From 6c8bce1b9d342645b751a3e396f15d9ea3423c40 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20LAIGRE?= <slaigre@silicom.fr>
Date: Fri, 28 May 2021 09:35:01 +0200
Subject: [PATCH] Fix multiple connect/disconnect in NodeBreakerVoltageLevel to
 avoid unwanted topology change (#285)
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Signed-off-by: Sébastien LAIGRE <slaigre@silicom.fr>
---
 src/iidm/NodeBreakerVoltageLevel.cpp |   8 ++
 test/iidm/CMakeLists.txt             |   1 +
 test/iidm/NodeBreakerConnectTest.cpp | 182 +++++++++++++++++++++++++++
 3 files changed, 191 insertions(+)
 create mode 100644 test/iidm/NodeBreakerConnectTest.cpp

diff --git a/src/iidm/NodeBreakerVoltageLevel.cpp b/src/iidm/NodeBreakerVoltageLevel.cpp
index 4dd8b852..ce99a0c3 100644
--- a/src/iidm/NodeBreakerVoltageLevel.cpp
+++ b/src/iidm/NodeBreakerVoltageLevel.cpp
@@ -86,6 +86,10 @@ void NodeBreakerVoltageLevel::clean() {
 bool NodeBreakerVoltageLevel::connect(Terminal& terminal) {
     auto& nodeTerminal = dynamic_cast<NodeTerminal&>(terminal);
 
+    if (terminal.isConnected()) {
+        return false;
+    }
+
     unsigned long node = nodeTerminal.getNode();
 
     // find all paths starting from the current terminal to a busbar section that does not contain an open disconnector
@@ -135,6 +139,10 @@ void NodeBreakerVoltageLevel::detach(Terminal& terminal) {
 bool NodeBreakerVoltageLevel::disconnect(Terminal& terminal) {
     auto& nodeTerminal = dynamic_cast<NodeTerminal&>(terminal);
 
+    if (!terminal.isConnected()) {
+        return false;
+    }
+
     unsigned long node = nodeTerminal.getNode();
 
     // find all paths starting from the current terminal to a busbar section that does not contain an open disconnector
diff --git a/test/iidm/CMakeLists.txt b/test/iidm/CMakeLists.txt
index 0a031e9b..8afb0cb1 100644
--- a/test/iidm/CMakeLists.txt
+++ b/test/iidm/CMakeLists.txt
@@ -29,6 +29,7 @@ set(UNIT_TEST_SOURCES
     NetworkFactory.cpp
     NetworkIndexTest.cpp
     NetworkTest.cpp
+    NodeBreakerConnectTest.cpp
     NodeBreakerVoltageLevelTest.cpp
     PhaseTapChangerTest.cpp
     RatioTapChangerTest.cpp
diff --git a/test/iidm/NodeBreakerConnectTest.cpp b/test/iidm/NodeBreakerConnectTest.cpp
new file mode 100644
index 00000000..56404995
--- /dev/null
+++ b/test/iidm/NodeBreakerConnectTest.cpp
@@ -0,0 +1,182 @@
+/**
+ * Copyright (c) 2021, RTE (http://www.rte-france.com)
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * 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/.
+ */
+
+#include <boost/test/unit_test.hpp>
+
+#include <powsybl/iidm/Generator.hpp>
+#include <powsybl/iidm/GeneratorAdder.hpp>
+#include <powsybl/iidm/Load.hpp>
+#include <powsybl/iidm/LoadAdder.hpp>
+#include <powsybl/iidm/Network.hpp>
+#include <powsybl/iidm/Substation.hpp>
+#include <powsybl/iidm/SubstationAdder.hpp>
+#include <powsybl/iidm/Switch.hpp>
+#include <powsybl/iidm/SwitchAdder.hpp>
+#include <powsybl/iidm/TopologyKind.hpp>
+#include <powsybl/iidm/VoltageLevel.hpp>
+#include <powsybl/iidm/VoltageLevelAdder.hpp>
+
+namespace powsybl {
+
+namespace iidm {
+
+/**
+ * <pre>
+ *           LD        G
+ *           |    B1   |
+ *           |---[+]---|
+ *       B2 [-]       [+] B3
+ *           |    C    |
+ *  BBS1 --------[-]-------- BBS2
+ * </pre>
+ */
+Network createNbkNetwork() {
+    Network network("test", "test");
+    Substation& s = network.newSubstation()
+        .setId("S")
+        .setCountry(Country::FR)
+        .add();
+    VoltageLevel& vl = s.newVoltageLevel()
+        .setId("VL")
+        .setNominalV(400.0)
+        .setTopologyKind(TopologyKind::NODE_BREAKER)
+        .add();
+    vl.getNodeBreakerView().newBusbarSection()
+        .setId("BBS1")
+        .setNode(0)
+        .add();
+    vl.getNodeBreakerView().newBusbarSection()
+        .setId("BBS2")
+        .setNode(1)
+        .add();
+    vl.getNodeBreakerView().newBreaker()
+        .setId("C")
+        .setNode1(1)
+        .setNode2(0)
+        .setOpen(true)
+        .add();
+    vl.getNodeBreakerView().newBreaker()
+        .setId("B2")
+        .setNode1(0)
+        .setNode2(2)
+        .setOpen(true)
+        .add();
+    vl.getNodeBreakerView().newBreaker()
+        .setId("B1")
+        .setNode1(2)
+        .setNode2(3)
+        .setOpen(false)
+        .add();
+    vl.getNodeBreakerView().newBreaker()
+        .setId("B3")
+        .setNode1(3)
+        .setNode2(1)
+        .setOpen(false)
+        .add();
+    vl.newLoad()
+        .setId("LD")
+        .setNode(2)
+        .setP0(1)
+        .setQ0(1)
+        .add();
+    vl.newGenerator()
+        .setId("G")
+        .setNode(3)
+        .setMinP(-9999.99)
+        .setMaxP(9999.99)
+        .setVoltageRegulatorOn(true)
+        .setTargetV(400)
+        .setTargetP(1)
+        .setTargetQ(0)
+        .add();
+    return network;
+}
+
+/**
+ * <pre>
+ *     L
+ *     |
+ *  ---1---
+ *  |     |
+ * BR1   BR2
+ *  |     |
+ *  ---0--- BBS1
+ * </pre>
+ */
+Network createDiamondNetwork() {
+    Network network("test", "test");
+    Substation& s = network.newSubstation()
+        .setId("S")
+        .setCountry(Country::FR)
+        .add();
+    VoltageLevel& vl = s.newVoltageLevel()
+        .setId("VL")
+        .setNominalV(400.0)
+        .setTopologyKind(TopologyKind::NODE_BREAKER)
+        .add();
+    vl.getNodeBreakerView().newBusbarSection()
+        .setId("BBS1")
+        .setNode(0)
+        .add();
+    vl.newLoad()
+        .setId("L")
+        .setNode(1)
+        .setP0(1)
+        .setQ0(1)
+        .add();
+    vl.getNodeBreakerView().newBreaker()
+        .setId("BR1")
+        .setNode1(1)
+        .setNode2(0)
+        .setOpen(false)
+        .add();
+    vl.getNodeBreakerView().newBreaker()
+        .setId("BR2")
+        .setNode1(1)
+        .setNode2(0)
+        .setOpen(false)
+        .add();
+    return network;
+}
+
+BOOST_AUTO_TEST_SUITE(NetworkTestSuite)
+
+BOOST_AUTO_TEST_CASE(NodeBreakerConnectConnectedLoad) {
+    Network network = createNbkNetwork();
+    Load& l = network.getLoad("LD");
+    BOOST_CHECK(l.getTerminal().isConnected());
+    BOOST_CHECK(network.getSwitch("B2").isOpen());
+
+    l.getTerminal().connect();
+    BOOST_CHECK(network.getSwitch("B2").isOpen());
+    BOOST_CHECK(l.getTerminal().isConnected());
+}
+
+BOOST_AUTO_TEST_CASE(NodeBreakerDisconnectDisconnectedLoad) {
+    Network network = createNbkNetwork();
+    network.getSwitch("B3").setOpen(true);
+    Load& l = network.getLoad("LD");
+    BOOST_CHECK(!l.getTerminal().isConnected());
+
+    l.getTerminal().disconnect();
+    BOOST_CHECK(!network.getSwitch("B1").isOpen());
+    BOOST_CHECK(!l.getTerminal().isConnected());
+}
+
+BOOST_AUTO_TEST_CASE(NodeBreakerDisconnectionDiamond) {
+    Network network = createDiamondNetwork();
+    Load& l = network.getLoad("L");
+    BOOST_CHECK(l.getTerminal().isConnected());
+    l.getTerminal().disconnect();
+    BOOST_CHECK(!l.getTerminal().isConnected());
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}  // namespace iidm
+
+}  // namespace powsybl