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.yml) must define the ampl section to find your dynawo installation and defaults parameters Here is an example of a simple config.yml 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)