Buildings.Electrical.AC.OnePhase.Lines
Package with models for AC electrical lines
Information
This package contains models for transmission lines and electrical networks.
Extends from Modelica.Icons.Package (Icon for standard packages).
Package Content
| Name | Description |
|---|---|
 Line
|
Model of an electrical line |
 Network
|
Single phase AC network |
 TwoPortInductance
|
Model of an inductive element with two electrical ports |
 TwoPortRL
|
Model of a resistive-inductive element with two electrical ports |
 TwoPortRLC
|
Model of an RLC element with two electrical ports |
 TwoPortResistance
|
Model of a resistance with two electrical ports |
 Examples
|
Package with example models |
Buildings.Electrical.AC.OnePhase.Lines.Line
Model of an electrical line
Information
This model represents an AC single phase cable. The model is based on Buildings.Electrical.AC.OnePhase.Lines.TwoPortRLC and provides functionalities to parametrize the values of R, L and C, either using commercial cables or using default values.
Extends from Buildings.Electrical.Transmission.BaseClasses.PartialLine (Partial cable line dispersion model).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package PhaseSystem_p | PartialPhaseSystem | Phase system of terminal p | |
| replaceable package PhaseSystem_n | PartialPhaseSystem | Phase system of terminal n | |
| Length | l | Length of the line [m] | |
| Power | P_nominal | Nominal power of the line [W] | |
| Model | |||
| Assumptions | |||
| Boolean | use_C | false | Set to true to add a capacitance in the center of the line |
| Load | modelMode | Buildings.Electrical.Types.L... | Select between steady state and dynamic model |
| Thermal | |||
| Boolean | use_T | false | If true, enables the input for the temperature of the cable |
| Temperature | TCable | T_ref | Fixed temperature of the cable [K] |
| Tech. specification | |||
| Auto/Manual mode | |||
| CableMode | mode | Buildings.Electrical.Types.C... | Select if choosing the cable automatically or between a list of commercial options |
| Manual mode | |||
| Generic | commercialCable | Buildings.Electrical.Transmi... | Commercial cables options |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package PhaseSystem_p | Phase system of terminal p | |
| replaceable package PhaseSystem_n | Phase system of terminal n | |
| input RealInput | T | Temperature of the cable |
Modelica definition
model Line "Model of an electrical line"
extends Buildings.Electrical.Transmission.BaseClasses.PartialLine(
V_nominal(start=110),
redeclare package PhaseSystem_p = PhaseSystems.OnePhase,
redeclare package PhaseSystem_n = PhaseSystems.OnePhase,
redeclare replaceable Interfaces.Terminal_n terminal_n,
redeclare replaceable Interfaces.Terminal_p terminal_p,
commercialCable=Buildings.Electrical.Transmission.Functions.selectCable_low
(P_nominal, V_nominal));
protected
replaceable TwoPortRL line(
R=R/3,
L=L/3,
mode=modelMode) constrainedby
Buildings.Electrical.Transmission.BaseClasses.PartialTwoPortRLC(
useHeatPort=true,
M=M,
T_ref=T_ref) "Model of the line";
equation
connect(cableTemp.port, line.heatPort);
connect(line.terminal_n, terminal_n);
connect(terminal_p, line.terminal_p);
end Line;
Buildings.Electrical.AC.OnePhase.Lines.Network
Single phase AC network
Information
This model represents a generalized electrical AC single phase network.
See Buildings.Electrical.Transmission.BaseClasses.PartialNetwork for information about the network model.
See Buildings.Electrical.Transmission.Grids.PartialGrid for more information about the topology of the network, such as the number of nodes, how they are connected, and the length of each connection.
Extends from Buildings.Electrical.Transmission.BaseClasses.PartialNetwork (Partial model that represent an electric network).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Model | |||
| Assumptions | |||
| Boolean | use_C | false | If true, model the cable capacity |
| Load | modelMode | Types.Load.FixedZ_steady_state | Select between steady state and dynamic model |
Modelica definition
model Network "Single phase AC network"
extends Buildings.Electrical.Transmission.BaseClasses.PartialNetwork(
V_nominal(start=110),
redeclare Interfaces.Terminal_p terminal,
redeclare replaceable Transmission.Grids.TestGrid2Nodes grid,
redeclare Line lines(
commercialCable=grid.cables,
each use_C=use_C,
each modelMode=modelMode));
parameter Boolean use_C=false "If true, model the cable capacity";
parameter Buildings.Electrical.Types.Load modelMode=Types.Load.FixedZ_steady_state
"Select between steady state and dynamic model";
Modelica.SIunits.Voltage VAbs[grid.nNodes] "RMS voltage of the grid nodes";
equation
for i in 1:grid.nLinks loop
connect(lines[i].terminal_p, terminal[grid.fromTo[i, 1]]);
connect(lines[i].terminal_n, terminal[grid.fromTo[i, 2]]);
end for;
for i in 1:grid.nNodes loop
VAbs[i] = Buildings.Electrical.PhaseSystems.OnePhase.systemVoltage(terminal[
i].v);
end for;
end Network;
Buildings.Electrical.AC.OnePhase.Lines.TwoPortInductance
Model of an inductive element with two electrical ports
Information
This model represents an inductance that connects two AC one phase interfaces. This model can be used to represent a single phase cable in a AC grid.
The model represents the lumped inductance as shown in the figure below.
Extends from Buildings.Electrical.Transmission.BaseClasses.PartialTwoPortInductance (Partial model of an inductive element that links two electrical connectors).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package PhaseSystem_p | PartialPhaseSystem | Phase system of terminal p | |
| replaceable package PhaseSystem_n | PartialPhaseSystem | Phase system of terminal n | |
| Inductance | L | Inductance [H] | |
| Modeling assumption | |||
| Load | mode | Buildings.Electrical.Types.L... | Type of model (e.g., steady state, dynamic, prescribed power consumption, etc.) |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package PhaseSystem_p | Phase system of terminal p | |
| replaceable package PhaseSystem_n | Phase system of terminal n | |
Modelica definition
model TwoPortInductance
"Model of an inductive element with two electrical ports"
extends Buildings.Electrical.Transmission.BaseClasses.PartialTwoPortInductance
(
redeclare package PhaseSystem_p = PhaseSystems.OnePhase,
redeclare package PhaseSystem_n = PhaseSystems.OnePhase,
redeclare Interfaces.Terminal_n terminal_n,
redeclare Interfaces.Terminal_p terminal_p);
parameter Buildings.Electrical.Types.Load mode(
min=Buildings.Electrical.Types.Load.FixedZ_steady_state,
max=Buildings.Electrical.Types.Load.VariableZ_y_input) = Buildings.Electrical.Types.Load.FixedZ_steady_state
"Type of model (e.g., steady state, dynamic, prescribed power consumption, etc.)";
protected
Modelica.SIunits.AngularVelocity omega
"Frequency of the quasi-stationary sine waves";
Modelica.SIunits.Angle theRef "Absolute angle of rotating reference system";
equation
theRef = PhaseSystem_p.thetaRef(terminal_p.theta);
omega = der(theRef);
if mode == Buildings.Electrical.Types.Load.FixedZ_dynamic then
// Dynamics of the system
der(L*terminal_p.i) + L*omega*PhaseSystem_p.j(terminal_p.i) = terminal_p.v -
terminal_n.v;
else
// Steady state relationship
L*omega*PhaseSystem_p.j(terminal_p.i) = terminal_p.v - terminal_n.v;
end if;
end TwoPortInductance;
Buildings.Electrical.AC.OnePhase.Lines.TwoPortRL
Model of a resistive-inductive element with two electrical ports
Information
This model represents a resistance and an inductance connected in series with two AC one phase interfaces. This model can be used to represent a single phase cable in a AC grid.
The model represents the lumped RL cable as shown in the figure below.
Extends from Buildings.Electrical.Transmission.BaseClasses.PartialTwoPortRLC (Partial model of an RLC element that links two electrical connectors).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package PhaseSystem_p | PartialPhaseSystem | Phase system of terminal p | |
| replaceable package PhaseSystem_n | PartialPhaseSystem | Phase system of terminal n | |
| Boolean | useHeatPort | false | =true, if heatPort is enabled |
| Temperature | T | T_ref | Fixed device temperature if useHeatPort = false [K] |
| Resistance | R | Resistance at temperature T_ref [Ohm] | |
| Temperature | T_ref | 298.15 | Reference temperature [K] |
| Temperature | M | 507.65 | Temperature constant (R_actual = R*(M + T_heatPort)/(M + T_ref)) [K] |
| Capacitance | C | 0 | Capacity [F] |
| Inductance | L | Inductance [H] | |
| Current | i_start[PhaseSystem_p.n] | zeros(PhaseSystem_p.n) | Initial current phasor of the line (positive if entering from terminal p) [A] |
| Nominal conditions | |||
| Voltage | V_nominal | 0 | Nominal voltage (V_nominal >= 0) [V] |
| Modeling assumption | |||
| Load | mode | Buildings.Electrical.Types.L... | Type of model (e.g., steady state, dynamic, prescribed power consumption, etc.) |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package PhaseSystem_p | Phase system of terminal p | |
| replaceable package PhaseSystem_n | Phase system of terminal n | |
| HeatPort_a | heatPort | Conditional heat port |
Modelica definition
model TwoPortRL
"Model of a resistive-inductive element with two electrical ports"
extends Buildings.Electrical.Transmission.BaseClasses.PartialTwoPortRLC(
final V_nominal=0,
redeclare package PhaseSystem_p = PhaseSystems.OnePhase,
redeclare package PhaseSystem_n = PhaseSystems.OnePhase,
redeclare Interfaces.Terminal_n terminal_n,
redeclare Interfaces.Terminal_p terminal_p,
final C=0);
parameter Modelica.SIunits.Current i_start[PhaseSystem_p.n]=zeros(
PhaseSystem_p.n)
"Initial current phasor of the line (positive if entering from terminal p)";
parameter Buildings.Electrical.Types.Load mode(
min=Buildings.Electrical.Types.Load.FixedZ_steady_state,
max=Buildings.Electrical.Types.Load.FixedZ_dynamic) = Buildings.Electrical.Types.Load.FixedZ_steady_state
"Type of model (e.g., steady state, dynamic, prescribed power consumption, etc.)";
protected
Modelica.SIunits.Current i_p[2](start=i_start, each stateSelect=StateSelect.prefer)
"Current phasor at terminal p";
Modelica.SIunits.AngularVelocity omega
"Frequency of the quasi-stationary sine waves";
Modelica.SIunits.Angle theRef "Absolute angle of rotating reference system";
initial equation
if mode == Buildings.Electrical.Types.Load.FixedZ_dynamic then
i_p = i_start;
end if;
equation
theRef = PhaseSystem_p.thetaRef(terminal_p.theta);
omega = der(theRef);
terminal_p.i = -terminal_n.i;
i_p = terminal_p.i;
if mode == Buildings.Electrical.Types.Load.FixedZ_dynamic then
// Dynamics of the system
der(L*i_p) + L*omega*PhaseSystem_p.j(i_p) + i_p*diagonal(ones(PhaseSystem_p.n)
*R_actual) = terminal_p.v - terminal_n.v;
else
// steady state relationship
L*omega*PhaseSystem_p.j(i_p) + i_p*diagonal(ones(PhaseSystem_p.n)*R_actual)
= terminal_p.v - terminal_n.v;
end if;
// Joule losses
LossPower = R_actual*(i_p[1]^2 + i_p[2]^2);
end TwoPortRL;
Buildings.Electrical.AC.OnePhase.Lines.TwoPortRLC
Model of an RLC element with two electrical ports
Information
This model represents a series of two resistive-inductive impedances and a capacitance that connects two AC single phase interfaces. This model can be used to represent a cable in a AC grid.
The model represents the lumped resistances and capacity, as a T-model, as shown in the figure below.
As can be seen in the figure, the resistance R and the inductance L are split in two halves
and the capacitance is located in the center.
The capacitance in the center is optional. If it is not present, set the
parameter C=0.
The model is either dynamic or static depending on the
presence of the capacitive effect.
Extends from Buildings.Electrical.Transmission.BaseClasses.PartialTwoPortRLC (Partial model of an RLC element that links two electrical connectors).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package PhaseSystem_p | PartialPhaseSystem | Phase system of terminal p | |
| replaceable package PhaseSystem_n | PartialPhaseSystem | Phase system of terminal n | |
| Boolean | useHeatPort | false | =true, if heatPort is enabled |
| Temperature | T | T_ref | Fixed device temperature if useHeatPort = false [K] |
| Resistance | R | Resistance at temperature T_ref [Ohm] | |
| Temperature | T_ref | 298.15 | Reference temperature [K] |
| Temperature | M | 507.65 | Temperature constant (R_actual = R*(M + T_heatPort)/(M + T_ref)) [K] |
| Capacitance | C | Capacity [F] | |
| Inductance | L | Inductance [H] | |
| Voltage | Vc_start[2] | {V_nominal,0} | Initial voltage phasor of the capacitance located in the middle of the line [V] |
| Modeling assumption | |||
| Load | mode | Buildings.Electrical.Types.L... | Type of model (e.g., steady state, dynamic, prescribed power consumption, etc.) |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package PhaseSystem_p | Phase system of terminal p | |
| replaceable package PhaseSystem_n | Phase system of terminal n | |
| HeatPort_a | heatPort | Conditional heat port |
Modelica definition
model TwoPortRLC "Model of an RLC element with two electrical ports"
extends Buildings.Electrical.Transmission.BaseClasses.PartialTwoPortRLC(
V_nominal(start=110),
redeclare package PhaseSystem_p = PhaseSystems.OnePhase,
redeclare package PhaseSystem_n = PhaseSystems.OnePhase,
redeclare replaceable Interfaces.Terminal_n terminal_n(redeclare package
PhaseSystem = PhaseSystem_n),
redeclare replaceable Interfaces.Terminal_p terminal_p(redeclare package
PhaseSystem = PhaseSystem_p));
parameter Modelica.SIunits.Voltage Vc_start[2]={V_nominal,0}
"Initial voltage phasor of the capacitance located in the middle of the line";
parameter Buildings.Electrical.Types.Load mode(
min=Buildings.Electrical.Types.Load.FixedZ_steady_state,
max=Buildings.Electrical.Types.Load.FixedZ_dynamic) = Buildings.Electrical.Types.Load.FixedZ_steady_state
"Type of model (e.g., steady state, dynamic, prescribed power consumption, etc.)";
protected
Modelica.SIunits.Voltage Vc[2](start=Vc_start, each stateSelect=StateSelect.prefer)
"Voltage of the Capacitance located in the middle of the line";
Modelica.SIunits.Current Ic[2]
"Currenbt of the capacitance located in the middle of the line";
Modelica.SIunits.AngularVelocity omega
"Frequency of the quasi-stationary sine waves";
Modelica.SIunits.Angle theRef "Absolute angle of rotating reference system";
initial equation
if C > 0 and mode == Buildings.Electrical.Types.Load.FixedZ_dynamic then
Vc = Vc_start;
end if;
equation
theRef = PhaseSystem_p.thetaRef(terminal_p.theta);
omega = der(theRef);
terminal_p.i + terminal_n.i = Ic;
L/2*omega*Buildings.Electrical.PhaseSystems.OnePhase.j(terminal_p.i) +
terminal_p.i*diagonal(ones(PhaseSystem_p.n)*R_actual/2) = terminal_p.v - Vc;
L/2*omega*Buildings.Electrical.PhaseSystems.OnePhase.j(terminal_n.i) +
terminal_n.i*diagonal(ones(PhaseSystem_n.n)*R_actual/2) = terminal_n.v - Vc;
if C > 0 then
if mode == Buildings.Electrical.Types.Load.FixedZ_dynamic then
// Dynamics of the system
C*der(Vc) + omega*C*Buildings.Electrical.PhaseSystems.OnePhase.j(Vc) = Ic;
else
// steady state relationship
omega*C*Buildings.Electrical.PhaseSystems.OnePhase.j(Vc) = Ic;
end if;
else
// No capacitive effect, the voltage in the middle of the line is the linear
// interpolation of the two phasors
Vc = (terminal_p.v + terminal_n.v)/2;
end if;
// Joule losses
LossPower = R_actual/2*(terminal_p.i[1]^2 + terminal_p.i[2]^2) + R_actual/2*(
terminal_n.i[1]^2 + terminal_n.i[2]^2);
end TwoPortRLC;
Buildings.Electrical.AC.OnePhase.Lines.TwoPortResistance
Model of a resistance with two electrical ports
Information
This model represents a resistance that connects two AC one phase interfaces. This model can be used to represent a single phase cable in a AC grid.
The model represents the lumped resistance as shown in the figure below.
Extends from Buildings.Electrical.Transmission.BaseClasses.PartialTwoPortResistance (Partial model of a resistive element that links two electrical connectors).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package PhaseSystem_p | PartialPhaseSystem | Phase system of terminal p | |
| replaceable package PhaseSystem_n | PartialPhaseSystem | Phase system of terminal n | |
| Boolean | useHeatPort | false | =true, if heatPort is enabled |
| Temperature | T | T_ref | Fixed device temperature if useHeatPort = false [K] |
| Resistance | R | Resistance at temperature T_ref [Ohm] | |
| Temperature | T_ref | 298.15 | Reference temperature [K] |
| Temperature | M | 507.65 | Temperature constant (R_actual = R*(M + T_heatPort)/(M + T_ref)) [K] |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package PhaseSystem_p | Phase system of terminal p | |
| replaceable package PhaseSystem_n | Phase system of terminal n | |
| HeatPort_a | heatPort | Conditional heat port |
Modelica definition
model TwoPortResistance
"Model of a resistance with two electrical ports"
extends Buildings.Electrical.Transmission.BaseClasses.PartialTwoPortResistance
(
redeclare package PhaseSystem_p = PhaseSystems.OnePhase,
redeclare package PhaseSystem_n = PhaseSystems.OnePhase,
redeclare Interfaces.Terminal_n terminal_n,
redeclare Interfaces.Terminal_p terminal_p);
equation
terminal_p.v - terminal_n.v = terminal_p.i*diagonal(ones(PhaseSystem_p.n)*
R_actual);
// Joule losses
LossPower = R_actual*(terminal_p.i[1]^2 + terminal_p.i[2]^2);
end TwoPortResistance;