Design and optimization of magnetic gears with arrangement and mechanical constraints for wind turbine applications

Abstract

This article focuses on the design and optimization of magnetic and mechanical (structural) parts of magnetic gears for wind turbine applications. In particular, this design takes into account the structural aspects of magnetic gears as well as the system's mechanical constraints (deformation and stress). Geometric parameters have been optimized in order to minimize the material costs for a 3.9 MW, 15 rpm wind turbine. This optimization strategy includes both magnetostatic and mechanical stationary finite element analyses. Optimization results underscore the necessity to take mechanical constraints into account, especially for the fixed ferromagnetic pole pieces.

Supporting the Laminated Ferromagnetic Pole Pieces in a Magnetic Gear: A Structure Behaviour Analysis from a Multibody Model

“…7a shows the displacements of the support bars generated by the magneto-mechanical loads; Fig. 7b shows the displacements generated by the weight with a coefficient of amplification for the magnetic gear studied in [3]. For this magnetic gear, the maximum calculated radial displacement is 0.5 mm.…”

“…Support bar will then transmit to the structural parts the magneto-mechanical load of the laminated pole pieces. Support bars are thus subjected to variable radial and tangential magneto-mechanical loads; their induced displacements and stresses must be then taken into account for their sizing (see [3]).…”

“…In return, mechanical gearboxes induce production interruptions and repairs, which increase operating costs [2]. In this context, an interesting way is to develop a conversion chain with a mediumspeed generator and a magnetic gear [3] (with non-contact power transmission) ( fig.1c). The most studied topology of magnetic gears has been proposed by Martin [4] and was the subject of different behaviour studies proposed by Atallah [5].…”

Gear ratio optimization of a full magnetic indirect drive chain for wind turbine applications

“…We call it full magnetic indirect drive (FMID) [4]- [5]. The most attractive magnetic gears topology has been proposed by Martin [6] and was the subject of different studies proposed by Atallah [7]- [8] and others [9]- [10].…”

“…Then, it is possible to define the ratio (2) and the Willis relation for a magnetic gear (3) like a planetary gear [16] where /0 , /0 and /0 are the speed rotation of the internal ring, the external ring and the pole pieces ring respectively. Depending on the fixed ring, the gear ratio is given by (4). In this article, only the case where the external permanent magnet ring is fixed is studied because this case maximizes the gear ratio and then minimizes the output torque.…”