Note

You can download this example as a Jupyter notebook or start it in interactive mode.

Meshed AC-DC example

This example has a 3-node AC network coupled via AC-DC converters to a 3-node DC network. There is also a single point-to-point DC using the Link component.

The data files for this example are in the examples folder of the github repository: https://github.com/PyPSA/PyPSA.

[1]:
import pypsa
import numpy as np
import pandas as pd
import os
import matplotlib.pyplot as plt
import cartopy.crs as ccrs

%matplotlib inline
plt.rc("figure", figsize=(8, 8))
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Cell In [1], line 1
----> 1 import pypsa
      2 import numpy as np
      3 import pandas as pd

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/site-packages/pypsa/__init__.py:10
      1 # -*- coding: utf-8 -*-
      4 """
      5 Python for Power Systems Analysis (PyPSA)
      6
      7 Grid calculation library.
      8 """
---> 10 from pypsa import (
     11     components,
     12     contingency,
     13     descriptors,
     14     examples,
     15     geo,
     16     io,
     17     linopf,
     18     linopt,
     19     networkclustering,
     20     opf,
     21     opt,
     22     optimization,
     23     pf,
     24     plot,
     25 )
     26 from pypsa.components import Network, SubNetwork
     28 __version__ = "0.21.2"

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/site-packages/pypsa/components.py:50
     37 from pypsa.io import (
     38     export_to_csv_folder,
     39     export_to_hdf5,
   (...)
     47     import_series_from_dataframe,
     48 )
     49 from pypsa.opf import network_lopf, network_opf
---> 50 from pypsa.optimization.optimize import OptimizationAccessor
     51 from pypsa.pf import (
     52     calculate_B_H,
     53     calculate_dependent_values,
   (...)
     62     sub_network_pf,
     63 )
     64 from pypsa.plot import iplot, plot

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/site-packages/pypsa/optimization/__init__.py:7
      1 #!/usr/bin/env python3
      2 # -*- coding: utf-8 -*-
      3 """
      4 Build optimisation problems from PyPSA networks with Linopy.
      5 """
----> 7 from pypsa.optimization import abstract, constraints, optimize, variables
      8 from pypsa.optimization.optimize import create_model

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/site-packages/pypsa/optimization/constraints.py:9
      6 import logging
      8 import pandas as pd
----> 9 from linopy.expressions import LinearExpression, merge
     10 from numpy import arange, cumsum, inf, nan, roll
     11 from scipy import sparse

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/site-packages/linopy/__init__.py:9
      1 #!/usr/bin/env python3
      2 # -*- coding: utf-8 -*-
      3 """
      4 Created on Wed Mar 10 11:03:06 2021.
      5
      6 @author: fabulous
      7 """
----> 9 from linopy import model, remote
     10 from linopy.expressions import merge
     11 from linopy.io import read_netcdf

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/site-packages/linopy/model.py:22
     20 from linopy import solvers
     21 from linopy.common import best_int, replace_by_map
---> 22 from linopy.constraints import (
     23     AnonymousConstraint,
     24     AnonymousScalarConstraint,
     25     Constraints,
     26 )
     27 from linopy.eval import Expr
     28 from linopy.expressions import LinearExpression, ScalarLinearExpression

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/site-packages/linopy/constraints.py:21
     18 from scipy.sparse import coo_matrix
     19 from xarray import DataArray, Dataset
---> 21 from linopy import expressions, variables
     22 from linopy.common import (
     23     _merge_inplace,
     24     has_assigned_model,
   (...)
     27     replace_by_map,
     28 )
     31 class Constraint(DataArray):

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/site-packages/linopy/expressions.py:23
     20 from xarray.core.dataarray import DataArrayCoordinates
     21 from xarray.core.groupby import _maybe_reorder, peek_at
---> 23 from linopy import constraints, variables
     24 from linopy.common import as_dataarray
     27 def exprwrap(method, *default_args, **new_default_kwargs):

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/site-packages/linopy/variables.py:398
    393     roll = varwrap(DataArray.roll)
    395     rolling = varwrap(DataArray.rolling)
--> 398 @dataclass(repr=False)
    399 class Variables:
    400     """
    401     A variables container used for storing multiple variable arrays.
    402     """
    404     labels: Dataset = Dataset()

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/dataclasses.py:1211, in dataclass.<locals>.wrap(cls)
   1210 def wrap(cls):
-> 1211     return _process_class(cls, init, repr, eq, order, unsafe_hash,
   1212                           frozen, match_args, kw_only, slots,
   1213                           weakref_slot)

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/dataclasses.py:959, in _process_class(cls, init, repr, eq, order, unsafe_hash, frozen, match_args, kw_only, slots, weakref_slot)
    956         kw_only = True
    957     else:
    958         # Otherwise it's a field of some type.
--> 959         cls_fields.append(_get_field(cls, name, type, kw_only))
    961 for f in cls_fields:
    962     fields[f.name] = f

File ~/checkouts/readthedocs.org/user_builds/pypsa/conda/v0.21.2/lib/python3.11/dataclasses.py:816, in _get_field(cls, a_name, a_type, default_kw_only)
    812 # For real fields, disallow mutable defaults.  Use unhashable as a proxy
    813 # indicator for mutability.  Read the __hash__ attribute from the class,
    814 # not the instance.
    815 if f._field_type is _FIELD and f.default.__class__.__hash__ is None:
--> 816     raise ValueError(f'mutable default {type(f.default)} for field '
    817                      f'{f.name} is not allowed: use default_factory')
    819 return f

ValueError: mutable default <class 'xarray.core.dataset.Dataset'> for field labels is not allowed: use default_factory
[2]:
network = pypsa.examples.ac_dc_meshed(from_master=True)
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [2], line 1
----> 1 network = pypsa.examples.ac_dc_meshed(from_master=True)

NameError: name 'pypsa' is not defined
[3]:
# get current type (AC or DC) of the lines from the buses
lines_current_type = network.lines.bus0.map(network.buses.carrier)
lines_current_type
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [3], line 2
      1 # get current type (AC or DC) of the lines from the buses
----> 2 lines_current_type = network.lines.bus0.map(network.buses.carrier)
      3 lines_current_type

NameError: name 'network' is not defined
[4]:
network.plot(
    line_colors=lines_current_type.map(lambda ct: "r" if ct == "DC" else "b"),
    title="Mixed AC (blue) - DC (red) network - DC (cyan)",
    color_geomap=True,
    jitter=0.3,
)
plt.tight_layout()
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [4], line 1
----> 1 network.plot(
      2     line_colors=lines_current_type.map(lambda ct: "r" if ct == "DC" else "b"),
      3     title="Mixed AC (blue) - DC (red) network - DC (cyan)",
      4     color_geomap=True,
      5     jitter=0.3,
      6 )
      7 plt.tight_layout()

NameError: name 'network' is not defined
[5]:
network.links.loc["Norwich Converter", "p_nom_extendable"] = False
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [5], line 1
----> 1 network.links.loc["Norwich Converter", "p_nom_extendable"] = False

NameError: name 'network' is not defined

We inspect the topology of the network. Therefore use the function determine_network_topology and inspect the subnetworks in network.sub_networks.

[6]:
network.determine_network_topology()
network.sub_networks["n_branches"] = [
    len(sn.branches()) for sn in network.sub_networks.obj
]
network.sub_networks["n_buses"] = [len(sn.buses()) for sn in network.sub_networks.obj]

network.sub_networks
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [6], line 1
----> 1 network.determine_network_topology()
      2 network.sub_networks["n_branches"] = [
      3     len(sn.branches()) for sn in network.sub_networks.obj
      4 ]
      5 network.sub_networks["n_buses"] = [len(sn.buses()) for sn in network.sub_networks.obj]

NameError: name 'network' is not defined

The network covers 10 time steps. These are given by the snapshots attribute.

[7]:
network.snapshots
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [7], line 1
----> 1 network.snapshots

NameError: name 'network' is not defined

There are 6 generators in the network, 3 wind and 3 gas. All are attached to buses:

[8]:
network.generators
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [8], line 1
----> 1 network.generators

NameError: name 'network' is not defined

We see that the generators have different capital and marginal costs. All of them have a p_nom_extendable set to True, meaning that capacities can be extended in the optimization.

The wind generators have a per unit limit for each time step, given by the weather potentials at the site.

[9]:
network.generators_t.p_max_pu.plot.area(subplots=True)
plt.tight_layout()
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [9], line 1
----> 1 network.generators_t.p_max_pu.plot.area(subplots=True)
      2 plt.tight_layout()

NameError: name 'network' is not defined

Alright now we know how the network looks like, where the generators and lines are. Now, let’s perform a optimization of the operation and capacities.

[10]:
network.lopf(pyomo=False);
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [10], line 1
----> 1 network.lopf(pyomo=False);

NameError: name 'network' is not defined

The objective is given by:

[11]:
network.objective
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [11], line 1
----> 1 network.objective

NameError: name 'network' is not defined

Why is this number negative? It considers the starting point of the optimization, thus the existent capacities given by network.generators.p_nom are taken into account.

The real system cost are given by

[12]:
network.objective + network.objective_constant
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [12], line 1
----> 1 network.objective + network.objective_constant

NameError: name 'network' is not defined

The optimal capacities are given by p_nom_opt for generators, links and storages and s_nom_opt for lines.

Let’s look how the optimal capacities for the generators look like.

[13]:
network.generators.p_nom_opt.div(1e3).plot.bar(ylabel="GW", figsize=(8, 3))
plt.tight_layout()
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [13], line 1
----> 1 network.generators.p_nom_opt.div(1e3).plot.bar(ylabel="GW", figsize=(8, 3))
      2 plt.tight_layout()

NameError: name 'network' is not defined

Their production is again given as a time-series in network.generators_t.

[14]:
network.generators_t.p.div(1e3).plot.area(subplots=True, ylabel="GW")
plt.tight_layout()
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [14], line 1
----> 1 network.generators_t.p.div(1e3).plot.area(subplots=True, ylabel="GW")
      2 plt.tight_layout()

NameError: name 'network' is not defined

What are the Locational Marginal Prices in the network. From the optimization these are given for each bus and snapshot.

[15]:
network.buses_t.marginal_price.mean(1).plot.area(figsize=(8, 3), ylabel="Euro per MWh")
plt.tight_layout()
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [15], line 1
----> 1 network.buses_t.marginal_price.mean(1).plot.area(figsize=(8, 3), ylabel="Euro per MWh")
      2 plt.tight_layout()

NameError: name 'network' is not defined

We can inspect futher quantities as the active power of AC-DC converters and HVDC link.

[16]:
network.links_t.p0
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [16], line 1
----> 1 network.links_t.p0

NameError: name 'network' is not defined
[17]:
network.lines_t.p0
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [17], line 1
----> 1 network.lines_t.p0

NameError: name 'network' is not defined

…or the active power injection per bus.

[18]:
network.buses_t.p
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In [18], line 1
----> 1 network.buses_t.p

NameError: name 'network' is not defined