refactor: update transformer creation test

Author: danielolsen

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

@@ -190,27 +190,35 @@ def test_create_transformers():
     )
     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": 100, "rateA": 100},
-            {"from_bus_id": 1, "to_bus_id": 101, "rateA": 300},
-            # Two branches to low-voltage side of buses (2, 3) transformer
-            {"from_bus_id": 102, "to_bus_id": 2, "rateA": 50},
-            {"from_bus_id": 103, "to_bus_id": 2, "rateA": 100},
+            {"from_bus_id": 1, "to_bus_id": 101, "rateA": 100},
+            {"from_bus_id": 1, "to_bus_id": 102, "rateA": 300},
+            # Three 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": 104, "rateA": 500},
-            {"from_bus_id": 5, "to_bus_id": 105, "rateA": 250},
+            {"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},
         ]
     )
+    # 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(
         {
-            "from_bus_id": [0, 0, 2, 2, 4, 5],
-            "to_bus_id": [1, 1, 3, 3, 5, 6],
-            "x": [0.07, 0.07, 0.19, 0.19, 0.044, 0.018],
-            "r": [0.001, 0.001, 0.01, 0.01, 0.001, 5e-4],
-            "rateA": [250.0, 250.0, 60.0, 60.0, 280.0, 580.0],
+            "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],
         }
     )
     transformers = create_transformers(bus, lines, transformer_designs)