Electrodynamic suspension (EDS) is based on the repulsive force created by induced eddy currents in a conductive body (rail), a magnetic excitation system and a relative speed between the magnet field and the rail. When the excitation system is realized as Halbach array of permanent magnets and mounted on a moving vehicle (pod), it can create the required lift to levitate the pod and no further mechanical suspension is needed. EDS is one of the few vehicle suspension concepts that could operate reliably at high speeds. Therefore, it gains interest for high-speed transportation applications as for the Hyperloop project, which is mainly driven by the Space Exploration Technologies Corporation (SpaceX). Electrodynamic fields and forces have been analysed in detail in literature; however, the sophistication and/or limited applicability of analytical approaches or the computational burden of FEM/numerical methods render those impractical for the initial design of EDS systems. Therefore, power and loss scaling laws for EDS systems are derived in this work. A 3D simulation for a design example shows that the scaling law is within 10% deviation. Finally, the drag coefficient of EDS systems are compared to other forms of commercial high-speed ground and air transportation systems. A pod with EDS running in vacuum has the potential of decreasing energy consumption significantly above the cruising speeds of modern subsonic airliners.
The stator winding is known to be a key factor to enhance the performance of electrical machines in terms of efficiency, lifetime, volume and consequently the costs. Therefore, the selection of the suitable winding technology and a proper design are mandatory to fulfill the challenging requirements defined by transportation electrification. The paper deals with the comparison of stator winding technologies to be used for high speed electrical machines for propulsion applications. The most commonly used winding configurations in automotive applications such as stranded wire and hairpin are compared with an innovative winding solution featuring formed litz wires. The analysis is carried out by comparing the main figures of merit such as the phase resistance, the AC loss factor and the thermal behavior of the different winding configurations. The reference machine explicitly designed for the analysis is a 24 krpm Permanent Magnet assisted Synchronous Reluctance Machine featuring a peak power of 200 kW. The performance assessment, supported by analytical and numerical electromagnetic and thermal simulations, highlights the main features of each design solution.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.