A green hybrid energy harvesting system for rotational motion

This thesis describes a novel, innovative high powe r density electromagnetic energy harvester device powered by rotational motion. The primary ai m of the thesis was to develop high power density energy scavenging device extracting power from rota tion l motion. In this thesis, a novel permanent magnet array based energy harvesting device is deve loped and a charging circuit was prototyped to extr act the power generated by energy harvester and deliver it to battery. The design of the rotational energy harvester improves the performance, and the use of the axial flux permanent magnets enables inducing strong magnetic field in the coil, which resulted i n large induced voltage. Most of the research work published in the scienti fic journals has used ambient vibrations in the environment as the energy source. These devices hav e not achieved the desired power levels, which can enable their practical real life implantations as r eliable energy harvesting sources. Most of the rota tion l motion energy harvesters published in the scientifi c journals also have not been able to achieve high power density levels. The rotational motion energy harves ters have very important applications such as tire pressure sensing, and MEMS sensors in the automobil e, as wells as flywheel rotating mechanisms. In thi s work, it is demonstrated that in many applications, a rotational energy harvester can offer significan t improvements in power density over its vibration-dr iven counterparts. In thesis, using axial flux permanent magnet array s, a prototype of rotational electromagnetic energy harvester was developed. The rotational moti on was coupled to rotor in the laboratory to genera te the rotational torque. This creates a relative angu lar speed between rotor and stator, which enable th e power to be generated. The novel approach used in the des ign nables magneto static coupling between coils a nd permanent magnets that leads to higher flux change d greater induced voltage, which eventually lead to high power output. The detailed analysis of the mag netic material and air gap flux density distributio n is conducted in the thesis work. The detailed analytical model of the rotational en ergy harvested was created and implement using MatlabTM. The FEM modeling of the rotational motion e ergy harvester was created in FEM simulation software ANSYS MaxwellTM. The result of both analyti cal and FEM simulation matched well with the experimental data collected on the generator. A det ailed optimization procedure of boost converter was implemented using MatlabTM in order to maximize the power in the circuit. Using a novel approach to reduce the transformer losses in the boost converte r was developed which reduced the circuit losses. T he final charging circuit tests were conducted on the en rgy harvester. The power output of 2.5 Watts was calculated from a single harvester. The device gene rated open circuit voltage of 6.3V and short circui t current of 0.355 A at 2200 RPMs. Under maximum powe r transfer a single harvester delivered 0.6 W of power to load resistance of 18.2 ohms. To my Mom and Dad, family and friends I always wanted to live a genuine innovative life and this thesis is testament to who I am