Hub Objects

This section presents an in-depth description of all objects available in SAInt to model a hub system. A hub system aims at modeling coupled energy systems, and at assessing interdependencies and cascading effects. Figure 1 shows the hierarchy and the parent-child relationships between base objects. Table 1 gives a quick and short description of the base objects.

For example, the top-level base object in a hub system model is the "hub system" object HUBS. A hub system contains only one energy hub HUB, which is a child of the system. An energy hub contains many other different base objects, such as, for example, gas-fired generator GFG, power-to-gas facilities P2G, or electric-driven gas storages EDGSTR. A hub system object has no parents but only children. A hub component object GFG cannot be a parent but only a child. See the schematic below for a visual representation of the complete hierarchical object structure for a hub system model in SAInt.

Figure 1. Relationship between objects in a hub system. A child object is indicated by the head of a pointed arrow, while a parent is by the tail.

Table 1. Icons and descriptions of object types in a hub system.
ObjType	Display Name	Description
`HUBS`	Hub System	Models the operation of facilities coupling different energy network types. Serves as a container for all hub objects
`GFG`	Gas-Fired Generator	Models the coupling between a Fuel Generator (FGEN) and a Gas Demand (GDEM)
`P2G`	Power-To-Gas Facility	Models the coupling between an Electric Demand (EDEM) and a Gas Supply (GSUP). A prime example of a Power-To-Gas Facility is an electrolyzer plant, in which electric power is used to convert water into oxygen and hydrogen. The latter is then injected into the gas network
`EDGCS`	Electric-Driven Gas Compressor	Models the coupling between an Electric Demand (EDEM) and a Gas Compressor (GCS). In an Electric-Driven Gas Compressor, electric power is converted into the mechanical power needed to increase the gas pressure
`EDGSTR`	Electric-Driven Gas Storage	Models the coupling between an Electric Demand (EDEM) and a Gas Storage (GSTR). It models the electricity consumption needed to operate the gas storage
`EDLNG`	Electric-Driven LNG Terminal	Models the coupling between an Electric Demand (EDEM) and an LNG Terminal (LNG). It models the electric power consumption needed to operate the LNG terminal

1. Gas-electric hubs (HUBS)

The hub network contains objects representing coupling points between objects from different network types. Coupling between objects is unique; thus a coupled object cannot be coupled to a third object. A coupled object can be either electric or gas driven. Coupled objects are visualized in the map window with a cyan dash line when the hub is turned on.

The events assigned to the coupled objects are not created on the hub network. For example, for an EDGCS, the POSET event for the gas compressor is applied on the gas network.

Intro
net-input
net-read-only

Summaries for the properties and the events of HUBS.

Summary for the net-input properties of HUBS.
Extension	Description	UnitType
CRSType	Network coordinate reference system for the node locations
ENETNAME	Name of Electric Network	NO
GNETNAME	Name of Gas Network	NO
Info	Information related to the network model. Any character, including non-alphanumeric, is allowed
TNETNAME	Name of Thermal Network	NO

Summary for the net-read-only properties of HUBS.
Extension	Description	UnitType
Name	Name of the network model. Permitted characters are letters, numbers, and underscore ("_"). The name should start with a letter, and have a length of 1 to 30 characters.
NetType	Network Type
NUMHUBS	Number of Hubs	NO
ObjType	Object Type
UID	Unique identifier for the object which cannot be changed during the lifetime of the object

1.1. Electric-driven gas compressor (EDGCS)

The electric-driven gas compressor EDGCS is an object allowing to model the coupling between a gas compressor station (GCS) and an electric demand (EDEM). The object describes the electric power consumption needed to operate the gas compressor. The gas event leads to the combined simulation. For example, by setting the POSET (pressure outlet set point) event for a gas compressor, the simulation determines the required electric demand P to achieve the POSET. If a PSET (active power set point) event is assigned to the electric demand, it will be neglected.

The only considered events for the EDEM object are OFF, ON, and PMAX events. For example, if the EDEM has an OFF event, the EDGCS will not operate.

Intro
derived-result
net-input
net-read-only

Summaries for the properties and the events of EDGCS.

Summary for the derived-result properties of EDGCS.
Extension	Description	UnitType
PD	Active Power Demand	PPOW
POWD	Driver Power	POW
PI	Inlet Pressure	P
State	Current operating state of object. Permitted states are ON and OFF. When referred to a node, all externals connected to the node inherit the state
PO	Outlet Pressure	P
QD	Reactive Power Demand	QPOW

Summary for the net-input properties of EDGCS.
Extension	Description	UnitType
Alias	Alternative object name. Any character, including non-alphanumeric, is allowed
EDEMNAME	Electric Demand Name	NO
GCSNAME	Gas Compressor Name	NO
Info	Information entered for the object. Any character, including non-alphanumeric, is allowed
InService	Indicates if an object is considered or disregarded in the execution of a scenario. Externals connected to the node inherit the "inService" status of the node
Name	Object Name. Permitted characters are letters, numbers, and underscore ("_"). The name should start with a letter, and have a length of 1 to 30 characters. The name should be unique for each object type
PWF	Power factor, PWF=cos(phi)=P/S	ND
PWFType	Power factor type "ind" for lagging (inductive load) and "cap" for leading (capacitive load) power factor. The type doesn’t matter for a resistive load (unity power factor) as far as the PowerFactor is set to 1. Used for calculating QSET from PSET if no QSET event is defined	NO
Visible	If true, the object symbol will be visible in maps	NO

Summary for the net-read-only properties of EDGCS.
Extension	Description	UnitType
EFFM	Average driver efficiency	ND
NetType	Network Type
ID	Object Identification
UID	Unique identifier for the object which cannot be changed during the lifetime of the object

1.2. Electric-driven gas storage (EDGSTR)

The electric-driven gas storage EDGSTR is an object allowing to model the coupling between a gas storage (GSTR) and an electric demand (EDEM). The object describes the electric power consumption needed to operate the gas storage. The gas event leads to the combined simulation. For example, by setting the QSET (flow set point) event for a gas storage, the simulation determines the required electric demand P to achieve the QSET. If a PSET (power set point) event is assigned to the electric demand, it will be neglected.

The only considered events for the EDEM object are OFF, ON, and PMAX events. For example, if the EDEM has an OFF event, the EDGSTR will not operate.

Intro
derived-result
net-input
net-read-only

Summaries for the properties and the events of EDGSTR.

Summary for the derived-result properties of EDGSTR.
Extension	Description	UnitType
PD	Active Power Demand	PPOW
P	Gas Pressure	P
Q	Gas Supply/Demand	Q
State	Current operating state of object. Permitted states are ON and OFF. When referred to a node, all externals connected to the node inherit the state
QD	Reactive Power Demand	QPOW

Summary for the net-input properties of EDGSTR.
Extension	Description	UnitType
Alias	Alternative object name. Any character, including non-alphanumeric, is allowed
K0	Coefficient of constant term for the coupling equation	ND
EDEMNAME	Electric Demand Name	NO
GSTRNAME	Gas Storage Name
Info	Information entered for the object. Any character, including non-alphanumeric, is allowed
InService	Indicates if an object is considered or disregarded in the execution of a scenario. Externals connected to the node inherit the "inService" status of the node
K1	Coefficient of linear term for the coupling equation	ND
Name	Object Name. Permitted characters are letters, numbers, and underscore ("_"). The name should start with a letter, and have a length of 1 to 30 characters. The name should be unique for each object type
PWF	Power factor, PWF=cos(phi)=P/S	ND
PWFType	Power factor type "ind" for lagging (inductive load) and "cap" for leading (capacitive load) power factor. The type doesn’t matter for a resistive load (unity power factor) as far as the PowerFactor is set to 1. Used for calculating QSET from PSET if no QSET event is defined	NO
K2	Coefficient of quadratic term for the coupling equation	ND
Visible	If true, the object symbol will be visible in maps	NO

Summary for the net-read-only properties of EDGSTR.
Extension	Description	UnitType
NetType	Network Type
ID	Object Identification
UID	Unique identifier for the object which cannot be changed during the lifetime of the object

1.3. Electric-driven LNG terminal (EDLNG)

The electric-driven LNG terminal EDLNG is an object allowing to model the coupling between a LNG terminal (LNG) and an electric demand (EDEM). The object describes the electric power consumption needed to operate the terminal. The gas event leads to the combined simulation. For example, by setting the QSET (flow set point) event for a gas LNG terminal, the simulation determines the required electric demand P to achieve the QSET. If a PSET (power set point) event is assigned to the electric demand, it will be neglected.

The only considered events for the EDEM object are OFF, ON, and PMAX events. For example, if the EDEM has an OFF event, the EDLNG will not operate.

Intro
derived-result
net-input
net-read-only

Summaries for the properties and the events of EDLNG.

Summary for the derived-result properties of EDLNG.
Extension	Description	UnitType
PD	Active Power Demand	PPOW
P	Gas Pressure	P
Q	Gas Supply	Q
State	Current operating state of object. Permitted states are ON and OFF. When referred to a node, all externals connected to the node inherit the state
QD	Reactive Power Demand	QPOW

Summary for the net-input properties of EDLNG.
Extension	Description	UnitType
Alias	Alternative object name. Any character, including non-alphanumeric, is allowed
K0	Coefficient of constant term for the coupling equation	ND
EDEMNAME	Electric Demand Name	NO
Info	Information entered for the object. Any character, including non-alphanumeric, is allowed
InService	Indicates if an object is considered or disregarded in the execution of a scenario. Externals connected to the node inherit the "inService" status of the node
K1	Coefficient of linear term for the coupling equation	ND
LNGNAME	LNG Terminal Name
Name	Object Name. Permitted characters are letters, numbers, and underscore ("_"). The name should start with a letter, and have a length of 1 to 30 characters. The name should be unique for each object type
PWF	Power factor, PWF=cos(phi)=P/S	ND
PWFType	Power factor type "ind" for lagging (inductive load) and "cap" for leading (capacitive load) power factor. The type doesn’t matter for a resistive load (unity power factor) as far as the PowerFactor is set to 1. Used for calculating QSET from PSET if no QSET event is defined	NO
K2	Coefficient of quadratic term for the coupling equation	ND
Visible	If true, the object symbol will be visible in maps	NO

Summary for the net-read-only properties of EDLNG.
Extension	Description	UnitType
NetType	Network Type
ID	Object Identification
UID	Unique identifier for the object which cannot be changed during the lifetime of the object

1.4. Gas-fired generator (GFG)

The gas-fired generator GFG is an object allowing to model the coupling between a generator (FGEN) and a gas demand (GDEM). The object describes the gas demand needed to operate the gas generator. The electric event leads the combined simulation. For example, by setting the PSET (active power set point) event for a fuel generator, the simulation determines the required gas demand Q to achieve the PSET. If a QSET (flow set point) event is assigned to the gas demand, it will be neglected.

The only considered events for the GDEM object are OFF, ON, PMIN, and QMAX events. For example, if the GDEM has an QMAX event, the GFG operation will be constrained by the maximum flow of the gas demand.

Intro
derived-result
net-input
net-read-only

Summaries for the properties and the events of GFG.

Summary for the derived-result properties of GFG.
Extension	Description	UnitType
PG	Active Power Generation	PPOW
Q	Gas Demand	Q
P	Gas Pressure	P
GCV	Gross calorific value	CV
HR	Heat rate as a function of active power generation	HR
State	Current operating state of object. Permitted states are ON and OFF. When referred to a node, all externals connected to the node inherit the state
QG	Reactive Power Generation	QPOW
TQ	Thermal flow	TQ

Summary for the net-input properties of GFG.
Extension	Description	UnitType
Alias	Alternative object name. Any character, including non-alphanumeric, is allowed
HR0	Constant heat rate coefficient	HR
FGENNAME	Fuel Generator Name
GDEMNAME	GasDemandName
Info	Information entered for the object. Any character, including non-alphanumeric, is allowed
InService	Indicates if an object is considered or disregarded in the execution of a scenario. Externals connected to the node inherit the "inService" status of the node
HR1	Linear heat rate coefficient	POWHR
Name	Object Name. Permitted characters are letters, numbers, and underscore ("_"). The name should start with a letter, and have a length of 1 to 30 characters. The name should be unique for each object type
HR2	Quadratic heat rate coefficient	POW2HR
Visible	If true, the object symbol will be visible in maps	NO

Summary for the net-read-only properties of GFG.
Extension	Description	UnitType
NetType	Network Type
ID	Object Identification
UID	Unique identifier for the object which cannot be changed during the lifetime of the object

1.5. Power-to-gas facility (P2G)

The power-to-gas facility P2G is an object allowing to model the coupling between an electric demand (EDEM) and a gas supply (GSUP). The object describes the electric power consumption needed to operate the gas supply (e.g., electrolyzer). The electric event leads the combined simulation. For example, by setting the PSET (active power set point) event for an electric demand, the simulation determines the amount of gas (Q) that can be delivered by the gas supply. If a QSET (flow set point) event is assigned to the Gas Supply, it will be neglected. The gas quality and composition delivered by the gas supply can be modified by the user.

The only considered events for the GSUP object are OFF, ON, and QMAX events. For example, if the GSUP has an OFF event, the P2G will not operate.

Intro
derived-result
net-input
net-read-only

Summaries for the properties and the events of P2G.

Summary for the derived-result properties of P2G.
Extension	Description	UnitType
PD	Active Power Demand	PPOW
P	Gas Pressure	P
Q	Gas Supply	Q
State	Current operating state of object. Permitted states are ON and OFF. When referred to a node, all externals connected to the node inherit the state
QD	Reactive Power Demand	QPOW

Summary for the net-input properties of P2G.
Extension	Description	UnitType
Alias	Alternative object name. Any character, including non-alphanumeric, is allowed
EDEMNAME	Electric Demand Name	NO
GSUPNAME	Gas Supply Name
Info	Information entered for the object. Any character, including non-alphanumeric, is allowed
InService	Indicates if an object is considered or disregarded in the execution of a scenario. Externals connected to the node inherit the "inService" status of the node
Name	Object Name. Permitted characters are letters, numbers, and underscore ("_"). The name should start with a letter, and have a length of 1 to 30 characters. The name should be unique for each object type
Eff	Efficiency factor for the power-to-gas conversion	ND
PWF	Power factor, PWF=cos(phi)=P/S	ND
PWFType	Power factor type "ind" for lagging (inductive load) and "cap" for leading (capacitive load) power factor. The type doesn’t matter for a resistive load (unity power factor) as far as the PowerFactor is set to 1. Used for calculating QSET from PSET if no QSET event is defined	NO
Visible	If true, the object symbol will be visible in maps	NO

Summary for the net-read-only properties of P2G.
Extension	Description	UnitType
NetType	Network Type
ID	Object Identification
UID	Unique identifier for the object which cannot be changed during the lifetime of the object