Torque Density Improvement Of Spoke Type BLDC Motor Using Hollow Rotor Topology

• Main Author: Sulaiman, Farina
• Format: Thesis
• Language: English; English
• Published: 2016
• Subjects: T Technology (General); TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.utem.edu.my/id/eprint/18352/1/Torque%20Density%20Improvement%20Of%20Spoke%20Type%20BLDC%20Motor%20Using%20Hollow%20Rotor%20Topology.pdf; http://eprints.utem.edu.my/id/eprint/18352/2/Torque%20Density%20Improvement%20Of%20Spoke%20Type%20BLDC%20Motor%20Using%20Hollow%20Rotor%20Topology.pdf; http://eprints.utem.edu.my/id/eprint/18352/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=100134

A spoke type motor has high torque because it uses reluctance torque and magnetic torque simultaneously. Rotor spoke type BLDC have a large amount of circling flux below the permanent magnet. This means that the motor cannot operates in optimum condition due to large unused flux. To overcome this problem, thickness of inner rotor radius, r3 is increase in order to study effect of edge magnet. Hollow rotor is designed to maximize the usage of flux by contributing all the unused flux to circulate around coil. Finite Element Method(FEM) is used to analyze the characteristic and performance of spoke type BLDC machine which include radial flux density, tangential flux density, back emf, inductance, flux linkage and torque. Then, a new spoke type BLDC motor called as Hollow rotor is proposed to overcome the usage of flux in spoke type BLDC motor. For the methodology,some value for design of stator, coil and permanent magnet are selected based on the required specification. After that, electromagnetic characteristic of the selected conventional model is analyzed and parameter for the flux leakage reduction is carried out. In addition, performance analysis of the proposed hollow-rotor also been carried out.Hollow rotor spoke type BLDC motor is been fabricated and experimentally evaluated. The simulation results from the FEM are verified with the measurement result in term of back emf, static torque, torque vs speed, mechanical power, output power, dynamic torque and efficiency and has shown a good agreement. Torque density of hollow-rotor increase almost 50% compared to conventional spoke type BLDC motor. In conclusions, the research proposed a new improvement in spoke type BLDC motor that could provide higher torque density with reasonable motor size. Finally, this thesis provides guidelines, suggestions and proposes a better improved structure in designing BLDC motor.