Candidate: James Ugwuogo
Title: Multi-purpose Electromagnetic Energy Harvesting System
Date: March 27, 2019
Time: 12:00 PM
Place: EIT 3142
Supervisor(s): Safavi-Naeini, Safieddin
This PhD thesis presents the design of a multi-purpose energy harvesting system that harvests mechanical energy and coverts them into low power electrical energy which are then used to power low power electronic devices.
As low-power ubiquitous electronic gadgets are increasingly becoming common place these days, the demand for battery-free operations for these portable devices are correspondingly becoming very popular.
The idea of battery-less or battery-free portable electronic devices is thought of as not only a solution for the problem of having to replace batteries in micro electronic devices but also as an environmental friendly solution for the health and environmental concerns occasioned by the disposal of electrochemical cells in landfills.
Achieving a battery-free operation, on the other hand, requires the conversion of one form of available energy into another form for which it was not naturally intended for (preferably into an electrical form). This process is what is generally referred to as energy harvesting. Although the field of energy harvesting is relatively new, it presents a vast area of study with enormous research potentials. Some of which are Solar, Thermal, Wind, Mechanical, Electromagnetic and Piezo electric.
This thesis presents an energy harvesting system that harvests electrical energy from diverse types of mechanical motion sources to supply power to an externally connected load or store the harvested power in an internal storage battery for a later use.
While there has already been a considerable amount of work done in this area, much of the published research works report low level harvested power in the order of micro- or milli- watt level. While others harvest energy from one source, this thesis demonstrates a system that is multi-purpose in nature. The system could be worn by a human on the knee, elbow, or hip and can also be hand-cranked as well as could be installed on any enclosure with fixed and movable parts – e.g., doors and windows.
The human body has been touted as a ‘potential source for energy harvesting’ and rightly so as various parts of the human body support diverse forms of energy harvesting technology. By using the appropriate energy harvesting technology, it was estimated that the potential amount of energy available for harvesting from the heel strike while walking could be up to 1 W while the motion of bending the knee while performing the same act offers a potential of as much as 50 W of electrical power.
On the other hand, it is a well-known fact that the electromagnetic generator is one of the most efficient energy harvesting technology available. Designing an energy harvesting system with the electromagnetic energy harvester from ground up offers the advantage of fine-tuning the harvester specification for target or intended application.
This thesis takes advantage of the preceding and many more in the design of an electromagnetic energy harvesting system that takes advantage of the enormous amount of power available through the human motion – Knee, Hip, Elbow – to design an efficient system that can also be adapted in other application with fixed and movable parts.
The target of this research work is to design a light-weight, highly efficient system that could harvest enough electrical power that would be used in powering low power electronic devices such as Personal Digital Assistants (PDA), Mobile phones, and Health monitoring systems. At the core of this multi-purpose electromagnetic energy harvesting system is a new Brushless AC Electromagnetic Generator, an adaptive motion translation mechanism and a smart power management system.
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