Design and parameter effect analysis of dual-rotor, radial-flux, toroidally wound, permanent-magnet machines

A novel machine family-the dual-rotor, radial-flux, toroidally wound, permanent-magnet (RFTPM) machine-has been proven in a previous paper to be able to improve the machine efficiency and boost the torque density. This paper will present the key design equations and design procedure of the RFTPM machines, analyze parameter effects on machine performance, and give design guidelines to achieve specific design objectives. In addition, finite-element analysis is employed to prove the effectiveness of the design equations and find the machine overload capability. Experimental measurements of a prototype, which match the design specifications well, verify the effectiveness of the design equations.