Slotless motor is a suitable propulsion component candidate for high-speed aerospace applications due to their lightweight, low iron losses, and superior efficiency at high fundamental operating frequencies. The winding insulation design of the slotless machines requires special attention to ensure partial discharge (PD)-free operation due to the lower pressure levels at higher altitudes in aerospace applications. Finite-element analysis (FEA)-based simulations revealed that the maximum electric field strength is impacted by the separation distance between the random wound magnet wire conductors, thereby increasing the risk for PD in a low-pressure environment. Encapsulating the winding with high-strength dielectric material ensures reliable insulation, enhances manufacturing robustness, and improves thermal conductivity. The effect of potting thickness, defects in the potting, and relative permittivity of insulation have been analyzed using finite-element (FE) methods. The PD inception at reduced pressures was experimentally analyzed and corroborated with FEA using several samples of encapsulated coils.
Partial Discharge Free Insulation Design for Slotless Machines With Magnet Wire Conductors and Winding Encapsulation for Aerospace Applications
IEEE Transactions on Transportation Electrification ; 11 , 1 ; 787-796
2025-02-01
3942117 byte
Article (Journal)
Electronic Resource
English