Problems solving initial system for Order5test2 in System Modeler

[maltelenz]

System Modeler has trouble solving the initial system for OpenIPSL.Tests.Machines.PSAT.Order5test2:

The initialization problem is structurally singular, the following equations cannot be solved for any variable:
	  0.0 = 6.28318530717959 * order5Type1_Inputs_Outputs.fn * (order5Type1_Inputs_Outputs.w + (-1.0))
	  pwLine1.n.ir + pwLine2.n.ir + pwLine3.p.ir + pwLine4.p.ir + pwLinewithOpening1.p.ir = 0.0

We can see that OpenModelica also has some trouble, warning:

Warning: It was not possible to determine if the initialization problem is consistent, because of not evaluable parameters/start values during compile time: $DER.order5Type1_Inputs_Outputs.delta = 0.0 (order5Type1_Inputs_Outputs.w_b * (-1.0 + $START.order5Type1_Inputs_Outputs.w) = 0.0)
Warning: The initial conditions are over specified. The following 1 initial equations are redundant, so they are removed from the initialization system:
         $DER.order5Type1_Inputs_Outputs.delta = 0.0.

Unfortunately the messaging in System Modeler isn't very helpful to pinpoint a more specific place.

Maybe someone with knowledge of the model is able to improve the specification of the initialization to make it easier to solve?

[gkhalley]

gkhalley@d289e2c
It seems reasonable to comment out 'der(delta) = 0;' in the initial equation of Order5Type1.

[maltelenz]

This change does resolve the issue in System Modeler.

[dietmarw]

Thankse @gkhalley I've now applied your fix (by removing it completely) in master.