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Full text release has been delayed at the author's request until August 01, 2025

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Dual Slotless Stator and Single Coreless Rotor Axial-Flux Permanent Magnet Machine for Integrated Motor-Compressor Systems

Bandarkar, Abdul Wahab
http://orcid.org/0000-0002-6410-5835
http://rave.ohiolink.edu/etdc/view?acc_num=akron1722512347067681

Abstract Details

2024, Doctor of Philosophy, University of Akron, Electrical Engineering.
Researchers worldwide are fervently working on developing efficient, lightweight, and compact electric machines across various industries to meet the growing demands of today’s world. To achieve these goals, a holistic system-level approach is necessary, moving beyond motor design alone. In the heating, ventilation, and air conditioning (HVAC) industry, where motor-driven compressors are extensively used, optimizing overall system efficiency is paramount. Recent advancements are focused on integrating the motor directly into the compressor housing, resulting in a more streamlined, cost-effective, and energy-efficient system. Radial-flux induction machines used in HVAC systems are less efficient than advanced permanent magnet (PM) machines. Axial-flux machines (AFMs) offer superior torque and power density but face adoption challenges due to cost and infrastructure. AFMs are well-suited for space-constrained applications like electric vehicles. Their planar design and adjustable airgaps provide advantages over radial-flux machines (RFMs). This dissertation proposes integrating the compressor impeller into the rotor of an electric motor for centrifugal motor-compressor systems in HVAC. The ideal motor for this integration is determined to be the axial-flux permanent magnet (AFPM) motor. While the Slotted version of this motor fits the design requirements, this study proposes the use of a Slotless structure due to its ease of manufacturability and smooth torque performance with a dual Slotless stator and single Coreless rotor (SL-AFPM) motor. Foremost, the research compares SL-AFPM with its counterpart, the Slotted axial-flux permanent magnet (S-AFPM) motor, focusing on two different slot/pole configurations. The study aims to explore the full potential of both designs while disregarding their application in integrated motor-compressor systems and associated limitations. The findings reveal that the SL-AFPM motor has smoother torque quality. Although the SL-AFPM motor incurs higher magnet costs, the absence of stator slots and processing expenses reduces the overall material cost compared to the S-AFPM motor. Despite its advantages, the SL-AFPM motor has a higher copper loss, relatively lower efficiency, and higher current ripple due to lower inductance. Conversely, the S-AFPM motor requires a lower magnet weight to generate the same torque, but its overall weight surpasses that of the SL-AFPM motor due to the presence of slots. The S-AFPM motor exhibits better efficiency due to lower magnetic airgap resulting in higher torque constant. Furthermore, a brief analysis of the impeller is addressed using computational fluid dynamics for a 5-tonnage air conditioning unit. This determines the size and power requirements of the SL-AFPM motor. Finite Element Analysis is employed to design the motor, considering identified constraints and using a multi-physics analysis approach for comprehensive optimization. A proof-of-concept prototype confirms the feasibility of the SL-AFPM concept and showcases its successful operation in meeting the application’s requirements. The prototype is evaluated both as a motor and a compressor, with measurements and performance data validating its effectiveness. This work provides valuable insights into motor-compressor integration and driving advancements in the HVAC, aerospace, and automotive industries.
Yilmaz Sozer (Advisor)
J. Alexis De Abreu Garcia (Committee Member)
J. Patrick Wilber (Committee Member)
Alper Buldum (Committee Member)
Malik E. Elbuluk (Committee Member)
192 p.
Electrical Engineering; Electromagnetics; Engineering; Fluid Dynamics; Mechanical Engineering
axial-flux machines; axial-flux permanent magnet machines; slotless axial-flux; slotted axial-flux; integrated motor-compressor system; motor-compressor; slotted; slotless; dual-stator; single-rotor; cost-effective; coreless rotor; comparison of radial and axial-flux machines

Recommended Citations

Citations

  • Bandarkar, A. W. (2024). Dual Slotless Stator and Single Coreless Rotor Axial-Flux Permanent Magnet Machine for Integrated Motor-Compressor Systems [Doctoral dissertation, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1722512347067681

    APA Style (7th edition)

  • Bandarkar, Abdul Wahab. Dual Slotless Stator and Single Coreless Rotor Axial-Flux Permanent Magnet Machine for Integrated Motor-Compressor Systems. 2024. University of Akron, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1722512347067681.

    MLA Style (8th edition)

  • Bandarkar, Abdul Wahab. "Dual Slotless Stator and Single Coreless Rotor Axial-Flux Permanent Magnet Machine for Integrated Motor-Compressor Systems." Doctoral dissertation, University of Akron, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=akron1722512347067681

    Chicago Manual of Style (17th edition)

akron1722512347067681
© 2024, all rights reserved.
This open access ETD is published by University of Akron and OhioLINK.