Borders, Obstacles & Buffering¶

OptiWindNet models site bounds with an exterior border (build area) and interior obstacles (exclusions), and keeps electrical network design compliant with the bounds. This notebook walks from initialization and optimization under constraints, through cleaning and buffering the geometry, to validating turbine/substation placement. We will explore following features (methods):

  • Optimize under bounds: .optimize(): optimize electrical network while enforcing border/obstacle constraints.

  • Merge & clean boundary: .merge_obstacles_into_border(): resolve intersections/touching constriants, absorb irrelevant obstacles, and simplify the exterior boundary.

  • Buffer geometry: .add_buffer(buffer_dist=...): expand the border and shrink obstacles to add safety margins; might smooth concavities or remove obstacles depending on buffer_dist.

  • Compare originals vs buffered: .plot_original_vs_buffered(): overlay plot of border/obstacles before and after buffering to inspect how buffering changed shapes.

  • Validate placement: .is_layout_within_bounds(): confirm turbines/substations lie inside the border and outside obstacles.

Import required packages

[1]:
from optiwindnet.api import WindFarmNetwork
import numpy as np
import matplotlib.pyplot as plt
[2]:
# Display figures as SVG in Jupyter notebooks
%config InlineBackend.figure_formats = ['svg']

Borders and obstacles¶

1. Initialize¶

Create a WindFarmNetwork instances from an `osm.pbf´ file and optimize it.

[3]:
wfn1 = WindFarmNetwork.from_pbf(filepath='data/DTU_letters.osm.pbf', cables=7)

Plot the location geometry and the optimized network to confirm that the borders and obstacles are properly initailized and considered for optimization.

[4]:
wfn1
[4]:
../_images/notebooks_a06_border_obstacles_9_0.svg
[5]:
wfn1.L.graph['T']
[5]:
40
[6]:
res_optimize = wfn1.optimize()
wfn1
[6]:
../_images/notebooks_a06_border_obstacles_11_0.svg

Note: OptiWindNet works properly without borders/obstacles also.

2. Obstacles intersecting with the exterior borders¶

Let’s create an instance of WindFarmNetwork directly via coordinates to have full control over border/obstacle definition.

[7]:
turbinesC = np.array([
       [ 316976, 6175410],
       [ 316998, 6175380],
       [ 316965, 6175368],
       [ 316997, 6175347],
       [ 316967 , 6175314],
       [ 317009 , 6175267],
       [ 317044, 6175282],
       [ 316994 , 6175296],
       [ 317065, 6175335],
       [ 317030, 6175318],
       [ 317029 , 6175366],
       [ 317026, 6175401],
       [ 317057, 6175379],
       [ 317085, 6175354],
       [ 317068, 6175406],
       [ 317144, 6175403],
       [ 317115, 6175342],
       [ 317091, 6175320],
       [ 317240, 6175259],
       [ 317111 , 6175293],
       [ 317126, 6175262],
       [ 317152, 6175320],
       [ 317102, 6175385],
       [ 317179, 6175383],
       [ 317143, 6175367],
       [ 317223, 6175399],
       [ 317222, 6175358],
       [ 317185, 6175347],
       [ 317208, 6175323],
       [ 317188, 6175299],
       [ 317205, 6175270],
       [ 317231, 6175296],
       [ 317272, 6175287],
       [ 317244, 6175340],
       [ 317283, 6175321],
       [ 317285, 6175360],
       [ 316960, 6175270],
       [ 317253, 6175380],
       [ 317287, 6175397],
       [ 317152, 6175286],
       ])

borderC = np.array([
       [316956, 6175267],
       [317022, 6175265],
       [317043, 6175275],
       [317059 , 6175295],
       [317068, 6175322],
       [317069, 6175349],
       [317090, 6175348],
       [317086, 6175262],
       [317153, 6175259],
       [317157, 6175346],
       [317178 , 6175345],
       [317177, 6175316],
       [317184, 6175289],
       [317199, 6175268],
       [317218, 6175256],
       [317240, 6175256],
       [317260, 6175266],
       [317276, 6175286],
       [317285, 6175312],
       [317289, 6175399],
       [317242, 6175401],
       [317239, 6175319],
       [317238, 6175312],
       [317235, 6175308],
       [317232, 6175305],
       [317229, 6175305],
       [317226, 6175308],
       [317224, 6175313],
       [317223, 6175319],
       [317227, 6175402],
       [316963, 6175413],
       ])

obstaclesC_ = [
    np.array([
       [316998, 6175301],
       [317001 , 6175376],
       [317013, 6175375],
       [317021, 6175369],
       [317026, 6175359],
       [317029, 6175345],
       [317029, 6175330],
       [317025, 6175316],
       [317019, 6175306],
       [317011, 6175301],
       ]),
    np.array([
       [316920, 6175300],
       [316920, 6175400],
       [316950, 6175400],
       [316950, 6175300],
       ]),
    np.array([
       [317100, 6175450],
       [317100, 6175400],
       [317080, 6175400],
       [317080, 6175450],
       ]),
       ]

substationsC = np.array([
       [317167 , 6175351]])
[8]:
wfn2 = WindFarmNetwork(turbinesC=turbinesC, substationsC=substationsC, borderC=borderC, obstacleC_=obstaclesC_, cables=7)
wfn2
[8]:
../_images/notebooks_a06_border_obstacles_16_0.svg
[9]:
res_optimize = wfn2.optimize()
wfn2
[9]:
../_images/notebooks_a06_border_obstacles_17_0.svg

We can use .merge_obstacles_into_border() to refine the borders, simplify the boundary constraints and remove unrelavant obstacles.

[10]:
wfn2.merge_obstacles_into_border()
res_optimize = wfn2.optimize()
wfn2
Obstacle at index 1 is completely outside the border and is neglected.
Obstacle at index 2 intersects with the exteriour border and is merged into the exterior border.
[10]:
../_images/notebooks_a06_border_obstacles_19_1.svg

Buffering¶

After initializing the WindFarmNetwork, a buffer can be applied to borders and obstacles via .buffer_border_obstacles method. The exterior border will be expanded, while interior obstacles will be shrunk accordingly.

Initialize WindFarmNetwork instance

[11]:
wfn3 = WindFarmNetwork.from_pbf(filepath='data/DTU_letters.osm.pbf', cables=7)
res_optimize = wfn3.optimize()
wfn3
[11]:
../_images/notebooks_a06_border_obstacles_22_0.svg

apply buffering to wfn3.

[12]:
wfn3.add_buffer(buffer_dist=5)
res_optimize = wfn3.optimize()
wfn3
The defined border is non-convex and buffering may introduce unexpected changes. For visual comparison use plot_original_vs_buffered().
[12]:
../_images/notebooks_a06_border_obstacles_24_1.svg

Original vs buffered border/obstacles can be visualized using plot_original_vs_buffered()

[13]:
wfn3.plot_original_vs_buffered()
../_images/notebooks_a06_border_obstacles_26_0.svg

Removal of a concavity¶

In this case a message is printed out, providing information about the potential changes in the border.

[14]:
wfn4 = WindFarmNetwork.from_pbf(filepath='data/DTU_letters.osm.pbf', cables=7)
wfn4.add_buffer(buffer_dist=10)
The defined border is non-convex and buffering may introduce unexpected changes. For visual comparison use plot_original_vs_buffered().

Plotting original vs buffered borders confirms that one of the concavities is removed after buffering.

[15]:
wfn4.plot_original_vs_buffered()
../_images/notebooks_a06_border_obstacles_30_0.svg

Optimize

The optimized network might change and use new routes after buffering.

[16]:
res_optimize = wfn4.optimize()
wfn4
[16]:
../_images/notebooks_a06_border_obstacles_32_0.svg

Removal of an obstacle¶

[17]:
wfn5 = WindFarmNetwork.from_pbf(filepath='data/DTU_letters.osm.pbf', cables=7)
wfn5.add_buffer(buffer_dist=15)
The defined border is non-convex and buffering may introduce unexpected changes. For visual comparison use plot_original_vs_buffered().
Buffering by 15.00 completely removed the obstacle at index 0. For visual comparison use plot_original_vs_buffered().

Plotting original vs buffered borders confirms that abostacle (inside D letter) is removed after buffering.

[18]:
wfn5.plot_original_vs_buffered()
../_images/notebooks_a06_border_obstacles_36_0.svg

Optimize

The optimized network might change and use new routes after buffering.

[19]:
wfn5.optimize()
wfn5
[19]:
../_images/notebooks_a06_border_obstacles_38_0.svg

Turbines outside the border or inside the obstacles¶

OptiWindNet provide a method .is_layout_within_bounds to checks if the turbinesC/substationsC are defined properly with respect to the given border and obstacles.

[20]:
turbinesC = np.array([
       [0, 0],
       [ 316976, 6175410],
       [ 316998, 6175380],
       ])

borderC = np.array([
       [316956, 6175267],
       [317022, 6175265],
       [317043, 6175275],
       [317059 , 6175295],
       [317068, 6175322],
       [317069, 6175349],
       [317090, 6175348],
       [317086, 6175262],
       [317153, 6175259],
       [317157, 6175346],
       [317178 , 6175345],
       [317177, 6175316],
       [317184, 6175289],
       [317199, 6175268],
       [317218, 6175256],
       [317240, 6175256],
       [317260, 6175266],
       [317276, 6175286],
       [317285, 6175312],
       [317289, 6175399],
       [317242, 6175401],
       [317239, 6175319],
       [317238, 6175312],
       [317235, 6175308],
       [317232, 6175305],
       [317229, 6175305],
       [317226, 6175308],
       [317224, 6175313],
       [317223, 6175319],
       [317227, 6175402],
       [316963, 6175413],
       ])

substationsC = np.array([
       [317167 , 6175351]])
[25]:
wfn6 = WindFarmNetwork(turbinesC=turbinesC, substationsC=substationsC, borderC=borderC, obstacleC_=obstaclesC_, cables=7)
wfn6.optimize()
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Cell In[25], line 2
      1 wfn6 = WindFarmNetwork(turbinesC=turbinesC, substationsC=substationsC, borderC=borderC, obstacleC_=obstaclesC_, cables=7)
----> 2 wfn6.optimize()

File C:\code\OptiWindNet\optiwindnet\api.py:591, in WindFarmNetwork.optimize(self, turbinesC, substationsC, router, verbose)
    587 else:
    588     warmstart = {}
    590 self._S, self._G = router.route(
--> 591     P=self.P,
    592     A=self.A,
    593     cables=self.cables,
    594     cables_capacity=self.cables_capacity,
    595     verbose=verbose,
    596     **warmstart,
    597 )
    598 self._is_stale_SG = False
    600 terse_links = self.terse_links()

File C:\code\OptiWindNet\optiwindnet\api.py:268, in WindFarmNetwork.P(self)
    265 @property
    266 def P(self) -> nx.PlanarEmbedding:
    267     if self._is_stale_PA:
--> 268         self._refresh_planar()
    269     return self._P

File C:\code\OptiWindNet\optiwindnet\api.py:229, in WindFarmNetwork._refresh_planar(self)
    225             out_of_bounds -= obstacle.exterior
    226     if not out_of_bounds.is_empty:
    227         # TODO: if relevant, get coordinates of turbines from out_of_bounds
    228         #  print(list(out_of_bounds.geoms))
--> 229         raise ValueError('Turbine out of bounds!')
    230 self._P, self._A = make_planar_embedding(self._L)
    231 self._is_stale_PA = False

ValueError: Turbine out of bounds!