diff --git a/src/main/java/com/powsybl/openloadflow/AcLoadFlowFromCache.java b/src/main/java/com/powsybl/openloadflow/AcLoadFlowFromCache.java
index a829a78a6a..43038c51f2 100644
--- a/src/main/java/com/powsybl/openloadflow/AcLoadFlowFromCache.java
+++ b/src/main/java/com/powsybl/openloadflow/AcLoadFlowFromCache.java
@@ -17,7 +17,7 @@
 import com.powsybl.openloadflow.ac.nr.NewtonRaphsonStatus;
 import com.powsybl.openloadflow.lf.outerloop.OuterLoopStatus;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
+import com.powsybl.openloadflow.network.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
diff --git a/src/main/java/com/powsybl/openloadflow/network/LfAction.java b/src/main/java/com/powsybl/openloadflow/network/LfAction.java
index 9b971bf622..ea0cda0305 100644
--- a/src/main/java/com/powsybl/openloadflow/network/LfAction.java
+++ b/src/main/java/com/powsybl/openloadflow/network/LfAction.java
@@ -126,6 +126,9 @@ public static Optional<LfAction> create(Action action, LfNetwork lfNetwork, Netw
             case PhaseTapChangerTapPositionAction.NAME:
                 return create((PhaseTapChangerTapPositionAction) action, lfNetwork);
 
+            case RatioTapChangerTapPositionAction.NAME:
+                return create((RatioTapChangerTapPositionAction) action, lfNetwork);
+
             case LoadAction.NAME:
                 return create((LoadAction) action, lfNetwork, network, breakers);
 
@@ -185,12 +188,22 @@ private static Optional<LfAction> create(LoadAction action, LfNetwork lfNetwork,
     private static Optional<LfAction> create(PhaseTapChangerTapPositionAction action, LfNetwork lfNetwork) {
         String branchId = action.getSide().map(side -> LfLegBranch.getId(side, action.getTransformerId())).orElseGet(action::getTransformerId);
         LfBranch branch = lfNetwork.getBranchById(branchId);
+        return create(branch, action.getId(), action.isRelativeValue(), action.getTapPosition(), lfNetwork);
+    }
+
+    private static Optional<LfAction> create(RatioTapChangerTapPositionAction action, LfNetwork lfNetwork) {
+        String branchId = action.getSide().map(side -> LfLegBranch.getId(side, action.getTransformerId())).orElseGet(action::getTransformerId);
+        LfBranch branch = lfNetwork.getBranchById(branchId);
+        return create(branch, action.getId(), action.isRelativeValue(), action.getTapPosition(), lfNetwork);
+    }
+
+    private static Optional<LfAction> create(LfBranch branch, String actionId, boolean isRelative, int tapPosition, LfNetwork lfNetwork) {
         if (branch != null) {
             if (branch.getPiModel() instanceof SimplePiModel) {
-                throw new UnsupportedOperationException("Phase tap changer tap connection action: only one tap in branch " + branch.getId());
+                throw new UnsupportedOperationException("Tap position action: only one tap in branch " + branch.getId());
             } else {
-                var tapPositionChange = new TapPositionChange(branch, action.getTapPosition(), action.isRelativeValue());
-                return Optional.of(new LfAction(action.getId(), null, null, tapPositionChange, null, null, null));
+                var tapPositionChange = new TapPositionChange(branch, tapPosition, isRelative);
+                return Optional.of(new LfAction(actionId, null, null, tapPositionChange, null, null, null));
             }
         }
         return Optional.empty(); // could be in another component
diff --git a/src/main/java/com/powsybl/openloadflow/network/LfNetwork.java b/src/main/java/com/powsybl/openloadflow/network/LfNetwork.java
index 731ac86ad3..9ea6199ea3 100644
--- a/src/main/java/com/powsybl/openloadflow/network/LfNetwork.java
+++ b/src/main/java/com/powsybl/openloadflow/network/LfNetwork.java
@@ -561,15 +561,15 @@ public static <T> List<LfNetwork> load(T network, LfNetworkLoader<T> networkLoad
         return load(network, networkLoader, parameters, Reporter.NO_OP);
     }
 
-    public static <T> List<LfNetwork> load(T network, LfNetworkLoader<T> networkLoader, SlackBusSelector slackBusSelector, Reporter reporter) {
-        return load(network, networkLoader, new LfNetworkParameters().setSlackBusSelector(slackBusSelector), reporter);
+    public static <T> List<LfNetwork> load(T network, LfNetworkLoader<T> networkLoader, LfNetworkParameters parameters, Reporter reporter) {
+        return load(network, networkLoader, new LfTopoConfig(), parameters, reporter);
     }
 
-    public static <T> List<LfNetwork> load(T network, LfNetworkLoader<T> networkLoader, LfNetworkParameters parameters, Reporter reporter) {
+    public static <T> List<LfNetwork> load(T network, LfNetworkLoader<T> networkLoader, LfTopoConfig topoConfig, LfNetworkParameters parameters, Reporter reporter) {
         Objects.requireNonNull(network);
         Objects.requireNonNull(networkLoader);
         Objects.requireNonNull(parameters);
-        List<LfNetwork> lfNetworks = networkLoader.load(network, parameters, reporter);
+        List<LfNetwork> lfNetworks = networkLoader.load(network, topoConfig, parameters, reporter);
         for (LfNetwork lfNetwork : lfNetworks) {
             Reporter reporterNetwork = Reports.createPostLoadingProcessingReporter(lfNetwork.getReporter());
             lfNetwork.fix(parameters.isMinImpedance(), parameters.getLowImpedanceThreshold());
diff --git a/src/main/java/com/powsybl/openloadflow/network/LfNetworkLoader.java b/src/main/java/com/powsybl/openloadflow/network/LfNetworkLoader.java
index 7617c69792..d2796fb289 100644
--- a/src/main/java/com/powsybl/openloadflow/network/LfNetworkLoader.java
+++ b/src/main/java/com/powsybl/openloadflow/network/LfNetworkLoader.java
@@ -24,5 +24,5 @@ public interface LfNetworkLoader<T> {
      * components number (hence sorted by descending connected components size then by descending synchronous components
      * size)
      */
-    List<LfNetwork> load(T network, LfNetworkParameters parameters, Reporter reporter);
+    List<LfNetwork> load(T network, LfTopoConfig topoConfig, LfNetworkParameters parameters, Reporter reporter);
 }
diff --git a/src/main/java/com/powsybl/openloadflow/network/impl/LfTopoConfig.java b/src/main/java/com/powsybl/openloadflow/network/LfTopoConfig.java
similarity index 61%
rename from src/main/java/com/powsybl/openloadflow/network/impl/LfTopoConfig.java
rename to src/main/java/com/powsybl/openloadflow/network/LfTopoConfig.java
index d77733c781..99e9cb99c5 100644
--- a/src/main/java/com/powsybl/openloadflow/network/impl/LfTopoConfig.java
+++ b/src/main/java/com/powsybl/openloadflow/network/LfTopoConfig.java
@@ -4,7 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
-package com.powsybl.openloadflow.network.impl;
+package com.powsybl.openloadflow.network;
 
 import com.powsybl.iidm.network.Switch;
 
@@ -22,6 +22,10 @@ public class LfTopoConfig {
 
     private final Set<String> busIdsToLose = new HashSet<>();
 
+    private final Set<String> branchIdsWithPtcToRetain = new HashSet<>();
+
+    private final Set<String> branchIdsWithRtcToRetain = new HashSet<>();
+
     public Set<Switch> getSwitchesToOpen() {
         return switchesToOpen;
     }
@@ -34,7 +38,23 @@ public Set<String> getBusIdsToLose() {
         return busIdsToLose;
     }
 
+    public void addBranchIdsWithPtcToRetain(String branchId) {
+        branchIdsWithPtcToRetain.add(branchId);
+    }
+
+    public void addBranchIdsWithRtcToRetain(String branchId) {
+        branchIdsWithRtcToRetain.add(branchId);
+    }
+
     public boolean isBreaker() {
         return !(switchesToOpen.isEmpty() && switchesToClose.isEmpty() && busIdsToLose.isEmpty());
     }
+
+    public boolean isRetainedPtc(String branchId) {
+        return branchIdsWithPtcToRetain.contains(branchId);
+    }
+
+    public boolean isRetainedRtc(String branchId) {
+        return branchIdsWithRtcToRetain.contains(branchId);
+    }
 }
diff --git a/src/main/java/com/powsybl/openloadflow/network/impl/LfBranchImpl.java b/src/main/java/com/powsybl/openloadflow/network/impl/LfBranchImpl.java
index de6e5fdaff..c19acc876b 100644
--- a/src/main/java/com/powsybl/openloadflow/network/impl/LfBranchImpl.java
+++ b/src/main/java/com/powsybl/openloadflow/network/impl/LfBranchImpl.java
@@ -113,7 +113,7 @@ private static LfBranchImpl createLine(Line line, LfNetwork network, LfBus bus1,
     }
 
     private static LfBranchImpl createTransformer(TwoWindingsTransformer twt, LfNetwork network, LfBus bus1, LfBus bus2,
-                                                  LfNetworkParameters parameters) {
+                                                  boolean retainPtc, boolean retainRtc, LfNetworkParameters parameters) {
         PiModel piModel = null;
 
         double baseRatio = Transformers.getRatioPerUnitBase(twt);
@@ -122,8 +122,8 @@ private static LfBranchImpl createTransformer(TwoWindingsTransformer twt, LfNetw
 
         PhaseTapChanger ptc = twt.getPhaseTapChanger();
         if (ptc != null
-                && ptc.isRegulating()
-                && ptc.getRegulationMode() != PhaseTapChanger.RegulationMode.FIXED_TAP) {
+                && (ptc.isRegulating()
+                && ptc.getRegulationMode() != PhaseTapChanger.RegulationMode.FIXED_TAP || retainPtc)) {
             // we have a phase control, whatever we also have a voltage control or not, we create a pi model array
             // based on phase taps mixed with voltage current tap
             Integer rtcPosition = Transformers.getCurrentPosition(twt.getRatioTapChanger());
@@ -136,7 +136,7 @@ private static LfBranchImpl createTransformer(TwoWindingsTransformer twt, LfNetw
         }
 
         RatioTapChanger rtc = twt.getRatioTapChanger();
-        if (rtc != null && rtc.isRegulating() && rtc.hasLoadTapChangingCapabilities()) {
+        if (rtc != null && (rtc.isRegulating() && rtc.hasLoadTapChangingCapabilities() || retainRtc)) {
             if (piModel == null) {
                 // we have a voltage control, we create a pi model array based on voltage taps mixed with phase current
                 // tap
@@ -162,14 +162,16 @@ private static LfBranchImpl createTransformer(TwoWindingsTransformer twt, LfNetw
         return new LfBranchImpl(network, bus1, bus2, piModel, twt, parameters);
     }
 
-    public static LfBranchImpl create(Branch<?> branch, LfNetwork network, LfBus bus1, LfBus bus2, LfNetworkParameters parameters) {
+    public static LfBranchImpl create(Branch<?> branch, LfNetwork network, LfBus bus1, LfBus bus2, LfTopoConfig topoConfig,
+                                      LfNetworkParameters parameters) {
         Objects.requireNonNull(branch);
         Objects.requireNonNull(network);
         Objects.requireNonNull(parameters);
         if (branch instanceof Line line) {
             return createLine(line, network, bus1, bus2, parameters);
         } else if (branch instanceof TwoWindingsTransformer twt) {
-            return createTransformer(twt, network, bus1, bus2, parameters);
+            return createTransformer(twt, network, bus1, bus2, topoConfig.isRetainedPtc(twt.getId()),
+                    topoConfig.isRetainedRtc(twt.getId()), parameters);
         } else {
             throw new PowsyblException("Unsupported type of branch for flow equations of branch: " + branch.getId());
         }
diff --git a/src/main/java/com/powsybl/openloadflow/network/impl/LfLegBranch.java b/src/main/java/com/powsybl/openloadflow/network/impl/LfLegBranch.java
index 0bb5b6102c..c01fc3b255 100644
--- a/src/main/java/com/powsybl/openloadflow/network/impl/LfLegBranch.java
+++ b/src/main/java/com/powsybl/openloadflow/network/impl/LfLegBranch.java
@@ -39,8 +39,8 @@ private ThreeWindingsTransformer.Leg getLeg() {
         return legRef.get();
     }
 
-    public static LfLegBranch create(LfNetwork network, LfBus bus1, LfBus bus0, ThreeWindingsTransformer twt, ThreeWindingsTransformer.Leg leg,
-                                     LfNetworkParameters parameters) {
+    public static LfLegBranch create(LfNetwork network, LfBus bus1, LfBus bus0, ThreeWindingsTransformer twt,
+                                     ThreeWindingsTransformer.Leg leg, boolean retainPtc, boolean retainRtc, LfNetworkParameters parameters) {
         Objects.requireNonNull(bus0);
         Objects.requireNonNull(twt);
         Objects.requireNonNull(leg);
@@ -52,8 +52,8 @@ public static LfLegBranch create(LfNetwork network, LfBus bus1, LfBus bus0, Thre
         double baseRatio = Transformers.getRatioPerUnitBase(leg, twt);
         PhaseTapChanger ptc = leg.getPhaseTapChanger();
         if (ptc != null
-                && ptc.isRegulating()
-                && ptc.getRegulationMode() != PhaseTapChanger.RegulationMode.FIXED_TAP) {
+                && (ptc.isRegulating()
+                && ptc.getRegulationMode() != PhaseTapChanger.RegulationMode.FIXED_TAP || retainPtc)) {
             // we have a phase control, whatever we also have a voltage control or not, we create a pi model array
             // based on phase taps mixed with voltage current tap
             Integer rtcPosition = Transformers.getCurrentPosition(leg.getRatioTapChanger());
@@ -66,7 +66,7 @@ public static LfLegBranch create(LfNetwork network, LfBus bus1, LfBus bus0, Thre
         }
 
         RatioTapChanger rtc = leg.getRatioTapChanger();
-        if (rtc != null && rtc.isRegulating() && rtc.hasLoadTapChangingCapabilities()) {
+        if (rtc != null && (rtc.isRegulating() && rtc.hasLoadTapChangingCapabilities() || retainRtc)) {
             if (piModel == null) {
                 // we have a voltage control, we create a pi model array based on voltage taps mixed with phase current
                 // tap
diff --git a/src/main/java/com/powsybl/openloadflow/network/impl/LfNetworkLoaderImpl.java b/src/main/java/com/powsybl/openloadflow/network/impl/LfNetworkLoaderImpl.java
index c2882d5467..7b5b214247 100644
--- a/src/main/java/com/powsybl/openloadflow/network/impl/LfNetworkLoaderImpl.java
+++ b/src/main/java/com/powsybl/openloadflow/network/impl/LfNetworkLoaderImpl.java
@@ -360,12 +360,13 @@ private static void addBranch(LfNetwork lfNetwork, LfBranch lfBranch, LfNetworkL
         }
     }
 
-    private static void createBranches(List<LfBus> lfBuses, LfNetwork lfNetwork, LoadingContext loadingContext, LfNetworkLoadingReport report,
-                                       LfNetworkParameters parameters, List<LfNetworkLoaderPostProcessor> postProcessors) {
+    private static void createBranches(List<LfBus> lfBuses, LfNetwork lfNetwork, LfTopoConfig topoConfig, LoadingContext loadingContext,
+                                       LfNetworkLoadingReport report, LfNetworkParameters parameters,
+                                       List<LfNetworkLoaderPostProcessor> postProcessors) {
         for (Branch<?> branch : loadingContext.branchSet) {
             LfBus lfBus1 = getLfBus(branch.getTerminal1(), lfNetwork, parameters.isBreakers());
             LfBus lfBus2 = getLfBus(branch.getTerminal2(), lfNetwork, parameters.isBreakers());
-            LfBranchImpl lfBranch = LfBranchImpl.create(branch, lfNetwork, lfBus1, lfBus2, parameters);
+            LfBranchImpl lfBranch = LfBranchImpl.create(branch, lfNetwork, lfBus1, lfBus2, topoConfig, parameters);
             addBranch(lfNetwork, lfBranch, report);
             postProcessors.forEach(pp -> pp.onBranchAdded(branch, lfBranch));
         }
@@ -393,27 +394,23 @@ private static void createBranches(List<LfBus> lfBuses, LfNetwork lfNetwork, Loa
                         pp.onBusAdded(danglingLine, lfBus2);
                         pp.onBranchAdded(danglingLine, lfBranch);
                     });
-                });
+            });
         }
 
         for (ThreeWindingsTransformer t3wt : loadingContext.t3wtSet) {
             LfStarBus lfBus0 = new LfStarBus(lfNetwork, t3wt, parameters);
             lfNetwork.addBus(lfBus0);
-            LfBus lfBus1 = getLfBus(t3wt.getLeg1().getTerminal(), lfNetwork, parameters.isBreakers());
-            LfBus lfBus2 = getLfBus(t3wt.getLeg2().getTerminal(), lfNetwork, parameters.isBreakers());
-            LfBus lfBus3 = getLfBus(t3wt.getLeg3().getTerminal(), lfNetwork, parameters.isBreakers());
-            LfLegBranch lfBranch1 = LfLegBranch.create(lfNetwork, lfBus1, lfBus0, t3wt, t3wt.getLeg1(), parameters);
-            LfLegBranch lfBranch2 = LfLegBranch.create(lfNetwork, lfBus2, lfBus0, t3wt, t3wt.getLeg2(), parameters);
-            LfLegBranch lfBranch3 = LfLegBranch.create(lfNetwork, lfBus3, lfBus0, t3wt, t3wt.getLeg3(), parameters);
-            addBranch(lfNetwork, lfBranch1, report);
-            addBranch(lfNetwork, lfBranch2, report);
-            addBranch(lfNetwork, lfBranch3, report);
-            postProcessors.forEach(pp -> {
-                pp.onBusAdded(t3wt, lfBus0);
-                pp.onBranchAdded(t3wt, lfBranch1);
-                pp.onBranchAdded(t3wt, lfBranch2);
-                pp.onBranchAdded(t3wt, lfBranch3);
-            });
+            postProcessors.forEach(pp -> pp.onBusAdded(t3wt, lfBus0));
+            for (ThreeWindingsTransformer.Side side : ThreeWindingsTransformer.Side.values()) {
+                ThreeWindingsTransformer.Leg leg = t3wt.getLeg(side);
+                LfBus lfBus = getLfBus(leg.getTerminal(), lfNetwork, parameters.isBreakers());
+                LfLegBranch lfBranch = LfLegBranch.create(lfNetwork, lfBus, lfBus0, t3wt, leg,
+                        topoConfig.isRetainedPtc(LfLegBranch.getId(side, t3wt.getId())),
+                        topoConfig.isRetainedRtc(LfLegBranch.getId(side, t3wt.getId())),
+                        parameters);
+                addBranch(lfNetwork, lfBranch, report);
+                postProcessors.forEach(pp -> pp.onBranchAdded(t3wt, lfBranch));
+            }
         }
 
         if (parameters.isPhaseControl()) {
@@ -648,7 +645,7 @@ private static LfBus getLfBus(Terminal terminal, LfNetwork lfNetwork, boolean br
         return bus != null ? lfNetwork.getBusById(bus.getId()) : null;
     }
 
-    private LfNetwork create(int numCC, int numSC, Network network, List<Bus> buses, List<Switch> switches, LfNetworkParameters parameters, Reporter reporter) {
+    private LfNetwork create(int numCC, int numSC, Network network, List<Bus> buses, List<Switch> switches, LfTopoConfig topoConfig, LfNetworkParameters parameters, Reporter reporter) {
         LfNetwork lfNetwork = new LfNetwork(numCC, numSC, parameters.getSlackBusSelector(), parameters.getMaxSlackBusCount(),
                 parameters.getConnectivityFactory(), reporter);
 
@@ -661,7 +658,7 @@ private LfNetwork create(int numCC, int numSC, Network network, List<Bus> buses,
 
         List<LfBus> lfBuses = new ArrayList<>();
         createBuses(buses, parameters, lfNetwork, lfBuses, loadingContext, report, postProcessors);
-        createBranches(lfBuses, lfNetwork, loadingContext, report, parameters, postProcessors);
+        createBranches(lfBuses, lfNetwork, topoConfig, loadingContext, report, parameters, postProcessors);
 
         if (parameters.getLoadFlowModel() == LoadFlowModel.AC) {
             createVoltageControls(lfBuses, parameters);
@@ -849,7 +846,7 @@ private static void createVoltageAngleLimits(Network network, LfNetwork lfNetwor
     }
 
     @Override
-    public List<LfNetwork> load(Network network, LfNetworkParameters parameters, Reporter reporter) {
+    public List<LfNetwork> load(Network network, LfTopoConfig topoConfig, LfNetworkParameters parameters, Reporter reporter) {
         Objects.requireNonNull(network);
         Objects.requireNonNull(parameters);
 
@@ -895,8 +892,8 @@ public List<LfNetwork> load(Network network, LfNetworkParameters parameters, Rep
                     int numCc = networkKey.getLeft();
                     int numSc = networkKey.getRight();
                     List<Bus> lfBuses = e.getValue();
-                    return create(numCc, numSc, network, lfBuses, switchesByCc.get(networkKey), parameters,
-                            Reports.createLfNetworkReporter(reporter, numCc, numSc));
+                    return create(numCc, numSc, network, lfBuses, switchesByCc.get(networkKey), topoConfig,
+                            parameters, Reports.createLfNetworkReporter(reporter, numCc, numSc));
                 })
                 .collect(Collectors.toList());
 
diff --git a/src/main/java/com/powsybl/openloadflow/network/impl/Networks.java b/src/main/java/com/powsybl/openloadflow/network/impl/Networks.java
index f8b3d3cea7..46d15c1628 100644
--- a/src/main/java/com/powsybl/openloadflow/network/impl/Networks.java
+++ b/src/main/java/com/powsybl/openloadflow/network/impl/Networks.java
@@ -106,6 +106,10 @@ public static List<LfNetwork> load(Network network, LfNetworkParameters paramete
         return LfNetwork.load(network, new LfNetworkLoaderImpl(), parameters, reporter);
     }
 
+    public static List<LfNetwork> load(Network network, LfTopoConfig topoConfig, LfNetworkParameters parameters, Reporter reporter) {
+        return LfNetwork.load(network, new LfNetworkLoaderImpl(), topoConfig, parameters, reporter);
+    }
+
     private static void retainAndCloseNecessarySwitches(Network network, LfTopoConfig topoConfig) {
         network.getSwitchStream()
                 .filter(sw -> sw.getVoltageLevel().getTopologyKind() == TopologyKind.NODE_BREAKER)
@@ -145,7 +149,7 @@ public static LfNetworkList load(Network network, LfNetworkParameters networkPar
     public static LfNetworkList load(Network network, LfNetworkParameters networkParameters, LfTopoConfig topoConfig,
                                      LfNetworkList.VariantCleanerFactory variantCleanerFactory, Reporter reporter) {
         if (!topoConfig.isBreaker()) {
-            return new LfNetworkList(load(network, networkParameters, reporter));
+            return new LfNetworkList(load(network, topoConfig, networkParameters, reporter));
         } else {
             if (!networkParameters.isBreakers()) {
                 throw new PowsyblException("LF networks have to be built from bus/breaker view");
@@ -160,7 +164,7 @@ public static LfNetworkList load(Network network, LfNetworkParameters networkPar
             // and close switches that could be closed during the simulation
             retainAndCloseNecessarySwitches(network, topoConfig);
 
-            List<LfNetwork> lfNetworks = load(network, networkParameters, reporter);
+            List<LfNetwork> lfNetworks = load(network, topoConfig, networkParameters, reporter);
 
             if (!topoConfig.getSwitchesToClose().isEmpty()) {
                 for (LfNetwork lfNetwork : lfNetworks) {
diff --git a/src/main/java/com/powsybl/openloadflow/sa/AbstractSecurityAnalysis.java b/src/main/java/com/powsybl/openloadflow/sa/AbstractSecurityAnalysis.java
index b6dd4d992e..2d9096a578 100644
--- a/src/main/java/com/powsybl/openloadflow/sa/AbstractSecurityAnalysis.java
+++ b/src/main/java/com/powsybl/openloadflow/sa/AbstractSecurityAnalysis.java
@@ -12,8 +12,7 @@
 import com.powsybl.computation.CompletableFutureTask;
 import com.powsybl.computation.ComputationManager;
 import com.powsybl.contingency.ContingenciesProvider;
-import com.powsybl.iidm.network.Network;
-import com.powsybl.iidm.network.Switch;
+import com.powsybl.iidm.network.*;
 import com.powsybl.loadflow.LoadFlowResult;
 import com.powsybl.math.matrix.MatrixFactory;
 import com.powsybl.openloadflow.ac.nr.NewtonRaphsonStatus;
@@ -22,7 +21,7 @@
 import com.powsybl.openloadflow.lf.AbstractLoadFlowParameters;
 import com.powsybl.openloadflow.lf.LoadFlowContext;
 import com.powsybl.openloadflow.network.*;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
+import com.powsybl.openloadflow.network.impl.LfLegBranch;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import com.powsybl.security.*;
 import com.powsybl.security.action.*;
@@ -128,11 +127,13 @@ protected static void checkActions(Network network, List<Action> actions) {
                     break;
                 }
 
-                case PhaseTapChangerTapPositionAction.NAME: {
-                    PhaseTapChangerTapPositionAction phaseTapChangerTapPositionAction = (PhaseTapChangerTapPositionAction) action;
-                    if (network.getTwoWindingsTransformer(phaseTapChangerTapPositionAction.getTransformerId()) == null
-                            && network.getThreeWindingsTransformer(phaseTapChangerTapPositionAction.getTransformerId()) == null) {
-                        throw new PowsyblException("Transformer '" + phaseTapChangerTapPositionAction.getTransformerId() + NOT_FOUND);
+                case PhaseTapChangerTapPositionAction.NAME,
+                     RatioTapChangerTapPositionAction.NAME: {
+                    String transformerId = action.getType().equals(PhaseTapChangerTapPositionAction.NAME) ?
+                            ((PhaseTapChangerTapPositionAction) action).getTransformerId() : ((RatioTapChangerTapPositionAction) action).getTransformerId();
+                    if (network.getTwoWindingsTransformer(transformerId) == null
+                            && network.getThreeWindingsTransformer(transformerId) == null) {
+                        throw new PowsyblException("Transformer '" + transformerId + NOT_FOUND);
                     }
                     break;
                 }
@@ -268,6 +269,30 @@ protected static void findAllSwitchesToOperate(Network network, List<Action> act
                 });
     }
 
+    protected static void findAllPtcToOperate(List<Action> actions, LfTopoConfig topoConfig) {
+        for (Action action : actions) {
+            if (PhaseTapChangerTapPositionAction.NAME.equals(action.getType())) {
+                PhaseTapChangerTapPositionAction ptcAction = (PhaseTapChangerTapPositionAction) action;
+                ptcAction.getSide().ifPresentOrElse(
+                        side -> topoConfig.addBranchIdsWithPtcToRetain(LfLegBranch.getId(side, ptcAction.getTransformerId())), // T3WT
+                        () -> topoConfig.addBranchIdsWithPtcToRetain(ptcAction.getTransformerId()) // T2WT
+                );
+            }
+        }
+    }
+
+    protected static void findAllRtcToOperate(List<Action> actions, LfTopoConfig topoConfig) {
+        for (Action action : actions) {
+            if (RatioTapChangerTapPositionAction.NAME.equals(action.getType())) {
+                RatioTapChangerTapPositionAction rtcAction = (RatioTapChangerTapPositionAction) action;
+                rtcAction.getSide().ifPresentOrElse(
+                        side -> topoConfig.addBranchIdsWithRtcToRetain(LfLegBranch.getId(side, rtcAction.getTransformerId())), // T3WT
+                        () -> topoConfig.addBranchIdsWithRtcToRetain(rtcAction.getTransformerId()) // T2WT
+                );
+            }
+        }
+    }
+
     protected OperatorStrategyResult runActionSimulation(LfNetwork network, C context, OperatorStrategy operatorStrategy,
                                                          List<String> actionsIds,
                                                          LimitViolationManager preContingencyLimitViolationManager,
diff --git a/src/main/java/com/powsybl/openloadflow/sa/AcSecurityAnalysis.java b/src/main/java/com/powsybl/openloadflow/sa/AcSecurityAnalysis.java
index 9f6d3ba4a7..2fcf337a08 100644
--- a/src/main/java/com/powsybl/openloadflow/sa/AcSecurityAnalysis.java
+++ b/src/main/java/com/powsybl/openloadflow/sa/AcSecurityAnalysis.java
@@ -26,7 +26,6 @@
 import com.powsybl.openloadflow.graph.GraphConnectivityFactory;
 import com.powsybl.openloadflow.network.*;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import com.powsybl.openloadflow.network.util.ActivePowerDistribution;
@@ -80,6 +79,10 @@ SecurityAnalysisReport runSync(String workingVariantId, SecurityAnalysisParamete
         LfTopoConfig topoConfig = new LfTopoConfig();
         findAllSwitchesToOperate(network, actions, topoConfig);
 
+        // try to find all pst and rtc to retain because involved in pst and rtc actions
+        findAllPtcToOperate(actions, topoConfig);
+        findAllRtcToOperate(actions, topoConfig);
+
         // load contingencies
         List<Contingency> contingencies = contingenciesProvider.getContingencies(network);
         // try to find all switches impacted by at least one contingency and for each contingency the branches impacted
@@ -95,7 +98,6 @@ SecurityAnalysisReport runSync(String workingVariantId, SecurityAnalysisParamete
 
         // create networks including all necessary switches
         try (LfNetworkList lfNetworks = Networks.load(network, acParameters.getNetworkParameters(), topoConfig, saReporter)) {
-
             // complete definition of contingencies after network loading
             PropagatedContingency.completeList(propagatedContingencies, lfParameters.isShuntCompensatorVoltageControlOn(),
                     lfParameters.getBalanceType() == LoadFlowParameters.BalanceType.PROPORTIONAL_TO_CONFORM_LOAD, lfParameters.isHvdcAcEmulation(), breakers);
diff --git a/src/main/java/com/powsybl/openloadflow/sa/DcSecurityAnalysis.java b/src/main/java/com/powsybl/openloadflow/sa/DcSecurityAnalysis.java
index b4cd5d7b3f..315749e54e 100644
--- a/src/main/java/com/powsybl/openloadflow/sa/DcSecurityAnalysis.java
+++ b/src/main/java/com/powsybl/openloadflow/sa/DcSecurityAnalysis.java
@@ -24,7 +24,6 @@
 import com.powsybl.openloadflow.graph.GraphConnectivityFactory;
 import com.powsybl.openloadflow.network.*;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import com.powsybl.openloadflow.sensi.OpenSensitivityAnalysisProvider;
@@ -236,6 +235,9 @@ private List<OperatorStrategyResult> createOperatorStrategyResults(DcSecurityAna
         LfTopoConfig topoConfig = new LfTopoConfig();
         findAllSwitchesToOperate(network, actions, topoConfig);
 
+        // try to find all pst to retain because involved in pst actions
+        findAllPtcToOperate(actions, topoConfig);
+
         List<PropagatedContingency> propagatedContingencies = PropagatedContingency.createList(network, context.getContingencies(), topoConfig, false);
 
         Map<String, Action> actionsById = indexActionsById(actions);
diff --git a/src/main/java/com/powsybl/openloadflow/sensi/AcSensitivityAnalysis.java b/src/main/java/com/powsybl/openloadflow/sensi/AcSensitivityAnalysis.java
index 3de5d183b6..0779033395 100644
--- a/src/main/java/com/powsybl/openloadflow/sensi/AcSensitivityAnalysis.java
+++ b/src/main/java/com/powsybl/openloadflow/sensi/AcSensitivityAnalysis.java
@@ -24,7 +24,6 @@
 import com.powsybl.openloadflow.graph.GraphConnectivityFactory;
 import com.powsybl.openloadflow.network.*;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import com.powsybl.openloadflow.network.util.ActivePowerDistribution;
diff --git a/src/main/java/com/powsybl/openloadflow/sensi/DcSensitivityAnalysis.java b/src/main/java/com/powsybl/openloadflow/sensi/DcSensitivityAnalysis.java
index 8adbf80404..56377ee5c3 100644
--- a/src/main/java/com/powsybl/openloadflow/sensi/DcSensitivityAnalysis.java
+++ b/src/main/java/com/powsybl/openloadflow/sensi/DcSensitivityAnalysis.java
@@ -30,7 +30,6 @@
 import com.powsybl.openloadflow.graph.GraphConnectivityFactory;
 import com.powsybl.openloadflow.network.*;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import com.powsybl.openloadflow.network.util.ParticipatingElement;
diff --git a/src/main/java/com/powsybl/openloadflow/sensi/OpenSensitivityAnalysisProvider.java b/src/main/java/com/powsybl/openloadflow/sensi/OpenSensitivityAnalysisProvider.java
index 70fc930340..2b8ff24fc8 100644
--- a/src/main/java/com/powsybl/openloadflow/sensi/OpenSensitivityAnalysisProvider.java
+++ b/src/main/java/com/powsybl/openloadflow/sensi/OpenSensitivityAnalysisProvider.java
@@ -30,7 +30,7 @@
 import com.powsybl.openloadflow.graph.GraphConnectivityFactory;
 import com.powsybl.openloadflow.network.LfBranch;
 import com.powsybl.openloadflow.network.LfBus;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
+import com.powsybl.openloadflow.network.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import com.powsybl.openloadflow.util.DebugUtil;
 import com.powsybl.openloadflow.util.ProviderConstants;
diff --git a/src/test/java/com/powsybl/openloadflow/ZeroImpedanceFlowsTest.java b/src/test/java/com/powsybl/openloadflow/ZeroImpedanceFlowsTest.java
index 1b53284c1b..b28bc261e3 100644
--- a/src/test/java/com/powsybl/openloadflow/ZeroImpedanceFlowsTest.java
+++ b/src/test/java/com/powsybl/openloadflow/ZeroImpedanceFlowsTest.java
@@ -18,7 +18,6 @@
 import com.powsybl.openloadflow.graph.NaiveGraphConnectivityFactory;
 import com.powsybl.openloadflow.network.*;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
diff --git a/src/test/java/com/powsybl/openloadflow/ac/NonImpedantBranchDisablingTest.java b/src/test/java/com/powsybl/openloadflow/ac/NonImpedantBranchDisablingTest.java
index 77af8e7800..663b2e1e15 100644
--- a/src/test/java/com/powsybl/openloadflow/ac/NonImpedantBranchDisablingTest.java
+++ b/src/test/java/com/powsybl/openloadflow/ac/NonImpedantBranchDisablingTest.java
@@ -20,7 +20,6 @@
 import com.powsybl.openloadflow.network.*;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
 import com.powsybl.openloadflow.network.impl.LfNetworkLoaderImpl;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import com.powsybl.openloadflow.util.LoadFlowAssert;
 import com.powsybl.openloadflow.util.PerUnit;
diff --git a/src/test/java/com/powsybl/openloadflow/dc/DcLoadFlowTest.java b/src/test/java/com/powsybl/openloadflow/dc/DcLoadFlowTest.java
index 2698700d0e..efa0e72f58 100644
--- a/src/test/java/com/powsybl/openloadflow/dc/DcLoadFlowTest.java
+++ b/src/test/java/com/powsybl/openloadflow/dc/DcLoadFlowTest.java
@@ -19,7 +19,6 @@
 import com.powsybl.openloadflow.dc.equations.DcEquationSystemCreationParameters;
 import com.powsybl.openloadflow.network.*;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import com.powsybl.openloadflow.util.LoadFlowAssert;
 import com.powsybl.openloadflow.util.PerUnit;
diff --git a/src/test/java/com/powsybl/openloadflow/sa/LfActionTest.java b/src/test/java/com/powsybl/openloadflow/sa/LfActionTest.java
index af65a92b88..8405b9c374 100644
--- a/src/test/java/com/powsybl/openloadflow/sa/LfActionTest.java
+++ b/src/test/java/com/powsybl/openloadflow/sa/LfActionTest.java
@@ -20,7 +20,6 @@
 import com.powsybl.openloadflow.graph.NaiveGraphConnectivityFactory;
 import com.powsybl.openloadflow.network.*;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import com.powsybl.openloadflow.util.PerUnit;
diff --git a/src/test/java/com/powsybl/openloadflow/sa/LfContingencyTest.java b/src/test/java/com/powsybl/openloadflow/sa/LfContingencyTest.java
index c0ebda65dc..63a3c07941 100644
--- a/src/test/java/com/powsybl/openloadflow/sa/LfContingencyTest.java
+++ b/src/test/java/com/powsybl/openloadflow/sa/LfContingencyTest.java
@@ -20,7 +20,6 @@
 import com.powsybl.openloadflow.graph.EvenShiloachGraphDecrementalConnectivityFactory;
 import com.powsybl.openloadflow.graph.GraphConnectivityFactory;
 import com.powsybl.openloadflow.network.*;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import org.junit.jupiter.api.AfterEach;
diff --git a/src/test/java/com/powsybl/openloadflow/sa/OpenSecurityAnalysisGraphTest.java b/src/test/java/com/powsybl/openloadflow/sa/OpenSecurityAnalysisGraphTest.java
index dfada545a8..bedf1c95fe 100644
--- a/src/test/java/com/powsybl/openloadflow/sa/OpenSecurityAnalysisGraphTest.java
+++ b/src/test/java/com/powsybl/openloadflow/sa/OpenSecurityAnalysisGraphTest.java
@@ -17,7 +17,6 @@
 import com.powsybl.openloadflow.graph.NaiveGraphConnectivityFactory;
 import com.powsybl.openloadflow.network.*;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.Networks;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import org.junit.jupiter.api.BeforeEach;
diff --git a/src/test/java/com/powsybl/openloadflow/sa/OpenSecurityAnalysisWithActionsTest.java b/src/test/java/com/powsybl/openloadflow/sa/OpenSecurityAnalysisWithActionsTest.java
index cefb9e238c..f6a964f37e 100644
--- a/src/test/java/com/powsybl/openloadflow/sa/OpenSecurityAnalysisWithActionsTest.java
+++ b/src/test/java/com/powsybl/openloadflow/sa/OpenSecurityAnalysisWithActionsTest.java
@@ -9,10 +9,7 @@
 import com.powsybl.commons.reporter.Reporter;
 import com.powsybl.commons.reporter.ReporterModel;
 import com.powsybl.contingency.*;
-import com.powsybl.iidm.network.HvdcLine;
-import com.powsybl.iidm.network.Network;
-import com.powsybl.iidm.network.PhaseTapChanger;
-import com.powsybl.iidm.network.ThreeWindingsTransformer;
+import com.powsybl.iidm.network.*;
 import com.powsybl.iidm.network.extensions.HvdcAngleDroopActivePowerControlAdder;
 import com.powsybl.iidm.xml.test.MetrixTutorialSixBusesFactory;
 import com.powsybl.loadflow.LoadFlowParameters;
@@ -39,10 +36,7 @@
 import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Set;
+import java.util.*;
 import java.util.concurrent.CompletionException;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -1137,6 +1131,86 @@ void testPhaseTapChangerActionThreeWindingsTransformer() {
                 new TrueCondition(), List.of("pst_leg_1")));
         CompletionException exception = assertThrows(CompletionException.class, () -> runSecurityAnalysis(network, contingencies, monitors, securityAnalysisParameters,
                 operatorStrategies1, actions1, Reporter.NO_OP));
-        assertEquals("Phase tap changer tap connection action: only one tap in branch PS1_leg_1", exception.getCause().getMessage());
+        assertEquals("Tap position action: only one tap in branch PS1_leg_1", exception.getCause().getMessage());
+    }
+
+    @Test
+    void testActionOnRetainedPtc() {
+        Network network = PhaseControlFactory.createNetworkWithT2wt();
+        network.newLine()
+                .setId("L3")
+                .setVoltageLevel1("VL1")
+                .setBus1("B1")
+                .setVoltageLevel2("VL2")
+                .setBus2("B2")
+                .setR(4.0)
+                .setX(200.0)
+                .add();
+
+        List<Contingency> contingencies = List.of(new Contingency("CL3", new BranchContingency("L3")));
+        List<StateMonitor> monitors = createAllBranchesMonitors(network);
+        List<Action> actions = List.of(new PhaseTapChangerTapPositionAction("Aps1", "PS1", false, 2));
+        List<OperatorStrategy> operatorStrategies = List.of(new OperatorStrategy("strategy1", ContingencyContext.specificContingency("CL3"), new TrueCondition(), List.of("Aps1")));
+        SecurityAnalysisResult result = runSecurityAnalysis(network, contingencies, monitors, new SecurityAnalysisParameters(),
+                operatorStrategies, actions, Reporter.NO_OP);
+
+        network.getLine("L3").getTerminal1().disconnect();
+        network.getLine("L3").getTerminal2().disconnect();
+        network.getTwoWindingsTransformer("PS1").getPhaseTapChanger().setTapPosition(2);
+        loadFlowRunner.run(network);
+
+        assertEquals(network.getLine("L1").getTerminal1().getP(), getOperatorStrategyResult(result, "strategy1").getNetworkResult().getBranchResult("L1").getP1(), LoadFlowAssert.DELTA_POWER);
+        assertEquals(network.getLine("L1").getTerminal2().getP(), getOperatorStrategyResult(result, "strategy1").getNetworkResult().getBranchResult("L1").getP2(), LoadFlowAssert.DELTA_POWER);
+        assertEquals(network.getLine("L2").getTerminal1().getP(), getOperatorStrategyResult(result, "strategy1").getNetworkResult().getBranchResult("L2").getP1(), LoadFlowAssert.DELTA_POWER);
+        assertEquals(network.getLine("L2").getTerminal2().getP(), getOperatorStrategyResult(result, "strategy1").getNetworkResult().getBranchResult("L2").getP2(), LoadFlowAssert.DELTA_POWER);
+    }
+
+    @Test
+    void testActionOnRetainedT3wtPtc() {
+        Network network = PhaseControlFactory.createNetworkWithT3wt();
+        network.newLine()
+                .setId("L3")
+                .setVoltageLevel1("VL1")
+                .setBus1("B1")
+                .setVoltageLevel2("VL2")
+                .setBus2("B2")
+                .setR(4.0)
+                .setX(200.0)
+                .add();
+
+        List<Contingency> contingencies = List.of(new Contingency("CL3", new BranchContingency("L3")));
+        List<StateMonitor> monitors = createAllBranchesMonitors(network);
+        List<Action> actions = List.of(new PhaseTapChangerTapPositionAction("Aps1", "PS1", false, 2, ThreeWindingsTransformer.Side.TWO));
+        List<OperatorStrategy> operatorStrategies = List.of(new OperatorStrategy("strategy1", ContingencyContext.specificContingency("CL3"), new TrueCondition(), List.of("Aps1")));
+        SecurityAnalysisResult result = runSecurityAnalysis(network, contingencies, monitors, new SecurityAnalysisParameters(),
+                operatorStrategies, actions, Reporter.NO_OP);
+
+        network.getLine("L3").getTerminal1().disconnect();
+        network.getLine("L3").getTerminal2().disconnect();
+        network.getThreeWindingsTransformer("PS1").getLeg2().getPhaseTapChanger().setTapPosition(2);
+        loadFlowRunner.run(network);
+
+        assertEquals(network.getLine("L1").getTerminal1().getP(), getOperatorStrategyResult(result, "strategy1").getNetworkResult().getBranchResult("L1").getP1(), LoadFlowAssert.DELTA_POWER);
+        assertEquals(network.getLine("L1").getTerminal2().getP(), getOperatorStrategyResult(result, "strategy1").getNetworkResult().getBranchResult("L1").getP2(), LoadFlowAssert.DELTA_POWER);
+        assertEquals(network.getLine("L2").getTerminal1().getP(), getOperatorStrategyResult(result, "strategy1").getNetworkResult().getBranchResult("L2").getP1(), LoadFlowAssert.DELTA_POWER);
+        assertEquals(network.getLine("L2").getTerminal2().getP(), getOperatorStrategyResult(result, "strategy1").getNetworkResult().getBranchResult("L2").getP2(), LoadFlowAssert.DELTA_POWER);
+    }
+
+    @Test
+    void testActionOnRetainedRtc() {
+        Network network = VoltageControlNetworkFactory.createNetworkWithT2wt();
+        List<Contingency> contingencies = List.of(new Contingency("contingency", new LoadContingency("LOAD_2")));
+        List<StateMonitor> monitors = createNetworkMonitors(network);
+        List<Action> actions = List.of(new RatioTapChangerTapPositionAction("action", "T2wT", false, 2));
+        List<OperatorStrategy> operatorStrategies = List.of(new OperatorStrategy("strategy", ContingencyContext.specificContingency("contingency"), new TrueCondition(), List.of("action")));
+        SecurityAnalysisResult result = runSecurityAnalysis(network, contingencies, monitors, new SecurityAnalysisParameters(),
+                operatorStrategies, actions, Reporter.NO_OP);
+
+        network.getLoad("LOAD_2").getTerminal().disconnect();
+        network.getTwoWindingsTransformer("T2wT").getRatioTapChanger().setTapPosition(2);
+        loadFlowRunner.run(network);
+
+        assertEquals(network.getBusBreakerView().getBus("BUS_2").getV(),
+                getOperatorStrategyResult(result, "strategy").getNetworkResult().getBusResult("BUS_2").getV(), LoadFlowAssert.DELTA_POWER);
     }
 }
diff --git a/src/test/java/com/powsybl/openloadflow/sensi/DcSensitivityAnalysisTest.java b/src/test/java/com/powsybl/openloadflow/sensi/DcSensitivityAnalysisTest.java
index 63659a7212..879e5accb2 100644
--- a/src/test/java/com/powsybl/openloadflow/sensi/DcSensitivityAnalysisTest.java
+++ b/src/test/java/com/powsybl/openloadflow/sensi/DcSensitivityAnalysisTest.java
@@ -21,7 +21,6 @@
 import com.powsybl.openloadflow.equations.EquationSystem;
 import com.powsybl.openloadflow.equations.EquationSystemIndex;
 import com.powsybl.openloadflow.network.*;
-import com.powsybl.openloadflow.network.impl.LfTopoConfig;
 import com.powsybl.openloadflow.network.impl.PropagatedContingency;
 import com.powsybl.openloadflow.util.LoadFlowAssert;
 import com.powsybl.sensitivity.*;