ST5C
Exc IEEE ST5C model
This article is incomplete, some sections must be written.
Context
This voltage regulator model first appeared in the IEEE Std 421.5-2016 (of Electrical & Engineers, 2016). It has been reproduced identically in the IEC 61970-302:2024 version (Commission, 2024). In the previous standard version (2005), its predecessor model was called ST5B. Compared to ST5B, ST5C has additional options for connecting OEL and UEL inputs.
Model use, assumptions, validity domain and limitations
To be completed
Model inputs and output
The input variables are :
| Variable | Description | Units |
|---|---|---|
| IrPu | rotor current | pu (base SNom, user-selected base voltage) |
| UsPu | measured stator voltage | pu (base UNom) |
| UsRefPu | reference stator voltage | pu (base UNom) |
| UOelPu (optional) | output voltage of overexcitation limiter | pu (base UNom) |
| UPssPu (optional) | output voltage of power system stabilizer | pu (base UNom) |
| USclOelPu (optional) | output voltage of stator current overexcitation limiter | pu (base UNom) |
| USclUelPu (optional) | output voltage of stator current underexcitation limiter | pu (base UNom) |
| UUelPu (optional) | output voltage of underexcitation limiter | pu (base UNom) |
The output signal is EfdPu, the excitation voltage in pu (user-selected base voltage).
Model parameters
| Parameter | Description | Units |
|---|---|---|
| Kc | Rectifier loading factor proportional to commutating reactance, | pu |
| Kr | Gain of voltage after overexcitation and underexcitation limitations, | pu |
| PositionOel | Input location : (0) none, (1) voltage error summation, (2) take-over at AVR input | - |
| PositionScl | Input location : (0) none, (1) voltage error summation, (2) take-over at AVR input | - |
| PositionUel | Input location : (0) none, (1) voltage error summation, (2) take-over at AVR input | - |
| t1 | Inverse timing current constant | s |
| tB1 | Second lag time constant | s |
| tB2 | First lag time constant | s |
| tC1 | Second lead time constant | s |
| tC2 | First lead time constant | s |
| tOB1 | Second lag time constant (overexcitation limitation) | s |
| tOB2 | First lag time constant (overexcitation limitation) | s |
| tOC1 | Second lead time constant (overexcitation limitation) | s |
| tOC2 | First lead time constant (overexcitation limitation) | s |
| tR | Stator voltage filter time constant | s |
| tUB1 | Second lag time constant (underexcitation limitation) | s |
| tUB2 | First lag time constant (underexcitation limitation) | s |
| tUC1 | Second lead time constant (underexcitation limitation) | s |
| tUC2 | First lead time constant (underexcitation limitation) | s |
| VrMaxPu | Maximum field voltage | pu (user-selected base voltage) |
| VrMinPu | Minimum field voltage | pu (user-selected base voltage) |
Model diagram
Model variant
In the ST5B model :
- the overexcitation and underexcitation limitation voltages are applied at the AVR input
- there is no stator current limiter
Open source implementations
This model has been successfully implemented in :
| Software | URL | Language | Open-Source License | Last consulted date | Comments |
|---|---|---|---|---|---|
| Dynawo | Link | Modelica | MPL v2.0 | 24/05/2024 |
References
- of Electrical, T. I., & Engineers, E. (2016). IEEE recommended practice for excitation system models for power system stability studies . IEEE Std 421.5-2016. https://home.engineering.iastate.edu/ jdm/ee554/IEEEstd421.5-2016RecPracExSysModsPwrSysStabStudies.pdf
- Commission, I. E. (2024). Energy management system application program interface (EMS-API) Part 302: Common information model (CIM) dynamics. IEC 61970-302. https://webstore.iec.ch/preview/info_iec61970-302%7Bed2.0%7Db.pdf