Analysis of a radial permanent magnetic bearing for 1 MW horizontal axis wind turbine

Abstract

Permanent magnetic bearing applies the principle of electromagnetic levitation that makes it able to support various forces and loads in HAWT operational conditions without friction. The design of PMB in this study uses permanent magnet Nd2Fe14B material that a Coulombian model radially magnetized. The finite element analysis was used to model the radial magnetic force from radial displacement between rotor-stator magnets. Modeling was also used to obtain magnetic flux density at magnet geometry (BMax), magnetic flux density at air gap magnet (Bairmax), radial magnetic force (Fr), and radial displacement (dX). The PMB models were designed on the magnets thickness (0.9 m; 1.35 m; and 1.8 m) and the radial air gaps (0.02 m; 0.03 m; and 0.04 m). The lower radial air gap of the PMB model produces a greater radial magnetic force (Fr). Furthermore, the thicker the PMB magnet increases the magnetic flux density and radial magnetic force. The PMB model V3 yields a radial magnetic force of 254 kN with the shortest radial displacement (15.3 mm).