Over Excitation Limiter Model: OEL2C

 

Following checks and corrections are applied during Validation and AutoCorrection.

  • If Kscalse <= 0.0001 then Kscalse = 0.0001

  • If TFCL <= 0.0001 then TFCL = 0.0001
  • If ITFpu <= 0.0001 then ITFpu = 0.0001
  • If 0.0 < TB1oel < 0.25*Mult*TimeStep then TB1oel = 0.0
    ElseIf 0.25*Mult*TimeStep < TB1oel < 0.5*Mult*TimeStep then TB1oel = 0.5*Mult*TimeStep
  • If 0.0 < Tb2oel < 0.25*Mult*TimeStep then Tb2oel = 0.0
    ElseIf 0.25*Mult*TimeStep < Tb2oel < 0.5*Mult*TimeStep then Tb2oel = 0.5*Mult*TimeStep
  • If 0.0 < TDoel < 0.25*Mult*TimeStep then TDoel = 0.0
    ElseIf 0.25*Mult*TimeStep < TDoel < 0.5*Mult*TimeStep then TDoel = 0.5*Mult*TimeStep
  • If 0.0 < TRoel < 0.25*Mult*TimeStep then TRoel = 0.0
    ElseIf 0.25*Mult*TimeStep < TRoel < 0.5*Mult*TimeStep then TRoel = 0.5*Mult*TimeStep
  • If 0.0 < TAoel < 0.25*Mult*TimeStep then TAoel = 0.0
    ElseIf 0.25*Mult*TimeStep < TAoel < 0.5*Mult*TimeStep then TAoel = 0.5*Mult*TimeStep
  • If VOELmax1 < VOELmin1 then swap the values. If VOELmax1 < 0 then VOELmax1 change sign to positive. If VOELmin1 > 0 then change sign to negative.
  • If VOELmax2 < VOELmin2 then swap the values. If VOELmax2 < 0 then VOELmax2 change sign to positive. If VOELmin2 > 0 then change sign to negative.
  • If VOELmax3 < VOELmin3 then swap the values. If VOELmax3 < 0 then VOELmax3 change sign to positive. If VOELmin3 > 0 then change sign to negative.
  • If VINVmax < VINVmin 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 LeadLagC1B1 > VOELmax1, then VOELmax1 = LeadLagC1B1 limits or if LeadLagC1B1 < VOELmin1, then VOELmin1 = LeadLagC1B1
  • If LeadLagC1B2 > VOELmax2, then VOELmax2 = LeadLagC1B2 limits or if LeadLagC1B2 < VOELmin2, then VOELmin2 = LeadLagC1B2
  • If VOELPID > VOELmax3, then VOELmax3 = VOELPID limits or if VOELPID < VOELmin3, then VOELmin3 = VOELPID
  • if IERRinv2 > VINVmax , then VINVmax = IERRinv2 limits or if IERRinv2 < VINVmin, then VINVmin = IERRinv2

Model Equations and/or Block Diagrams

Parameters:

OELInput OELInput: OEL Input, 0=Ifd, 1=Efd, 2=VFE
TC1oel TC1oel: OEL regulator denominator (lag) time constant 1 (s)
TB1oel TB1oel: OEL regulator numerator (lead) time constant 1 (s)
TC2oel TC2oel: OEL regulator denominator (lag) time constant 2 (s)
Tb2oel Tb2oel: OEL regulator numerator (lead) time constant 2 (s)
KPoel KPoel: OEL PID regulator proportional gain (pu)
KIoel KIoel: OEL PID regulator integral gain (pu/s)
KDoel KDoel: OEL PID regulator differential gain (pu)
TDoel TDoel: OEL PID regulator differential time constant (s)
VOELmax3 VOELmax3: Maximum OEL PID output limit (pu)
VOELmin3 VOELmin3: Minimum OEL PID output limit (pu)
VOELmax2 VOELmax2: Maximum OEL lead-lag 1 output limit (pu)
VOELmin2 VOELmin2: Minimum OEL lead-lag 1 output limit (pu)
VOELmax1 VOELmax1: Maximum OEL output limit (pu)
VOELmin1 VOELmin1: Minimum OEL output limit (pu)
Ireset Ireset: OEL reset reference, if OEL is inactive (pu)
Ten Ten: OEL activation delay time (s)
Toff Toff: OEL reset delay time (s)
ITHoff ITHoff: OEL reset threshold value (pu)
Kscale Kscale: OEL input signal scaling factor (pu)
TRoel TRoel: OEL input signal filter time constant (s)
Kact Kact: OEL actual value scaling factor (pu)
ITFpu ITFpu: OEL reference for inverse time calculations (pu)
Iinst Iinst: OEL instantaneous field current limit (pu)
Ilim Ilim: OEL thermal field current limit (pu)
TAoel TAoel: OEL reference filter time constant (s)
c1 c1: OEL exponent for calculation of IERRinv1
K1 K1: OEL gain for calculation of IERRinv1 (pu/pu)
c2 c2: OEL exponent for calculation of IERRinv2
K2 K2: OEL gain for calculation of IERRinv2 (pu/pu)
VINVmax VINVmax: OEL maximum inverse time output (pu)
VINVmin VINVmin: OEL minimum inverse time output (pu)
Fixedru Fixedru: OEL fixed delay time output (pu)
Fixedrd Fixedrd: OEL fixed cooling down time output (pu)
TFCL TFCL: OEL timer reference (pu)
Tmax Tmax: OEL timer maximum level (pu)
Tmin Tmin: OEL timer minimum level (pu)
KFB KFB: OEL timer feedback gain (pu)
Krd Krd: OEL reference ramp down rate (pu/s)
Kru Kru: OEL reference ramp up rate (pu/s)
KZRU KZRU: OEL thermal reference release threshold
IFDrated IFDrated: Rated field current (pu)
SW1 SW1: User selected logic, which will select fixed ramp rates or a ramp rate function of the field current