def _lazy_ptdf_dcopf_model_solve_loop(m, md, solver, timelimit, solver_tee=True, symbolic_solver_labels=False, iteration_limit=100000):
from pyomo.solvers.plugins.solvers.persistent_solver import PersistentSolver
PTDF = m._PTDF
ptdf_options = m._ptdf_options
rel_flow_tol = ptdf_options['rel_flow_tol']
abs_flow_tol = ptdf_options['abs_flow_tol']
branch_limits = PTDF.branch_limits_array
## only enforce the relative and absolute, within tollerance
PTDF.enforced_branch_limits = np.maximum(branch_limits*(1+rel_flow_tol), branch_limits+abs_flow_tol)
persistent_solver = isinstance(solver, PersistentSolver)
for i in range(iteration_limit):
PFV, viol_num, mon_viol_num, gt_viol_lazy, lt_viol_lazy = lpu.check_violations(m, md, PTDF, ptdf_options['max_violations_per_iteration'])
iter_status_str = "iteration {0}, found {1} violation(s)".format(i,viol_num)
if mon_viol_num:
iter_status_str += ", {} of which are already monitored".format(mon_viol_num)
print(iter_status_str)
if viol_num <= 0:
## in this case, there are no violations!
## load the duals now too, if we're using a persistent solver
if persistent_solver:
solver.load_duals()
return lpu.LazyPTDFTerminationCondition.NORMAL
elif viol_num == mon_viol_num:
print('WARNING: Terminating with monitored violations!')
print(' Result is not transmission feasible.')
if persistent_solver:
solver.load_duals()
return lpu.LazyPTDFTerminationCondition.FLOW_VIOLATION
lpu.add_violations(gt_viol_lazy, lt_viol_lazy, PFV, m, md, solver, ptdf_options, PTDF)
#m.ineq_pf_branch_thermal_lb.pprint()
#m.ineq_pf_branch_thermal_ub.pprint()
if persistent_solver:
solver.solve(m, tee=solver_tee, load_solutions=False, save_results=False)
solver.load_vars()
else:
solver.solve(m, tee=solver_tee, symbolic_solver_labels=symbolic_solver_labels)
else: # we hit the iteration limit
print('WARNING: Exiting on maximum iterations for lazy PTDF model.')
print(' Result is not transmission feasible.')
if persistent_solver:
solver.load_duals()
return lpu.LazyPTDFTerminationCondition.ITERATION_LIMIT
def _lazy_ptdf_dcopf_model_solve_loop(m,
md,
solver,
solver_tee=True,
symbolic_solver_labels=False,
iteration_limit=100000):
'''
The lazy PTDF DCOPF solver loop. This function iteratively
adds violated transmission constraints until either the result is
transmission feasible or we're tracking every violated constraint
in the model
Parameters
----------
m : pyomo.environ.ConcreteModel
An egret DCOPF model with no transmission constraints
md : egret.data.ModelData
An egret ModelData object
solver : pyomo.opt.solver
A pyomo solver object
solver_tee : bool (optional)
For displaying the solver log (default is True)
symbolic_solver_labels : bool (optional)
Use symbolic solver labels when writing to the solver (default is False)
iteration_limit : int (optional)
Number of iterations before a hard termination (default is 100000)
Returns
-------
egret.common.lazy_ptdf_utils.LazyPTDFTerminationCondition : the termination status
pyomo.opt.results.SolverResults : The results object from the pyomo solver
int : The number of iterations before termination
'''
from pyomo.solvers.plugins.solvers.persistent_solver import PersistentSolver
PTDF = m._PTDF
ptdf_options = m._ptdf_options
persistent_solver = isinstance(solver, PersistentSolver)
for i in range(iteration_limit):
PFV, PFV_I, viol_num, mon_viol_num, viol_lazy, int_viol_lazy \
= lpu.check_violations(m, md, PTDF, ptdf_options['max_violations_per_iteration'])
iter_status_str = "iteration {0}, found {1} violation(s)".format(
i, viol_num)
if mon_viol_num:
iter_status_str += ", {} of which are already monitored".format(
mon_viol_num)
logger.info(iter_status_str)
if viol_num <= 0:
## in this case, there are no violations!
## load the duals now too, if we're using a persistent solver
if persistent_solver:
solver.load_duals()
return lpu.LazyPTDFTerminationCondition.NORMAL
elif viol_num == mon_viol_num:
logger.warning(
'WARNING: Terminating with monitored violations! Result is not transmission feasible.'
)
if persistent_solver:
solver.load_duals()
return lpu.LazyPTDFTerminationCondition.FLOW_VIOLATION
lpu.add_violations(viol_lazy, int_viol_lazy, PFV, PFV_I, m, md, solver,
ptdf_options, PTDF)
total_flow_constr_added = len(viol_lazy) + len(int_viol_lazy)
logger.info("iteration {0}, added {1} flow constraint(s)".format(
i, total_flow_constr_added))
if persistent_solver:
solver.solve(m,
tee=solver_tee,
load_solutions=False,
save_results=False)
solver.load_vars()
else:
solver.solve(m,
tee=solver_tee,
symbolic_solver_labels=symbolic_solver_labels)
else: # we hit the iteration limit
logger.warning(
'WARNING: Exiting on maximum iterations for lazy PTDF model. Result is not transmission feasible.'
)
if persistent_solver:
solver.load_duals()
return lpu.LazyPTDFTerminationCondition.ITERATION_LIMIT
def _lazy_ptdf_dcopf_model_solve_loop(m,
md,
solver,
timelimit,
solver_tee=True,
symbolic_solver_labels=False,
iteration_limit=100000):
from pyomo.solvers.plugins.solvers.persistent_solver import PersistentSolver
PTDF = m._PTDF
ptdf_options = m._ptdf_options
lazy_rel_flow_tol = ptdf_options['lazy_rel_flow_tol']
rel_flow_tol = ptdf_options['rel_flow_tol']
abs_flow_tol = ptdf_options['abs_flow_tol']
branch_limits = PTDF.branch_limits_array
## if lazy_rel_flow_tol < 0, this narrows the branch limits
PTDF.lazy_branch_limits = branch_limits * (1 + lazy_rel_flow_tol)
## only enforce the relative and absolute, within tollerance
PTDF.enforced_branch_limits = np.maximum(
branch_limits * (1 + rel_flow_tol), branch_limits + abs_flow_tol)
persistent_solver = isinstance(solver, PersistentSolver)
for i in range(iteration_limit):
PFV, viol_num, viols_tup = lpu.check_violations(m, PTDF)
print("iteration {0}, found {1} violation(s)".format(i, viol_num))
if viol_num <= 0:
## in this case, there are no violations!
## load the duals now too, if we're using a persistent solver
if persistent_solver:
solver.load_duals()
return lpu.LazyPTDFTerminationCondition.NORMAL
all_viol_in_model = lpu.add_violations(viols_tup, PFV, m, md, solver,
ptdf_options, PTDF)
if all_viol_in_model:
print('WARNING: Terminating with monitored violations!')
print(' Result is not transmission feasible.')
if persistent_solver:
solver.load_duals()
return lpu.LazyPTDFTerminationCondition.FLOW_VIOLATION
#m.ineq_pf_branch_thermal_lb.pprint()
#m.ineq_pf_branch_thermal_ub.pprint()
if persistent_solver:
solver.solve(m,
tee=solver_tee,
load_solutions=False,
save_results=False)
solver.load_vars()
else:
solver.solve(m,
tee=solver_tee,
symbolic_solver_labels=symbolic_solver_labels)
else:
print('WARNING: Exiting on maximum iterations for lazy PTDF model.')
print(' Result is not transmission feasible.')
if persistent_solver:
solver.load_duals()
return lpu.LazyPTDFTerminationCondition.ITERATION_LIMIT