High-frequency, high-pole count design for improving specific power density of electric machines

Yoon, Andy Keehoon

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https://hdl.handle.net/2142/90749 Copy

Description

Title

High-frequency, high-pole count design for improving specific power density of electric machines

Author(s)

Yoon, Andy Keehoon

Issue Date

2016-04-19

Director of Research (if dissertation) or Advisor (if thesis)

Haran, Kiruba S.

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• AC Machines
• high pole count
• high frequency
• high power density
• induction machines
• permanent magnet machines

Abstract

This thesis introduces the high frequency, high pole count (HFHP) design for improving specific power density of electric machines for weight and/or volume sensitive applications. Although electric machine designs have reached a limit in terms of efficiency, reliability, and cost, newer applications such as in aviation or the oil and gas industry are demanding next-generation motors to be lighter and more compact. The benefit of HFHP design is shown analytically by observing the effect of frequency and pole count on air-gap flux density and torque, while its adverse effects on magnetizing reactance, leakage reactance, and iron/copper losses are realized. The concept is applied to two of the most ubiquitous electric machines today: induction machines and permanent magnet machines. Electrical equivalent circuits are utilized to analytically hypothesize the effect of HFHP designs, then finite element models (FEM) are built to verify the effects. For induction machines, significant reduction in magnetizing reactance is shown to result in growth in line current and low torque. For permanent magnet machines, however, reduction in magnetizing reactance is shown to not directly affect torque of the machine, thus increase in specific power density is shown. The design of a 1 MW, 13 kW/kg motor is described, based on the shown benefit of HFHP design in permanent magnet machines. The motor proves that adverse effects of high frequency and high pole count are manageable by employing air-gap windings, halbach arrays, and outer rotor topology.

Graduation Semester

2016-05

Type of Resource

text

Permalink

http://hdl.handle.net/2142/90749

Copyright and License Information

Copyright 2016 Andy K. Yoon

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