transformer_example.py

# -*- coding: utf-8 -*-
## Example of transformer with non-trivial phase shift and tap ratio
#
# This example is a copy of pandapower's minimal example.

import numpy as np

import pypsa

network = pypsa.Network()

network.add("Bus", "MV bus", v_nom=20, v_mag_pu_set=1.02)
network.add("Bus", "LV1 bus", v_nom=0.4)
network.add("Bus", "LV2 bus", v_nom=0.4)

network.add(
    "Transformer",
    "MV-LV trafo",
    type="0.4 MVA 20/0.4 kV",
    bus0="MV bus",
    bus1="LV1 bus",
)

network.add(
    "Line", "LV cable", type="NAYY 4x50 SE", bus0="LV1 bus", bus1="LV2 bus", length=0.1
)

network.add("Generator", "External Grid", bus="MV bus", control="Slack")

network.add("Load", "LV load", bus="LV2 bus", p_set=0.1, q_set=0.05)


def run_pf():
    network.lpf()
    network.pf(use_seed=True)
    print("Voltage angles:")
    print(network.buses_t.v_ang * 180.0 / np.pi)
    print("Voltage magnitudes:")
    print(network.buses_t.v_mag_pu)


run_pf()

network.transformers.tap_position = 2
run_pf()

network.transformers.tap_position = -2
run_pf()

### Now play with tap changer on LV side

new_trafo_lv_tap = network.transformer_types.loc[["0.4 MVA 20/0.4 kV"]]
new_trafo_lv_tap.index = ["New trafo"]
new_trafo_lv_tap.tap_side = 1
new_trafo_lv_tap

network.transformer_types = network.transformer_types.append(new_trafo_lv_tap)
network.transformers.type = "New trafo"

network.transformers.tap_position = 2
run_pf()

network.transformers.tap_position = -2
run_pf()

### Now make sure that the phase shift is also there in the LOPF

network.generators.p_nom = 1.0
network.lines.s_nom = 1.0
network.lopf()

print("Voltage angles:")
print(network.buses_t.v_ang * 180.0 / np.pi)
print("Voltage magnitudes:")
print(network.buses_t.v_mag_pu)