Exciter Model: ST9C

 

Following checks and corrections are applied during Validation and AutoCorrection.

  • If 0.0 < Tas < 0.5*Mult*TimeStep then Tas = 0, ElseIf 0.5*Mult*TimeStep < Tas < Mult*TimeStep then Tas = Mult*TimeStep
  • If 0.0 < Tr < 0.5*Mult*TimeStep then Tr = 0, ElseIf 0.5*Mult*TimeStep < Tr < Mult*TimeStep then Tr = Mult*TimeStep
  • If 0.0 < Tbd < 0.5*Mult*TimeStep then Tbd = 0, ElseIf 0.5*Mult*TimeStep < Tbd < Mult*TimeStep then Tbd = Mult*TimeStep
  • If Ta = 0 then Ta = Mult*TimeStep
  • If KA = 0 then KA = Mult*TimeStep
  • If TAUEL= 0 then TAUEL= 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

Model Equations and/or Block Diagrams

Parameters:

OEL OEL input: if = 2, LV gate; if < 2, add to error signal
UEL UEL input: if = 2, HV gate; if < 2, add to error signal
SCL SCL input: if = 2, Take Over; if < 2, add to error signal
SW1 Logical switch 1 (1 = Position A, 2 = Position B)
Tr Filter time constant, sec.
Tcd Time constant of differential part of AVR, sec.
Tbd Filter time constant of differential part of AVR, sec.
Za Dead-band for differential part influence on AVR, sec.
Ka AVR gain
Ku Gain associated with activation of takeover UEL
Ta Time constant of AVR, sec.
Tauel Time coonstant of underexcitation limiter, sec.
Vrmax Maximum regulator output, p.u.
Vrmin Minimum regulator output, p.u.
Kas Power converter gain, proportional to supply voltage, p.u.
Tas Equivalent time constant of power converter firing control, sec.
Kp Potential circuit voltage gain coefficient
ThetaPDeg Potential circuit phase angle, degrees
Ki Potential circuit current gain coefficient
Xl Reactance associated with compound source, p.u.
Kc Rectifier loading factor proportional to commutating reactance
VbMax Maximum limit on exciter voltage based on supply condition, p.u.