Design and Analysis of a High‐Speed Radial Flux Permanent Magnet Synchronous Coupler With Electromagnetic Disconnection

ABSTRACT

This paper presents the design and a comprehensive electromagnetic, thermal and mechanical design assessment of a high‐speed radial flux permanent magnet synchronous coupler (RFPMSC) integrated with an electromagnetic disconnection mechanism for reliable torque transmission in safety‐critical applications. The main novelty of this work lies in the development of a unified electromagnetic–thermal–mechanical design framework in which torque capability, thermal behaviour, temperature‐induced demagnetisation of permanent magnets, mechanical integrity, vibration characteristics and controlled electromagnetic disengagement are considered simultaneously. An analytical electromagnetic model based on a Halbach magnet arrangement is developed to estimate the transmitted torque and magnetic field distribution, and the results are validated using two‐ and three‐dimensional finite element simulations. A multi‐objective design study is conducted to investigate the trade‐offs among torque capability, rotor mass, torque‐to‐mass ratio and manufacturing cost, leading to an optimised coupler configuration suitable for high‐speed operation. The axial magnetic force acting between the rotors is also analysed, and a linear solenoid actuator (LSA) is designed to enable rapid and reliable disengagement of the magnetic coupling. Unlike most existing studies, the thermal behaviour of the coupler is explicitly modelled and quantitatively linked to permanent magnet demagnetisation and the associated reduction in transmitted torque under worst case operating conditions. The results show that the proposed RFPMSC can transmit a maximum torque of approximately 77.26 N·m under adverse thermal conditions. Furthermore, the designed LSA can generate up to 520 N axial force, enabling reliable electromagnetic disengagement within approximately 55 ms. These results demonstrate the effectiveness of the proposed integrated design methodology for high‐speed magnetic coupler systems.