Buildings.Fluid.Actuators.Motors

Information

Package Content

Name	Description
IdealMotor	Ideal motor model with hysteresis
Examples	Collection of models that illustrate model use and test models

Buildings.Fluid.Actuators.Motors.IdealMotor

Information

Ideal actuator motor model with hysteresis and finite actuation speed. If the current actuator position y is below (or above) the input signal u by an amount bigger than the hysteresis delta, then the position y is increased (decreased) until it reaches u. The output y is bounded between 0 and 1.

Note: This model can introduce state events which increase the computation time. For a more efficient implementation that approximates a motor, set in the valve or damper model the parameter filteredOpening=true instead of using this motor model. See also Buildings.Fluid.Actuators.UsersGuide.

Parameters

Type	Name	Default	Description
Real	delta	0.05	Hysteresis
Time	tOpe	120	Opening time [s]
Time	tClo	tOpe	Closing time [s]
Real	y_start	0.5	Start position

Connectors

Type	Name	Description
input RealInput	u	Connector of Real input signal
output RealOutput	y	Connector of Real output signal

Modelica definition

model IdealMotor "Ideal motor model with hysteresis"
  extends Modelica.Blocks.Interfaces.SISO;

  parameter Real delta(min=0, max=0.5) = 0.05 "Hysteresis";
  parameter Modelica.SIunits.Time tOpe(min=0) = 120 "Opening time";
  parameter Modelica.SIunits.Time tClo(min=0) = tOpe "Closing time";
  parameter Real y_start(min=0, max=1) = 0.5 "Start position";

  Modelica.Blocks.Logical.Hysteresis uppHys(final uLow=0, uHigh=delta,
    final pre_y_start=false);
  Modelica.Blocks.Logical.Hysteresis lowHys(uLow=-delta, final uHigh=0,
    final pre_y_start=true) "Lower hysteresis";
  Modelica.Blocks.Logical.Switch uppSwi;
  Modelica.Blocks.Continuous.LimIntegrator int(
    final y_start=y_start,
    final k=1,
    outMax=1,
    outMin=0,
    initType=Modelica.Blocks.Types.Init.InitialState,
    limitsAtInit=true,
    y(stateSelect=StateSelect.always)) "Integrator for valve opening position";

protected 
  final Modelica.Blocks.Sources.Constant zer(final k=0) "Zero signal";
  Modelica.Blocks.Sources.Constant vOpe(final k=1/tOpe) "Opening speed";
  Modelica.Blocks.Sources.Constant vClo(final k=-1/tClo) "Closing speed";
  Modelica.Blocks.Logical.Switch lowSwi;
  Modelica.Blocks.Math.Add add;
  Modelica.Blocks.Math.Feedback feeBac "Feedback to compute position error";
equation 
  connect(zer.y, uppSwi.u3);
  connect(uppHys.y, uppSwi.u2);
  connect(vOpe.y, uppSwi.u1);
  connect(lowHys.y, lowSwi.u2);
  connect(vClo.y, lowSwi.u3);
  connect(zer.y, lowSwi.u1);
  connect(add.y, int.u);
  connect(uppSwi.y, add.u1);
  connect(u, feeBac.u1);
  connect(feeBac.y, uppHys.u);
  connect(feeBac.y, lowHys.u);
  connect(lowSwi.y, add.u2);
  connect(int.y, y);
  connect(int.y, feeBac.u2);
end IdealMotor;