Load Characteristic Model: CMPLDW
Following checks and corrections are applied during Validation and AutoCorrection.
- If Vmax < Vmin then swap the values. If Vmax < 0 then Vmax change sign to positive. Also if Vmin < 0.96 then Vmin = 0.96; and also if Vmax < 0.96 then Vmax = 0.96
- Mtypa, Mtypb, Mtypc and Mtypd: Must be either 1 or 3. This is an error and do not autocorrect the values.
- FmA, FmB, FmC, FmD and Fel: Summation of (FmA + FmB + FmC + FmD + Fel) must be less or equal than 1.0, and if not then the values will be normalized so that sum equals 1.0.
- For Motor Type 1 Motors (LD1PAC):
- If 0.0 < Tv < 0.5*Mult*TimeStep then Tv = 0, ElseIf 0.5*Mult*TimeStep < Tv < Mult*TimeStep then Tv = Mult*TimeStep
- If 0.0 < Tth < 0.5*Mult*TimeStep then Tth = 0, ElseIf 0.5*Mult*TimeStep < Tth < Mult*TimeStep then Tth = Mult*TimeStep
- If 0.0 < Frst < 0.5*Mult*TimeStep then Frst = 0, ElseIf 0.5*Mult*TimeStep < Frst < Mult*TimeStep then Frst = Mult*TimeStep
- If 0.0 < CompPF < 0.01*Mult*TimeStep then CompPF = 0.0
ElseIf 0.01*Mult*TimeStep < CompPF < Mult*TimeStep then CompPF = Mult*TimeStep
- For Motor Type 3 Motors (MOTOR_CMP):
- If 0 < Tpo < Mult*TimeStep then Tpo = Mult*TimeStep
- If H < 0.01 then H = 0.01.
- If Lp > 0.4*Ls then Lp = 0.4*Ls
- If Lpp > Lp then Lpp = Lp
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
Model Equations and/or Block Diagrams
-Same model as CMPLDW.
-Model supported by PSSE
Parameters:
| Mbase | Load MVA basea |
| Bss | Substation shunt B (pu on Load MVA base) |
| Rfdr | Feeder R (pu on Load MVA base) |
| Xfdr | Feeder X (pu on Load MVA base)b |
| Fb | Fraction of Feeder Compensation at substation end |
| Xxf | Transformer Reactance - pu on load MVA basec |
| Tfixhs | High side fixed transformer tap |
| Tfixls | Low side fixed transformer tap |
| LTC | flag (1: active during simulation, 0: inactive, -1: active during initialization, but inactive during simulation) |
| Tmin | LTC min tap (on low side) |
| Tmax | LTC max tap (on low side) |
| Step | LTC Tstep (on low side) |
| Vmin | LTC Vmin tap (low side pu) |
| Vmax | LTC Vmax tap (low side pu) |
| TD | LTC Control time delay (sec) |
| TC | LTC Tap adJustment time delay (sec) |
| Rcmp | LTC Rcomp (pu on load MVA base) |
| Xcmp | LTC Xcomp (pu on load MVA base) |
| FmA | Motor A Fraction |
| FmB | Motor B Fraction |
| FmC | Motor C Fraction |
| FmD | Motor D Fraction |
| Fel | Electronic Load Fractiond |
| PFel | PF of Electronic Loads |
| Vd1 | Voltage at which elect. loads start to drop |
| Vd2 | Voltage at which all elect.load have dropped |
| PFs | Static Load Power Factor |
| P1e | P1 exponente |
| P1c | P1 coefficient |
| P2e | P2 exponent |
| P2c | P2 coefficient |
| Pfrq | Frequency sensitivity |
| Q1e | Q1 exponent |
| Q1c | Q1 coefficient |
| Q2e | Q2 exponent |
| Q2c | Q2 coefficient |
| Qfrq | Frequency sensitivity |
| MtypA | Motor typef |
| LFmA | Loading factor (MW/MVA rating) |
| RaA | Stator resistance |
| LsA | Synchronous reactance |
| LpA | Transient reactance |
| LppA | Sub-transient reactance |
| TpoA | Transient open circuit time constant |
| TppoA | Sub-transient open circuit time constant |
| HA | Inertia constant |
| etrqA | Torque speed exponent |
| Vtr1A | U/V Trip1 V (pu) |
| Ttr1A | U/V Trip1 Time (sec) |
| Ftr1A | U/V Trip1 fraction |
| Vrc1A | U/V Trip1 reclose V (pu) |
| Trc1A | U/V Trip1 reclose Time (sec) |
| Vtr2A | U/V Trip2 V (pu) |
| Ttr2A | U/V Trip2 Time (sec) |
| Ftrt2A | U/V Trip2 fraction |
| Vrc2A | U/V Trip2 reclose V (pu) |
| Trc2A | U/V Trip2 reclose Time (sec) |
| MtypB | Motor type |
| LFmB | Loading factor (MW/MVA rating) |
| RaB | Stator resistance |
| LsB | Synchronous reactance |
| LpB | Transient reactance |
| LppB | Sub-transient reactance |
| TpoB | Transient open circuit time constant |
| TppoB | Sub-transient open circuit time constant |
| HB | Inertia constant |
| etrqB | Torque speed exponent |
| Vtr1B | U/V Trip1 V (pu) |
| Ttr1B | U/V Trip1 Time (sec) |
| Ftr1B | U/V Trip1 fraction |
| Vrc1B | U/V Trip1 reclose V (pu) |
| Trc1B | U/V Trip1 reclose Time (sec) |
| Vtr2B | U/V Trip2 V (pu) |
| Ttr2B | U/V Trip2 Time (sec) |
| Ftrt2B | U/V Trip2 fraction |
| Vrc2B | U/V Trip2 reclose V (pu) |
| Trc2B | U/V Trip2 reclose Time (sec) |
| MtypC | Motor type |
| LFmC | Loading factor (MW/MVA rating) |
| RaC | Stator resistance |
| LsC | Synchronous reactance |
| LpC | Transient reactance |
| LppC | Sub-transient reactance |
| TpoC | Transient open circuit time constant |
| TppoC | Sub-transient open circuit time constant |
| HC | Inertia constant |
| etrqC | Torque speed exponent |
| Vtr1C | U/V Trip1 V (pu) |
| Ttr1C | U/V Trip1 Time (sec) |
| Ftr1C | U/V Trip1 fraction |
| Vrc1C | U/V Trip1 reclose V (pu) |
| Trc1C | U/V Trip1 reclose Time (sec) |
| Vtr2C | U/V Trip2 V (pu) |
| Ttr2C | U/V Trip2 Time (sec) |
| Ftrt2C | U/V Trip2 fraction |
| Vrc2C | U/V Trip2 reclose V (pu) |
| Trc2C | U/V Trip2 reclose Time (sec) |
| Tstall | stall delay (sec)g |
| Trestart | restart delay (sec) |
| Tv | voltage input time constant(sec) |
| Tf | frequency input time constant(sec) |
| CompLF | compressor load factor, pu of rated powerh |
| CompPF | compressor power factor at 1.0 pu voltage |
| Vstall | compressor stall voltage at base condition (pu) |
| Rstall | compressor motor res. with 1.0 pu currenti |
| Xstall | compressor motor stall reactance - unsat. |
| LFadj | Load factor adjustment to the stall voltagej |
| Kp1 | real power constant for running state 1k |
| Np1 | real power exponent for running state 1 |
| Kq1 | reactive power constant for running state 1 |
| Nq1 | reactive power exponent for running state 1 |
| Kp2 | real power constant for running state 2 |
| Np2 | real power exponent for running state 2 |
| Kq2 | reactive power constant for running state 2 |
| Nq2 | reactive power exponent for running state 2 |
| Vbrk | compressor motor "breakdown" voltage (pu) |
| Frst | fraction of motors capable of restart |
| Vrst | voltage at which motors can restart (pu) |
| CmpKpf | real power constant for freq dependencyl |
| CmpKqf | reactive power constnt for freq dependency |
| Vc1off | Voltage 1 at which contactors start dropping out (pu) |
| Vc2off | Voltage 2 at which all contactors drop out (pu) |
| Vc1on | Voltage 1 at which all contactors reclose (pu) |
| Vc2on | Voltage 2 at which contactors start reclosing (pu) |
| Tth | compressor motor heating time constant(sec)m |
| Th1t | temp at which comp. motor begin tripping |
| Th2t | temp at which comp. all motors are tripped |
| Fuvr | fraction of comp. motors with U/V relays |
| UVtr1 | 1st voltage pick-up (pu) |
| Ttr1 | 1st definite time voltage pickup (sec) |
| UVtr2 | 2nd voltage pick-up (pu) |
| Ttr2 | 2nd definite time voltage |
| Frcel | Fraction of eletronic load that can restart |