refactor: update values and logic for representative transformer designs

prereise/gather/griddata/hifld/const.py

@@ -127,33 +127,6 @@
     "500": 500,
 }
 
-transformer_reactance = {  # per-unit
-    (69, 115): 0.14242,
-    (69, 138): 0.10895,
-    (69, 161): 0.14943,
-    (69, 230): 0.09538,
-    (69, 345): 0.08896,
-    (115, 161): 0.04516,
-    (115, 230): 0.04299,
-    (115, 345): 0.04020,
-    (115, 500): 0.06182,
-    (138, 161): 0.02818,
-    (138, 230): 0.03679,
-    (138, 345): 0.03889,
-    (138, 500): 0.03279,
-    (138, 765): 0.02284,
-    (161, 230): 0.06539,
-    (161, 345): 0.03293,
-    (161, 500): 0.06978,
-    (230, 345): 0.02085,
-    (230, 500): 0.01846,
-    (230, 765): 0.01616,
-    (345, 500): 0.01974,
-    (345, 765): 0.01625,
-    (500, 765): 0.00436,
-}
-transformer_rating = 800  # MVA
-
 eia_storage_gen_types = {
     "Batteries",
     "Flywheels",

prereise/gather/griddata/hifld/data/transformer_impedance_ratios.csv

@@ -0,0 +1,9 @@
+high_kV,x_to_r_ratio
+69,20
+115,25
+138,27
+161,28
+230,30
+345,60
+500,70
+765,80

prereise/gather/griddata/hifld/data/transformer_number_assumptions.csv

@@ -0,0 +1,5 @@
+sub_id,low_kV,high_kV,number
+300060,69,138,4
+300940,69,138,2
+304621,69,138,3
+308608,69,138,3

prereise/gather/griddata/hifld/data/transformer_params.csv

@@ -0,0 +1,24 @@
+low_kV,high_kV,x,MVA
+69,115,0.19,60
+69,138,0.14,100
+69,161,0.12,85
+69,230,0.11,190
+69,345,0.07,250
+115,161,0.048,180
+115,230,0.044,290
+115,345,0.046,400
+115,500,0.047,300
+138,161,0.028,220
+138,230,0.041,330
+138,345,0.033,480
+138,500,0.045,470
+138,765,0.024,850
+161,230,0.042,330
+161,345,0.028,500
+161,500,0.016,1100
+230,345,0.018,580
+230,500,0.013,1100
+230,765,0.0165,1250
+345,500,0.0105,1100
+345,765,0.0085,2100
+500,765,0.0045,2100

prereise/gather/griddata/hifld/data_access/load.py

@@ -336,6 +336,58 @@ def get_hifld_electric_power_transmission_lines(path):
     return properties.query("STATUS == 'IN SERVICE' or STATUS == 'NOT AVAILABLE'")
 
 
+def get_transformer_number_overrides(path):
+    """Load overrides for the number of transformers between buses.
+
+    :param str path: path to a CSV file containing columns: 'sub_id', 'low_kV',
+        'high_kV', and 'number'.
+    :return: (*pandas.Series*) -- index is a MultiIndex of
+        ('sub_id', 'low_kV', 'high_kV'), values are 'number' integers.
+    """
+    return pd.read_csv(path).set_index(["sub_id", "low_kV", "high_kV"]).squeeze()
+
+
+def get_transformer_parameters(
+    data_dir=None, transformer_designs_path=None, impedance_ratios_path=None
+):
+    """Load transformer designs (by voltage pairs) and transformer impedance ratios
+    (by higher voltage) and combine into a single dataframe.
+
+    :param str data_dir: if this is not None, two files in this directory will be
+        loaded: 'transformer_params.csv' and 'transformer_impedance_ratios.csv'.
+        Required columns for each file are listed in the descriptions of
+        the ``transformer_designs_path`` and ``impedance_ratios_path`` parameters.
+    :param str transformer_designs_path: if ``data_dir`` is None, this file will be
+        loaded. Required columns are 'low_kV', 'high_kV', 'x', and 'MVA'.
+    :param str impedance_ratios_path: if ``data_dir`` is None, this file will be loaded.
+        Required columns are 'high_kV' and 'x_to_r_ratio'.
+    :raises TypeError: if ``data_dir`` is None and either of
+        ``transformer_designs_path`` or ``impedance_ratios_path`` is None.
+    :return: (*pandas.DataFrame*) -- index is (low_kV, high_kV), columns are 'x', 'r',
+        and 'MVA'. 'x' and 'r' values are per-unit, 'MVA' is in megawatts.
+    """
+    if data_dir is None and (
+        transformer_designs_path is None or impedance_ratios_path is None
+    ):
+        raise TypeError(
+            "Either data_dir or transformer_designs_path and impedance_ratios_path "
+            "must be specified."
+        )
+    if data_dir is not None:
+        transformer_designs_path = os.path.join(data_dir, "transformer_params.csv")
+        impedance_ratios_path = os.path.join(
+            data_dir, "transformer_impedance_ratios.csv"
+        )
+    transformer_designs = pd.read_csv(transformer_designs_path)
+    transformer_impedance_ratios = pd.read_csv(
+        impedance_ratios_path, index_col="high_kV"
+    )
+    transformer_designs["r"] = transformer_designs["x"] / transformer_designs[
+        "high_kV"
+    ].map(transformer_impedance_ratios["x_to_r_ratio"])
+    return transformer_designs.set_index(["low_kV", "high_kV"])[["x", "r", "MVA"]]
+
+
 def get_zone(path):
     """Read zone CSV file.
 

prereise/gather/griddata/hifld/data_process/tests/test_transmission.py

@@ -1,20 +1,15 @@
-from unittest.mock import Mock
-
 import pandas as pd
 import pytest
 from pandas.testing import assert_frame_equal, assert_series_equal
 
-from prereise.gather.griddata.hifld import const
 from prereise.gather.griddata.hifld.data_process.transmission import (
     add_b2bs_to_dc_lines,
-    add_impedance_and_rating,
+    add_lines_impedances_ratings,
     add_substation_info_to_buses,
     assign_buses_to_lines,
     augment_line_voltages,
     create_buses,
     create_transformers,
-    estimate_branch_impedance,
-    estimate_branch_rating,
     filter_islands_and_connect_with_mst,
     map_lines_to_substations_using_coords,
     split_lines_to_ac_and_dc,
@@ -37,7 +32,7 @@ def test_add_b2bs_to_dc_lines():
     assert_frame_equal(dc_lines.iloc[2:], expected_new_rows)
 
 
-def test_add_impedance_and_rating():
+def test_add_lines_impedances_ratings():
     branch = pd.DataFrame(
         {
             "VOLTAGE": [69, 75, 75, 138],
@@ -52,7 +47,7 @@ def test_add_impedance_and_rating():
         }
     )
     expected_modified_branch = pd.concat([branch, expected_new_columns], axis=1)
-    add_impedance_and_rating(branch, bus_voltages=None)
+    add_lines_impedances_ratings(branch)
     assert_frame_equal(branch, expected_modified_branch)
 
 
@@ -185,71 +180,49 @@ def test_create_transformers():
         },
         dtype="float",
     )
-    expected_transformers = pd.DataFrame(
-        {"from_bus_id": [0, 2, 4, 5], "to_bus_id": [1, 3, 5, 6]}
-    )
-    transformers = create_transformers(bus)
-    assert_frame_equal(transformers, expected_transformers)
-
-
-def test_estimate_branch_impedance_lines():
-    resistance = 0.01
-    reactance = 0.1
-    fake_lines = [Mock(series_impedance=(resistance + 1j * reactance))] * 3
-    branch = pd.DataFrame(
-        {"VOLTAGE": [69, 70, 345], "type": ["Line"] * 3, "line_object": fake_lines}
+    transformer_designs = pd.DataFrame(
+        {
+            "x": [0.19, 0.07, 0.044, 0.018],
+            "r": [0.01, 0.001, 0.001, 5e-4],
+            "MVA": [60, 250, 280, 580],
+        },
+        index=pd.MultiIndex.from_tuples([(69, 115), (69, 345), (115, 230), (230, 345)]),
     )
-    x = estimate_branch_impedance(branch.iloc[0], pd.Series())
-    assert x == reactance / (69**2 / const.s_base)
-    x = estimate_branch_impedance(branch.iloc[1], pd.Series())
-    assert x == reactance / (70**2 / const.s_base)
-    x = estimate_branch_impedance(branch.iloc[2], pd.Series())
-    assert x == reactance / (345**2 / const.s_base)
-
-
-def test_estimate_branch_impedance_transformers():
-    transformers = pd.DataFrame(
-        {"from_bus_id": [0, 1, 2], "to_bus_id": [1, 2, 3], "type": ["Transformer"] * 3}
+    lines = pd.DataFrame(
+        [
+            # One branch to low-voltage side of buses (0, 1) transformer
+            {"from_bus_id": 100, "to_bus_id": 0, "rateA": 75},
+            # Two branches to high-voltage side of buses (0, 1) transformer
+            {"from_bus_id": 1, "to_bus_id": 101, "rateA": 100},
+            {"from_bus_id": 1, "to_bus_id": 102, "rateA": 300},
+            # Two branches to low-voltage side of buses (2, 3) transformer
+            {"from_bus_id": 103, "to_bus_id": 2, "rateA": 50},
+            {"from_bus_id": 104, "to_bus_id": 2, "rateA": 100},
+            # One branch to high-voltage side of buses (2, 3) transformer
+            {"from_bus_id": 3, "to_bus_id": 105, "rateA": 300},
+            # One branch to each side of buses (5, 6) transformer
+            # The second of these is also on the high-voltage side of buses (4, 5) xfmr
+            {"from_bus_id": 6, "to_bus_id": 106, "rateA": 500},
+            {"from_bus_id": 5, "to_bus_id": 107, "rateA": 250},
+            # One branch connected to no transformers
+            {"from_bus_id": 998, "to_bus_id": 999, "rateA": 100e3},
+        ]
     )
-    bus_voltages = pd.Series([69, 230, 350, 500])
-    x = estimate_branch_impedance(transformers.iloc[0], bus_voltages)
-    assert x == const.transformer_reactance[(69, 230)]
-    x = estimate_branch_impedance(transformers.iloc[1], bus_voltages)
-    assert x == const.transformer_reactance[(230, 345)]
-    x = estimate_branch_impedance(transformers.iloc[2], bus_voltages)
-    assert x == const.transformer_reactance[(345, 500)]
-
-
-def test_estimate_branch_rating_lines():
-    fake_ratings = pd.Series([10, 20, 30, 40])
-    fake_thermal_ratings = pd.Series([100, 200, 300, 400])
-    fake_lines = [Mock(power_rating=i) for i in fake_ratings]
-    branch = pd.DataFrame(
+    # One transformer to (0, 1) (only needs to support the low-voltage power)
+    # Three transformer to (2, 3) (low-voltage side requires 3x transformers in total)
+    # One transformer to (4, 5) (only needs to support the low-voltage power)
+    # One transformer to (5, 6) (only needs to support the low-voltage power)
+    expected_transformers = pd.DataFrame(
         {
-            "VOLTAGE": [69, 140, 345, 499],
-            "type": ["Line"] * 4,
-            "line_object": fake_lines,
+            "from_bus_id": [0, 2, 2, 2, 4, 5],
+            "to_bus_id": [1, 3, 3, 3, 5, 6],
+            "x": [0.07, 0.19, 0.19, 0.19, 0.044, 0.018],
+            "r": [0.001, 0.01, 0.01, 0.01, 0.001, 5e-4],
+            "rateA": [250.0, 60.0, 60.0, 60.0, 280.0, 580.0],
         }
     )
-    assert_series_equal(
-        fake_ratings,
-        branch.apply(estimate_branch_rating, args=[None, fake_thermal_ratings], axis=1),
-    )
-
-
-def test_estimate_branch_rating_transformers():
-    thermal_ratings = pd.Series([100, 550, 1655, 2585], index=[69, 230, 345, 500])
-    transformers = pd.DataFrame(
-        {"from_bus_id": [0, 1, 2], "to_bus_id": [1, 2, 3], "type": ["Transformer"] * 3}
-    )
-    bus_voltages = pd.Series([69, 230, 350, 500])
-
-    rating = estimate_branch_rating(transformers.iloc[0], bus_voltages, thermal_ratings)
-    assert rating == const.transformer_rating
-    rating = estimate_branch_rating(transformers.iloc[1], bus_voltages, thermal_ratings)
-    assert rating == const.transformer_rating * 3
-    rating = estimate_branch_rating(transformers.iloc[2], bus_voltages, thermal_ratings)
-    assert rating == const.transformer_rating * 4
+    transformers = create_transformers(bus, lines, transformer_designs)
+    assert_frame_equal(transformers, expected_transformers)
 
 
 def test_filter_islands_and_connect_with_mst():