Decomposing Problems

split_network(net::Network, bus::String)::Tuple{Network, Network}

Split net into one Network for everything above bus and one Network for everything below bus.

split_network(net::Network, bus::String, out_busses::Vector{String})::Tuple{Network, Network}

Split net into net_above and net_below where net_below has only out_busses and net_above has union( [bus], setdiff(busses(net), out_busses) ). We want to keep bus in both networks because there can be multiple branches out of bus that are not in out_busses.

Note that out_busses must contain bus

init_split_networks!(nets::Vector{Network{SinglePhase}}; init_vs::Dict = Dict())

Set the loads on the upstream leaf nodes equal to the sum of all the loads in the downstream nodes. It is important that the order of nets is from leaf branches to trunk branches so that the sums of loads take into account all downstream sub-trees.

if init_vs is provided, the net.v0 is set for the Input with its net.substation_bus equal to the key in init_vs

init_vs = Dict(
    "sub_bus_1" => 0.98
)

for net in nets
    if net.substation_bus in keys(init_vs)
        net.v0 = init_vs[net.substation_bus]
    end
end

init_split_networks!(mg::MetaGraphsNext.MetaGraph; init_vs::Dict = Dict())

Use the :load_sum_order in mg to init_split_networks! in the correct order, i.e. set the loads at the leaf - substation connections as sums of all the loads (and the voltages at substations)

splitting_busses(net::Network, source::String; threshold::Int64=10)

Determine the busses to split a tree graph on by searching upward from the deepest leafs first and gathering the nearest busses until threshold is met for each subgraph.

Returns a Vector{String} for the bus names to split on and Vector{Vector{String}} for the corresponding busses within each sub-graph.

split_at_busses(net::Network, at_busses::Vector{String})

Split net.graph using the at_busses

returns directed MetaGraph with vertices containing Network for the sub-graphs using integer vertex labels. For example mg[2] is the Network at the second vertex of the graph created by splitting the network via the at_busses.

split_at_busses(net::Network, at_busses::Vector{String}, with_busses::Vector{Vector{String}})

Split up p using the at_busses as each new substation_bus and containing the corresponding with_busses. The at_busses and with_busses can be determined using splitting_busses.

NOTE: this variation of spltatbusses allows for more than two splits at the same bus; whereas the other implementation of splitatbusses only splits the network into two parts for everything above and everything below a splitting bus.