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=.4)
network.add("Bus","LV2 bus",v_nom=.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./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')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.026950 seconds

[4]:

	Voltage Angles	Volate Magnitude
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')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.026923 seconds

[5]:

	Voltage Angles	Volate Magnitude
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')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.026316 seconds

[6]:

	Voltage Angles	Volate Magnitude
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()

INFO:pypsa.pf:Performing linear load-flow on AC sub-network SubNetwork 0 for snapshot(s) Index(['now'], dtype='object')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.025110 seconds

[8]:

	Voltage Angles	Volate Magnitude
MV bus	0.000000	1.020000
LV1 bus	-150.755820	1.059317
LV2 bus	-149.964875	1.017221

[9]:

network.transformers.T

[9]:

	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')
INFO:pypsa.pf:Performing non-linear load-flow on AC sub-network SubNetwork 0 for snapshots Index(['now'], dtype='object')
INFO:pypsa.pf:Newton-Raphson solved in 3 iterations with error of 0.000000 in 0.027012 seconds

[10]:

	Voltage Angles	Volate Magnitude
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.
network.lines.s_nom = 1.
network.lopf()
pd.DataFrame({'Voltage Angles': network.buses_t.v_ang.loc['now']*180./np.pi,
                        'Volate Magnitude': network.buses_t.v_mag_pu.loc['now']})

INFO:pypsa.opf:Performed preliminary steps
INFO:pypsa.opf:Building pyomo model using `kirchhoff` formulation
INFO:pypsa.opf:Solving model using glpk
WARNING:pyomo.solvers:Could not locate the 'glpsol' executable, which is required for solver 'glpk'

---------------------------------------------------------------------------
ApplicationError                          Traceback (most recent call last)
/tmp/ipykernel_870/2785965588.py in <module>
      1 network.generators.p_nom = 1.
      2 network.lines.s_nom = 1.
----> 3 network.lopf()
      4 pd.DataFrame({'Voltage Angles': network.buses_t.v_ang.loc['now']*180./np.pi,
      5                         'Volate Magnitude': network.buses_t.v_mag_pu.loc['now']})

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pypsa/components.py in lopf(self, snapshots, pyomo, solver_name, solver_options, solver_logfile, formulation, keep_files, extra_functionality, multi_investment_periods, **kwargs)
    646
    647         if pyomo:
--> 648             return network_lopf(self, **args)
    649         else:
    650             return network_lopf_lowmem(self, **args)

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pypsa/opf.py in network_lopf(network, snapshots, solver_name, solver_io, skip_pre, extra_functionality, multi_investment_periods, solver_logfile, solver_options, keep_files, formulation, ptdf_tolerance, free_memory, extra_postprocessing)
   1663                               solver_logfile=solver_logfile, solver_options=solver_options,
   1664                               keep_files=keep_files, free_memory=free_memory,
-> 1665                               extra_postprocessing=extra_postprocessing)

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pypsa/opf.py in network_lopf_solve(network, snapshots, formulation, solver_options, solver_logfile, keep_files, free_memory, extra_postprocessing)
   1563             network.results = network.opt.solve(*args, suffixes=["dual"], keepfiles=keep_files, logfile=solver_logfile, options=solver_options)
   1564     else:
-> 1565         network.results = network.opt.solve(*args, suffixes=["dual"], keepfiles=keep_files, logfile=solver_logfile, options=solver_options)
   1566
   1567     if logger.isEnabledFor(logging.INFO):

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pyomo/opt/base/solvers.py in solve(self, *args, **kwds)
    510         """ Solve the problem """
    511
--> 512         self.available(exception_flag=True)
    513         #
    514         # If the inputs are models, then validate that they have been

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pyomo/opt/solver/shellcmd.py in available(self, exception_flag)
    123             if exception_flag:
    124                 msg = "No executable found for solver '%s'"
--> 125                 raise ApplicationError(msg % self.name)
    126             return False
    127         return True

ApplicationError: No executable found for solver 'glpk'