File IO

General Data Formats

The json file format is a direct JSON serialization of GasModels internal data model. As such, the json file format is intended to be a temporary storage format. GasModels does not maintain backwards compatability with serializations of earlier versions of the Gas Models internal data model.

parse_file(io)

Matlab Data Files

The following method is the main methods for parsing Matlab data files:

We also provide the following (internal) helper methods:

This format was designed to have a similar look a feel to the matlab MatPower format, however, it standardizes around data requirements developed by the GasModels development team. It is largely stable, though it has not yet standardized the data fields for valves, control valves, short pipes, resistors, and storage. Such data can be incorporated using the matlab extensions developed in InfrastructureModels.jl, with standard formats expected to be introduced at a later date.

The top of the file contains global information about the network like its name, gas temperature, etc.

function mgc = gaslib40                       % Name of the network model

mgc.sound_speed = 312.805;                    % Speed of sound
mgc.temperature = 273.15;                     % Gas temperature
mgc.R = 8.314;                                % Universal gas constant
mgc.compressibility_factor = 0.8;             % Gas compressibility factor
mgc.gas_molar_mass = 0.0185674;               % Molar mass of the gas
mgc.gas_specific_gravity = 0.6;               % Specific gravity of the gas
mgc.specific_heat_capacity_ratio = 1.4;       % Heat capacity ratio of the gas
mgc.standard_density = 1.0;                   % Standard density value
mgc.baseP = 8101325;                          % Normalization constant for pressure
mgc.baseF = 604.167;                          % Normalization constant for flow
mgc.per_unit = true;                          % Whether or not the parameters are in per unit

Junction data is defined with the following tabular format

%% junction data
%  junction_i type pmin pmax status p
mgc.junction = [
...
]

where junction_i is the unique identifier of the junction, type indicates whether or not the junction can be used as a slack node ('type=1'), pmin is the minimum pressure, pmax is the maximum pressure, status is the 0/1 status of the junction and p is a nominal pressure value.

Pipeline data is defined with the following tabular format

%% pipeline data
% pipeline_i f_junction t_junction diameter length friction_factor status
mgc.pipe = [
...
]

where pipeline_i is the unique identifier of the pipe, f_junction is the identifier of the from junction, t_junction is the identifier of the to junction, diameter is the diameter of the pipe, length is the length of the pipe, friction_factor is the friction level of the pipe, and status is the 0/1 status of the pipe.

Compressor data is defined with the following tabular format

%% compressor data
% compressor_i f_junction t_junction cmin cmax power_max fmin fmax status
mgc.compressor = [
...

where compressor_i is the unique identifier of the compressor, f_junction is the identifier of the from junction, t_junction is the identifier of the to junction, cmin is the minimum boost ratio of the compressor, cmax is the maximum boost ratio of the compressor, power_max is the maximum power for the compressor, fmin is the minimum flow through the compressor, fmax is the minimum flow through the compressor, and status is the 0/1 status of the pipe.

Producer data is defined with the following tabular format

%% producer
% producer_i junction fgmin fgmax fg status dispatchable
mgc.producer = [
...

where producer_i is the unique identifier of the producer, junction is the identifier of the junction, fgmin is the minimum production, fgmax is the maximum production, fg is the normal production, status is the 0/1 status of the pipe, and dispatchable indicates whether or not the producer can modify its production.

Consumer data is defined with the following tabular format

%% consumer
% consumer_i junction fd status dispatchable
mgc.consumer = [
...

where consumer_i is the unique identifier of the consumer, junction is the identifier of the junction, fd is the normal consumption, status is the 0/1 status of the pipe, and dispatchable indicates whether or not the producer can modify its production.