Merge pull request #1178 from NREL-Sienna/ps/quadratic_curves

fix: Adding support for quadratic functions using the table data parser

src/PowerSystems.jl

@@ -390,6 +390,9 @@ export get_compression_settings
 export CompressionSettings
 export CompressionTypes
 
+# Parsing functions
+export create_poly_cost
+
 #export make_time_series
 export get_bus_numbers
 export get_name

src/descriptors/power_system_inputs.json

@@ -366,6 +366,21 @@
             "description": "Heat required to startup from cold",
             "default_value": null
         },
+        {
+            "name": "heat_rate_a0",
+            "description": "Heat rate constant term",
+            "default_value": null
+        },
+        {
+            "name": "heat_rate_a1",
+            "description": "Heat rate proportional term",
+            "default_value": null
+        },
+        {
+            "name": "heat_rate_a2",
+            "description": "Heat rate quadratic term",
+            "default_value": null
+        },
         {
             "name": "heat_rate_avg_0",
             "description": "Heat rate Average 0 TODO",

src/parsers/power_system_table_data.jl

@@ -823,8 +823,16 @@ function make_cost(
 ) where {T <: ThermalGen}
     fuel_price = gen.fuel_price / 1000.0
 
-    cost_pairs = get_cost_pairs(gen, cost_colnames)
-    var_cost, fixed = create_pwinc_cost(cost_pairs)
+    # We check if there is any Quadratic or Linear Data defined. If not we fall back to create PiecewiseIncrementalCurve
+    quadratic_fields = (gen.heat_rate_a0, gen.heat_rate_a1, gen.heat_rate_a2)
+
+    if any(field -> field != nothing, quadratic_fields)
+        var_cost, fixed =
+            create_poly_cost(gen, ["heat_rate_a0", "heat_rate_a1", "heat_rate_a2"])
+    else
+        cost_pairs = get_cost_pairs(gen, cost_colnames)
+        var_cost, fixed = create_pwinc_cost(cost_pairs)
+    end
 
     startup_cost, shutdown_cost = calculate_uc_cost(data, gen, fuel_price)
 
@@ -956,6 +964,45 @@ function create_pwl_cost(
     return var_cost
 end
 
+"""
+    create_poly_cost(gen, cost_colnames)
+
+Return a Polynomial function cost based on the coeffiecients provided on gen.
+
+Three supported cases,
+  1. If three values are passed then we have data looking like: `a2 * x^2 + a1 * x + a0`,
+  2. If `a1` and `a0` are passed then we have data looking like: `a1 * x + a0`,
+  3. If only `a1` is passed then we have data looking like: `a1 * x`.
+"""
+function create_poly_cost(
+    gen, cost_colnames,
+)
+    fixed_cost = 0.0
+    parse_maybe_nothing(x) = isnothing(x) ? nothing : tryparse(Float64, x)
+    a2 = parse_maybe_nothing(getfield(gen, Symbol("heat_rate_a2")))
+    a1 = parse_maybe_nothing(getfield(gen, Symbol("heat_rate_a1")))
+    a0 = parse_maybe_nothing(getfield(gen, Symbol("heat_rate_a0")))
+
+    if !isnothing(a2) && (isnothing(a1) || isnothing(a0))
+        throw(
+            DataFormatError(
+                "All coefficients must be passed if quadratic term is passed.",
+            ),
+        )
+    end
+
+    if !any(isnothing.([a2, a1, a0]))
+        @debug "QuadraticCurve created for $(gen.name)"
+        return QuadraticCurve(a2, a1, a0), fixed_cost
+    end
+    if all(isnothing.([a2, a0])) && !isnothing(a1)
+        @debug "LinearCurve created for $(gen.name)"
+        return LinearCurve(a1), fixed_cost
+    end
+    @debug "LinearCurve created for $(gen.name)"
+    return LinearCurve(a1, a0), fixed_cost
+end
+
 function create_pwinc_cost(
     cost_pairs,
 )

test/test_power_system_table_data.jl

@@ -181,3 +181,85 @@ end
     g = get_components(ThermalStandard, sys)
     @test get_variable.(get_operation_cost.(g)) == get_variable.(get_operation_cost.(g))
 end
+
+@testset "Test create_poly_cost function" begin
+    cost_colnames = ["heat_rate_a0", "heat_rate_a1", "heat_rate_a2"]
+
+    # Coefficients for a CC using natural gas
+    a2 = -0.000531607
+    a1 = 0.060554675
+    a0 = 8.951100118
+
+    # First test that return quadratic if all coefficients are provided.
+    # We convert the coefficients to string to mimic parsing from csv
+    example_generator = (
+        name = "test-gen",
+        heat_rate_a0 = string(a0),
+        heat_rate_a1 = string(a1),
+        heat_rate_a2 = string(a2),
+    )
+    cost_curve, fixed_cost = create_poly_cost(example_generator, cost_colnames)
+    @assert cost_curve isa QuadraticCurve
+    @assert isapprox(get_quadratic_term(cost_curve), a2, atol = 0.01)
+    @assert isapprox(get_proportional_term(cost_curve), a1, atol = 0.01)
+    @assert isapprox(get_constant_term(cost_curve), a0, atol = 0.01)
+
+    # Test return linear with both proportional and constant term
+    example_generator = (
+        name = "test-gen",
+        heat_rate_a0 = string(a0),
+        heat_rate_a1 = string(a1),
+        heat_rate_a2 = nothing,
+    )
+    cost_curve, fixed_cost = create_poly_cost(example_generator, cost_colnames)
+    @assert cost_curve isa LinearCurve
+    @assert isapprox(get_proportional_term(cost_curve), a1, atol = 0.01)
+    @assert isapprox(get_constant_term(cost_curve), a0, atol = 0.01)
+
+    # Test return linear with just proportional term
+    example_generator = (
+        name = "test-gen",
+        heat_rate_a0 = nothing,
+        heat_rate_a1 = string(a1),
+        heat_rate_a2 = nothing,
+    )
+    cost_curve, fixed_cost = create_poly_cost(example_generator, cost_colnames)
+    @assert cost_curve isa LinearCurve
+    @assert isapprox(get_proportional_term(cost_curve), a1, atol = 0.01)
+
+    # Test raises error if a2 is passed but other coefficients are nothing
+    example_generator = (
+        name = "test-gen",
+        heat_rate_a0 = nothing,
+        heat_rate_a1 = nothing,
+        heat_rate_a2 = string(a2),
+    )
+    @test_throws IS.DataFormatError create_poly_cost(example_generator, cost_colnames)
+    example_generator = (
+        name = "test-gen",
+        heat_rate_a0 = nothing,
+        heat_rate_a1 = string(a1),
+        heat_rate_a2 = string(a2),
+    )
+    @test_throws IS.DataFormatError create_poly_cost(example_generator, cost_colnames)
+    example_generator = (
+        name = "test-gen",
+        heat_rate_a0 = string(a0),
+        heat_rate_a1 = nothing,
+        heat_rate_a2 = string(a2),
+    )
+    @test_throws IS.DataFormatError create_poly_cost(example_generator, cost_colnames)
+
+    # Test that it works with zero proportional and constant term
+    example_generator = (
+        name = "test-gen",
+        heat_rate_a0 = string(0.0),
+        heat_rate_a1 = string(0.0),
+        heat_rate_a2 = string(a2),
+    )
+    cost_curve, fixed_cost = create_poly_cost(example_generator, cost_colnames)
+    @assert cost_curve isa QuadraticCurve
+    @assert isapprox(get_quadratic_term(cost_curve), a2, atol = 0.01)
+    @assert isapprox(get_proportional_term(cost_curve), 0.0, atol = 0.01)
+    @assert isapprox(get_constant_term(cost_curve), 0.0, atol = 0.01)
+end