modelGovHydro4Base

Base class for Governors of hydraulic turbines

Information

This base model implements a control diagram wich can be specialized in governors for hydraulic turbines.

The upper part of the diagram implements the frequency primary regulation and the dynamic of the gates servomotor; the lower part completes the turbine model. 

The gates travel over a range of 1.0 per unit from fully closed to fully opened. The gates are at a position greater than zero at zero power and, normally, less than 1.0 when power is 1.0 pu. Gmax and Gmin are operating limits.

The caracteristic function of the turbine is omitted, because it depends on the turbine type (Pelton-Francis-Kaplan). Said characteristic shall connect the deadBandDb2 output to the input u1 of the div1 block, and shall be implemented in the specialized class.
In the specialized class can be also implemented additional inputs, if needed.

The caracteristic function describes the relationship of flow through the turbine to stroke of the gate actuating servomotor. 

This 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

TypeNameDefaultDescription
Control and Actuators
Modelica.SIunits.PerUnitdb10Intentional dead-band width
Modelica.SIunits.PerUnitdb20Unintentional dead-band width
Modelica.SIunits.TimeTp0.1Pilot servo time constant
Modelica.SIunits.TimeTg0.5Gate servo time constant
Modelica.SIunits.TimeTr5Dashpot time constant
Modelica.SIunits.PerUnituo0.2Max gate opening velocity
Modelica.SIunits.PerUnituc-0.2Max gate closing velocity
Modelica.SIunits.PerUnitgMax1Maximum gate opening
Modelica.SIunits.PerUnitgMin0Minimum gate opening
Modelica.SIunits.PerUnitrPerm0.05Permanent droop
Modelica.SIunits.PerUnitrTemp0.3Temporary droop
Turbine
Real[:,:]GvPgvTable[0, 0; 1, 1]Points to define the curve Pgv = f(Gv)
Modelica.Blocks.Types.SmoothnessGvPgvSmoothnessModelica.Blocks.Types.Smoothness.LinearSegmentsSmoothness of curve Pgv = f(Gv)
Modelica.SIunits.PerUnitat1.2Turbine gain
Modelica.SIunits.PerUnitqnl0.08No-load flow at nominal head
Modelica.SIunits.TimeTw1Water inertia time constant
Modelica.SIunits.PerUnithDam1Head available at dam
Modelica.SIunits.PerUnitdTurb0.5Turbine damping factor
Initialization
Modelica.SIunits.PerUnitqStartTurbine flow Start value

Connectors

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.RealInputdeltaOmegaPu
Modelica.Blocks.Interfaces.RealInputPrefPu
Modelica.Blocks.Interfaces.RealOutputPmPu

Components

TypeNameDefaultDescription
PowerGrids.Controls.DiscontinuousDeadBanddeadbandDb1
Modelica.Blocks.Math.Add3add1
PowerGrids.Controls.FirstOrderlagTp
Modelica.Blocks.Nonlinear.LimiterlimU
PowerGrids.Controls.IntegratorWithNonWindupLimiterlimIntG
Modelica.Blocks.Math.Addadd2
Modelica.Blocks.Math.GaingainRperm
PowerGrids.Controls.DerivativeLagderlagTrRtemp
Modelica.Blocks.Math.Divisiondiv1
Modelica.Blocks.Math.Productsquare1
Modelica.Blocks.Sources.ConstantconstHdam
Modelica.Blocks.Sources.ConstantconstQnl
Modelica.Blocks.Math.Productprod1
Modelica.Blocks.Math.GaingainAt
Modelica.Blocks.Math.Addadd3
Modelica.Blocks.Math.Addadd4
Modelica.Blocks.Math.Addadd5
Modelica.Blocks.Math.GaingainDturb
Modelica.Blocks.Math.Productproduct1
Modelica.Blocks.Math.GaingainTg
Modelica.Blocks.Math.GaingainRtemp
Modelica.Blocks.Continuous.IntegratorintTw
PowerGrids.Controls.DeadBanddeadBandDb2