type OperationModes = enumeration(
    occupied "Occupied",
    unoccupiedOff "Unoccupied off",
    unoccupiedNightSetBack "Unoccupied, night set back",
    unoccupiedWarmUp "Unoccupied, warm-up",
    unoccupiedPreCool "Unoccupied, pre-cool",
    safety "Safety (smoke, fire, etc.)") "Enumeration for modes of operation";

expandable connector ControlBus "Empty control bus that is adapted to the signals connected to it" extends Modelica.Icons.SignalBus; end ControlBus;

block CoolingCoilTemperatureSetpoint "Set point scheduler for cooling coil" extends Modelica.Blocks.Icons.Block; import Buildings.Examples.VAVReheat.Controls.OperationModes; parameter Modelica.SIunits.Temperature TCooOn=273.15+12 "Cooling setpoint during on"; parameter Modelica.SIunits.Temperature TCooOff=273.15+30 "Cooling setpoint during off"; Modelica.Blocks.Sources.RealExpression TSupSetCoo( y=if (mode.y == Integer(OperationModes.occupied) or mode.y == Integer(OperationModes.unoccupiedPreCool) or mode.y == Integer(OperationModes.safety)) then TCooOn else TCooOff) "Supply air temperature setpoint for cooling"; Modelica.Blocks.Interfaces.RealInput TSetHea "Set point for heating coil"; Modelica.Blocks.Math.Add add; Modelica.Blocks.Sources.Constant dTMin(k=1) "Minimum offset for cooling coil setpoint"; Modelica.Blocks.Math.Max max1; ControlBus controlBus; Modelica.Blocks.Routing.IntegerPassThrough mode; Modelica.Blocks.Interfaces.RealOutput TSet "Temperature set point"; equation connect(dTMin.y, add.u1); connect(add.y, max1.u1); connect(TSupSetCoo.y, max1.u2); connect(controlBus.controlMode, mode.u); connect(max1.y, TSet); connect(TSetHea, add.u2); end CoolingCoilTemperatureSetpoint;

model DuctStaticPressureSetpoint "Computes the duct static pressure setpoint" extends Modelica.Blocks.Interfaces.MISO; parameter Modelica.SIunits.AbsolutePressure pMin(displayUnit="Pa") = 100 "Minimum duct static pressure setpoint"; parameter Modelica.SIunits.AbsolutePressure pMax(displayUnit="Pa") = 410 "Maximum duct static pressure setpoint"; parameter Real k=0.1 "Gain of controller"; parameter Modelica.SIunits.Time Ti=60 "Time constant of Integrator block"; parameter Modelica.SIunits.Time Td=60 "Time constant of Derivative block"; parameter Modelica.Blocks.Types.SimpleController controllerType=Modelica.Blocks.Types.SimpleController.PID "Type of controller"; Buildings.Controls.Continuous.LimPID limPID( controllerType=controllerType, k=k, Ti=Ti, Td=Td, initType=Modelica.Blocks.Types.InitPID.InitialState, reverseAction=true); protected Buildings.Utilities.Math.Max max(final nin=nin); Modelica.Blocks.Sources.Constant ySet(k=0.9) "Setpoint for maximum damper position"; Modelica.Blocks.Math.Add dp(final k2=-1) "Pressure difference"; Modelica.Blocks.Sources.Constant pMaxSig(k=pMax); Modelica.Blocks.Sources.Constant pMinSig(k=pMin); Modelica.Blocks.Math.Add pSet "Pressure setpoint"; Modelica.Blocks.Math.Product product; public Modelica.Blocks.Logical.Hysteresis hysteresis(uLow=283.15, uHigh=284.15) "Hysteresis to put fan on minimum revolution"; Modelica.Blocks.Interfaces.RealInput TOut "Outside air temperature"; protected Modelica.Blocks.Sources.Constant zero(k=0) "Zero output signal"; public Modelica.Blocks.Logical.Switch switch1; equation connect(max.u, u); connect(ySet.y, limPID.u_s); connect(max.y, limPID.u_m); connect(limPID.y, product.u1); connect(pMaxSig.y, dp.u1); connect(pMinSig.y, dp.u2); connect(dp.y, product.u2); connect(pMinSig.y, pSet.u2); connect(pSet.y, y); connect(hysteresis.u, TOut); connect(product.y, switch1.u1); connect(zero.y, switch1.u3); connect(switch1.y, pSet.u1); connect(hysteresis.y, switch1.u2); end DuctStaticPressureSetpoint;

block Economizer "Controller for economizer" import Buildings.Examples.VAVReheat.Controls.OperationModes; parameter Modelica.SIunits.TemperatureDifference dT(min=0.1)= 1 "Temperture offset to activate economizer"; parameter Modelica.SIunits.VolumeFlowRate VOut_flow_min(min=0) "Minimum outside air volume flow rate"; Modelica.Blocks.Interfaces.RealInput TSupHeaSet "Supply temperature setpoint for heating"; Modelica.Blocks.Interfaces.RealInput TSupCooSet "Supply temperature setpoint for cooling"; Modelica.Blocks.Interfaces.RealInput TMix "Measured mixed air temperature"; ControlBus controlBus; Modelica.Blocks.Interfaces.RealInput VOut_flow "Measured outside air flow rate"; Modelica.Blocks.Interfaces.RealInput TRet "Return air temperature"; Modelica.Blocks.Math.Gain gain(k=1/VOut_flow_min) "Normalize mass flow rate"; Buildings.Controls.Continuous.LimPID conV_flow( controllerType=Modelica.Blocks.Types.SimpleController.PI, k=k, Ti=Ti, yMax=0.995, yMin=0.005, Td=60) "Controller for outside air flow rate"; Modelica.Blocks.Sources.Constant uni(k=1) "Unity signal"; parameter Real k=1 "Gain of controller"; parameter Modelica.SIunits.Time Ti "Time constant of Integrator block"; Modelica.Blocks.Interfaces.RealOutput yOA "Control signal for outside air damper"; Modelica.Blocks.Routing.Extractor extractor( nin=6, index(start=1, fixed=true)) "Extractor for control signal"; Modelica.Blocks.Sources.Constant closed(k=0) "Signal to close OA damper"; Modelica.Blocks.Math.Max max "Takes bigger signal (OA damper opens for temp. control or for minimum outside air)"; MixedAirTemperatureSetpoint TSetMix "Mixed air temperature setpoint"; EconomizerTemperatureControl yOATMix(Ti=Ti, k=k) "Control signal for outdoor damper to track mixed air temperature setpoint"; EconomizerTemperatureControl yOATFre(Ti=Ti, k=k) "Control signal for outdoor damper to track freeze temperature setpoint"; Modelica.Blocks.Math.Min min "Takes bigger signal (OA damper opens for temp. control or for minimum outside air)"; Modelica.Blocks.Sources.Constant TFre(k=273.15 + 3) "Setpoint for freeze protection"; equation connect(VOut_flow, gain.u); connect(gain.y, conV_flow.u_m); connect(uni.y, conV_flow.u_s); connect(controlBus.controlMode, extractor.index); connect(max.y, extractor.u[OperationModes.occupied]); connect(closed.y, extractor.u[OperationModes.unoccupiedOff]); connect(closed.y, extractor.u[OperationModes.unoccupiedNightSetBack]); connect(max.y, extractor.u[OperationModes.unoccupiedWarmUp]); connect(max.y, extractor.u[OperationModes.unoccupiedPreCool]); connect(closed.y, extractor.u[OperationModes.safety]); connect(TSupHeaSet, TSetMix.TSupHeaSet); connect(TSupCooSet, TSetMix.TSupCooSet); connect(controlBus, TSetMix.controlBus); connect(yOATMix.TRet, TRet); connect(controlBus.TOut, yOATMix.TOut); connect(yOATMix.TMix, TMix); connect(yOATMix.TMixSet, TSetMix.TSet); connect(yOATMix.yOA, max.u1); connect(min.u2, conV_flow.y); connect(min.y, max.u2); connect(min.u1, yOATFre.yOA); connect(yOATFre.TRet, TRet); connect(controlBus.TOut, yOATFre.TOut); connect(yOATFre.TMix, TMix); connect(TFre.y, yOATFre.TMixSet); connect(extractor.y, yOA); end Economizer;

block EconomizerTemperatureControl "Controller for economizer mixed air temperature" extends Modelica.Blocks.Icons.Block; import Buildings.Examples.VAVReheat.Controls.OperationModes; Buildings.Controls.Continuous.LimPID con( k=k, Ti=Ti, yMax=0.995, yMin=0.005, Td=60, controllerType=Modelica.Blocks.Types.SimpleController.PI) "Controller for mixed air temperature"; parameter Real k=1 "Gain of controller"; parameter Modelica.SIunits.Time Ti "Time constant of Integrator block"; Modelica.Blocks.Logical.Greater signGain "Sign of control gain"; Modelica.Blocks.Logical.Switch swi1; Modelica.Blocks.Logical.Switch swi2; Modelica.Blocks.Interfaces.RealOutput yOA "Control signal for outside air damper"; Modelica.Blocks.Interfaces.RealInput TRet "Return air temperature"; Modelica.Blocks.Interfaces.RealInput TOut "Outside air temperature"; Modelica.Blocks.Interfaces.RealInput TMix "Mixed air temperature"; Modelica.Blocks.Interfaces.RealInput TMixSet "Setpoint for mixed air temperature"; equation connect(signGain.y, swi1.u2); connect(swi1.y, con.u_s); connect(swi2.y, con.u_m); connect(signGain.y, swi2.u2); connect(con.y, yOA); connect(signGain.u1, TRet); connect(signGain.u2, TOut); connect(swi1.u1, TMix); connect(swi2.u3, TMix); connect(swi1.u3, TMixSet); connect(swi2.u1, TMixSet); end EconomizerTemperatureControl;

block FanVFD "Controller for fan revolution" extends Modelica.Blocks.Interfaces.SISO; import Buildings.Examples.VAVReheat.Controls.OperationModes; Buildings.Controls.Continuous.LimPID con( yMax=1, Td=60, yMin=r_N_min, k=k, Ti=Ti, controllerType=controllerType) "Controller"; Modelica.Blocks.Math.Gain gaiMea(k=1/xSet_nominal) "Gain to normalize measurement signal"; parameter Real xSet_nominal "Nominal setpoint (used for normalization)"; ControlBus controlBus; Modelica.Blocks.Routing.Extractor extractor( nin=6, index(start=1, fixed=true)) "Extractor for control signal"; Modelica.Blocks.Sources.Constant off(k=0) "Off signal"; Modelica.Blocks.Sources.Constant on(k=1) "On signal"; Modelica.Blocks.Math.Gain gaiSet(k=1/xSet_nominal) "Gain to normalize setpoint signal"; Modelica.Blocks.Interfaces.RealInput u_m "Connector of measurement input signal"; parameter Real r_N_min=0.01 "Minimum normalized fan speed"; parameter Modelica.Blocks.Types.Init initType=Modelica.Blocks.Types.Init.NoInit "Type of initialization (1: no init, 2: steady state, 3/4: initial output)"; parameter Real y_start=0 "Initial or guess value of output (= state)"; parameter Modelica.Blocks.Types.SimpleController controllerType=.Modelica.Blocks.Types.SimpleController.PI "Type of controller"; parameter Real k=0.5 "Gain of controller"; parameter Modelica.SIunits.Time Ti=15 "Time constant of Integrator block"; equation connect(gaiMea.y, con.u_m); connect(con.y, extractor.u[OperationModes.occupied]); connect(con.y, extractor.u[OperationModes.unoccupiedWarmUp]); connect(con.y, extractor.u[OperationModes.unoccupiedPreCool]); connect(off.y, extractor.u[OperationModes.unoccupiedOff]); connect(off.y, extractor.u[OperationModes.safety]); connect(on.y, extractor.u[OperationModes.unoccupiedNightSetBack]); connect(controlBus.controlMode, extractor.index); connect(gaiSet.y, con.u_s); connect(u_m, gaiMea.u); connect(gaiSet.u, u); connect(extractor.y, y); end FanVFD;

model MixedAirTemperatureSetpoint "Mixed air temperature setpoint for economizer" extends Modelica.Blocks.Icons.Block; Modelica.Blocks.Routing.Extractor TSetMix( nin=6, index(start=1, fixed=true)) "Mixed air setpoint temperature extractor"; Modelica.Blocks.Sources.Constant off(k=273.15 + 13) "Setpoint temperature to close damper"; Buildings.Utilities.Math.Average ave(nin=2); Modelica.Blocks.Interfaces.RealInput TSupHeaSet "Supply temperature setpoint for heating"; Modelica.Blocks.Interfaces.RealInput TSupCooSet "Supply temperature setpoint for cooling"; Modelica.Blocks.Sources.Constant TPreCoo(k=273.15 + 13) "Setpoint during pre-cooling"; ControlBus controlBus; Modelica.Blocks.Interfaces.RealOutput TSet "Mixed air temperature setpoint"; Modelica.Blocks.Routing.Multiplex2 multiplex2_1; equation connect(TSetMix.u[1], ave.y); connect(ave.y, TSetMix.u[1]); connect(off.y, TSetMix.u[2]); connect(off.y, TSetMix.u[3]); connect(off.y, TSetMix.u[4]); connect(TPreCoo.y, TSetMix.u[5]); connect(off.y, TSetMix.u[6]); connect(controlBus.controlMode, TSetMix.index); connect(TSetMix.y, TSet); connect(multiplex2_1.y, ave.u); connect(TSupCooSet, multiplex2_1.u2[1]); connect(TSupHeaSet, multiplex2_1.u1[1]); end MixedAirTemperatureSetpoint;

model ModeSelector "Finite State Machine for the operational modes" Modelica.StateGraph.InitialStep initialStep; Modelica.StateGraph.Transition start "Starts the system"; State unOccOff( mode=Buildings.Examples.VAVReheat.Controls.OperationModes.unoccupiedOff, nIn=3, nOut=4) "Unoccupied off mode, no coil protection"; State unOccNigSetBac( nOut=2, mode=Buildings.Examples.VAVReheat.Controls.OperationModes.unoccupiedNightSetBack, nIn=1) "Unoccupied night set back"; Modelica.StateGraph.Transition t2( enableTimer=true, waitTime=60, condition=TRooMinErrHea.y > delTRooOnOff/2); parameter Modelica.SIunits.TemperatureDifference delTRooOnOff(min=0.1)=1 "Deadband in room temperature between occupied on and occupied off"; parameter Modelica.SIunits.Temperature TRooSetHeaOcc=293.15 "Set point for room air temperature during heating mode"; parameter Modelica.SIunits.Temperature TRooSetCooOcc=299.15 "Set point for room air temperature during cooling mode"; parameter Modelica.SIunits.Temperature TSetHeaCoiOut=303.15 "Set point for air outlet temperature at central heating coil"; Modelica.StateGraph.Transition t1(condition=delTRooOnOff/2 < -TRooMinErrHea.y, enableTimer=true, waitTime=30*60); inner Modelica.StateGraph.StateGraphRoot stateGraphRoot; ControlBus cb; Modelica.Blocks.Routing.RealPassThrough TRooSetHea "Current heating setpoint temperature"; State morWarUp(mode=Buildings.Examples.VAVReheat.Controls.OperationModes.unoccupiedWarmUp, nIn=2, nOut=1) "Morning warm up"; Modelica.StateGraph.TransitionWithSignal t6(enableTimer=true, waitTime=60); Modelica.Blocks.Logical.LessEqualThreshold occThrSho(threshold=1800) "Signal to allow transition into morning warmup"; Modelica.StateGraph.TransitionWithSignal t5; State occ( mode=Buildings.Examples.VAVReheat.Controls.OperationModes.occupied, nIn=3) "Occupied mode"; Modelica.Blocks.Routing.RealPassThrough TRooMin; Modelica.Blocks.Math.Feedback TRooMinErrHea "Room control error for heating"; Modelica.StateGraph.Transition t3(condition=TRooMin.y + delTRooOnOff/2 > TRooSetHeaOcc or occupied.y); Modelica.Blocks.Routing.BooleanPassThrough occupied "outputs true if building is occupied"; Modelica.StateGraph.TransitionWithSignal t4(enableTimer=false); State morPreCoo( nIn=2, mode=Buildings.Examples.VAVReheat.Controls.OperationModes.unoccupiedPreCool, nOut=1) "Pre-cooling mode"; Modelica.StateGraph.Transition t7(condition=TRooMin.y - delTRooOnOff/2 < TRooSetCooOcc or occupied.y); Modelica.Blocks.Logical.And and1; Modelica.Blocks.Routing.RealPassThrough TRooAve "Average room temperature"; Modelica.Blocks.Sources.BooleanExpression booleanExpression(y=TRooAve.y < TRooSetCooOcc); PreCoolingStarter preCooSta(TRooSetCooOcc=TRooSetCooOcc) "Model to start pre-cooling"; Modelica.StateGraph.TransitionWithSignal t9; Modelica.Blocks.Logical.Not not1; Modelica.Blocks.Logical.And and2; Modelica.Blocks.Logical.Not not2; Modelica.StateGraph.TransitionWithSignal t8 "changes to occupied in case precooling is deactivated"; Modelica.Blocks.MathInteger.Sum sum(nu=5); equation connect(start.outPort, unOccOff.inPort[1]); connect(initialStep.outPort[1], start.inPort); connect(unOccOff.outPort[1], t2.inPort); connect(t2.outPort, unOccNigSetBac.inPort[1]); connect(unOccNigSetBac.outPort[1], t1.inPort); connect(t1.outPort, unOccOff.inPort[2]); connect(cb.dTNexOcc, occThrSho.u); connect(t6.outPort, morWarUp.inPort[1]); connect(t5.outPort, morWarUp.inPort[2]); connect(unOccNigSetBac.outPort[2], t5.inPort); connect(cb.TRooMin, TRooMin.u); connect(TRooSetHea.y, TRooMinErrHea.u1); connect(TRooMin.y, TRooMinErrHea.u2); connect(unOccOff.outPort[2], t6.inPort); connect(morWarUp.outPort[1], t3.inPort); connect(cb.occupied, occupied.u); connect(occ.outPort[1], t4.inPort); connect(t4.outPort, unOccOff.inPort[3]); connect(occThrSho.y, and1.u1); connect(and1.y, t6.condition); connect(and1.y, t5.condition); connect(cb.TRooAve, TRooAve.u); connect(booleanExpression.y, and1.u2); connect(preCooSta.y, t9.condition); connect(t9.outPort, morPreCoo.inPort[1]); connect(unOccOff.outPort[3], t9.inPort); connect(cb, preCooSta.controlBus); connect(morPreCoo.outPort[1], t7.inPort); connect(t7.outPort, occ.inPort[2]); connect(t3.outPort, occ.inPort[1]); connect(occThrSho.y, not1.u); connect(not1.y, and2.u2); connect(and2.y, t4.condition); connect(occupied.y, not2.u); connect(not2.y, and2.u1); connect(cb.TRooSetHea, TRooSetHea.u); connect(t8.outPort, occ.inPort[3]); connect(unOccOff.outPort[4], t8.inPort); connect(occupied.y, t8.condition); connect(morPreCoo.y, sum.u[1]); connect(morWarUp.y, sum.u[2]); connect(occ.y, sum.u[3]); connect(unOccOff.y, sum.u[4]); connect(unOccNigSetBac.y, sum.u[5]); connect(sum.y, cb.controlMode); end ModeSelector;

block PreCoolingStarter "Outputs true when precooling should start" extends Modelica.Blocks.Interfaces.BooleanSignalSource; parameter Modelica.SIunits.Temperature TOutLim = 286.15 "Limit for activating precooling"; parameter Modelica.SIunits.Temperature TRooSetCooOcc "Set point for room air temperature during cooling mode"; ControlBus controlBus; Modelica.Blocks.Logical.GreaterThreshold greater(threshold=TRooSetCooOcc); Modelica.Blocks.Logical.LessThreshold greater2(threshold=1800); Modelica.Blocks.Logical.LessThreshold greater1(threshold=TOutLim); Modelica.Blocks.MathBoolean.And and3(nu=3); equation connect(controlBus.dTNexOcc, greater2.u); connect(controlBus.TRooAve, greater.u); connect(controlBus.TOut, greater1.u); connect(and3.y, y); connect(greater.y, and3.u[1]); connect(greater1.y, and3.u[2]); connect(greater2.y, and3.u[3]); end PreCoolingStarter;

block RoomTemperatureSetpoint "Set point scheduler for room temperature" extends Modelica.Blocks.Icons.Block; import Buildings.Examples.VAVReheat.Controls.OperationModes; parameter Modelica.SIunits.Temperature THeaOn=293.15 "Heating setpoint during on"; parameter Modelica.SIunits.Temperature THeaOff=285.15 "Heating setpoint during off"; parameter Modelica.SIunits.Temperature TCooOn=297.15 "Cooling setpoint during on"; parameter Modelica.SIunits.Temperature TCooOff=303.15 "Cooling setpoint during off"; ControlBus controlBus; Modelica.Blocks.Routing.IntegerPassThrough mode; Modelica.Blocks.Sources.RealExpression setPoiHea( y=if (mode.y == Integer(OperationModes.occupied) or mode.y == Integer(OperationModes.unoccupiedWarmUp) or mode.y == Integer(OperationModes.safety)) then THeaOn else THeaOff); Modelica.Blocks.Sources.RealExpression setPoiCoo( y=if (mode.y == Integer(OperationModes.occupied) or mode.y == Integer(OperationModes.unoccupiedPreCool) or mode.y == Integer(OperationModes.safety)) then TCooOn else TCooOff) "Cooling setpoint"; equation connect(controlBus.controlMode,mode. u); connect(setPoiHea.y, controlBus.TRooSetHea); connect(setPoiCoo.y, controlBus.TRooSetCoo); end RoomTemperatureSetpoint;

block RoomVAV "Controller for room VAV box" extends Modelica.Blocks.Icons.Block; parameter Real kPDamHea = 0.5 "Proportional gain for VAV damper in heating mode"; Buildings.Controls.Continuous.LimPID conHea( yMax=1, xi_start=0.1, initType=Modelica.Blocks.Types.InitPID.InitialState, Td=60, yMin=0, controllerType=Modelica.Blocks.Types.SimpleController.PI, k=0.1, Ti=120) "Controller for heating"; Buildings.Controls.Continuous.LimPID conCoo( yMax=1, reverseAction=true, Td=60, controllerType=Modelica.Blocks.Types.SimpleController.PI, k=0.1, Ti=120) "Controller for cooling (acts on damper)"; ControlBus controlBus; Modelica.Blocks.Interfaces.RealInput TRoo(final quantity="ThermodynamicTemperature", final unit = "K", displayUnit = "degC", min=0) "Measured room temperature"; Modelica.Blocks.Interfaces.RealOutput yHea "Signal for heating coil valve"; Modelica.Blocks.Interfaces.RealOutput yDam "Signal for VAV damper"; Modelica.Blocks.Interfaces.RealInput TSup(displayUnit="degC") "Measured supply air temperature after heating coil"; Buildings.Utilities.Math.SmoothMax smoothMax2(deltaX=0.1); Modelica.Blocks.Sources.Constant one(k=1); Modelica.Blocks.Math.Add3 yDamHea(k2=kPDamHea, k3=-kPDamHea) "Outputs (unlimited) damper signal for heating."; Modelica.Blocks.Math.Add add; Modelica.Blocks.Sources.Constant zero(k=0.1); Buildings.Utilities.Math.SmoothMin smoothMin(deltaX=0.1); equation connect(controlBus.TRooSetHea, conHea.u_s); connect(controlBus.TRooSetCoo, conCoo.u_s); connect(conHea.u_m, TRoo); connect(conCoo.u_m, TRoo); connect(TRoo, yDamHea.u3); connect(yDamHea.u2, TSup); connect(one.y, yDamHea.u1); connect(conCoo.y, add.u2); connect(yDamHea.y, smoothMax2.u2); connect(smoothMax2.y, add.u1); connect(zero.y, smoothMax2.u1); connect(smoothMin.u1, add.y); connect(one.y, smoothMin.u2); connect(conHea.y, yHea); connect(smoothMin.y, yDam); end RoomVAV;

model State "Block that outputs the mode if the state is active, or zero otherwise" extends Modelica.StateGraph.StepWithSignal; parameter OperationModes mode "Enter enumeration of mode"; Modelica.Blocks.Interfaces.IntegerOutput y "Mode signal (=0 if not active)"; equation y = if localActive then Integer(mode) else 0; end State;