Hi Peter

Thank you so much for the advices!

I have tried the FourierSolver, but it calculates the loss at least after one or several rotational periods.

Actually, I want to optimize the motor with less calculation cost.

Hence, I tried the time-step method to calculate the hysteresis loss and eddy-current loss in each time-step, based on the reference

"V. Raulin, A. Radun and I. Husain, “Modeling of losses in switched reluctance machines,” IEEE Trans. Ind. Appl., vol. 40, no. 6, pp. 1560-1569, Nov/Dec 2004."

The principle is not very difficult.

If the core loss can be calculated in each time-step, less time steps are requried.

Today, I found the "CalcFields solver" sloves B field and tried to add a subroutine to solve the core loss in CalcFields.F90. A new variable is defined in the Solver 2 of the sif:

Code: Select all

```
Solver 2
Exec Solver = Always
Equation = MgDyn2D
Variable = A
Exported Variable 1 = -global -dofs 1 P_hys
Procedure = "MagnetoDynamics2D" "MagnetoDynamics2D"
Stabilize = False
Partition Local Constraints = Logical True
Nonlinear System Compute Change in Scaled System = Logical True
Nonlinear System Convergence Measure = Residual
Nonlinear System Convergence Tolerance = 1e-6
Nonlinear System Max Iterations = 20
Nonlinear System Min Iterations = 1
Nonlinear System Relaxation Factor = 1.0
Nonlinear System Newton After Iterations = 7
Export Lagrange Multiplier = Logical True
Linear System Abort Not Converged = False
Linear System Solver = Iterative
Linear System Iterative Method = GCR
Linear System GCR Restart = 500
Bicgstabl Polynomial Degree = 4
Linear System Preconditioning = ILU4
Linear System Max Iterations = 1500
Linear System Residual Output = Integer 20
Linear System Convergence Tolerance = 1e-7
Mortar BCs Additive = Logical True
End
Solver 3
Exec Solver = Always
Equation = CalcFields
Potential Variable = "A"
Procedure = "MagnetoDynamics" "MagnetoDynamicsCalcFields"
Calculate Nodal Forces = Logical True
Calculate Magnetic Torque = Logical True
Calculate Magnetic Force = Logical True
Calculate Current Density = Logical True
Calculate Magnetic Vector Potential = Logical True
Frequency = Real $ f
Linear System Solver = Direct
Linear System Iterative Method = MUMPS
End
Solver 4
Exec Solver = After timestep
Equation = "ResultOutput"
Procedure = "ResultOutputSolve" "ResultOutputSolver"
Output File Name = case
Output Directory = results_5krpm
Save Geometry Ids = Logical True
Vtu Format = Logical True
End
Solver 5
Exec Solver = After timestep
Equation = scalars
Procedure = "SaveData" "SaveScalars"
Filename = transient_results.dat
Output Directory = results_5krpm
Variable 1 = Time
End
```

The "Exported Variable 1 = -global -dofs 1 P_hys" is declared, but the variable is not outputed in the VTU file.

It seems that the defined variable in sif is not linked with the pointer in solver subroutine.

And the calculated results in the subroutine is not linked with the solver variable. So I guess this is the reason why it is not outputed in the VTU file.

Thank you again for your hints. Maybe I should try to call the B field in another defined solver, instead of revising the "CalcFields.F90".

If it works, I will upload the solver code here. In case anyone needs that.