Thrust force analysis based on H error evaluation and adaptive mesh for linear micromotor

To predict the thrust force accurately in the design of linear micromotor, the Coulomb virtual work (CVW) method was applied to calculate the electromagnetic thrust force based on the finite-element solution of the electromagnetic field. Since only the magnetic field intensity H in the air layer surrounding the moving part is used to calculate the thrust force in the CVW method, the local errors of H in the sheath air layer severely affect the calculation accuracy. To reduce the considerable local errors of H in finite-element field solution, an estimation method of H error with an adaptive mesh algorithm was proposed. The proposed method can adaptively refine the mesh according to the evaluation of H error and thus increase the accuracy of force calculation effectively while require less computation time.