Exciter Model: IEEEX4

Following checks and corrections are applied during Validation and AutoCorrection.

• If 0.0 < Tr < 0.25*Mult*TimeStep then T1 = 0.0
  ElseIf 0.25*Mult*TimeStep < Tr < 0.5*Mult*TimeStep then Tr = 0.5*Mult*TimeStep
• If 0 < Trh < Mult*TimeStep then Trh = Mult*TimeStep
• If 0 < Te < Mult*TimeStep then Te = Mult*TimeStep
• If Vrmax < Vrmin then swap the values

Mult represents the user-specified value Minimum time constant size as multiple of time step option on the Validation page of the Transient Stability Dialog

TimeStep represents the integration time step being used as described on TimeStep

Following treatment is handled during the transient numerical simulation

• If Vr > Vrmax, then Vrmax = Vr or if Vr < Vrmin, then Vrmin = Vr