，该电路可以在DSSH方案或增强型同步开关采集（ESSH）方案下运行。在DSSH方案中，后续的DC-DC电路在短时间内复用了整流器的两个二极管。原型电路使用16个分立元件实现。所提出的电路可以自供电且无需电池即可启动。实验结果表明，与全桥（FB）整流器相比，所提出的电路增加了从PE换能器采集到的功率。使用100 nF和320 nF两种不同的中间电容器时，所提出的电路分别实现了3.2倍和2.7倍的功率增加。与典型的DSSH电路相比，所提出电路的充电效率提高了5.1倍。
