Analytical Optimization of Surface-Mounted Machines With Odd-/Even-Piece Halbach Magnets

An analytical optimization technique for surface-mounted electrical machines having odd-/even-piece Halbach magnets has been proposed. The magnetic fields caused by the odd-/even-piece Halbach arranged magnets are solved. The electromagnetic parameters are analyzed and derived for odd- /even-piece Halbach machines. For the purpose of maximizing the electromagnetic torque, the optimal radian ratio of each magnet piece and/or the orientation angle of each side-magnet can be analytically determined. The performances of optimized three-/four-piece Halbach machines are better than those of corresponding conventional Halbach machines. The analytically optimized results are validated with a finite-element method.