Investigation of qualification methods for electric machines in urban air mobility application

Lewis, Maxwell

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https://hdl.handle.net/2142/116246 Copy

Description

Title

Investigation of qualification methods for electric machines in urban air mobility application

Author(s)

Lewis, Maxwell

Issue Date

2022-07-18

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

Haran, Kiruba A

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)

• Electrical engineering
• insulation
• reliability
• eVTOL
• Urban Air Mobility
• Thermomechanical reliability

Abstract

A significant challenge to developing electrified propulsion systems is ensuring the reliability of motor winding insulation. In an urban air taxi application, a motor responsible for propulsion will be operating under a unique mission profile. Traditionally, an aircraft will have a brief acceleration and climbing period and remain in a steady state operating condition while cruising. However, an urban air taxi application will require short mission profiles, featuring climbing much more frequently than a traditional mission. Concept machines for this application need to be made to optimize specific power to meet this demand, which in concept requires overloading these machines during climbing. The research community is investigating how this rapid overloading operation causes the electromechanical pieces to interact and how that impacts degradation of windings. With multiple pieces constantly heating and cooling, each with different thermal conductivities, the stresses applied to windings stand to vary considerably. This project has seen the procurement of samples representative of a concept eVTOL machine and will compare these operating cycles to the traditional Arrhenius aging relationship used to classify winding lifetimes. Degradation is tracked by quantifying changes in partial discharge phenomena and loss angle tests after varying operating conditions. The hope is to develop insulation lifetime models and identify trends associated with short mission cycles in a machine designed for an urban air taxi application to motivate future standards and lifetime models in the qualification of windings specific to this application.

Graduation Semester

2022-08

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Maxwell Lewis

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