modelGovHydro4PeltonFrancis
Extends from BaseClasses.GovHydro4Base (Base class for Governors of hydraulic turbines).
Information
This class extends the GovHydro4Base base class, implementing a governor which can be used for Pelton and Francis turbines.
The turbine characteristics is implemented as a linear interpolatipon of a given set of working points, which default values are shown in the following table:
| Stroke Position [PU] | Turbine Flow [PU] |
|---|---|
| 0.1 | 0 |
| 0.4 | 0.42 |
| 0.5 | 0.56 |
| 0.7 | 0.8 |
| 0.8 | 0.9 |
| 0.9 | 0.97 |
| 1 | 1 |
The points in the table describe the relationship of flow through the turbine to stroke of the gate actuating servomotor.
The first two data points will be used to extrapolate downward for stroke positions less than minimum in the table, while the last two data points will be used do extrapolate upward for stroke positions over than the maximum in the table.
The curve are smoothed by means of cubic Hermite splines such that the turbine flow preserves the monotonicity and its derivative is continuous, also if extrapolated (Fritsch-Butland interpolation).
The interpolated curve is proportional to turbine power, with the constant of proportionality being a function of available head. This constant must be specified by the turbine gain, At.
The typical value of At is slightly greater than unity while the typical range of Qnl is 0 - 0.15.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Control and Actuators | |||
| Modelica.SIunits.PerUnit | db1 (from GovHydro4Base) | 0 | Intentional dead-band width |
| Modelica.SIunits.PerUnit | db2 (from GovHydro4Base) | 0 | Unintentional dead-band width |
| Modelica.SIunits.Time | Tp (from GovHydro4Base) | 0.1 | Pilot servo time constant |
| Modelica.SIunits.Time | Tg (from GovHydro4Base) | 0.5 | Gate servo time constant |
| Modelica.SIunits.Time | Tr (from GovHydro4Base) | 5 | Dashpot time constant |
| Modelica.SIunits.PerUnit | uo (from GovHydro4Base) | 0.2 | Max gate opening velocity |
| Modelica.SIunits.PerUnit | uc (from GovHydro4Base) | -0.2 | Max gate closing velocity |
| Modelica.SIunits.PerUnit | gMax (from GovHydro4Base) | 1 | Maximum gate opening |
| Modelica.SIunits.PerUnit | gMin (from GovHydro4Base) | 0 | Minimum gate opening |
| Modelica.SIunits.PerUnit | rPerm (from GovHydro4Base) | 0.05 | Permanent droop |
| Modelica.SIunits.PerUnit | rTemp (from GovHydro4Base) | 0.3 | Temporary droop |
| Turbine | |||
| Real[:,:] | GvPgvTable (from GovHydro4Base) | [0, 0; 1, 1] | Points to define the curve Pgv = f(Gv) |
| Modelica.Blocks.Types.Smoothness | GvPgvSmoothness (from GovHydro4Base) | Modelica.Blocks.Types.Smoothness.LinearSegments | Smoothness of curve Pgv = f(Gv) |
| Modelica.SIunits.PerUnit | at (from GovHydro4Base) | 1.2 | Turbine gain |
| Modelica.SIunits.PerUnit | qnl (from GovHydro4Base) | 0.08 | No-load flow at nominal head |
| Modelica.SIunits.Time | Tw (from GovHydro4Base) | 1 | Water inertia time constant |
| Modelica.SIunits.PerUnit | hDam (from GovHydro4Base) | 1 | Head available at dam |
| Modelica.SIunits.PerUnit | dTurb (from GovHydro4Base) | 0.5 | Turbine damping factor |
| Initialization | |||
| Modelica.SIunits.PerUnit | qStart (from GovHydro4Base) | Turbine flow Start value | |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealInput | deltaOmegaPu (from GovHydro4Base) | ||
| Modelica.Blocks.Interfaces.RealInput | PrefPu (from GovHydro4Base) | ||
| Modelica.Blocks.Interfaces.RealOutput | PmPu (from GovHydro4Base) |