Buildings.Fluid.DataCenters.Racks.FanControllers
Package with fan controllers for racks
Information
Package with fan controllers.
Extends from Modelica.Icons.Package (Icon for standard packages).
Package Content
| Name | Description |
|---|---|
 BackPressure
|
Controller for fan that regulates speed to attain zero back pressure |
 Load
|
Controller for fan that regulates speed based on load signal |
| OutletTemperature
|
Controller for fan that regulates speed to track the rack outlet temperature set point |
 Types
|
Package with type definitions |
Buildings.Fluid.DataCenters.Racks.FanControllers.BackPressure
Controller for fan that regulates speed to attain zero back pressure
Information
PI-controller to regulate a fan to attain zero back pressure.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Controller | |||
| Real | k | 1 | Gain of PI controller [1] |
| Time | Ti | 60 | Integrator time constant of PI controller [s] |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | pMea | Measured pressure at inlet of rear door heat exchanger [Pa] |
| input RealInput | pSet | Set point for inlet air pressure [Pa] |
| output RealOutput | y | Fan control signal |
Modelica definition
model BackPressure
"Controller for fan that regulates speed to attain zero back pressure"
parameter Real k(
final unit="1",
min=Modelica.Constants.small) = 1
"Gain of PI controller";
parameter Modelica.Units.SI.Time Ti(min=Modelica.Constants.small) = 60
"Integrator time constant of PI controller";
Buildings.Controls.OBC.CDL.Interfaces.RealInput pMea(
final unit="Pa")
"Measured pressure at inlet of rear door heat exchanger";
Buildings.Controls.OBC.CDL.Interfaces.RealInput pSet(
final unit="Pa") "Set point for inlet air pressure";
Buildings.Controls.OBC.CDL.Reals.PID con(
controllerType=Buildings.Controls.OBC.CDL.Types.SimpleController.PI,
final k=k,
final Ti=Ti,
r(final unit="Pa") = 10,
final reverseActing=false,
u_s(final unit="Pa"),
u_m(final unit="Pa"))
"Fan speed PI controller";
Controls.OBC.CDL.Interfaces.RealOutput y "Fan control signal";
equation
connect(pSet, con.u_s);
connect(pMea, con.u_m);
connect(con.y, y);
end BackPressure;
Buildings.Fluid.DataCenters.Racks.FanControllers.Load
Controller for fan that regulates speed based on load signal
Information
Controller that outputs fan speed based on IT load.
The controller computes the normalized IT load based on PIT_nominal,
and then does a table look-up to compute the speed.
If the normalized fan speed signal is outside 0...1, the controller will saturate
the signal, e.g., there is no table extrapolation.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | fanSpeed[:, :] | [0.0, 0.0; 1.0, 1.0] | Table matrix (1st column normalized IT load, 2nd fan speed, e.g., fanSpeed=[0, 0; 0.5, 0.7; 1, 1]) |
| Nominal condition | |||
| HeatFlowRate | P_nominal | IT power consumption at u=1, also called Thermal Design Power (TDP) [W] | |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | P | Electrical power consumption of IT [W] |
| output RealOutput | y | Fan control signal |
Modelica definition
model Load
"Controller for fan that regulates speed based on load signal"
parameter Modelica.Units.SI.HeatFlowRate P_nominal(min=0)
"IT power consumption at u=1, also called Thermal Design Power (TDP)";
parameter Real fanSpeed[:,:]=[0.0,0.0; 1.0,1.0]
"Table matrix (1st column normalized IT load, 2nd fan speed, e.g., fanSpeed=[0, 0; 0.5, 0.7; 1, 1])";
Modelica.Blocks.Interfaces.RealInput P(final unit="W", min=0)
"Electrical power consumption of IT";
Controls.OBC.CDL.Interfaces.RealOutput y "Fan control signal";
Controls.OBC.CDL.Reals.MultiplyByParameter nor(
k=1/P_nominal,
u(final unit="W"),
y(final unit="1")) "Normalized IT power";
protected
Modelica.Blocks.Tables.CombiTable1Ds tab(
tableOnFile=false,
table=fanSpeed,
smoothness=Modelica.Blocks.Types.Smoothness.MonotoneContinuousDerivative1,
extrapolation=Modelica.Blocks.Types.Extrapolation.HoldLastPoint,
verboseExtrapolation=false) "Table look-up";
equation
connect(nor.y, tab.u);
connect(tab.y[1], y);
connect(nor.u, P);
end Load;
Buildings.Fluid.DataCenters.Racks.FanControllers.OutletTemperature
Controller for fan that regulates speed to track the rack outlet temperature set point
Information
PI controller to regulate the fan to track a rack outlet temperature.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Controller | |||
| Real | k | 1 | Gain of PI controller [1] |
| Time | Ti | 60 | Integrator time constant of PI controller [s] |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | TMea | Measured air temperature at rack outlet [K] |
| input RealInput | TSet | Set point for rack outlet air temperature [K] |
| output RealOutput | y | Fan control signal |
Modelica definition
model OutletTemperature
"Controller for fan that regulates speed to track the rack outlet temperature set point"
parameter Real k(
final unit="1",
min=Modelica.Constants.small) = 1
"Gain of PI controller";
parameter Modelica.Units.SI.Time Ti(min=Modelica.Constants.small) = 60
"Integrator time constant of PI controller";
Buildings.Controls.OBC.CDL.Interfaces.RealInput TMea(
final unit="K",
displayUnit="degC") "Measured air temperature at rack outlet";
Buildings.Controls.OBC.CDL.Interfaces.RealInput TSet(
final unit="K",
displayUnit="degC")
"Set point for rack outlet air temperature";
Buildings.Controls.OBC.CDL.Reals.PID con(
controllerType=Buildings.Controls.OBC.CDL.Types.SimpleController.PI,
final k=k,
final Ti=Ti,
r(final unit="K")=1,
final reverseActing=false,
u_s(final unit="K", displayUnit="degC"),
u_m(final unit="K", displayUnit="degC"))
"Fan speed PI controller";
Controls.OBC.CDL.Interfaces.RealOutput y "Fan control signal";
equation
connect(TSet, con.u_s);
connect(TMea, con.u_m);
connect(con.y, y);
end OutletTemperature;