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Insulation in electric machines is vital in determining system reliability and lifespan, especially under extreme environmental conditions. With the rapid shift toward More Electric Aircraft (MEA), All Electric Aircraft (AEA), and advanced space missions, electric motor components must perform reliably under low pressures, wide temperature ranges, and exposure to radiation. Magnet wires are central to motor operation, and their insulation must withstand high voltage stress in these demanding conditions. While prior research has predominantly focused on insulation performance under AC or pulse width modulated (PWM) waveforms and partial discharge (PD) behavior, there is a limited understanding of dielectric strength under direct current (DC) stress, particularly at reduced atmospheric pressures. This paper presents an experimental investigation into the DC dielectric strength of three magnet wire types (15 AWG, 18 AWG, and 20 AWG) tested at three pressure levels: 101kPa,80kPa, and 40 kPa. Using a voltage to breakdown with a constant ramp method, the study evaluates the insulation's withstand capacity across wire sizes and environmental pressures.
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This content will become publicly available on May 18, 2026
Breakdown Performance of Motor Winding Insulation Under Low Pressure Conditions
Electrical insulation is the limiting factor that reduces the lifetime of power components. The aging of insulation, which is heavily caused by partial discharges (PDs) and harsh environmental conditions, eventually leads to complete insulation breakdown. The advancement in developing more- and all-electric aircraft is limited by the existing apparatuses that operate at lower voltages. High applied voltage and lower ambient pressure, commonly envisaged in more and all-electric aircraft, pose significant challenges, as their effects on PD activity and space charge accumulation differ, thereby affecting the apparatus's lifetime. To improve the reliability of aircraft electric motors' performance, it is essential to accurately predict the breakdown performance of the magnet wires used as windings in the motors at low-pressure levels. In this article, we investigate the effect of low pressures on the breakdown voltage of magnet wires with insulation Type I.
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- Award ID(s):
- 2306093
- PAR ID:
- 10652880
- Publisher / Repository:
- IEEE
- Date Published:
- Page Range / eLocation ID:
- 830 to 833
- Format(s):
- Medium: X
- Location:
- Houston, TX, USA
- Sponsoring Org:
- National Science Foundation
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