Run the voltage initializer#

Prerequisites#

For now the voltage initializer tool rely on Ampl and Knitro. the binary knitroampl must be in your PATH.

The pypowsybl config file (generally located at ~/.itools/config.yaml) must define the ampl section to find your dynawaltz installation and defaults parameters Here is an example of a simple config.yaml file.

ampl:
    homeDir: PATH_TO_AMPL

Quick start#

Here is a simple starting example:

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
n = pp.network.create_eurostag_tutorial_example1_network()
some_gen_id = n.get_generators().iloc[0].name
params.add_constant_q_generators([some_gen_id])
some_2wt_id = n.get_2_windings_transformers().iloc[0].name
params.add_variable_two_windings_transformers([some_2wt_id])

params.set_objective(VoltageInitializerObjective.SPECIFIC_VOLTAGE_PROFILE)

results = v_init.run(n, params)
results.apply_all_modification(n)

print(results.status())
print(results.indicators())

Available settings in the VoltageInitializerParameters class#

  • Specify which buses will have reactive slacks attached in the ACOPF solving.

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.set_reactive_slack_buses_mode(va.VoltageInitializerReactiveSlackBusesMode.NO_GENERATION)

  • Specify what is the log level of the AMPL solving.

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.set_log_level_ampl(va.VoltageInitializerLogLevelAmpl.ERROR)
params.set_log_level_solver(va.VoltageInitializerLogLevelSolver.EVERYTHING)

  • Change plausible voltage level limits in ACOPF solving.

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.set_min_plausible_low_voltage_limit(0.45)
params.set_max_plausible_high_voltage_limit(1.2)

  • Tune the threshold defining null values in AMPL.

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.set_min_plausible_active_power_threshold(1)
params.set_low_impedance_threshold(1e-5)

  • Modify the parameters used for the correction of generator limits.

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.set_max_plausible_power_limit(7800)
params.set_high_active_power_default_limit(950)
params.set_low_active_power_default_limit(0.5)
params.set_default_minimal_qp_range(0.45)
params.set_default_qmax_pmax_ratio(0.45)

  • Tune the thresholds used to ignore buses or voltage level limits with nominal voltage lower than them.

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.set_min_nominal_voltage_ignored_bus(0.5)
params.set_min_nominal_voltage_ignored_voltage_bounds(1)

  • Specify which parameters will be variable or fixed in the ACOPF solving

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
n = pp.network.create_eurostag_tutorial_example1_network()
some_gen_id = n.get_generators().iloc[0].name
some_2wt_id = n.get_2_windings_transformers().iloc[0].name
some_shunt_id = n.get_shunt_compensators().iloc[0].name
params.add_constant_q_generators([some_gen_id])
params.add_variable_two_windings_transformers([some_2wt_id])
params.add_variable_shunt_compensators([some_shunt_id])

  • Override the network voltage limits:

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.add_specific_low_voltage_limits([("vl_id_1", False, 380)])
params.add_specific_high_voltage_limits([("vl_id_2", False, 420)])

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.add_specificvoltage_limits({"vl_id": (0.5, 1.2)})

  • Specify the objective function and the objective distance

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.set_objective(va.VoltageInitializerObjective.SPECIFIC_VOLTAGE_PROFILE)
params.set_objective_distance(1.3)

  • Tune scaling factors applied before ACOPF solving:

import pypowsybl as pp
import pypowsybl.voltage_initializer as v_init
params = v_init.VoltageInitializerParameters()
params.set_default_variable_scaling_factor(1.1)
params.set_default_constraint_scaling_factor(0.9)
params.set_reactive_slack_variable_scaling_factor(0.15)
params.set_twt_ratio_variable_scaling_factor(0.002)