Fix Parser for HVDC lines with PWL Costs (#317)

* do not add HVDC line costs when no HVDC lines exist
* fix non-increasing domain on default hvdc pwl costs, and added test case
* closes #316

CHANGELOG.md

@@ -9,6 +9,7 @@ PowerModels.jl Change Log
 - Added support for network data with multiple phases
 - Removed explicit series variables from branch flow model
 - Improved helper functions ref, var, con to work with multiple networks and phases
+- Minor issues closed #316
 
 ### v0.7.2
 - Removed Memento depreciation warnings

src/core/objective.jl

@@ -221,8 +221,9 @@ function objective_min_pwl_fuel_cost(pm::GenericPowerModel)
         # pwl cost
         dcline_lines = get_lines(nw_ref[:dcline])
         for (i, dcline) in nw_ref[:dcline]
+            arc = (i, dcline["f_bus"], dcline["t_bus"])
             for line in dcline_lines[i]
-                @constraint(pm.model, dc_p_cost[i] >= line["slope"]*sum(var(pm, n, h, :p_dc)[i] for h in phase_ids(pm, n)) + line["intercept"])
+                @constraint(pm.model, dc_p_cost[i] >= line["slope"]*sum(var(pm, n, h, :p_dc)[arc] for h in phase_ids(pm, n)) + line["intercept"])
             end
         end
 

src/io/matpower.jl

@@ -556,7 +556,7 @@ end
 
 "adds dcline costs, if gen costs exist"
 function add_dcline_costs(data::Dict{String,Any})
-    if length(data["gencost"]) > 0 && length(data["dclinecost"]) <= 0
+    if length(data["gencost"]) > 0 && length(data["dclinecost"]) <= 0 && length(data["dcline"]) > 0
         warn(LOGGER, "added zero cost function data for dclines")
         model = data["gencost"][1]["model"]
         if model == 1
@@ -567,7 +567,7 @@ function add_dcline_costs(data::Dict{String,Any})
                     "startup" => 0.0,
                     "shutdown" => 0.0,
                     "ncost" => 2,
-                    "cost" => [0.0, 0.0, 0.0, 0.0]
+                    "cost" => [dcline["pminf"], 0.0, dcline["pmaxf"], 0.0]
                 )
                 push!(data["dclinecost"], dclinecost)
             end

test/data/matpower/case5_pwlc.m

@@ -45,3 +45,7 @@
 	4	 10	 0.00297	 0.0297	 0.00674	 240.0	 240.0	 240.0	 0.0	 0.0	 1	 -30.0	 30.0;
 ];
 
+mpc.dcline = [
+	1	 10	 1	 10	 10	 25.91	 -4.16	 1.1	 0.92617	 10	 900 -900 900 -900 900	 0	 0	 0	 0	 0	 0	 0	 0
+]
+