src/oemof/solph/flows/experimental/_electrical_line.py
# -*- coding: utf-8 -*-
"""
In-development electrical line components.
SPDX-FileCopyrightText: Uwe Krien <krien@uni-bremen.de>
SPDX-FileCopyrightText: Simon Hilpert
SPDX-FileCopyrightText: Cord Kaldemeyer
SPDX-FileCopyrightText: Patrik Schönfeldt
SPDX-FileCopyrightText: Johannes Röder
SPDX-FileCopyrightText: jakob-wo
SPDX-FileCopyrightText: gplssm
SPDX-FileCopyrightText: jnnr
SPDX-FileCopyrightText: Johannes Kochems
SPDX-License-Identifier: MIT
"""
import logging
from pyomo.core.base.block import ScalarBlock
from pyomo.environ import BuildAction
from pyomo.environ import Constraint
from pyomo.environ import Set
from pyomo.environ import Var
from oemof.solph._plumbing import sequence as solph_sequence
from oemof.solph.buses.experimental._electrical_bus import ElectricalBus
from oemof.solph.flows._flow import Flow
class ElectricalLine(Flow):
r"""An ElectricalLine to be used in linear optimal power flow calculations.
based on angle formulation. Check out the Notes below before using this
component!
Parameters
----------
reactance : float or array of floats
Reactance of the line to be modelled
Note: This component is experimental. Use it with care.
Notes
-----
* To use this object the connected buses need to be of the type
:py:class:`~oemof.solph.experimental.ElectricalBus`.
* It does not work together with flows that have set the attr.`nonconvex`,
i.e. unit commitment constraints are not possible
* Input and output of this component are set equal, therefore just use
either only the input or the output to parameterize.
* Default attribute `min` of in/outflows is overwritten by -1 if not set
differently by the user
The following sets, variables, constraints and objective parts are created
* :py:class:`~oemof.solph.experimental.electrical_line.ElectricalLineBlock`
""" # noqa: E501
def __init__(self, **kwargs):
super().__init__(
nominal_value=kwargs.get("nominal_value"),
variable_costs=kwargs.get("variable_costs", 0),
min=kwargs.get("min"),
max=kwargs.get("max"),
fix=kwargs.get("fix"),
positive_gradient_limit=kwargs.get("positive_gradient_limit"),
negative_gradient_limit=kwargs.get("negative_gradient_limit"),
full_load_time_max=kwargs.get("full_load_time_max"),
full_load_time_min=kwargs.get("full_load_time_min"),
integer=kwargs.get("integer", False),
bidirectional=kwargs.get("bidirectiona", False),
investment=kwargs.get("investment"),
nonconvex=kwargs.get("nonconvex"),
custom_attributes=kwargs.get("costom_attributes"),
)
self.reactance = solph_sequence(kwargs.get("reactance", 0.00001))
self.input = kwargs.get("input")
self.output = kwargs.get("output")
# set input / output flow values to -1 by default if not set by user
if self.nonconvex is not None:
raise ValueError(
(
"Attribute `nonconvex` must be None for "
+ "component `ElectricalLine` from {} to {}!"
).format(self.input, self.output)
)
if self.min is None:
self.min = -1
# to be used in grouping for all bidi flows
self.bidirectional = True
def constraint_group(self):
return ElectricalLineBlock
class ElectricalLineBlock(ScalarBlock):
r"""Block for the linear relation of nodes with type
class:`.ElectricalLine`
Note: This component is experimental. Use it with care.
**The following constraints are created:**
Linear relation :attr:`om.ElectricalLine.electrical_flow[n,t]`
.. math::
flow(n, o, p, t) = 1 / reactance(n, t) \cdot
voltage\_angle(i(n), t) - voltage\_angle(o(n), t), \\
\forall p, t \in \textrm{TIMEINDEX}, \\
\forall n \in \textrm{ELECTRICAL\_LINES}.
TODO: Add equate constraint of flows
**The following variable are created:**
TODO: Add voltage angle variable
TODO: Add fix slack bus voltage angle to zero constraint / bound
TODO: Add tests
"""
CONSTRAINT_GROUP = True
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def _create(self, group=None):
"""Creates the linear constraint for the class:`ElectricalLine`
block.
Parameters
----------
group : list
List of oemof.solph.ElectricalLine (eline) objects for which
the linear relation of inputs and outputs is created
e.g. group = [eline1, eline2, ...]. The components inside the
list need to hold a attribute `reactance` of type Sequence
containing the reactance of the line.
"""
if group is None:
return None
m = self.parent_block()
# create voltage angle variables
self.ELECTRICAL_BUSES = Set(
initialize=[n for n in m.es.nodes if isinstance(n, ElectricalBus)]
)
def _voltage_angle_bounds(block, b, t):
return b.v_min, b.v_max
self.voltage_angle = Var(
self.ELECTRICAL_BUSES, m.TIMESTEPS, bounds=_voltage_angle_bounds
)
if True not in [b.slack for b in self.ELECTRICAL_BUSES]:
# TODO: Make this robust to select the same slack bus for
# the same problems
bus = [b for b in self.ELECTRICAL_BUSES][0]
logging.info(
"No slack bus set,setting bus {0} as slack bus".format(
bus.label
)
)
bus.slack = True
def _voltage_angle_relation(block):
for p, t in m.TIMEINDEX:
for n in group:
if n.input.slack is True:
self.voltage_angle[n.output, t].value = 0
self.voltage_angle[n.output, t].fix()
try:
lhs = m.flow[n.input, n.output, p, t]
rhs = (
1
/ n.reactance[t]
* (
self.voltage_angle[n.input, t]
- self.voltage_angle[n.output, t]
)
)
except ValueError:
raise ValueError(
"Error in constraint creation",
"of node {}".format(n.label),
)
block.electrical_flow.add((n, p, t), (lhs == rhs))
self.electrical_flow = Constraint(group, m.TIMEINDEX, noruleinit=True)
self.electrical_flow_build = BuildAction(rule=_voltage_angle_relation)