Make papers into modules, instead of structs; add StartupCostsFormulation

src/model/formulations/MorLatRam2013/scosts.jl

@@ -0,0 +1,50 @@
+# UnitCommitment.jl: Optimization Package for Security-Constrained Unit Commitment
+# Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
+# Released under the modified BSD license. See COPYING.md for more details.
+
+function _add_startup_cost_eqs!(
+    model::JuMP.Model,
+    g::Unit,
+    formulation::MorLatRam2013.StartupCosts,
+)::Nothing
+    eq_startup_choose = _init(model, :eq_startup_choose)
+    eq_startup_restrict = _init(model, :eq_startup_restrict)
+    S = length(g.startup_categories)
+    startup = model[:startup]
+    for t in 1:model[:instance].time
+        for s in 1:S
+            # If unit is switching on, we must choose a startup category
+            eq_startup_choose[g.name, t, s] = @constraint(
+                model,
+                model[:switch_on][g.name, t] ==
+                sum(startup[g.name, t, s] for s in 1:S)
+            )
+
+            # If unit has not switched off in the last `delay` time periods, startup category is forbidden.
+            # The last startup category is always allowed.
+            if s < S
+                range_start = t - g.startup_categories[s+1].delay + 1
+                range_end = t - g.startup_categories[s].delay
+                range = (range_start:range_end)
+                initial_sum = (
+                    g.initial_status < 0 && (g.initial_status + 1 in range) ? 1.0 : 0.0
+                )
+                eq_startup_restrict[g.name, t, s] = @constraint(
+                    model,
+                    startup[g.name, t, s] <=
+                    initial_sum + sum(
+                        model[:switch_off][g.name, i] for i in range if i >= 1
+                    )
+                )
+            end
+
+            # Objective function terms for start-up costs
+            add_to_expression!(
+                model[:obj],
+                startup[g.name, t, s],
+                g.startup_categories[s].cost,
+            )
+        end
+    end
+    return
+end