CPU-time for Energy Computations

Computation of power variables has no impact on the CPU-time of the model.

However, CPU-time may be impacted by the activation of energy variables (and activity variables) since in most cases they are state variables. These state variables are added to the list of existing state variables describing the physics of the system, so that the size of the system to be solved can increase significantly.

The choice to use some state variables for energy computations is guided by the accuracy in the energies computed, so that we can be sure they will match the accuracy of the other physical variables computed by the Simcenter Amesim solver.

We advise you to be careful to only select energy (and activity) computations when they are required. When not required, they should be deactivated.

Another way to proceed is to build two sets of models, the first set for usual dynamics analysis, and the second set for extended energy analysis.

Note

An alternative approach is to only activate power computations in Simcenter Amesim and to export the power results to be computed separately with a simple integration method. In doing this, you will not impact your CPU-time while still having access to the energy information afterwards, but you will lose some accuracy in the energy results since you will not get the accuracy of the variable time-step solver that is used to compute the physical quantities and power computations.