Exciter Model: AC7C
AutoCorrection Properties
Following checks and corrections are applied during Validation and AutoCorrection.
- If 0 < Te < Mult*TimeStep then Te = Mult*TimeStep
- If 0 < Tf < Mult*TimeStep then Tf = Mult*TimeStep
- If 0.0 < Tdr < 0.5*Mult*TimeStep then Tdr = 0, ElseIf 0.5*Mult*TimeStep < Tdr < Mult*TimeStep then Tdr = Mult*TimeStep
- If 0.0 < Tr < 0.25*Mult*TimeStep then Tr = 0.0
ElseIf 0.25*Mult*TimeStep < Tr < 0.5*Mult*TimeStep then Tr = 0.5*Mult*TimeStep - If Vrmax < Vrmin then swap the values
- If Vamax < Vamin then swap the values
- Kpr and Kir: Kpr can't be 0 if Kir = 0, if true then Kpr changed to 40.
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
- If Va > Vamax, then Vamax = Va or if Va < Vamin, then Vamin = Va
- If Ve > ((VFemax-Kd*Ifd)/(Ke + Se(Ve)), then VFemax = ((VFemax-Kd*Ifd)/(Ke + Se(Ve)) or if Ve < Vemin, then Vemin = Ve
Model Equations and/or Block Diagrams
Parameters:
| OEL | OEL input: if < 2, add to error signal; if = 2, LV gate 1; if = 3, LV gate 2; if = 4, LV gate 3; |
| UEL | UEL input: if < 2, add to error signal; if = 2, HV gate 1; if = 3, HV gate 2; |
| SCL | SCL input: if < 2, add to error signal; if = 2, HV gate 1; if = 3, HV gate 2; |
| VOS | PSS input: if = 1, add to error signal; if = 2, add after HV gate 1 |
| SW1 | Logical switch 1 (1 = Position A, 2 = Position B) |
| SW2 | Logical switch 2 (1 = Position A, 2 = Position B) |
| Tr | Filter time constant, sec |
| Kpr | Proportional gain, pu |
| Kir | Integral gain, pu |
| Kdr | Regulator derivative gain, pu |
| Tdr | Derivative gain washout time constant, sec |
| Vrmax | Maximum exciter control signal, pu |
| Vrmin | Minimum exciter control signal, pu |
| Kpa | Amplifier proportional gain, pu |
| Kia | Amplifier integral gain, pu |
| VaMax | Maximum control element output, pu |
| VaMin | Minimum control element output, pu |
| Kp | Potential source gain, pu |
| Kl | Exciter field current limiter gain, pu |
| KF1 | Generator field voltage feedback gain, pu |
| KF2 | Exciter field current feedback gain, pu |
| KF3 | Rate feedback gain, pu |
| Tf | Rate feedback constant, sec |
| KC | Rectifier loading factor proportional to commutating reactance |
| Kd | Exciter internal reactance, pu |
| Ke | Exciter field resistance constant, pu |
| Te | Exciter field time constant, sec |
| Vfemax | Exciter field current limit parameter, pu |
| Vemin | Minimimum exciter output voltage, pu |
| E1 | Field voltage value, 1 |
| SE1 | Saturation factor at E1 |
| E2 | Field voltage value, 2 |
| SE2 | Saturation factor at E2 |
| Ki | Potential circuit (current) gain coefficient |
| XL | Reactance associated with potential source |
| ThetaP | Potencial circuit phase angle, degrees |
| KC1 | Rectifier loading factor proportional to commutating reactance |
| Vbmax | Maximum available exciter field voltage |
| Kr | Field voltage feedback gain, pu |
| Spdmlt | If not zero, multiply output (Efd) by generator speed |