Volume 61 Issue 2 (2011) - Годишник на ТУ - София - Технически ...

3.5. Circuit-FEM CouplingBoth field problems are coupled with Matlab/Simulink circuit model interfacing withOctave/Lua, shown in Fig.3.In circuit model the electromagnet is represented with its coil resistance - R and inductance– L (Fig.4), both calculated by Femm. Interactions are successively and foreach time step the values of R and L are updated due to circuit current signal.Circuit model is represented with several Simulink sub-system blocks, shown inFig.4.Power electronics block is a DC-DC controllable converter which fed the electromagneticactuator circuit. In fact, it could be replaced by any supply source or electroniccircuit model.Fig.4. Electric circuit in Simulink.Fig.5. Electromagnetic actuator circuit sub-system.Calculated electromagnetic force is used for air-gap calculation in each time step by(9).Simulink block diagram of actuator circuit is presented in Fig.4. It realizes the Simulink-Octaveinterface. Octave-Femm interface is made by Lua-scrip file called bySimulink.118