Model of a single mode energy harvester and properties for optimal power generation

Abstract

The process of acquiring the energy surrounding a system and converting it into usable electrical energy is termed power harvesting. In the last few years, the field of power harvesting has experienced significant growth due to the ever increasing desire to produce portable and wireless electronics with extended life. Current portable and wireless devices must be designed to include electrochemical batteries as the power source. The use of batteries can be troublesome due to their finite energy supply, which necessitates their periodic replacement. In the case of wireless sensors that are to be placed in remote locations, the sensor must be easily accessible or of disposable nature to allow the device to function over extended periods of time. Energy scavenging devices are designed to capture the ambient energy surrounding the electronics and covert it into usable electrical energy. The concept of power harvesting works towards developing self-powered devices that do not require replaceable power supplies. The development of energy harvesting systems is greatly facilitated by an accurate model to assist in the design of the system. This paper will describe a theoretical model of a piezoelectric based energy harvesting system that is simple to apply yet provides an accurate prediction of the power generated around a single mode of vibration. Furthermore, this model will allow optimization of system parameters to be studied such that maximal performance can be achieved. Using this model an expression for the optimal resistance and a parameter describing the energy harvesting efficiency will be presented and evaluated through numerical simulations.The second part of this paper will present an experimental validation of the model and optimal parameters.

A 2DOF hybrid energy harvester based on combined piezoelectric and electromagnetic conversion mechanisms

“…7a that an increase of k p leads to an increase in power outputs in the 1DOF PEH, 2DOF PEH, and 2DOF hybrid P-EMEH models first, but finally the power outputs reach saturation in each case. The trends of power versus coupling from these energy harvesters are the same as the 1DOF PEH in previous studies (Guyomar et al, 2005;Liao and Sodano, 2008). Similarly, in Fig.…”

Theoretical and experimental studies of beam bimorph piezoelectric power harvesters

“…When a cantilever bimorph piezoelectric beam is attached to a vibrating base, electrical energy is produced continuously. Devices of this kind are often used to replace or extend the life time of electrochemical batteries for wireless sensors, implanted medical devices, handheld electronic devices, and other portable electronic devices [Roundy et al 2004;Yang 2006;Liao and Sodano 2008]. Compared with other energy scavenging methods such as electromagnetic [Glynne-Jones et al 2004] and electrostatic methods [Mitcheson et al 2004], piezoelectric vibration based energy harvesting systems have been attracting a lot of attention recently because of their simple structure, direct conversion of vibration energy into electrical energy with a high voltage level, lower number of additional electrical components, and not requiring an electric power source [Sodano et al 2004;Anton and Sodano 2007].…”

Distributed-Parameter Modeling of Energy Harvesting Structures with Discontinuities

“…entire structure) coupling coefficient for the r th mode is given by   22 2 0 er r kC   , a term that has been used to non-dimensionalize power in the literature, e.g. (Shu and Lien, 2006;Liao and Sodano, 2008;Wickenheiser and Garcia, 2010c). It has been shown by (Wickenheiser, 2011) that this term can be written in the form In the present study, the ratio 22 et kk is plotted, isolating the effects of geometry on the electromechanical coupling of the device.…”