Remove time events in ETS model with heat recovery chiller (#4059)

* Reduced number of time events for ETS model For #4058 * Added pre block to break algebraic loop during initialization This is needed for OpenModelica * Removed duplicate connection * Increase minimum cycle time * Update results --------- Co-authored-by: Antoine Gautier <[email protected]>
lbl-srg · Nov 25, 2024 · 32156a1 · 32156a1
1 parent ba8277f
commit 32156a1
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diff --git a/Buildings/DHC/ETS/Combined/ChillerBorefield.mo b/Buildings/DHC/ETS/Combined/ChillerBorefield.mo
@@ -317,6 +317,13 @@ equation
       revisions="<html>
 <ul>
 <li>
+November 22, 2024, by Michael Wetter:<br/>
+Reduced number of time events by replacing zero order hold with true and false hold,
+and increasing the minimum cycle time.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/4058\">#4058</a>.
+</li>
+<li>
 March 27, 2024, by David Blum:<br/>
 Update icon.<br/>
 This is for <a href=\"https://github.com/lbl-srg/modelica-buildings/issues/3606\">issue #3606</a>.

diff --git a/Buildings/DHC/ETS/Combined/Controls/SideCold.mo b/Buildings/DHC/ETS/Combined/Controls/SideCold.mo
@@ -123,14 +123,18 @@ model SideCold
     iconTransformation(extent={{100,-20},{140,20}})));
   Buildings.Controls.OBC.CDL.Conversions.BooleanToReal booToRea
     "Convert DO to AO signal"
-    annotation (Placement(transformation(extent={{40,-110},{60,-90}})));
+    annotation (Placement(transformation(origin = {40, 0}, extent = {{80, -110}, {100, -90}})));
   Buildings.Controls.OBC.CDL.Reals.GreaterThreshold greThr(
     t=0.01)
     "Control signal is non zero (with 1% tolerance)"
     annotation (Placement(transformation(extent={{0,-110},{20,-90}})));
-  Modelica.Blocks.Discrete.ZeroOrderHold zeroOrderHold(
-    samplePeriod=60)
-    annotation (Placement(transformation(extent={{80,-110},{100,-90}})));
+  Buildings.Controls.OBC.CDL.Logical.TrueFalseHold truFalHol(
+    trueHoldDuration=300) "Hold logical signal to avoid short cycling"
+    annotation (Placement(transformation(origin = {40, 0}, extent = {{40, -110}, {60, -90}})));
+protected
+  Buildings.Controls.OBC.CDL.Logical.Pre pre
+    "Block to avoid an algebraic loop during initialization" annotation(
+    Placement(transformation(origin = {50, -100}, extent = {{-10, -10}, {10, 10}})));
 equation
   connect(x1.y,mapFun.x1)
     annotation (Line(points={{62,20},{80,20},{80,8},{98,8}},color={0,0,127}));
@@ -172,12 +176,6 @@ equation
     annotation (Line(points={{-58,60},{0,60},{0,88},{98,88}},color={0,0,127}));
   connect(uCol,greThr.u)
     annotation (Line(points={{-200,0},{-160,0},{-160,-100},{-2,-100}},color={0,0,127}));
-  connect(greThr.y,booToRea.u)
-    annotation (Line(points={{22,-100},{38,-100}},color={255,0,255}));
-  connect(booToRea.y,zeroOrderHold.u)
-    annotation (Line(points={{62,-100},{78,-100}},color={0,0,127}));
-  connect(zeroOrderHold.y,yValIso)
-    annotation (Line(points={{101,-100},{160,-100},{160,0},{200,0}},color={0,0,127}));
   connect(mapFunTChiSupSet.y,ramLimHea.u)
     annotation (Line(points={{122,80},{138,80}},color={0,0,127}));
   connect(zer.y,max1.u2)
@@ -188,12 +186,27 @@ equation
     annotation (Line(points={{-128,-20},{-122,-20}}, color={0,0,127}));
   connect(gai.y, addPar.u)
     annotation (Line(points={{-98,-20},{-82,-20}}, color={0,0,127}));
+  connect(truFalHol.y, booToRea.u)
+    annotation (Line(points={{102,-100},{118,-100}}, color={255,0,255}));
+  connect(booToRea.y, yValIso) annotation (Line(points={{142,-100},{160,-100},{
+          160,0},{200,0}}, color={0,0,127}));
+  connect(greThr.y, pre.u) annotation(
+    Line(points = {{22, -100}, {38, -100}}, color = {255, 0, 255}));
+  connect(pre.y, truFalHol.u) annotation(
+    Line(points = {{62, -100}, {78, -100}}, color = {255, 0, 255}));
   annotation (
     defaultComponentName="conCol",
     Documentation(
       revisions="<html>
 <ul>
 <li>
+November 22, 2024, by Michael Wetter:<br/>
+Reduced number of time events by replacing zero order hold with true and false hold,
+and increasing the minimum cycle time.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/4058\">#4058</a>.
+</li>
+<li>
 July 31, 2020, by Antoine Gautier:<br/>
 First implementation.
 </li>
@@ -243,7 +256,7 @@ Control signal for the evaporator loop isolation valve <code>yIsoAmb</code><br/>
 
 The valve is commanded to be fully open whenever the cold rejection control signal
 is greater than zero.
-The command signal is held for 60s to avoid short cycling.
+The command signal is held for 5&nbsp;min to avoid short cycling.
 </li>
 </ul>
 </html>"),

diff --git a/Buildings/DHC/ETS/Combined/Controls/SideHot.mo b/Buildings/DHC/ETS/Combined/Controls/SideHot.mo
@@ -37,10 +37,10 @@ block SideHot
   Buildings.Controls.OBC.CDL.Reals.GreaterThreshold greThr(
     final t=0.01)
     "Control signal is non zero (with 1% tolerance)"
-    annotation (Placement(transformation(extent={{40,-10},{60,10}})));
+    annotation (Placement(transformation(origin = {-40, 0}, extent = {{40, -10}, {60, 10}})));
   Buildings.Controls.OBC.CDL.Conversions.BooleanToReal booToRea
     "Convert DO to AO signal"
-    annotation (Placement(transformation(extent={{80,-10},{100,10}})));
+    annotation (Placement(transformation(extent={{120,-10},{140,10}})));
   PIDWithEnable conHeaRej(
     final k=k,
     final Ti=Ti,
@@ -126,9 +126,6 @@ block SideHot
     p=dTDea)
     "Add dead band"
     annotation (Placement(transformation(extent={{-130,-10},{-110,10}})));
-  Modelica.Blocks.Discrete.ZeroOrderHold zeroOrderHold(
-    samplePeriod=60)
-    annotation (Placement(transformation(extent={{120,-10},{140,10}})));
   Buildings.Controls.OBC.CDL.Reals.AddParameter addLoc(
     p=dTLoc)
     "Add temperature difference for lockout"
@@ -137,6 +134,13 @@ block SideHot
     h=0.1)
     "Check if temperature is below cold rejection lockout"
     annotation (Placement(transformation(extent={{-90,50},{-70,70}})));
+  Buildings.Controls.OBC.CDL.Logical.TrueFalseHold truFalHol(
+    trueHoldDuration=300) "Hold logical signal to avoid short cycling"
+    annotation (Placement(transformation(extent={{80,-10},{100,10}})));
+protected
+  Buildings.Controls.OBC.CDL.Logical.Pre pre
+    "Block to avoid algebraic loop during initialization" annotation(
+    Placement(transformation(origin = {50, 0}, extent = {{-10, -10}, {10, 10}})));
 equation
   connect(mapFun.y,yAmb)
     annotation (Line(points={{122,60},{200,60}},color={0,0,127}));
@@ -145,7 +149,7 @@ equation
   connect(TTop,conColRej.u_m)
     annotation (Line(points={{-200,-40},{-160,-40},{-160,-58},{0,-58},{0,-52}},color={0,0,127}));
   connect(conHeaRej.y,greThr.u)
-    annotation (Line(points={{-68,0},{38,0}},color={0,0,127}));
+    annotation (Line(points={{-68,0},{-2,0}},color={0,0,127}));
   connect(x1.y,mapFun.x1)
     annotation (Line(points={{82,80},{90,80},{90,68},{98,68}},color={0,0,127}));
   connect(conHeaRej.y,rep.u)
@@ -174,30 +178,39 @@ equation
     annotation (Line(points={{-200,0},{-132,0}},color={0,0,127}));
   connect(addDea.y,conHeaRej.u_s)
     annotation (Line(points={{-108,0},{-92,0}},color={0,0,127}));
-  connect(greThr.y,booToRea.u)
-    annotation (Line(points={{62,0},{78,0}},color={255,0,255}));
-  connect(booToRea.y,zeroOrderHold.u)
-    annotation (Line(points={{102,0},{118,0}},color={0,0,127}));
-  connect(zeroOrderHold.y,yValIso)
-    annotation (Line(points={{141,0},{200,0}},color={0,0,127}));
   connect(TSet,addLoc.u)
     annotation (Line(points={{-200,0},{-140,0},{-140,40},{-132,40}},color={0,0,127}));
   connect(TTop,isBelLoc.u1)
     annotation (Line(points={{-200,-40},{-160,-40},{-160,60},{-92,60}},color={0,0,127}));
   connect(addLoc.y,isBelLoc.u2)
     annotation (Line(points={{-108,40},{-100,40},{-100,52},{-92,52}},color={0,0,127}));
   connect(uHeaCoo,mulAnd.u[1])
-    annotation (Line(points={{-200,100},{-56,100},{-56,-75.3333},{-42,-75.3333}},color={255,0,255}));
+    annotation (Line(points={{-200,100},{-56,100},{-56,-82.3333},{-42,-82.3333}},color={255,0,255}));
   connect(isValIsoConClo.y,mulAnd.u[2])
     annotation (Line(points={{-138,-80},{-42,-80}},color={255,0,255}));
   connect(isBelLoc.y,mulAnd.u[3])
-    annotation (Line(points={{-68,60},{-60,60},{-60,-84.6667},{-42,-84.6667}},color={255,0,255}));
+    annotation (Line(points={{-68,60},{-60,60},{-60,-77.6667},{-42,-77.6667}},color={255,0,255}));
+  connect(truFalHol.y, booToRea.u)
+    annotation (Line(points={{102,0},{118,0}}, color={255,0,255}));
+  connect(booToRea.y, yValIso)
+    annotation (Line(points={{142,0},{200,0}}, color={0,0,127}));
+  connect(greThr.y, pre.u) annotation(
+    Line(points = {{22, 0}, {38, 0}}, color = {255, 0, 255}));
+  connect(pre.y, truFalHol.u) annotation(
+    Line(points = {{62, 0}, {78, 0}}, color = {255, 0, 255}));
   annotation (
     defaultComponentName="conHot",
     Documentation(
       revisions="<html>
 <ul>
 <li>
+November 22, 2024, by Michael Wetter:<br/>
+Reduced number of time events by replacing zero order hold with true and false hold,
+and increasing the minimum cycle time.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/4058\">#4058</a>.
+</li>
+<li>
 July 31, 2020, by Antoine Gautier:<br/>
 First implementation.
 </li>
@@ -260,7 +273,7 @@ Control signal for the condenser loop isolation valve <code>yIsoAmb</code><br/>
 
 The valve is commanded to be fully open whenever the controller
 for heat rejection yields an output signal greater than zero.
-The command signal is held for 60s to avoid short cycling.
+The command signal is held for 5&nbsp;min to avoid short cycling.
 </li>
 </ul>
 </html>"),

diff --git a/Buildings/DHC/ETS/Combined/Examples/ChillerOnly.mo b/Buildings/DHC/ETS/Combined/Examples/ChillerOnly.mo
@@ -53,8 +53,6 @@ equation
     annotation (Line(points={{-266,60},{-252,60}},color={0,0,127}));
   connect(loaNorCoo.y,loaCooNor.u)
     annotation (Line(points={{286,60},{272,60}},color={0,0,127}));
-  connect(TDisWatSup.y[1],disWat.T_in)
-    annotation (Line(points={{-309,-140},{-140,-140},{-140,-136},{-122,-136}},color={0,0,127}));
   annotation (
     __Dymola_Commands(
       file="modelica://Buildings/Resources/Scripts/Dymola/DHC/ETS/Combined/Examples/ChillerOnly.mos" "Simulate and plot"),
@@ -66,6 +64,10 @@ equation
       revisions="<html>
 <ul>
 <li>
+November 22, 2024, by Michael Wetter:<br/>
+Removed duplicate connection.
+</li>
+<li>
 July 31, 2020, by Antoine Gautier:<br/>
 First implementation.
 </li>

diff --git a/Buildings/DHC/ETS/Combined/Validation/ChillerOnly.mo b/Buildings/DHC/ETS/Combined/Validation/ChillerOnly.mo
@@ -17,8 +17,6 @@ model ChillerOnly
     "District water supply temperature"
     annotation (Placement(transformation(extent={{-330,-150},{-310,-130}})));
 equation
-  connect(TDisWatSup.y[1],disWat.T_in)
-    annotation (Line(points={{-309,-140},{-140,-140},{-140,-136},{-122,-136}},color={0,0,127}));
   connect(loa.y[2],heaLoaNor.u)
     annotation (Line(points={{-309,160},{-300,160},{-300,60},{-252,60}},color={0,0,127}));
   connect(loa.y[1],loaCooNor.u)
@@ -33,6 +31,10 @@ equation
       revisions="<html>
 <ul>
 <li>
+November 22, 2024, by Michael Wetter:<br/>
+Removed duplicate connection.
+</li>
+<li>
 July 31, 2020, by Antoine Gautier:<br/>
 First implementation.
 </li>

diff --git a/Buildings/DHC/ETS/Combined/Validation/ChillerWSE.mo b/Buildings/DHC/ETS/Combined/Validation/ChillerWSE.mo
@@ -19,8 +19,6 @@ model ChillerWSE
     "District water supply temperature"
     annotation (Placement(transformation(extent={{-330,-150},{-310,-130}})));
 equation
-  connect(TDisWatSup.y[1],disWat.T_in)
-    annotation (Line(points={{-309,-140},{-140,-140},{-140,-136},{-122,-136}},color={0,0,127}));
   connect(loa.y[2],heaLoaNor.u)
     annotation (Line(points={{-309,160},{-300,160},{-300,60},{-252,60}},color={0,0,127}));
   connect(loa.y[1],loaCooNor.u)
@@ -36,6 +34,10 @@ equation
       revisions="<html>
 <ul>
 <li>
+November 22, 2024, by Michael Wetter:<br/>
+Removed duplicate connection.
+</li>
+<li>
 July 31, 2020, by Antoine Gautier:<br/>
 First implementation.
 </li>