Design and Analysis of a High-Speed Wet-Type Fault-Tolerant Permanent Magnet Motor Considering Oil Frictional Loss for Aerospace Electrohydrostatic Actuator Application

This article proposes a new high-speed wet-type fault-tolerant permanent magnet synchronous motor (WFTPMSM) for aerospace electrohydrostatic actuator (EHA) application, which can solve the rotating oil seal issue of the EHA via the motor stator and rotor all immersed in hydraulic oil. The topological structure of the five-phase WFTPMSM is first proposed, in which the flux-intensifying rotor is used to improve the power density. The analytic expression of the oil frictional loss is proposed, while the multiphysics model of the WFTPMSM is established to accurately calculate the electromagnetic–thermal fluid performance. The oil frictional loss and thermal behavior are systematically analyzed. Finally, a 15-kW 20 000-r/min WFTPMSM is designed and manufactured. The experimental results show that the proposed WFTPMSM has the excellent electromagnetic performance with the power density of 3.3 kW/kg.