Asymmetric SECE Piezoelectric Energy Harvester Under Weak Excitation

Abstract

Piezoelectric energy harvesters (PEHs) are widely used to convert energy from a piezoelectric transducer into a stable DC form, which enables low-power IoT devices to have an unlimited operating life without using batteries. Under weak excitation conditions, however, the power-extraction efficiency of conventional PEHs is too low to provide power even to low-power IoT devices that requires low operation voltages less than 2 V. This paper proposes an asymmetric synchronous electric charge extraction (ASECE) scheme that improves the extraction efficiency of PEHs at low output voltages under weak excitation. The proposed ASECE is implemented using 0.18 μm CMOS technology. The figure-ofmerits (FOMs) of the proposed ASECE while operating under 2 V of output voltage are 7.14 and 6.24 at weak and strong excitations, respectively. The maximum FOM for various different excitation levels is observed to be as high as 7.7. The proposed ASECE is superior to prior art with respect to FOM, by at least 1.15×, 1.63×, and 2.21× under 2 V, 1 V, and 0.5 V outputs, respectively, under strong excitation.

A Low-Profile Autonomous Interface Circuit for Piezoelectric Micro-Power Generators

“…Furthermore, this calculation is true for low electromechanically coupled PEHs under purely sinusoidal vibrations [31], which are good assumptions for the targeted PEH and operating conditions. Table I presents theoretical maximum output power expressions of FBR [16], voltage doubler [10], [16], and SECE [32] which are well studies in the literature. Furthermore, if we substitute for optimum storage voltage V ST O R,O PT expression (9) into equation (7), we can achieve P S S H expression for the maximum output power of synchronized switch harvesting (SSH) based techniques (SSHI, SSHC, and SSHCI).…”

A self-powered PSSHI and SECE hybrid rectifier for piezoelectric energy harvesting

“…Thus, the hybrid rectifier is able to charge the load to a higher voltage. [8] and [26], but is inferior to [38]. However, the SICE rectifier in [38] cannot cold-start without the external power supply.…”

“…[8] and [26], but is inferior to [38]. However, the SICE rectifier in [38] cannot cold-start without the external power supply. Also, because the SICE in [38] adopts CMOS technology, so it takes a great advantage in power loss.…”

“…However, the SICE rectifier in [38] cannot cold-start without the external power supply. Also, because the SICE in [38] adopts CMOS technology, so it takes a great advantage in power loss. As a whole, the proposed hybrid rectifier demonstrates the advantages in topology, cold-start ability, peak output power and load voltage range.…”

“…Although the SSHI, SECE and their variants have been intensively investigated, there is relatively little research on the combination of these fundamental techniques. As an attempt, some recent works proposed the so-called synchronous inversion and charge extraction (SICE) technique [36,37,38]. The SICE only flips the PE voltage in one half-cycle of vibration, and extracts the PE energy in the other half-cycle, which combines the flipping operation and SECE operation together.…”