function frequency_ranges(
    f_min,
    f_max,
    subnet::Int64,
    directory::String,
    objective::String,
    x_axis::Array,
    y_axis::Array;
    gen_areas=Int64[],
    area_transfer=Int64[],
    gen_zones=[],
    zone_transfer=[],
    plot_vert_line::Tuple=([],""),
    plot_horiz_line::Tuple=([],""),
    xlimits::Array{Any,1}=[],
    ylimits::Array{Any,1}=[],
    output_plot_label::Tuple{String,String}=("",""),
    scopf::Bool=false,
    contingency::Tuple=(0,),
    k_cond=[],
    k_ins=[],
    scale_load=1.0,
    scale_areas=Int64[],
    no_converter_loss=false
)

Models and solves an OPF with frequency in specified ranges between f_min and f_max.

Arguments

• f_min: lower bounds on frequency, one for each point in the frequency sweep
• f_max: upper bounds on frequency, one for each point in the frequency sweep. Must have the same length as f_min.
• subnet::Int64: subnetwork for which the frequency bounds are applied
• directory::String: the directory containing all subnetwork data, subnetworks.csv, and interfaces.csv
• objective::String: the objective function to use, from the following:
  • "mincost": minimize generation cost
  • "areagen": minimize generation in the areas specified in gen_areas
  • "zonegen": minimize generation in the zones specified in gen_zones
  • "minredispatch": minimize the change in generator dispatch from the initial values defined in the network data
• x_axis::Array: Array of Tuples identifying the x axis series for which plots should be generated over the points in the frequency sweep. A separate folder of plots is generated for each Tuple in the array. The series can be specified in the Tuple in one of three ways:
  • results dictionary values: A two-element Tuple, where the first element is a String matching a key in the results dictionary output from multifrequency_opf and the second element is an Int specifying a subnetwork. This plots the values of this key and subnetwork entry on the x axis.
  • network data values: A Tuple with elements corresponding to keys at each level of the network data dictionary, identifying any network variable value. This plots the values of the specified network variable on the x axis. Any key in the Tuple may be an Array, in which case a separate plot is generated for each key. For example, to generate four plots, the active and reactive power at the origin ("f") bus and destination ("t") bus for branch 1 in subnetwork 2, use the Tuple ("sn",2,"branch",1,["pt","pf","qt","qf"])
  • custom values: A two-element Tuple, where the first element is a String not matching any keys in the results dictionary and the second element is an Array. This plots the values in the Array on the x axis with the label in the String.
• y_axis::Array: Array of Tuples identifying the y axis series for which plots should be generated over the points in the frequency sweep. A separate folder of plots is generated for each Tuple in the array. These are specified in the same way as x_axis.
• gen_areas: all areas in which generation should be minimized if obj=="areagen"
• area_transfer: two areas with power transfer between them that should be saved and plotted. Results for P, Q, S, and loss are saved for power transfer between the two areas. Must have exactly two elements.
• gen_zones: all zones in which generation should be minimized if obj=="zonegen"
• zone_transfer: two zones with power transfer between them that should be saved and plotted. Results for P, Q, S, and loss are saved for power transfer between the two zones. Must have exactly two elements.
• plot_vert_line::Tuple: x values of vertical lines to overlay on the plot. The first element is a scalar or Array specifying one or more x values to plot, and the second element is a String or Array of Strings specifying the label or labels. Default ([],"") does not add any lines to the plot.
• plot_horiz_line::Tuple: y values of horizontal lines to overlay on the plot. The first element is a scalar or Array specifying one or more y values to plot, and the second element is a String or Array of Strings specifying the label or labels. Default ([],"") does not add any lines to the plot.
• xlimits::Array{Any,1}: Array of two values specifying the min and max x axis limits to apply to the plots, overriding any other limits. Default [] does not change the plot.
• ylimits::Array{Any,1}: Array of two values specifying the min and max y axis limits to apply to the plots, overriding any other limits. Default [] does not change the plot.
• output_plot_label::Tuple{String,String}: specifies the plot to pass to the output. The first element must match the x axis label, and the second must match the y axis label.
• scopf::Bool: if true, model and solve the N-1 security constrained OPF for each network. Each network folder must contain a contingency specification file (*.con) for each subnetwork. Default false.
• contingency::Tuple: indices of the contingency to plot. The precontingency index is (0,). Default (0,).
• k_cond: conductor utilization parameter for HVDC. Only used when f==0. Default [].
• k_ins: insulation factor parameter for HVDC. Only used when f==0. Default [].
• scale_load: factor for scaling the load in the frequency sweep. Default 1.0.
• scale_areas: array of integer area indices for which the load scaling factor scale_load should be applied. Applies to all areas if this array is empty. Default Int64[].
• no_converter_loss: override all converter loss parameters specified in the data and replace them with the the lossless converter model.

function make_mn_data(
    subnetworks,
    interfaces,
    networks::Dict{String,Any}
)

Builds the mn_data dictionary from the specifications of the subnetworks and interfaces DataFrames and the network data in the networks Dict.

Arguments

• subnetworks: a DataFrame in the format of subnetworks.csv, and interfaces.csv
• interfaces: a DataFrame in the format of interfaces.csv
• networks::Dict{String,Any}: a Dict of all subnetworks, as PowerModels networks

multifrequency_opf(
    folder::String,
    obj::String;
    gen_areas=[],
    area_interface=[],
    gen_zones=[],
    zone_interface=[],
    print_results::Bool=false,
    override_param::Dict{Any}=Dict(),
    fix_f_override::Bool=false,
    direct_pq::Bool=true,
    master_subnet::Int64=1,
    suffix::String="",
    start_vals=Dict{String, Dict}("sn"=>Dict()),
    no_converter_loss::Bool=false,
    uniform_gen_scaling::Bool=false,
    unbounded_pg::Bool=false
)

Models and solves the OPF for a single network with data contained in folder.

Arguments

• folder::String: the directory containing all subnetwork data, subnetworks.csv, and interfaces.csv
• obj::String: the objective function to use, from the following:
  • "mincost": minimize generation cost
  • "areagen": minimize generation in the areas specified in gen_areas
  • "zonegen": minimize generation in the zones specified in gen_zones
  • "minredispatch": minimize the change in generator dispatch from the initial values defined in the network data
• gen_areas: integer array of all areas in which generation should be minimized if obj=="areagen"
• area_interface: two areas with power transfer between them that should be saved and plotted. Results for P, Q, S, and loss are saved for power transfer between the two areas. Must have exactly two elements.
• gen_zones: integer array of all zones in which generation should be minimized if obj=="zonegen"
• zone_interface: two zones with power transfer between them that should be saved and plotted. Results for P, Q, S, and loss are saved for power transfer between the two zones. Must have exactly two elements.
• print_results::Bool: if true, print the DataFrames containing the output values for buses, branches, generators, and interfaces. These values are always saved to the output .csv files whether true or false.
• override_param::Dict{Any}: values to override in the network data defined in folder. Must follow the same structure as the full network data dictionary, beginning with key "sn". Default empty Dict.
• fix_f_override::Bool: if true, fix the frequency in every subnetwork to the base value, overriding the variable_f parameter to variable_f=false for every subnetwork. Default false.
• direct_pq::Bool: If direct_pq is false, then the interface is treated as a single node and power flow respects Kirchoff Laws, by constraining the voltage magnitude and angle on each side to be equal and enforcing reactive power balance. Default true.
• master_subnet::Int64: if direct_pq==false, the angle reference must be defined for exactly one subnetwork, since the other subnetwork angles are coupled through the interfaces. Value of master_subnet defines which subnetwork provides this reference. Default 1.
• suffix::String: suffix to add to the output directory when saving results. Default empty string.
• start_vals: Nested dictionary populated with values to be used as a starting point in the optimization model. Applies to bus vm and va, gen pg and qg, branch pt, pf, qt and qf and subnet f. Any of these values which are present in the dictionary will be applied; other values will be ignored. A full network data dictionary can be used. Default Dict{String, Dict}("sn"=>Dict()).

read_sn_data(folder::String)

Reads a network folder and builds the mn_data dictionary.

Arguments

• folder::String: the path to the folder containing all the network data

runsubnets( parentfolder::String, objective::String; genareas::Array=[], areatransfer::Array=[], genzones::Array=[], zonetransfer::Array=[], enumbranches::Bool=false, plotbestx::Int64=-1, scopf::Bool=false, ctgplots::Array{Int64,1}=[0], runfixf::Bool=false, runindirPQ::Bool=false, print_results::Bool=false )

Models and solves an OPF for every network in a directory.

Arguments

• parent_folder::String: a directory containing full network data for one or more networks, each in a folder containing all subnetwork data, subnetworks.csv, and interfaces.csv
• obj::String: the objective function to use, from the following:
  • "mincost": minimize generation cost
  • "areagen": minimize generation in the areas specified in gen_areas
  • "zonegen": minimize generation in the zones specified in gen_zones
  • "minredispatch": minimize the change in generator dispatch from the initial values defined in the network data
• gen_areas::Array{Int64,1}: all areas in which generation should be minimized if obj=="areagen"
• area_transfer::Array{Int64,1}: two areas with power transfer between them that should be saved and plotted. Results for P, Q, S, and loss are saved for power transfer between the two areas. Must have exactly two elements.
• gen_zones::Array{Int64,1}: all zones in which generation should be minimized if obj=="zonegen"
• zone_transfer::Array{Int64,1}: two zones with power transfer between them that should be saved and plotted. Results for P, Q, S, and loss are saved for power transfer between the two zones. Must have exactly two elements.
• enum_branches::Bool: if true, collect results from each folder for plotting bar graphs. This is used when the possible branch upgrades have been enumerated and a comparison is desired. Default false.
• plot_best_x::Int64: number of results to plot, sorted from smallest to largest objective. If plot_best_x <= 1, the results of all networks which gave feasible solutions are plotted. Default -1.
• scopf::Bool: if true, model and solve the N-1 security constrained OPF for each network. Each network folder must contain a contingency specification file (*.con) for each subnetwork. Default false.
• ctg_plots::Array{Int64,1}: indices of the contingencies to plot. The base case index is 0. Default [0].

function upgrade_branches(
   base_network::String,
   output_location::String,
   fbase;
   indices=[],
   output_type="input"
   )

Creates a folder of network data for the network base_network with one line converted to LFAC, one for each index in indices, or if indices is empty, for every non-transformer branch in the network.