Power conversion and integrated circuit architecture for high voltage piezoelectric energy harvesting

Abstract

Using harvesting energy to extend Wireless Sensor Nodes (WSN) operating life or even supply them, has become a topic of growing interest over the last decades. This paper presents the architecture of a fully autonomous Integrated Circuit which efficiently harvests energy from low frequency mechanical stresses. This circuit uses a high voltage piezoelectric transducer and provides energy to a storage element (battery or capacitor) at lower voltage (2.8 to 3.4V). We propose an innovative way to extract the electrostatic energy by using a modified Flyback topology and multiple magnetic transfers. Measurements show that our solution increases the energy transfer with a gain of 15% compared to the classical technique. We show that this work improves the efficiencies of both power and control stages. Finally, the control circuit of the Flyback converter will perform a self-starting operation from an empty energy storage element and is currently being designed in AMS0.35 CMOS technology.

A Review of MEMS Scale Piezoelectric Energy Harvester

“…As to larger scale PEHs, they are mainly motivated by ambient vibration, especially vibration with fixed frequency. At present, there are still problems that limit the application of PEH: (1) the power loss in rectification circuit caused by the low output voltage [18]; (2) the narrow working frequency bandwidth of the energy harvester [9,19,20]; and (3) the mismatch of the frequency between the PEH and the environment [21,22].…”

A Nanopower Synchronous Charge Extractor IC for Low-Voltage Piezoelectric Energy Harvesting With Residual Charge Inversion

“…The proposed power management policy is similar to that introduced in [16], [38]- [40] and makes use of two different capacitors, as shown in Fig. 5: the converter power supply is provided by C DD whereas the load is powered from C ST .…”

“…Furthermore, this scheme, which will be referred to in this paper as two-way energy storage (TWS), allows the load to completely drain C ST without affecting the operation of the active power converter. In [16], [38], [39], C DD is charged initially through a passive path to start the active converter and, when the voltage on C ST is sufficient, the two capacitors are shorted or connected through a diode so that the incoming power sustains both the converter and the load. In the presented architecture, during the start-up phase C DD is passively charged trough a secondary passive rectifier, implemented with a NVC with a diode in series (NVCD), until the minimum voltage V DDmin required for properly powering the active conversion process.…”