Purpose

Existing control circuits for piezoelectric energy harvesting (PEH) suffers from long startup time or high power consumption. This paper aims to design an ultra-low power control circuit that can harvest weak ambient vibrational energy on the order of several microwatts to power heavy loads such as wireless sensors.

Design/methodology/approach

A self-powered control circuit is proposed, functioning for very brief periods at the maximum power point, resulting in a low duty cycle. The circuit can start to function at low input power thresholds and can promptly achieve optimal operating conditions when cold-starting. The circuit is designed to be able to operate without stable DC power supply and powered by the piezoelectric transducers.

Findings

When using the series-synchronized switch harvesting on inductor circuit with a large 1 mF energy storage capacitor, the proposed circuit can perform 322% better than the standard energy harvesting circuit in terms of energy harvested. This control circuit can also achieve an ultra-low consumption of 0.3 µW, as well as capable of cold-starting with input power as low as 5.78 µW.

Originality/value

The intermittent control strategy proposed in this paper can drastically reduce power consumption of the control circuit. Without dedicated cold-start modules and DC auxiliary supply, the circuit can achieve optimal efficiency within one input cycle, if the input signal is larger than voltage threshold. The proposed control strategy is especially favorable for harvesting energy from natural vibrations and can be a promising solution for other PEH circuits as well.

中文翻译：

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一种用于压电能量收集的自供电超低功耗间歇控制 SSHI 电路

目的

现有的压电能量收集 (PEH) 控制电路存在启动时间长或功耗高的问题。本文旨在设计一种超低功耗控制电路，可以收集几微瓦量级的微弱环境振动能量，为无线传感器等重负载供电。

设计/方法/途径

提出了一种自供电控制电路，在最大功率点运行非常短暂的时间，从而导致低占空比。该电路可以在低输入功率阈值下开始工作，并且可以在冷启动时迅速达到最佳工作条件。该电路被设计成能够在没有稳定直流电源的情况下工作，并由压电换能器供电。

发现

当在具有 1 mF 大储能电容器的电感器电路上使用串联同步开关收集时，所提出的电路在能量收集方面比标准能量收集电路好 322%。该控制电路还可以实现0.3µW的超低功耗，并能够在输入功率低至5.78µW的情况下冷启动。

原创性/价值

本文提出的间歇控制策略可以大大降低控制电路的功耗。在没有专用冷启动模块和直流辅助电源的情况下，如果输入信号大于电压阈值，电路可以在一个输入周期内实现最佳效率。所提出的控制策略特别有利于从自然振动中收集能量，并且也可以成为其他 PEH 电路的有前途的解决方案。