modelDerivativeLag

Derivative filter with lag

Extends from Modelica.Blocks.Interfaces.SISO (Single Input Single Output continuous control block).

Information

Implements a derivative filter with lag, a.k.a. real differentiator:

y s*Td
- = -------------
u     1 + s*T1

If Td = T1 > 0, a high-pass or washout filter with cut-off frequency 1/Td is obtained.

If Td = T1 = 0 a filter with transfer function 1 is obtained. 

By default, T1 and T2 are structural parameters, so they cannot be changed at runtime without recompiling the model. In order to do so, set the noDynamics parameter explicitly to false (note that you can't set T1  and T2 to zero = 0 at runtime in this case).

Parameters

TypeNameDefaultDescription
SI.TimeT1Lag time constant
SI.TimeTdT1Derivative time constant
BooleannoDynamicsnot (T1 > 0)Trivial configuration with no dynamics G(s) = 1
Initialization
Modelica.Blocks.Types.InitinitTypeModelica.Blocks.Types.Init.NoInitType of initialization (1: no init, 2: steady state, 3/4: initial output)
RealyStart0Initial or guess value of output (= state)

Connectors

TypeNameDefaultDescription
RealInputu (from SISO)Connector of Real input signal
RealOutputy (from SISO)Connector of Real output signal

Components

TypeNameDefaultDescription
Modelica.Blocks.Math.Feedbackfeedback
Modelica.Blocks.Math.Gaingain
Modelica.Blocks.Continuous.Integratorintegrator
Modelica.Blocks.Sources.RealExpressionzero