Set up multi-formulation architecture; start merging akazachk's code

src/UnitCommitment.jl

@@ -6,6 +6,9 @@ module UnitCommitment
 
 include("instance/structs.jl")
 include("solution/structs.jl")
+include("model/formulations/base/structs.jl")
+include("model/formulations/ArrCon00/structs.jl")
+include("model/formulations/DamKucRajAta16/structs.jl")
 include("solution/methods/XaQiWaTh19/structs.jl")
 
 include("import/egret.jl")
@@ -16,6 +19,9 @@ include("model/formulations/base/line.jl")
 include("model/formulations/base/psload.jl")
 include("model/formulations/base/system.jl")
 include("model/formulations/base/unit.jl")
+include("model/formulations/base/sensitivity.jl")
+include("model/formulations/DamKucRajAta16/unit.jl")
+include("model/formulations/ArrCon00/unit.jl")
 include("model/jumpext.jl")
 include("solution/fix.jl")
 include("solution/methods/XaQiWaTh19/enforce.jl")
@@ -28,7 +34,6 @@ include("solution/warmstart.jl")
 include("solution/write.jl")
 include("transform/initcond.jl")
 include("transform/slice.jl")
-include("transmission/sensitivity.jl")
 include("utils/log.jl")
 include("validation/repair.jl")
 include("validation/validate.jl")

src/model/build.jl

@@ -55,45 +55,25 @@ julia> model = UnitCommitment.build_model(
 """
 function build_model(;
     instance::UnitCommitmentInstance,
-    isf::Union{Matrix{Float64},Nothing} = nothing,
-    lodf::Union{Matrix{Float64},Nothing} = nothing,
-    isf_cutoff::Float64 = 0.005,
-    lodf_cutoff::Float64 = 0.001,
     optimizer = nothing,
     variable_names::Bool = false,
 )::JuMP.Model
-    if length(instance.buses) == 1
+    return _build_model(
-        isf = zeros(0, 0)
+        instance,
-        lodf = zeros(0, 0)
+        _GeneratorFormulation(),
-    else
+        _ShiftFactorsFormulation(),
-        if isf === nothing
+        optimizer = optimizer,
-            @info "Computing injection shift factors..."
+        variable_names = variable_names,
-            time_isf = @elapsed begin
+    )
-                isf = UnitCommitment._injection_shift_factors(
+end
-                    lines = instance.lines,
-                    buses = instance.buses,
-                )
-            end
-            @info @sprintf("Computed ISF in %.2f seconds", time_isf)
-            @info "Computing line outage factors..."
-            time_lodf = @elapsed begin
-                lodf = UnitCommitment._line_outage_factors(
-                    lines = instance.lines,
-                    buses = instance.buses,
-                    isf = isf,
-                )
-            end
-            @info @sprintf("Computed LODF in %.2f seconds", time_lodf)
 
-            @info @sprintf(
+function _build_model(
-                "Applying PTDF and LODF cutoffs (%.5f, %.5f)",
+    instance::UnitCommitmentInstance,
-                isf_cutoff,
+    fg::_GeneratorFormulation,
-                lodf_cutoff
+    ft::_TransmissionFormulation;
-            )
+    optimizer = nothing,
-            isf[abs.(isf).<isf_cutoff] .= 0
+    variable_names::Bool = false,
-            lodf[abs.(lodf).<lodf_cutoff] .= 0
+)::JuMP.Model
-        end
-    end
     @info "Building model..."
     time_model = @elapsed begin
         model = Model()
@@ -102,12 +82,19 @@ function build_model(;
         end
         model[:obj] = AffExpr()
         model[:instance] = instance
-        model[:isf] = isf
+        _setup_transmission(model, ft)
-        model[:lodf] = lodf
+        for l in instance.lines
-        _add_transmission_line!.(model, instance.lines)
+            _add_transmission_line!(model, l, ft)
-        _add_bus!.(model, instance.buses)
+        end
-        _add_unit!.(model, instance.units)
+        for b in instance.buses
-        _add_price_sensitive_load!.(model, instance.price_sensitive_loads)
+            _add_bus!(model, b)
+        end
+        for g in instance.units
+            _add_unit!(model, g, fg)
+        end
+        for ps in instance.price_sensitive_loads
+            _add_price_sensitive_load!(model, ps)
+        end
         _add_system_wide_eqs!(model)
         @objective(model, Min, model[:obj])
     end

src/model/formulations/ArrCon00/structs.jl

@@ -0,0 +1,12 @@
+# 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.
+
+"""
+Formulation described in:
+
+    Arroyo, J. M., & Conejo, A. J. (2000). Optimal response of a thermal unit
+    to an electricity spot market. IEEE Transactions on power systems, 15(3), 
+    1098-1104.
+"""
+mutable struct _ArrCon00 <: _RampingFormulation end

src/model/formulations/ArrCon00/unit.jl

@@ -0,0 +1,92 @@
+# 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_ramp_eqs!(
+    model::JuMP.Model,
+    g::Unit,
+    formulation::_ArrCon00,
+)::Nothing
+    # TODO: Move upper case constants to model[:instance]
+    RESERVES_WHEN_START_UP = true
+    RESERVES_WHEN_RAMP_UP = true
+    RESERVES_WHEN_RAMP_DOWN = true
+    RESERVES_WHEN_SHUT_DOWN = true
+    gn = g.name
+    RU = g.ramp_up_limit
+    RD = g.ramp_down_limit
+    SU = g.startup_limit
+    SD = g.shutdown_limit
+    is_on = model[:is_on]
+    prod_above = model[:prod_above]
+    reserve = model[:reserve]
+    switch_off = model[:switch_off]
+    switch_on = model[:switch_on]
+    eq_ramp_down = _init(model, :eq_ramp_down)
+    eq_ramp_up = _init(model, :eq_ramp_up)
+    is_initially_on = (g.initial_status > 0)
+
+    for t in 1:model[:instance].time
+        # Ramp up limit
+        if t == 1
+            if is_initially_on
+                # min power is _not_ multiplied by is_on because if !is_on, then ramp up is irrelevant
+                eq_ramp_up[gn, t] = @constraint(
+                    mip,
+                    g.min_power[t] +
+                    prod_above[gn, t] +
+                    (RESERVES_WHEN_RAMP_UP ? reserve[gn, t] : 0.0) <=
+                    g.initial_power + RU
+                )
+            end
+        else
+            max_prod_this_period =
+                g.min_power[t] * is_on[gn, t] +
+                prod_above[gn, t] +
+                (
+                    RESERVES_WHEN_START_UP || RESERVES_WHEN_RAMP_UP ?
+                    reserve[gn, t] : 0.0
+                )
+            min_prod_last_period =
+                g.min_power[t-1] * is_on[gn, t-1] + prod_above[gn, t-1]
+
+            # Equation (24) in Kneuven et al. (2020)
+            eq_ramp_up[gn, t] = @constraint(
+                mip,
+                max_prod_this_period - min_prod_last_period <=
+                RU * is_on[gn, t-1] + SU * switch_on[gn, t]
+            )
+        end
+
+        # Ramp down limit
+        if t == 1
+            if is_initially_on
+                # TODO If RD < SD, or more specifically if
+                #      min_power + RD < initial_power < SD
+                #      then the generator should be able to shut down at time t = 1,
+                #      but the constraint below will force the unit to produce power
+                eq_ramp_down[gn, t] = @constraint(
+                    mip,
+                    g.initial_power - (g.min_power[t] + prod_above[gn, t]) <= RD
+                )
+            end
+        else
+            max_prod_last_period =
+                g.min_power[t-1] * is_on[gn, t-1] +
+                prod_above[gn, t-1] +
+                (
+                    RESERVES_WHEN_SHUT_DOWN || RESERVES_WHEN_RAMP_DOWN ?
+                    reserve[gn, t-1] : 0.0
+                )
+            min_prod_this_period =
+                g.min_power[t] * is_on[gn, t] + prod_above[gn, t]
+
+            # Equation (25) in Kneuven et al. (2020)
+            eq_ramp_down[gn, t] = @constraint(
+                mip,
+                max_prod_last_period - min_prod_this_period <=
+                RD * is_on[gn, t] + SD * switch_off[gn, t]
+            )
+        end
+    end
+end

src/model/formulations/DamKucRajAta16/structs.jl

@@ -0,0 +1,11 @@
+# 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.
+
+"""
+Formulation described in:
+
+    Damcı-Kurt, P., Küçükyavuz, S., Rajan, D., & Atamtürk, A. (2016). A polyhedral
+    study of production ramping. Mathematical Programming, 158(1), 175-205.
+"""
+mutable struct _DamKucRajAta16 <: _RampingFormulation end

src/model/formulations/DamKucRajAta16/unit.jl

@@ -0,0 +1,116 @@
+# 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_ramp_eqs!(
+    model::JuMP.Model,
+    g::Unit,
+    formulation::_DamKucRajAta16,
+)::Nothing
+    # TODO: Move upper case constants to model[:instance]
+    RESERVES_WHEN_START_UP = true
+    RESERVES_WHEN_RAMP_UP = true
+    RESERVES_WHEN_RAMP_DOWN = true
+    RESERVES_WHEN_SHUT_DOWN = true
+    known_initial_conditions = true
+    is_initially_on = (g.initial_status > 0)
+    SU = g.startup_limit
+    SD = g.shutdown_limit
+    RU = g.ramp_up_limit
+    RD = g.ramp_down_limit
+    gn = g.name
+    eq_str_ramp_down = _init(model, :eq_str_ramp_down)
+    eq_str_ramp_up = _init(model, :eq_str_ramp_up)
+    is_on = model[:is_on]
+    prod_above = model[:prod_above]
+    reserve = model[:reserve]
+    switch_off = model[:switch_off]
+    switch_on = model[:switch_on]
+
+    for t in 1:model[:instance].time
+        time_invariant =
+            (t > 1) ? (abs(g.min_power[t] - g.min_power[t-1]) < 1e-7) : true
+
+        if t > 1 && !time_invariant
+            warning(
+                "Ramping according to Damcı-Kurt et al. (2016) requires " *
+                "time-invariant minimum power. This does not hold for " *
+                "generator $(gn): min_power[$t] = $(g.min_power[t]); " *
+                "min_power[$(t-1)] = $(g.min_power[t-1]). Reverting to " *
+                "Arroyo and Conejo (2000) formulation for this generator.",
+            )
+        end
+
+        max_prod_this_period =
+            prod_above[gn, t] + (
+                RESERVES_WHEN_START_UP || RESERVES_WHEN_RAMP_UP ?
+                reserve[gn, t] : 0.0
+            )
+        min_prod_last_period = 0.0
+        if t > 1 && time_invariant
+            min_prod_last_period = prod_above[gn, t-1]
+
+            # Equation (35) in Kneuven et al. (2020)
+            # Sparser version of (24)
+            eq_str_ramp_up[gn, t] = @constraint(
+                model,
+                max_prod_this_period - min_prod_last_period <=
+                (SU - g.min_power[t] - RU) * switch_on[gn, t] +
+                RU * is_on[gn, t]
+            )
+        elseif (t == 1 && is_initially_on) || (t > 1 && !time_invariant)
+            if t > 1
+                min_prod_last_period =
+                    prod_above[gn, t-1] + g.min_power[t-1] * is_on[gn, t-1]
+            else
+                min_prod_last_period = max(g.initial_power, 0.0)
+            end
+
+            # Add the min prod at time t back in to max_prod_this_period to get _total_ production
+            # (instead of using the amount above minimum, as min prod for t < 1 is unknown)
+            max_prod_this_period += g.min_power[t] * is_on[gn, t]
+
+            # Modified version of equation (35) in Kneuven et al. (2020)
+            # Equivalent to (24)
+            eq_str_ramp_up[gn, t] = @constraint(
+                model,
+                max_prod_this_period - min_prod_last_period <=
+                (SU - RU) * switch_on[gn, t] + RU * is_on[gn, t]
+            )
+        end
+
+        max_prod_last_period =
+            min_prod_last_period + (
+                t > 1 && (RESERVES_WHEN_SHUT_DOWN || RESERVES_WHEN_RAMP_DOWN) ?
+                reserve[gn, t-1] : 0.0
+            )
+        min_prod_this_period = prod_above[gn, t]
+        on_last_period = 0.0
+        if t > 1
+            on_last_period = is_on[gn, t-1]
+        elseif (known_initial_conditions && g.initial_status > 0)
+            on_last_period = 1.0
+        end
+
+        if t > 1 && time_invariant
+            # Equation (36) in Kneuven et al. (2020)
+            eq_str_ramp_down[gn, t] = @constraint(
+                model,
+                max_prod_last_period - min_prod_this_period <=
+                (SD - g.min_power[t] - RD) * switch_off[gn, t] +
+                RD * on_last_period
+            )
+        elseif (t == 1 && is_initially_on) || (t > 1 && !time_invariant)
+            # Add back in min power
+            min_prod_this_period += g.min_power[t] * is_on[gn, t]
+
+            # Modified version of equation (36) in Kneuven et al. (2020)
+            # Equivalent to (25)
+            eq_str_ramp_down[gn, t] = @constraint(
+                model,
+                max_prod_last_period - min_prod_this_period <=
+                (SD - RD) * switch_off[gn, t] + RD * on_last_period
+            )
+        end
+    end
+end

src/model/formulations/base/bus.jl

@@ -3,9 +3,9 @@
 # Released under the modified BSD license. See COPYING.md for more details.
 
 function _add_bus!(model::JuMP.Model, b::Bus)::Nothing
-    net_injection = _get(model, :expr_net_injection)
+    net_injection = _init(model, :expr_net_injection)
-    reserve = _get(model, :expr_reserve)
+    reserve = _init(model, :expr_reserve)
-    curtail = _get(model, :curtail)
+    curtail = _init(model, :curtail)
     for t in 1:model[:instance].time
         # Fixed load
         net_injection[b.name, t] = AffExpr(-b.load[t])

src/model/formulations/base/line.jl

@@ -2,11 +2,60 @@
 # Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
 # Released under the modified BSD license. See COPYING.md for more details.
 
-function _add_transmission_line!(model, lm)::Nothing
+function _add_transmission_line!(
-    overflow = _get(model, :overflow)
+    model::JuMP.Model,
+    lm::TransmissionLine,
+    f::_TransmissionFormulation,
+)::Nothing
+    overflow = _init(model, :overflow)
     for t in 1:model[:instance].time
-        v = overflow[lm.name, t] = @variable(model, lower_bound = 0)
+        overflow[lm.name, t] = @variable(model, lower_bound = 0)
-        add_to_expression!(model[:obj], v, lm.flow_limit_penalty[t])
+        add_to_expression!(
+            model[:obj],
+            overflow[lm.name, t],
+            lm.flow_limit_penalty[t],
+        )
     end
     return
 end
+
+function _setup_transmission(
+    model::JuMP.Model,
+    formulation::_TransmissionFormulation,
+)::Nothing
+    instance = model[:instance]
+    isf = formulation.precomputed_isf
+    lodf = formulation.precomputed_lodf
+    if length(instance.buses) == 1
+        isf = zeros(0, 0)
+        lodf = zeros(0, 0)
+    elseif isf === nothing
+        @info "Computing injection shift factors..."
+        time_isf = @elapsed begin
+            isf = UnitCommitment._injection_shift_factors(
+                lines = instance.lines,
+                buses = instance.buses,
+            )
+        end
+        @info @sprintf("Computed ISF in %.2f seconds", time_isf)
+        @info "Computing line outage factors..."
+        time_lodf = @elapsed begin
+            lodf = UnitCommitment._line_outage_factors(
+                lines = instance.lines,
+                buses = instance.buses,
+                isf = isf,
+            )
+        end
+        @info @sprintf("Computed LODF in %.2f seconds", time_lodf)
+        @info @sprintf(
+            "Applying PTDF and LODF cutoffs (%.5f, %.5f)",
+            formulation.isf_cutoff,
+            formulation.lodf_cutoff
+        )
+        isf[abs.(isf).<formulation.isf_cutoff] .= 0
+        lodf[abs.(lodf).<formulation.lodf_cutoff] .= 0
+    end
+    model[:isf] = isf
+    model[:lodf] = lodf
+    return
+end

src/model/formulations/base/psload.jl

@@ -6,8 +6,8 @@ function _add_price_sensitive_load!(
     model::JuMP.Model,
     ps::PriceSensitiveLoad,
 )::Nothing
-    loads = _get(model, :loads)
+    loads = _init(model, :loads)
-    net_injection = _get(model, :expr_net_injection)
+    net_injection = _init(model, :expr_net_injection)
     for t in 1:model[:instance].time
         # Decision variable
         loads[ps.name, t] =

src/model/formulations/base/sensitivity.jl

@@ -72,10 +72,9 @@ function _line_outage_factors(;
     lines::Array{TransmissionLine,1},
     isf::Array{Float64,2},
 )::Array{Float64,2}
-    n_lines, n_buses = size(isf)
     incidence = Array(_reduced_incidence_matrix(lines = lines, buses = buses))
     lodf::Array{Float64,2} = isf * transpose(incidence)
-    m, n = size(lodf)
+    _, n = size(lodf)
     for i in 1:n
         lodf[:, i] *= 1.0 / (1.0 - lodf[i, i])
         lodf[i, i] = -1

src/model/formulations/base/structs.jl

@@ -0,0 +1,57 @@
+# 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.
+
+abstract type _RampingFormulation end
+abstract type _TransmissionFormulation end
+
+struct _GeneratorFormulation
+    ramping::_RampingFormulation
+
+    function _GeneratorFormulation(
+        ramping::_RampingFormulation = _DamKucRajAta16(),
+    )
+        return new(ramping)
+    end
+end
+
+"""
+    mutable struct _ShiftFactorsFormulation <: _TransmissionFormulation
+        isf_cutoff::Float64
+        lodf_cutoff::Float64
+        precomputed_isf::Union{Nothing,Matrix{Float64}}
+        precomputed_lodf::Union{Nothing,Matrix{Float64}}
+    end
+
+Transmission formulation based on Injection Shift Factors (ISF) and Line
+Outage Distribution Factors (LODF). Constraints are enforced in a lazy way.
+
+Arguments
+---------
+- `precomputed_isf::Union{Matrix{Float64},Nothing} = nothing`:
+    the injection shift factors matrix. If not provided, it will be computed.
+- `precomputed_lodf::Union{Matrix{Float64},Nothing} = nothing`: 
+    the line outage distribution factors matrix. If not provided, it will be
+    computed.
+- `isf_cutoff::Float64 = 0.005`: 
+    the cutoff that should be applied to the ISF matrix. Entries with magnitude
+    smaller than this value will be set to zero.
+- `lodf_cutoff::Float64 = 0.001`: 
+    the cutoff that should be applied to the LODF matrix. Entries with magnitude
+    smaller than this value will be set to zero.
+"""
+mutable struct _ShiftFactorsFormulation <: _TransmissionFormulation
+    isf_cutoff::Float64
+    lodf_cutoff::Float64
+    precomputed_isf::Union{Nothing,Matrix{Float64}}
+    precomputed_lodf::Union{Nothing,Matrix{Float64}}
+
+    function _ShiftFactorsFormulation(;
+        isf_cutoff = 0.005,
+        lodf_cutoff = 0.001,
+        precomputed_isf = nothing,
+        precomputed_lodf = nothing,
+    )
+        return new(isf_cutoff, lodf_cutoff, precomputed_isf, precomputed_lodf)
+    end
+end

src/model/formulations/base/system.jl

@@ -10,9 +10,9 @@ end
 
 function _add_net_injection_eqs!(model::JuMP.Model)::Nothing
     T = model[:instance].time
-    net_injection = _get(model, :net_injection)
+    net_injection = _init(model, :net_injection)
-    eq_net_injection_def = _get(model, :eq_net_injection_def)
+    eq_net_injection_def = _init(model, :eq_net_injection_def)
-    eq_power_balance = _get(model, :eq_power_balance)
+    eq_power_balance = _init(model, :eq_power_balance)
     for t in 1:T, b in model[:instance].buses
         n = net_injection[b.name, t] = @variable(model)
         eq_net_injection_def[t, b.name] =
@@ -28,7 +28,7 @@ function _add_net_injection_eqs!(model::JuMP.Model)::Nothing
 end
 
 function _add_reserve_eqs!(model::JuMP.Model)::Nothing
-    eq_min_reserve = _get(model, :eq_min_reserve)
+    eq_min_reserve = _init(model, :eq_min_reserve)
     for t in 1:model[:instance].time
         eq_min_reserve[t] = @constraint(
             model,

src/model/formulations/base/unit.jl

@@ -2,7 +2,7 @@
 # Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
 # Released under the modified BSD license. See COPYING.md for more details.
 
-function _add_unit!(model::JuMP.Model, g::Unit)
+function _add_unit!(model::JuMP.Model, g::Unit, f::_GeneratorFormulation)
     if !all(g.must_run) && any(g.must_run)
         error("Partially must-run units are not currently supported")
     end
@@ -11,26 +11,31 @@ function _add_unit!(model::JuMP.Model, g::Unit)
     end
 
     # Variables
-    _add_production_vars!(model, g)
+    _add_production_vars!(model, g, f)
-    _add_reserve_vars!(model, g)
+    _add_reserve_vars!(model, g, f)
-    _add_startup_shutdown_vars!(model, g)
+    _add_startup_shutdown_vars!(model, g, f)
-    _add_status_vars!(model, g)
+    _add_status_vars!(model, g, f)
 
     # Constraints and objective function
-    _add_min_uptime_downtime_eqs!(model, g)
+    _add_min_uptime_downtime_eqs!(model, g, f)
-    _add_net_injection_eqs!(model, g)
+    _add_net_injection_eqs!(model, g, f)
-    _add_production_eqs!(model, g)
+    _add_production_eqs!(model, g, f)
-    _add_ramp_eqs!(model, g)
+    _add_ramp_eqs!(model, g, f.ramping)
-    _add_startup_shutdown_costs_eqs!(model, g)
+    _add_startup_shutdown_costs_eqs!(model, g, f)
-    _add_startup_shutdown_limit_eqs!(model, g)
+    _add_startup_shutdown_limit_eqs!(model, g, f)
-    return _add_status_eqs!(model, g)
+    _add_status_eqs!(model, g, f)
+    return
 end
 
 _is_initially_on(g::Unit)::Float64 = (g.initial_status > 0 ? 1.0 : 0.0)
 
-function _add_production_vars!(model::JuMP.Model, g::Unit)::Nothing
+function _add_production_vars!(
-    prod_above = _get(model, :prod_above)
+    model::JuMP.Model,
-    segprod = _get(model, :segprod)
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::Nothing
+    prod_above = _init(model, :prod_above)
+    segprod = _init(model, :segprod)
     for t in 1:model[:instance].time
         for k in 1:length(g.cost_segments)
             segprod[g.name, t, k] = @variable(model, lower_bound = 0)
@@ -40,10 +45,14 @@ function _add_production_vars!(model::JuMP.Model, g::Unit)::Nothing
     return
 end
 
-function _add_production_eqs!(model::JuMP.Model, g::Unit)::Nothing
+function _add_production_eqs!(
-    eq_prod_above_def = _get(model, :eq_prod_above_def)
+    model::JuMP.Model,
-    eq_prod_limit = _get(model, :eq_prod_limit)
+    g::Unit,
-    eq_segprod_limit = _get(model, :eq_segprod_limit)
+    formulation::_GeneratorFormulation,
+)::Nothing
+    eq_prod_above_def = _init(model, :eq_prod_above_def)
+    eq_prod_limit = _init(model, :eq_prod_limit)
+    eq_segprod_limit = _init(model, :eq_segprod_limit)
     is_on = model[:is_on]
     K = length(g.cost_segments)
     prod_above = model[:prod_above]
@@ -82,8 +91,12 @@ function _add_production_eqs!(model::JuMP.Model, g::Unit)::Nothing
     return
 end
 
-function _add_reserve_vars!(model::JuMP.Model, g::Unit)::Nothing
+function _add_reserve_vars!(
-    reserve = _get(model, :reserve)
+    model::JuMP.Model,
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::Nothing
+    reserve = _init(model, :reserve)
     for t in 1:model[:instance].time
         if g.provides_spinning_reserves[t]
             reserve[g.name, t] = @variable(model, lower_bound = 0)
@@ -94,7 +107,11 @@ function _add_reserve_vars!(model::JuMP.Model, g::Unit)::Nothing
     return
 end
 
-function _add_reserve_eqs!(model::JuMP.Model, g::Unit)::Nothing
+function _add_reserve_eqs!(
+    model::JuMP.Model,
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::Nothing
     reserve = model[:reserve]
     for t in 1:model[:instance].time
         add_to_expression!(expr_reserve[g.bus.name, t], reserve[g.name, t], 1.0)
@@ -102,8 +119,12 @@ function _add_reserve_eqs!(model::JuMP.Model, g::Unit)::Nothing
     return
 end
 
-function _add_startup_shutdown_vars!(model::JuMP.Model, g::Unit)::Nothing
+function _add_startup_shutdown_vars!(
-    startup = _get(model, :startup)
+    model::JuMP.Model,
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::Nothing
+    startup = _init(model, :startup)
     for t in 1:model[:instance].time
         for s in 1:length(g.startup_categories)
             startup[g.name, t, s] = @variable(model, binary = true)
@@ -112,9 +133,13 @@ function _add_startup_shutdown_vars!(model::JuMP.Model, g::Unit)::Nothing
     return
 end
 
-function _add_startup_shutdown_limit_eqs!(model::JuMP.Model, g::Unit)::Nothing
+function _add_startup_shutdown_limit_eqs!(
-    eq_shutdown_limit = _get(model, :eq_shutdown_limit)
+    model::JuMP.Model,
-    eq_startup_limit = _get(model, :eq_startup_limit)
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::Nothing
+    eq_shutdown_limit = _init(model, :eq_shutdown_limit)
+    eq_startup_limit = _init(model, :eq_startup_limit)
     is_on = model[:is_on]
     prod_above = model[:prod_above]
     reserve = model[:reserve]
@@ -147,9 +172,13 @@ function _add_startup_shutdown_limit_eqs!(model::JuMP.Model, g::Unit)::Nothing
     return
 end
 
-function _add_startup_shutdown_costs_eqs!(model::JuMP.Model, g::Unit)::Nothing
+function _add_startup_shutdown_costs_eqs!(
-    eq_startup_choose = _get(model, :eq_startup_choose)
+    model::JuMP.Model,
-    eq_startup_restrict = _get(model, :eq_startup_restrict)
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::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
@@ -190,10 +219,14 @@ function _add_startup_shutdown_costs_eqs!(model::JuMP.Model, g::Unit)::Nothing
     return
 end
 
-function _add_status_vars!(model::JuMP.Model, g::Unit)::Nothing
+function _add_status_vars!(
-    is_on = _get(model, :is_on)
+    model::JuMP.Model,
-    switch_on = _get(model, :switch_on)
+    g::Unit,
-    switch_off = _get(model, :switch_off)
+    formulation::_GeneratorFormulation,
+)::Nothing
+    is_on = _init(model, :is_on)
+    switch_on = _init(model, :switch_on)
+    switch_off = _init(model, :switch_off)
     for t in 1:model[:instance].time
         if g.must_run[t]
             is_on[g.name, t] = 1.0
@@ -208,9 +241,13 @@ function _add_status_vars!(model::JuMP.Model, g::Unit)::Nothing
     return
 end
 
-function _add_status_eqs!(model::JuMP.Model, g::Unit)::Nothing
+function _add_status_eqs!(
-    eq_binary_link = _get(model, :eq_binary_link)
+    model::JuMP.Model,
-    eq_switch_on_off = _get(model, :eq_switch_on_off)
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::Nothing
+    eq_binary_link = _init(model, :eq_binary_link)
+    eq_switch_on_off = _init(model, :eq_switch_on_off)
     is_on = model[:is_on]
     switch_off = model[:switch_off]
     switch_on = model[:switch_on]
@@ -240,11 +277,15 @@ function _add_status_eqs!(model::JuMP.Model, g::Unit)::Nothing
     return
 end
 
-function _add_ramp_eqs!(model::JuMP.Model, g::Unit)::Nothing
+function _add_ramp_eqs!(
+    model::JuMP.Model,
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::Nothing
     prod_above = model[:prod_above]
     reserve = model[:reserve]
-    eq_ramp_up = _get(model, :eq_ramp_up)
+    eq_ramp_up = _init(model, :eq_ramp_up)
-    eq_ramp_down = _get(model, :eq_ramp_down)
+    eq_ramp_down = _init(model, :eq_ramp_down)
     for t in 1:model[:instance].time
         # Ramp up limit
         if t == 1
@@ -282,12 +323,16 @@ function _add_ramp_eqs!(model::JuMP.Model, g::Unit)::Nothing
     end
 end
 
-function _add_min_uptime_downtime_eqs!(model::JuMP.Model, g::Unit)::Nothing
+function _add_min_uptime_downtime_eqs!(
+    model::JuMP.Model,
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::Nothing
     is_on = model[:is_on]
     switch_off = model[:switch_off]
     switch_on = model[:switch_on]
-    eq_min_uptime = _get(model, :eq_min_uptime)
+    eq_min_uptime = _init(model, :eq_min_uptime)
-    eq_min_downtime = _get(model, :eq_min_downtime)
+    eq_min_downtime = _init(model, :eq_min_downtime)
     T = model[:instance].time
     for t in 1:T
         # Minimum up-time
@@ -325,25 +370,29 @@ function _add_min_uptime_downtime_eqs!(model::JuMP.Model, g::Unit)::Nothing
     end
 end
 
-function _add_net_injection_eqs!(model::JuMP.Model, g::Unit)::Nothing
+function _add_net_injection_eqs!(
+    model::JuMP.Model,
+    g::Unit,
+    formulation::_GeneratorFormulation,
+)::Nothing
     expr_net_injection = model[:expr_net_injection]
-    expr_reserve = model[:expr_reserve]
-    is_on = model[:is_on]
-    prod_above = model[:prod_above]
-    reserve = model[:reserve]
     for t in 1:model[:instance].time
         # Add to net injection expression
         add_to_expression!(
             expr_net_injection[g.bus.name, t],
-            prod_above[g.name, t],
+            model[:prod_above][g.name, t],
             1.0,
         )
         add_to_expression!(
             expr_net_injection[g.bus.name, t],
-            is_on[g.name, t],
+            model[:is_on][g.name, t],
             g.min_power[t],
         )
         # Add to reserves expression
-        add_to_expression!(expr_reserve[g.bus.name, t], reserve[g.name, t], 1.0)
+        add_to_expression!(
+            model[:expr_reserve][g.bus.name, t],
+            model[:reserve][g.name, t],
+            1.0,
+        )
     end
 end

src/model/jumpext.jl

@@ -19,7 +19,7 @@ function set_name(x::Float64, n::String)
     # nop
 end
 
-function _get(model::JuMP.Model, key::Symbol)::OrderedDict
+function _init(model::JuMP.Model, key::Symbol)::OrderedDict
     if !(key in keys(object_dictionary(model)))
         model[key] = OrderedDict()
     end

src/model/structs.jl

@@ -1,5 +0,0 @@
-# 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.
-
-abstract type Formulation end