Switched Shunt Model: SVSMO3
Some important SVC Control Considerations when running Transient Stability.
AutoCorrection Properties
Following checks and corrections are applied during Validation and AutoCorrection.
- If 0.0 < Tb1 < 0.5*Mult*TimeStep then Tb1 = 0, ElseIf 0.5*Mult*TimeStep < Tb1 < Mult*TimeStep then Tb1 = Mult*TimeStep
- If 0.0 < Tb2 < 0.5*Mult*TimeStep then Tb2 = 0, ElseIf 0.5*Mult*TimeStep < Tb2 < Mult*TimeStep then Tb2 = Mult*TimeStep
- If 0.0 < Tdelay1 < 0.5*Mult*TimeStep then Tdelay1 = 0, ElseIf 0.5*Mult*TimeStep < Tdelay1 < Mult*TimeStep then Tdelay1 = Mult*TimeStep
- If 0.0 < Tdelay2 < 0.5*Mult*TimeStep then Tdelay2 = 0, ElseIf 0.5*Mult*TimeStep < Tdelay2 < Mult*TimeStep then Tdelay2 = Mult*TimeStep
- Xc0: Xc0 value should matchthe Xc value in the power flow model, if not the same the then Xc1 parameter is autocorrected to the Xc value of the power flow model.
- Ki: If Ki > 1/(2*TimeStep) then Ki = 1/(2*TimeStep)
- Kir: If Kir > 1/(2*TimeStep) then Kir = 1/(2*TimeStep)
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 SlowB > Vrmax, then Vrmax = SlowB or if SlowB < Vrmin, then Vrmin = SlowB
- If Vref > Vefrmax, then Vrefmax = Vref or if Vref < Vrefmin, then Vrefmin = Vref
- If Verr > Vemax, then Vemax = Verr or if Verr < Vemin, then Vemin = Verr
- If Bpi > Bmax, then Bmax = Bpi or if Bpi < Bmin, then Bmin = Bpi
Model Equations and/or Block Diagrams
Parameters:
| modbase | Model Base, MVA |
| Xc0 | Constant linear drop, pu) |
| Tc1 | Voltage measurement lead time constant, sec |
| Tb1 | Voltage measurement lag time constant, sec |
| Kp | Voltage regulator proportional gain, pu/pu |
| Ki | Voltage regulator integral gain, pu/pu sec |
| vemax | Max. allowed voltage error, pu |
| vemin | Min. allowed voltage error, pu |
| To | Firing sequence control delay, sec |
| Imax1 | Max. continuous current rating, pu on model MVA base |
| dbd | Voltage control deadband, pu |
| Kdbd | Ratio of outer to inner deadband, pu |
| Tdbd | Deadband time, sec |
| Kpr | Proportional gain for slow reset control, pu/pu |
| Kir | Integral gain for slow reset control, pu/pu sec |
| Idbd | Deadband range for slow reset control, pu |
| Vrmax | Maximum limit of slow reset control, pu |
| Vrmin | Minimum limit of slow reset control, pu |
| Ishrt | Max. short term current rating as multiple of continuous rating, pu |
| UV1 | Voltage at which performance limit starts to be reduced lineraly, pu |
| UV2 | Voltage below which performance limit is blocked, pu |
| OV1 | Voltage above which limit lineraly drops, pu |
| OV2 | Voltage above which blocks its output, pu |
| Vtrip | Voltage above which trips after Tdelay2, pu |
| Tdelay1 | Short term rating delay, sec |
| Tdelay2 | Trip time for V > Vtrip, sec |
| ecap | Enable(1) or disable(0) MSS switching |
| Iupr | Upper threshold for switching MSS, pu |
| Ilwr | Lower threshold for switching MSS, pu |
| TdelLC | Time delay for switching in a shunt, sec |
| Tout | Time cap. bank should be out before switching back, sec |
| sdelay | Delay, sec |
| I2t | I2t limit, pu pu sec |
| Reset | Reset rate I2t limit, pu pu |
| hyst | Hysteresis, pu |
| Flag1 | Slow reset is On(1) or Off(0) |
| Flag2 | Non-linear droop is On(1) or Off(0) |
| Xc1 | Non-linear droop slope 1, pu/pu) |
| Xc2 | Non-linear droop slope 2, pu/pu |
| Xc3 | Non-linear droop slope 3, pu/pu |
| V1 | Non-linear droop upper voltage, pu |
| V2 | Non-linear droop lower voltage, pu |
| Tc2 | Lead time constant, sec |
| Tb2 | Lag time constant, sec |
| Tmssbrk | MSS breaker switch delay, sec |