Finite element modelling of magnetic fields and calculation of static characteristics of linear step motors for control rod drives of nuclear reactors

Describes an accurate method for the calculation of the static characteristics of linear step motors (LSMs) used as actuators in control rod drives of nuclear reactors. By static characteristics, the authors mean the electromagnetic force developed by the motor versus armature displacement curve that determines motor performance in its standing and dynamic modes of operation. The method is based on the modelling and computation of nonlinear axisymmetric magnetic fields in the LSM using the finite element technique. Some of the simulation results are compared with available experimental data which validates the developed method