fix bfa sign bug, closes #779 (#780)

CHANGELOG.md

@@ -2,6 +2,7 @@ PowerModels.jl Change Log
 =========================
 
 ### Staged
+- Fixed sign bug in BFA models (#779)
 - Fixed `correct_component_refrence_bus!` when no active generators are present (#776)
 
 ### v0.18.1

src/form/bf.jl

@@ -162,8 +162,8 @@ function constraint_power_losses(pm::AbstractBFAModel, n::Int, i, f_bus, t_bus,
     w_fr = var(pm, n, :w, f_bus)
     w_to = var(pm, n, :w, t_bus)
 
-    JuMP.@constraint(pm.model, p_fr + p_to == g_sh_fr*(w_fr/tm^2) + g_sh_to*w_to)
-    JuMP.@constraint(pm.model, q_fr + q_to == b_sh_fr*(w_fr/tm^2) + b_sh_to*w_to)
+    JuMP.@constraint(pm.model, p_fr + p_to ==  g_sh_fr*(w_fr/tm^2) + g_sh_to*w_to)
+    JuMP.@constraint(pm.model, q_fr + q_to == -b_sh_fr*(w_fr/tm^2) - b_sh_to*w_to)
 end
 
 

test/multinetwork.jl

@@ -385,22 +385,22 @@ TESTLOG = Memento.getlogger(PowerModels)
             @test isapprox(result["objective"], 57980.0; atol = 1e0)
 
             @test isapprox(result["solution"]["nw"]["1"]["storage"]["1"]["ps"],  0.0000000; atol = 1e-3)
-            @test isapprox(result["solution"]["nw"]["1"]["storage"]["1"]["qs"],  0.0543982; atol = 1e-3)
+            @test isapprox(result["solution"]["nw"]["1"]["storage"]["1"]["qs"],  0.0562204; atol = 1e-3)
             @test isapprox(result["solution"]["nw"]["1"]["storage"]["2"]["ps"], -0.0834412; atol = 1e-3)
             @test isapprox(result["solution"]["nw"]["1"]["storage"]["2"]["qs"],  0.0801070; atol = 1e-3)
 
             @test isapprox(result["solution"]["nw"]["2"]["storage"]["1"]["ps"],  0.0000000; atol = 1e-3)
-            @test isapprox(result["solution"]["nw"]["2"]["storage"]["1"]["qs"],  0.0552175; atol = 1e-3)
+            @test isapprox(result["solution"]["nw"]["2"]["storage"]["1"]["qs"],  0.0569621; atol = 1e-3)
             @test isapprox(result["solution"]["nw"]["2"]["storage"]["2"]["ps"],  0.0000000; atol = 1e-3)
             @test isapprox(result["solution"]["nw"]["2"]["storage"]["2"]["qs"],  0.0803519; atol = 1e-3)
 
             @test isapprox(result["solution"]["nw"]["3"]["storage"]["1"]["ps"],  0.0000000; atol = 1e-3)
-            @test isapprox(result["solution"]["nw"]["3"]["storage"]["1"]["qs"],  0.0535058; atol = 1e-3)
+            @test isapprox(result["solution"]["nw"]["3"]["storage"]["1"]["qs"],  0.0553956; atol = 1e-3)
             @test isapprox(result["solution"]["nw"]["3"]["storage"]["2"]["ps"], -0.1565587; atol = 1e-3)
             @test isapprox(result["solution"]["nw"]["3"]["storage"]["2"]["qs"],  0.0806228; atol = 1e-3)
 
             @test isapprox(result["solution"]["nw"]["4"]["storage"]["1"]["ps"], -0.1800000; atol = 1e-3)
-            @test isapprox(result["solution"]["nw"]["4"]["storage"]["1"]["qs"],  0.0549343; atol = 1e-3)
+            @test isapprox(result["solution"]["nw"]["4"]["storage"]["1"]["qs"],  0.0566681; atol = 1e-3)
             @test isapprox(result["solution"]["nw"]["4"]["storage"]["2"]["ps"],  0.0000000; atol = 1e-3)
             @test isapprox(result["solution"]["nw"]["4"]["storage"]["2"]["qs"],  0.0802049; atol = 1e-3)
 

test/opf.jl

@@ -748,7 +748,7 @@ end
         result = run_opf_bf("../test/data/matpower/case3.m", BFAPowerModel, ipopt_solver)
 
         @test result["termination_status"] == LOCALLY_SOLVED
-        @test isapprox(result["objective"], 5658.22; atol = 1e0)
+        @test isapprox(result["objective"], 5638.97; atol = 1e0)
     end
     @testset "5-bus transformer swap case" begin
         data = PowerModels.parse_file("../test/data/matpower/case5.m")