ForceCurrentBehaviourComparison of the forcecurrent characteristics of both converter models with armature blocked at midposition 
This information is part of the Modelica Standard Library maintained by the Modelica Association.
Have a look at ConstantActuator and at PermeanceActuator for an explanation of both converter models.
Simulation of the forcecurrent characteristics of both converter models with the armature blocked at midposition x=0 reveals the difference between the two models. In the ConstantActuator, force is proportional to current. In the simple PermeanceActuator there is an additional nonlinear force component that is due to the dependency of the inductance on the armature position. Comparison with FEA results validates the higher accuracy of the PermeanceActuator. In the FEA model, the relative permeability of the stator iron was set to mu_rFe=const.=1000 in order to avoid additional nonlinear force components due to saturation. Simulate for 6 s and plot vs. current (e.g., iSensor.i)
pmFixedPos.flange_b.f // force of permeance model cFixedPos.flange_b.f // force of converter constant model comparisonWithFEA.y[1] // force of FEA model for comparison
pmGround 
Type: Ground 


pmActuator 
Type: PermeanceActuator Description: Moving coil actuator described with permeance model 

pmFixedPos 
Type: Fixed Description: Fixed armature position 

pmRampCurrent 
Type: RampCurrent Description: Ideal current source 

cGround 
Type: Ground 

cFixedPos 
Type: Fixed Description: Fixed armature position 

cRampCurrent 
Type: RampCurrent Description: Ideal current source 

cActuator 
Type: ConstantActuator Description: Moving coil actuator described with converter constant 

comparisonWithFEA 
Type: CombiTable1Ds Description: Column 1: current, col. 2: force; mu_rFe=const.=1000 in FEA model 

iSensor 
Type: CurrentSensor Description: Input value for lookup table with FEA results 