This paper describes a general method for preliminary design of fast-acting
solenoid actuators, Moving armature, drive circuit, and nonlinearities are
modeled, as well as eddy currents for solid iron devices. The electromagne
tic model is obtained by computing two magnetization characteristics corres
ponding to the extreme positions of the armature and a novel interpolation
function for the intermediate positions. This function, characterizing the
magnetic configuration of the actuator, is computed analytically and leads
also to an analytical formulation of the magnetic force. In order to achiev
e extremely fast computation, eddy currents are modeled through a new type
of electric equivalent network, derived directly from Maxwell's equations a
nd taking into account the actual BH nonlinearities, moving armature, and d
evice geometry. The method is demonstrated on a pot-core solenoid actuator
and compares favorably with finite-element results and measurements.