Division by zero in PowerSystems.Examples.AC3ph.Generation.Islanding

[maltelenz]

The Islanding example:

PowerSystems/PowerSystems/Examples/AC3ph/Generation.mo

Lines 1129 to 1135 in 67d22eb

	PowerSystems.AC3ph.Generation.TurboPMgenerator turboGen(
	redeclare model Governor = PowerSystems.Control.Governors.Governor1st
	"1st order",
	redeclare model Generator = PowerSystems.AC3ph.Machines.Synchron_pm (
	redeclare record Data =
	PowerSystems.Examples.Data.Machines.Synchron_pm560V_100kVA)
	"nth order")

has a division by zero problem.

Through a series of extends, we end up in PowerSystems.AC3ph.Machines.Partials.SynchronBase, specifically this line:

PowerSystems/PowerSystems/AC3ph/Machines.mo

Line 1008 in 67d22eb

v_f = v_rd[1]/c.wf;

In this context, c.wf is 0. It is computed here:

PowerSystems/PowerSystems/Utilities/Precalculation.mo

Line 493 in 67d22eb

c.wf := omega_nom*c.L_md[1]*p.If_nom/p.V_nom;

In this context, p is PowerSystems.Examples.Data.Machines.Synchron_pm560V_100kVA, which has:

PowerSystems/PowerSystems/Examples/Data/Machines.mo

Line 253 in 67d22eb

If_nom=0);