Note
You can download this example as a Jupyter notebook or start it in interactive mode.
Transformer with non-trivial phase shift and tap ratio#
This example is a copy of pandapower’s minimal example.
[1]:
import pypsa
import numpy as np
import pandas as pd
[2]:
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)
[3]:
def run_pf():
network.lpf()
network.pf(use_seed=True)
return pd.DataFrame(
{
"Voltage Angles": network.buses_t.v_ang.loc["now"] * 180.0 / np.pi,
"Volate Magnitude": network.buses_t.v_mag_pu.loc["now"],
}
)
[4]:
run_pf()
INFO:pypsa.pf:Performing linear load-flow on AC sub-network SubNetwork 0 for snapshot(s) Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.017178 seconds
[4]:
Voltage Angles | Volate Magnitude | |
---|---|---|
Bus | ||
MV bus | 0.000000 | 1.020000 |
LV1 bus | -150.760126 | 1.008843 |
LV2 bus | -149.884141 | 0.964431 |
[5]:
network.transformers.tap_position = 2
run_pf()
INFO:pypsa.pf:Performing linear load-flow on AC sub-network SubNetwork 0 for snapshot(s) Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.018206 seconds
[5]:
Voltage Angles | Volate Magnitude | |
---|---|---|
Bus | ||
MV bus | 0.000000 | 1.020000 |
LV1 bus | -150.843911 | 0.959655 |
LV2 bus | -149.870837 | 0.912713 |
[6]:
network.transformers.tap_position = -2
run_pf()
INFO:pypsa.pf:Performing linear load-flow on AC sub-network SubNetwork 0 for snapshot(s) Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.018034 seconds
[6]:
Voltage Angles | Volate Magnitude | |
---|---|---|
Bus | ||
MV bus | 0.000000 | 1.020000 |
LV1 bus | -150.681666 | 1.063133 |
LV2 bus | -149.896634 | 1.021202 |
Now play with tap changer on LV side
[7]:
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.T
[7]:
New trafo | |
---|---|
f_nom | 50.0 |
s_nom | 0.4 |
v_nom_0 | 20.0 |
v_nom_1 | 0.4 |
vsc | 6.0 |
vscr | 1.425 |
pfe | 1.35 |
i0 | 0.3375 |
phase_shift | 150.0 |
tap_side | 1 |
tap_neutral | 0 |
tap_min | -2 |
tap_max | 2 |
tap_step | 2.5 |
references | pandapower;Oswald - Transformatoren - Vorlesun... |
[8]:
network.transformer_types = network.transformer_types.append(new_trafo_lv_tap)
network.transformers.type = "New trafo"
network.transformers.tap_position = 2
run_pf()
/tmp/ipykernel_5348/2416978983.py:1: FutureWarning: The frame.append method is deprecated and will be removed from pandas in a future version. Use pandas.concat instead.
network.transformer_types = network.transformer_types.append(new_trafo_lv_tap)
INFO:pypsa.pf:Performing linear load-flow on AC sub-network SubNetwork 0 for snapshot(s) Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.019036 seconds
[8]:
Voltage Angles | Volate Magnitude | |
---|---|---|
Bus | ||
MV bus | 0.000000 | 1.020000 |
LV1 bus | -150.755820 | 1.059317 |
LV2 bus | -149.964875 | 1.017221 |
[9]:
network.transformers.T
[9]:
Transformer | MV-LV trafo |
---|---|
attribute | |
bus0 | MV bus |
bus1 | LV1 bus |
type | New trafo |
model | t |
x | 0.058283 |
r | 0.01425 |
g | 0.003375 |
b | -0.0 |
s_nom | 0.4 |
s_nom_extendable | False |
s_nom_min | 0.0 |
s_nom_max | inf |
s_max_pu | 1.0 |
capital_cost | 0.0 |
num_parallel | 1.0 |
tap_ratio | 1.05 |
tap_side | 1 |
tap_position | 2 |
phase_shift | 150.0 |
build_year | 0 |
lifetime | inf |
v_ang_min | -inf |
v_ang_max | inf |
sub_network | 0 |
x_pu | 0.145712 |
r_pu | 0.035618 |
g_pu | 0.00135 |
b_pu | -0.0 |
x_pu_eff | 0.152994 |
r_pu_eff | 0.037406 |
s_nom_opt | 0.0 |
[10]:
network.transformers.tap_position = -2
run_pf()
INFO:pypsa.pf:Performing linear load-flow on AC sub-network SubNetwork 0 for snapshot(s) Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object', name='snapshot')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.017161 seconds
[10]:
Voltage Angles | Volate Magnitude | |
---|---|---|
Bus | ||
MV bus | 0.000000 | 1.020000 |
LV1 bus | -150.765232 | 0.958366 |
LV2 bus | -149.789394 | 0.911353 |
Now make sure that the phase shift is also there in the LOPF
[11]:
network.generators.p_nom = 1.0
network.lines.s_nom = 1.0
network.lopf()
pd.DataFrame(
{
"Voltage Angles": network.buses_t.v_ang.loc["now"] * 180.0 / np.pi,
"Volate Magnitude": network.buses_t.v_mag_pu.loc["now"],
}
)
INFO:pypsa.linopf:Prepare linear problem
INFO:pypsa.linopf:Total preparation time: 0.1s
INFO:pypsa.linopf:Solve linear problem using Glpk solver
INFO:pypsa.linopf:Optimization successful. Objective value: 0.00e+00
[11]:
Voltage Angles | Volate Magnitude | |
---|---|---|
Bus | ||
MV bus | 0.627810 | 1.020000 |
LV1 bus | -0.165294 | 0.958366 |
LV2 bus | -0.462516 | 0.911353 |