Buildings.Examples.VAVReheat.Controls

Information

Package Content

Name	Description
ControlBus	Empty control bus that is adapted to the signals connected to it
Economizer	Controller for economizer
FanVFD	Controller for fan revolution
IntegerSum	Sums all the integer signals
ModeSelector	Finite State Machine for the operational modes
OperationModes	Enumeration for modes of operation
PreCoolingStarter	Outputs true when precooling should start
RoomTemperatureSetpoint	Set point scheduler for room temperature
RoomVAV	Controller for room VAV box
State	Block that outputs the mode if the state is active, or zero otherwise
UnoccupiedOn	Controller for unoccupied on state
DuctStaticPressureSetpoint	Computes the duct static pressure setpoint
CoolingCoilTemperatureSetpoint	Set point scheduler for cooling coil
MixedAirTemperatureSetpoint	Mixed air temperature setpoint for economizer
EconomizerTemperatureControl	Controller for economizer mixed air temperature
Examples	Example models to test the components

Types and constants

  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";

Buildings.Examples.VAVReheat.Controls.ControlBus

Information

This connector defines the expandable connector ControlBus that is used to connect control signals. Note, this connector is empty. When using it, the actual content is constructed by the signals connected to this bus.

Modelica definition

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

Buildings.Examples.VAVReheat.Controls.Economizer

Parameters

Type	Name	Default	Description
TemperatureDifference	dT	1	Temperture offset to activate economizer [K]
VolumeFlowRate	VOut_flow_min		Minimum outside air volume flow rate [m3/s]
Real	k	1	Gain of controller
Time	Ti		Time constant of Integrator block [s]

Connectors

Type	Name	Description
input RealInput	TSupHeaSet	Supply temperature setpoint for heating
input RealInput	TSupCooSet	Supply temperature setpoint for cooling
input RealInput	TMix	Measured mixed air temperature
ControlBus	controlBus
input RealInput	VOut_flow	Measured outside air flow rate
input RealInput	TRet	Return air temperature
output RealOutput	yOA	Control signal for outside air damper

Modelica definition

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);
  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;

Buildings.Examples.VAVReheat.Controls.FanVFD

Information

Parameters

Type	Name	Default	Description
Real	xSet_nominal		Nominal setpoint (used for normalization)
Real	r_N_min	0.01	Minimum normalized fan speed
Init	initType	Modelica.Blocks.Types.Init.N...	Type of initialization (1: no init, 2: steady state, 3/4: initial output)
Real	y_start	0	Initial or guess value of output (= state)

Connectors

Type	Name	Description
input RealInput	u	Connector of Real input signal
output RealOutput	y	Connector of Real output signal
ControlBus	controlBus
input RealInput	u_m	Connector of measurement input signal

Modelica definition

block FanVFD "Controller for fan revolution"
  extends Modelica.Blocks.Interfaces.SISO;
  import Buildings.Examples.VAVReheat.Controls.OperationModes;
  Buildings.Controls.Continuous.LimPID con(
    yMax=1,
    yMin=0,
    controllerType=Modelica.Blocks.Types.SimpleController.PI,
    Td=60,
    k=0.5,
    Ti=15) "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);
  Modelica.Blocks.Sources.Constant off(k=r_N_min) "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)";

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;

Buildings.Examples.VAVReheat.Controls.IntegerSum

Information

Parameters

Type	Name	Default	Description
Integer	nin		Number of inputs

Connectors

Type	Name	Description
output IntegerOutput	y	Connector of Integer output signal
input IntegerInput	u[nin]	Input signal

Modelica definition

block IntegerSum "Sums all the integer signals"
  extends Modelica.Blocks.Interfaces.IntegerSO;
  parameter Integer nin "Number of inputs";
  Modelica.Blocks.Interfaces.IntegerInput u[nin] "Input signal";
equation 
  y = sum(u);
end IntegerSum;

Buildings.Examples.VAVReheat.Controls.ModeSelector

Parameters

Type	Name	Default	Description
TemperatureDifference	delTRooOnOff	1	Deadband in room temperature between occupied on and occupied off [K]
Temperature	TRooSetHeaOcc	293.15	Set point for room air temperature during heating mode [K]
Temperature	TRooSetCooOcc	299.15	Set point for room air temperature during cooling mode [K]
Temperature	TSetHeaCoiOut	303.15	Set point for air outlet temperature at central heating coil [K]

Connectors

Type	Name	Description
ControlBus	cb

Modelica definition

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);
  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;

Buildings.Examples.VAVReheat.Controls.PreCoolingStarter

Information

Parameters

Type	Name	Default	Description
Temperature	TOutLim	286.15	Limit for activating precooling [K]
Temperature	TRooSetCooOcc		Set point for room air temperature during cooling mode [K]

Connectors

Type	Name	Description
output BooleanOutput	y	Connector of Boolean output signal
ControlBus	controlBus

Modelica definition

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;

Buildings.Examples.VAVReheat.Controls.RoomTemperatureSetpoint

Information

Parameters

Type	Name	Default	Description
Temperature	THeaOn	293.15	Heating setpoint during on [K]
Temperature	THeaOff	285.15	Heating setpoint during off [K]
Temperature	TCooOn	297.15	Cooling setpoint during on [K]
Temperature	TCooOff	303.15	Cooling setpoint during off [K]

Connectors

Type	Name	Description
ControlBus	controlBus

Modelica definition

block RoomTemperatureSetpoint 
  "Set point scheduler for room temperature"
  extends Modelica.Blocks.Interfaces.BlockIcon;
  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 ==
        OperationModes.occupied or mode.y == OperationModes.unoccupiedWarmUp
         or mode.y == OperationModes.safety) then THeaOn else THeaOff);
  Modelica.Blocks.Sources.RealExpression setPoiCoo(y=if (mode.y ==
        OperationModes.occupied or mode.y == OperationModes.unoccupiedPreCool
         or mode.y == 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;

Buildings.Examples.VAVReheat.Controls.RoomVAV

Information

Connectors

Type	Name	Description
ControlBus	controlBus
input RealInput	TRoo	Measured room temperature [K]
output RealOutput	yHea	Signal for heating coil valve
output RealOutput	yDam	Signal for VAV damper
input RealInput	TSup	Measured supply air temperature after heating coil

Modelica definition

block RoomVAV "Controller for room VAV box"
  extends Modelica.Blocks.Interfaces.BlockIcon;
  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(k3=-1) 
    "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;

Buildings.Examples.VAVReheat.Controls.State

Information

Parameters

Type	Name	Default	Description
Integer	nIn	1	Number of input connections
Integer	nOut	1	Number of output connections
OperationModes	mode		Enter enumeration of mode

Connectors

Type	Name	Description
Step_in	inPort[nIn]	Vector of step input connectors
Step_out	outPort[nOut]	Vector of step output connectors
output BooleanOutput	active
output IntegerOutput	y	Mode signal (=0 if not active)

Modelica definition

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 mode else 0;
end State;

Buildings.Examples.VAVReheat.Controls.UnoccupiedOn

Information

Parameters

Type	Name	Default	Description
Integer	nIn	1	Number of input connections
Integer	nOut	1	Number of output connections

Connectors

Type	Name	Description
Step_in	inPort[nIn]	Vector of step input connectors
Step_out	outPort[nOut]	Vector of step output connectors
output BooleanOutput	active

Modelica definition

model UnoccupiedOn "Controller for unoccupied on state"
  extends Modelica.StateGraph.StepWithSignal;
end UnoccupiedOn;

Buildings.Examples.VAVReheat.Controls.DuctStaticPressureSetpoint

Information

Parameters

Type	Name	Default	Description
Integer	nin	1	Number of inputs
AbsolutePressure	pMin	100	Minimum duct static pressure setpoint [Pa]
AbsolutePressure	pMax	410	Maximum duct static pressure setpoint [Pa]
Real	k	0.1	Gain of controller
Time	Ti	60	Time constant of Integrator block [s]
Time	Td	60	Time constant of Derivative block [s]
SimpleController	controllerType	Modelica.Blocks.Types.Simple...	Type of controller

Connectors

Type	Name	Description
input RealInput	u[nin]	Connector of Real input signals
output RealOutput	y	Connector of Real output signal
input RealInput	TOut	Outside air temperature

Modelica definition

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;

Buildings.Examples.VAVReheat.Controls.CoolingCoilTemperatureSetpoint

Information

Parameters

Type	Name	Default	Description
Temperature	TCooOn	273.15 + 12	Cooling setpoint during on [K]
Temperature	TCooOff	273.15 + 30	Cooling setpoint during off [K]

Connectors

Type	Name	Description
input RealInput	TSetHea	Set point for heating coil
ControlBus	controlBus
output RealOutput	TSet	Temperature set point

Modelica definition

block CoolingCoilTemperatureSetpoint 
  "Set point scheduler for cooling coil"
  extends Modelica.Blocks.Interfaces.BlockIcon;
  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 == OperationModes.occupied or mode.y == OperationModes.unoccupiedPreCool or mode.y == 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;

Buildings.Examples.VAVReheat.Controls.MixedAirTemperatureSetpoint

Information

Connectors

Type	Name	Description
input RealInput	TSupHeaSet	Supply temperature setpoint for heating
input RealInput	TSupCooSet	Supply temperature setpoint for cooling
ControlBus	controlBus
output RealOutput	TSet	Mixed air temperature setpoint

Modelica definition

model MixedAirTemperatureSetpoint 
  "Mixed air temperature setpoint for economizer"
  extends Modelica.Blocks.Interfaces.BlockIcon;
  Modelica.Blocks.Routing.Extractor TSetMix(nin=6) 
    "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;

Buildings.Examples.VAVReheat.Controls.EconomizerTemperatureControl

Information

Parameters

Type	Name	Default	Description
Real	k	1	Gain of controller
Time	Ti		Time constant of Integrator block [s]

Connectors

Type	Name	Description
output RealOutput	yOA	Control signal for outside air damper
input RealInput	TRet	Return air temperature
input RealInput	TOut	Outside air temperature
input RealInput	TMix	Mixed air temperature
input RealInput	TMixSet	Setpoint for mixed air temperature

Modelica definition

block EconomizerTemperatureControl 
  "Controller for economizer mixed air temperature"
  extends Modelica.Blocks.Interfaces.BlockIcon;
  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;