blockActuatorFilter

Filter used for actuators of valves, dampers and movers

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

Information

This block implements a filter that is used to approximate the actuators of valves, dampers and fans.

Implementation

The implementation is based on Modelica.Blocks.Continuous.CriticalDamping. It differs from that model in that the internal state of the filter s is transformed using x = u_nominal*s. It turns out that this transformation leads to smaller system of nonlinear equations if u_nominal ≠ 0, see IBPSA, #1498 for a discussion.

Parameters

TypeNameDefaultDescription
Integern2Order of filter
Modelica.Units.SI.FrequencyfCut-off frequency
Booleannormalizedtrue= true, if amplitude at f_cut is 3 dB, otherwise unmodified filter
Realu_nominal1Magnitude of input
Initialization
Modelica.Blocks.Types.InitinitTypeModelica.Blocks.Types.Init.NoInitType of initialization (1: no init, 2: steady state, 3: initial state, 4: initial output)
Real[n]x_startzeros(n)Initial or guess values of states
Realy_start0.0Initial value of output (remaining states are in steady state)

Connectors

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

Components

TypeNameDefaultDescription
Real[n]xu_nom*sTransformed filter states

Revisions

  • February 7, 2025, by Jelger Jansen:
    Removed import statement. This is for IBPSA, #1961.
  • July 22, 2021, by Michael Wetter:
    First implementation for IBPSA, #1498