FLEHAP: A Wind Powered Supply for Autonomous Sensor Nodes

Abstract

Abstract:The development of the Internet of Things infrastructure requires the deployment of millions of heterogeneous sensors embedded in the environment. The powering of these sensors cannot be done with wired connections, and the use of batteries is often impracticable. Energy harvesting is the common proposed solution, and many devices have been developed for this purpose, using light, mechanical vibrations, and temperature differences as energetic sources. In this paper we present a novel energy-harvester device able to capture the kinetic energy from a fluid in motion and transform it in electrical energy. This device, named FLEHAP (FLuttering Energy Harvester for Autonomous Powering), is based on an aeroelastic effect, named fluttering, in which a totally passive airfoil shows large and regular self-sustained motions (limit cycle oscillations) even in extreme conditions (low Reynolds numbers), thanks to its peculiar mechanical configuration. This system shows, in some centimeter-sized configurations, an electrical conversion efficiency that exceeds 8% at low wind speed (3.5 m/s). By using a specialized electronic circuit, it is possible to store the electrical energy in a super capacitor, and so guarantee self-powering in such environmental conditions.

A Low Power AC/DC Interface for Wind-Powered Sensor Nodes

“…The diodes have been always perceived as a source of power loss and have been actively substituted in low power circuits. A mathematical model based on equations from [8] was developed and simulated in MATLAB to simulate the power consumption of different parts in the converter circuit with only the switches, coil, diode and output capacitor. The following equations represent the average power dissipated in the diode and switches and the output energy stored in the capacitor during one PWM cycle.…”

“…The choice of the DC/DC buck-boost converter is due to the ability to control its equivalent input resistance by changing the PWM duty cycle. In DCM mode, the input resistance can be independent of the load on the output of the DC/DC converter, and it can be expressed with the following equation [8]: The choice of the DC/DC buck-boost converter is due to the ability to control its equivalent input resistance by changing the PWM duty cycle. In DCM mode, the input resistance can be independent of the load on the output of the DC/DC converter, and it can be expressed with the following equation [8]:…”

“…The scope of this work is to design an electronic system to condition the signal generated by the novel wind harvester named Fluttering Energy Harvester for Autonomous Powering (FLEHAP) shown in Figure 1 [8]. This harvester is based on the fluttering instability effect as an alternative method to harvest energy from low wind speeds.…”

“…Different algorithms are often used and many researchers suggest various ways to implement such algorithms, as well as their variations, using customized circuits [1][2][3][4][5][6][7][8][9][10], or by programming a microcontroller [11]. However, the freedom of choice among such algorithms is not allowed in low-power systems, due to the inherent trade-off between computational complexity and power consumption.…”

A Self-Powered Wireless Water Quality Sensing Network Enabling Smart Monitoring of Biological and Chemical Stability in Supply Systems

“…A demonstration of this nexus is the flourishing of self-powered devices and networks for smart metering, leveraging Internet-of-Things (IoT) electronics for monitoring water quality and consumption, especially aiming at leakage reduction [28,29]. Energy can be harvested from the flow of fluids in several ways [30,31], improving the efficiency, stability, and compactness commonly achieved, for instance, by solar panels [8]. Here, we demonstrated the possibility to self-power the proposed sensing node by means of an energy harvesting unit that enables its installation in remote sites, off the grid.…”