Gas Model

mutable struct GenericGasModel{T<:AbstractGasFormulation}
    model::JuMP.Model
    data::Dict{String,Any}
    setting::Dict{String,Any}
    solution::Dict{String,Any}
    var::Dict{Symbol,Any} # model variable lookup
    constraint::Dict{Symbol, Dict{Any, ConstraintRef}} # model constraint lookup
    ref::Dict{Symbol,Any} # reference data
    ext::Dict{Symbol,Any} # user extensions
end

where

• data is the original data, usually from reading in a .json file,
• setting usually looks something like Dict("output" => Dict("flows" => true)), and
• ref is a place to store commonly used pre-computed data from of the data dictionary, primarily for converting data-types, filtering out deactivated components, and storing system-wide values that need to be computed globally. See build_ref(data) for further details.

Methods on GenericGasModel for defining variables and adding constraints should

• work with the ref dict, rather than the original data dict,
• add them to model::JuMP.Model, and
• follow the conventions for variable and constraint names.

Returns a dict that stores commonly used pre-computed data from of the data dictionary, primarily for converting data-types, filtering out deactivated components, and storing system-wide values that need to be computed globally.

Some of the common keys include:

• :max_mass_flow (see max_mass_flow(data)),
• :connection – the set of connections that are active in the network (based on the component status values),
• :pipe – the set of connections that are pipes (based on the component type values),
• :short_pipe – the set of connections that are short pipes (based on the component type values),
• :compressor – the set of connections that are compressors (based on the component type values),
• :valve – the set of connections that are valves (based on the component type values),
• :control_valve – the set of connections that are control valves (based on the component type values),
• :resistor – the set of connections that are resistors (based on the component type values),
• :parallel_connections – the set of all existing connections between junction pairs (i,j),
• :all_parallel_connections – the set of all existing and new connections between junction pairs (i,j),
• :junction_connections – the set of all existing connections of junction i,
• :junction_ne_connections – the set of all new connections of junction i,
• :junction_consumers – the mapping Dict(i => [consumer["ql_junc"] for (i,consumer) in ref[:consumer]]).
• :junction_producers – the mapping Dict(i => [producer["qg_junc"] for (i,producer) in ref[:producer]]).
• :degree – the degree of junction i using existing connections (see degree_ref!)),
• degree_ne – the degree of junction i using existing and new connections (see degree_ne_ref!)),
• :pd_min,:pd_max – the max and min square pressure difference (see calc_pd_bounds_sqr)),