A semi-analytical, numerical and experimental study on performance characteristics of a novel hybrid-rotor CVT magnetic gearbox

Abstract

With the development of hybrid electric vehicles and wind turbines, the demand for improved efficiency, increased maintenance life, increased reliability, reduced noise, and environmental considerations has increased. Meanwhile, magnetic gearboxes, in particular the technology of continuous variable transmission (CVT) systems, provide an opportunity to meet these needs. In this paper, while presenting four topologies of a novel coaxial hybrid-rotor CVT magnetic gearbox with a consequent-pole high-speed rotor, a simple precise semi-analytical model is presented based on the subdomain method for calculating the magnetic performance characteristics of the gearboxes. Magnetic equations have been rewritten in a pseudo-Cartesian coordinate system, and by applying the appropriate boundary conditions and interface conditions, the general solution and their coefficients have been extracted using the separation of the variables method. The performance characteristics of four studied gearboxes were compared semi-analytically and numerically. A prototype coaxial consequent-pole magnetic gearbox has been fabricated and the results of semi-analytical modeling have been compared with the results of numerical simulations and the experimental tests. The maximum error percentage of the results of numerical simulations and experimental tests is about three, which shows that the proposed semi-analytical model has a high accuracy. A comparison of magnetic torque, torque ripple and induced voltage is carried out between the investigated designs.