Source code for oemof.solph.constraints.integral_limit

# -*- coding: utf-8 -*-

"""Constraints to limit total values that are dependent on several Flows.

SPDX-FileCopyrightText: Uwe Krien <krien@uni-bremen.de>
SPDX-FileCopyrightText: Simon Hilpert
SPDX-FileCopyrightText: Patrik Schönfeldt
SPDX-FileCopyrightText: Johannes Röder

SPDX-License-Identifier: MIT

"""

from pyomo import environ as po

from oemof.solph.plumbing import sequence


[docs]def emission_limit(om, flows=None, limit=None): r""" Short handle for generic_integral_limit() with keyword="emission_factor". Note ---- Flow objects required an attribute "emission_factor"! """ generic_integral_limit( om, keyword="emission_factor", flows=flows, limit=limit )
[docs]def generic_integral_limit(om, keyword, flows=None, limit=None): r"""Set a global limit for flows weighted by attribute called keyword. The attribute named by keyword has to be added to every flow you want to take into account. Total value of keyword attributes after optimization can be retrieved calling the :attr:`om.oemof.solph.Model.integral_limit_${keyword}()`. Parameters ---------- om : oemof.solph.Model Model to which constraints are added. flows : dict Dictionary holding the flows that should be considered in constraint. Keys are (source, target) objects of the Flow. If no dictionary is given all flows containing the keyword attribute will be used. keyword : string attribute to consider limit : numeric Absolute limit of keyword attribute for the energy system. Note ---- Flow objects required an attribute named like keyword! **Constraint:** .. math:: \sum_{i \in F_E} \sum_{t \in T} P_i(t) \cdot w_i(t) \cdot \tau(t) \leq M With `F_I` being the set of flows considered for the integral limit and `T` being the set of time steps. The symbols used are defined as follows (with Variables (V) and Parameters (P)): ================ ==== ===================================================== math. symbol type explanation ================ ==== ===================================================== :math:`P_n(t)` V power flow :math:`n` at time step :math:`t` :math:`w_N(t)` P weight given to Flow named according to `keyword` :math:`\tau(t)` P width of time step :math:`t` :math:`L` P global limit given by keyword `limit` ================ ==== ===================================================== Examples -------- >>> import pandas as pd >>> from oemof import solph >>> date_time_index = pd.date_range('1/1/2012', periods=5, freq='H') >>> energysystem = solph.EnergySystem(timeindex=date_time_index) >>> bel = solph.Bus(label='electricityBus') >>> flow1 = solph.Flow(nominal_value=100, my_factor=0.8) >>> flow2 = solph.Flow(nominal_value=50) >>> src1 = solph.Source(label='source1', outputs={bel: flow1}) >>> src2 = solph.Source(label='source2', outputs={bel: flow2}) >>> energysystem.add(bel, src1, src2) >>> model = solph.Model(energysystem) >>> flow_with_keyword = {(src1, bel): flow1, } >>> model = solph.constraints.generic_integral_limit( ... model, "my_factor", flow_with_keyword, limit=777) """ if flows is None: flows = {} for (i, o) in om.flows: if hasattr(om.flows[i, o], keyword): flows[(i, o)] = om.flows[i, o] else: for (i, o) in flows: if not hasattr(flows[i, o], keyword): raise AttributeError( ( "Flow with source: {0} and target: {1} " "has no attribute {2}." ).format(i.label, o.label, keyword) ) limit_name = "integral_limit_" + keyword setattr( om, limit_name, po.Expression( expr=sum( om.flow[inflow, outflow, t] * om.timeincrement[t] * sequence(getattr(flows[inflow, outflow], keyword))[t] for (inflow, outflow) in flows for t in om.TIMESTEPS ) ), ) setattr( om, limit_name + "_constraint", po.Constraint(expr=(getattr(om, limit_name) <= limit)), ) return om