Merge pull request e2nIEE#1365 from rbolgaryn/tap_dependent_impedance

Tap dependent impedance

CHANGELOG.rst

@@ -4,6 +4,7 @@ Change Log
 - [ADDED] "results" initialization for runopp()
 - [CHANGED] toolbox function nets_equal()
 - [ADDED] toolbox function merge_same_bus_generation_plants()
+- [ADDED] TapDependentImpedance controller that adjusts the transformer parameters (e.g. vk_percent, vkr_percent) according to the tap position, based on a specified characteristic
 
 [2.7.1]- 2021-07-22
 ----------------------

pandapower/control/__init__.py

@@ -6,6 +6,7 @@
 from pandapower.control.controller.trafo.ContinuousTapControl import ContinuousTapControl
 from pandapower.control.controller.trafo.DiscreteTapControl import DiscreteTapControl
 from pandapower.control.controller.trafo.USetTapControl import USetTapControl
+from pandapower.control.controller.trafo.TapDependentImpedance import TapDependentImpedance
 from pandapower.control.controller.trafo_control import TrafoController
 
 # --- Other ---

pandapower/control/controller/trafo/TapDependentImpedance.py

@@ -0,0 +1,46 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2016-2021 by University of Kassel and Fraunhofer Institute for Energy Economics
+# and Energy System Technology (IEE), Kassel. All rights reserved.
+
+from pandapower.control.controller.characteristic_control import CharacteristicControl
+from pandapower.control.util.characteristic import Characteristic
+
+class TapDependentImpedance(CharacteristicControl):
+    """
+    Controller that adjusts the impedance of a transformer (or multiple transformers) depending to the actual tap position and
+    according to a defined characteristic.
+
+    INPUT:
+        **net** (attrdict) - Pandapower net
+
+        **tid** (int or list or numpy array) - ID of the transformer or multiple transfromers
+
+        **characteristic** (object of class Characteristic) - Characteristic that describes the relationship between transformer tap
+                                                                position and transformer impedance
+
+    OPTIONAL:
+
+        **in_service** (bool, True) - Indicates if the controller is currently in_service
+
+        **drop_same_existing_ctrl** (bool, False) - Indicates if already existing controllers of the same type and with the same matching parameters (e.g. at same element) should be dropped
+    """
+
+    def __init__(self, net, transformer_index, characteristic, trafotable="trafo", output_variable="vk_percent", tol=1e-3, restore=True,
+                 in_service=True, order=0, level=0, drop_same_existing_ctrl=False, matching_params=None, **kwargs):
+        if matching_params is None:
+            matching_params = {"transformer_index": transformer_index, 'output_variable': output_variable}
+        super().__init__(net, output_element=trafotable, output_variable=output_variable, output_element_index=transformer_index,
+                         input_element=trafotable, input_variable="tap_pos", input_element_index=transformer_index,
+                         characteristic=characteristic, tol=tol, in_service=in_service, order=order,
+                         level=level, drop_same_existing_ctrl=drop_same_existing_ctrl, matching_params=matching_params, **kwargs)
+        self.restore=restore
+        self.initial_values = net[trafotable].loc[transformer_index, output_variable].copy()
+
+    def initialize_control(self, net):
+        if self.restore:
+            self.initial_values = net[self.output_element].loc[self.output_element_index, self.output_variable].copy()
+
+    def finalize_control(self, net):
+        if self.restore:
+            net[self.output_element].loc[self.output_element_index, self.output_variable] = self.initial_values

pandapower/test/control/test_tap_dependent_impedance.py

@@ -0,0 +1,75 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2016-2021 by University of Kassel and Fraunhofer Institute for Energy Economics
+# and Energy System Technology (IEE), Kassel. All rights reserved.
+
+import pytest
+import pandapower as pp
+from pandapower.control import Characteristic, TapDependentImpedance
+
+
+def test_tap_dependent_impedance_control():
+    net = pp.create_empty_network()
+    b1 = pp.create_bus(net, 110)
+    b2 = pp.create_bus(net, 20)
+    pp.create_ext_grid(net, b1)
+    pp.create_transformer_from_parameters(net, b1, b2, 40, 110, 21, 0.5, 12.3, 25, 0.11, 0, 'hv', 10, 20, 0, 1.8, 180, 10)
+
+    characteristic_vk = Characteristic.from_points(((0, 13.5), (10, 12.3), (20, 11.1)))
+    characteristic_vkr = Characteristic.from_points(((0, 0.52), (10, 0.5), (20, 0.53)))
+    TapDependentImpedance(net, 0, characteristic_vk, output_variable='vk_percent', restore=False)
+    TapDependentImpedance(net, 0, characteristic_vkr, output_variable='vkr_percent', restore=False)
+
+    pp.runpp(net, run_control=True)
+    assert net.trafo.vk_percent.at[0] == 12.3
+    assert net.trafo.vkr_percent.at[0] == 0.5
+
+    net.trafo.tap_pos = 0
+    pp.runpp(net, run_control=True)
+    assert net.trafo.vk_percent.at[0] == 13.5
+    assert net.trafo.vkr_percent.at[0] == 0.52
+
+    net.trafo.tap_pos = 20
+    pp.runpp(net, run_control=True)
+    assert net.trafo.vk_percent.at[0] == 11.1
+    assert net.trafo.vkr_percent.at[0] == 0.53
+
+
+def test_tap_dependent_impedance_restore():
+    net = pp.create_empty_network()
+    b1 = pp.create_bus(net, 110)
+    b2 = pp.create_bus(net, 20)
+    pp.create_ext_grid(net, b1)
+    pp.create_load(net, b2, 20)
+    pp.create_transformer_from_parameters(net, b1, b2, 40, 110, 21, 0.5, 12.3, 25, 0.11, 0, 'hv', 10, 20, 0, 1.8, 180, 10)
+
+    characteristic_vk = Characteristic.from_points(((0, 13.5), (10, 12.3), (20, 11.1)))
+    characteristic_vkr = Characteristic.from_points(((0, 0.52), (10, 0.5), (20, 0.53)))
+    TapDependentImpedance(net, 0, characteristic_vk, output_variable='vk_percent', restore=True)
+    TapDependentImpedance(net, 0, characteristic_vkr, output_variable='vkr_percent', restore=True)
+
+    pp.runpp(net, run_control=True)
+    # remember the losses for the neutral position
+    pl_mw_neutral = net.res_trafo.pl_mw.at[0]
+    assert net.trafo.vk_percent.at[0] == 12.3
+    assert net.trafo.vkr_percent.at[0] == 0.5
+
+    net.trafo.tap_pos = 0
+    pp.runpp(net, run_control=True)
+    # check if the impedance has been restored
+    assert net.trafo.vk_percent.at[0] == 12.3
+    assert net.trafo.vkr_percent.at[0] == 0.5
+    # check if the losses are different than at the neutral position -> the tap-dependent impedance has been conbsidered
+    assert abs(net.res_trafo.pl_mw.at[0] - pl_mw_neutral) > 0.015
+
+    net.trafo.tap_pos = 20
+    pp.runpp(net, run_control=True)
+    # check if the impedance has been restored
+    assert net.trafo.vk_percent.at[0] == 12.3
+    assert net.trafo.vkr_percent.at[0] == 0.5
+    # check if the losses are different than at the neutral position -> the tap-dependent impedance has been conbsidered
+    assert abs(net.res_trafo.pl_mw.at[0] - pl_mw_neutral) > 0.002
+
+
+if __name__ == '__main__':
+    pytest.main(['-xs', __file__])