[Flow decomposition] Observer, NetworkUtil and Losses compensator imp…

…rovements (#147)

improved Observer, NetworkUtil and Losses compensator

Signed-off-by: Caio Luke <caioluke97@gmail.com>

docs/flow_decomposition/algorithm-description.md

@@ -33,6 +33,15 @@ compensated at both sides proportionally to the resistance of each half line.
 
 ## Nodal Injections partitioning
 
+> **_NOTE:_** In PowSyBl terminology, nodal injections are injection connectables that 
+> - are not paired dangling lines, 
+> - are connected to the network,
+> - are in the main synchronous component (for sensitivity computation reasons),
+> - are not a bus bar section (because of a lack of reference injection),
+> - are not shunt compensator or static var compensator (for sensitivity computation reasons).
+
+> **_NOTE:_** In PowSyBl terminology, xnodes are unpaired dangling lines connected to the network and in the main synchronous component. 
+
 In order to distinguish internal/loop flows and allocated flows, the nodal injections in each zone must de decomposed in two parts:
 - Nodal injections for allocated flows
 - Nodal injections for loop flows and internal flows
@@ -63,6 +72,16 @@ where:
 
 ## Sensitivity analysis
 
+> **_NOTE:_** In PowSyBl terminology, only two windings transformers are considered. PSTs must:
+> - be connected to the network,
+> - have a phase tap changer,
+> - have a neutral step on the phase tap changer,
+> - have a bus at each terminal,
+> - be connected to the main synchronous component.
+> Therefore, three windings transformers are not supported. 
+
+> **_NOTE:_** Each element of the sensitivity computation must be connected to the main synchronous component (variables (injections) and functions (branches)). 
+
 In order to assess the linear impact (implied by the DC approximation) of each nodal injection and phase shift transformer
 on the network elements' flow, a sensitivity analysis is run.
 
@@ -89,7 +108,7 @@ where:
 - $\mathrm{F}_\mathrm{PST}$ is the vector of the network element PST (phase shift transformer) flow,
 - $\mathrm{F}_\mathrm{X}$ is the vector of the network element xnode flow,
 - $\mathrm{AM}$ is the allocation matrix, which associates each injection to its zone. $\mathrm{AM}_{ij}$ = 1 if node i is in zone j, 0 otherwise,
-- $\mathrm{\Delta}_\mathrm{PST}$ is the phase shift transformers angle vector,
+- $\mathrm{\Delta}_\mathrm{PST}$ is the phase shift transformers angle vector. The neutral tap position of each PST is used to compute this difference.
 
 ## Flow parts rescaling
 

flow-decomposition/pom.xml

@@ -14,95 +14,102 @@
     <description>Implementation of ACER methodology for flow decomposition</description>
 
     <dependencies>
+        <!-- Compile dependencies -->
         <dependency>
             <groupId>com.powsybl</groupId>
             <artifactId>powsybl-commons</artifactId>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-iidm-api</artifactId>
+            <artifactId>powsybl-glsk-document-api</artifactId>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-loadflow-api</artifactId>
+            <artifactId>powsybl-iidm-api</artifactId>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-glsk-document-api</artifactId>
+            <artifactId>powsybl-loadflow-api</artifactId>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
             <artifactId>powsybl-sensitivity-analysis-api</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-csv</artifactId>
+            <version>${commonscsv.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.ejml</groupId>
             <artifactId>ejml-all</artifactId>
             <version>${ejml.version}</version>
         </dependency>
+        <!-- Runtime dependencies -->
         <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-csv</artifactId>
-            <version>${commonscsv.version}</version>
+            <groupId>com.powsybl</groupId>
+            <artifactId>powsybl-iidm-impl</artifactId>
+            <scope>runtime</scope>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-glsk-document-io-api</artifactId>
-            <scope>test</scope>
+            <artifactId>powsybl-iidm-serde</artifactId>
+            <scope>runtime</scope>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-glsk-document-ucte</artifactId>
-            <scope>test</scope>
+            <artifactId>powsybl-open-loadflow</artifactId>
+            <scope>runtime</scope>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-iidm-impl</artifactId>
+            <artifactId>powsybl-ucte-converter</artifactId>
             <scope>runtime</scope>
         </dependency>
         <dependency>
-            <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-iidm-serde</artifactId>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
             <scope>runtime</scope>
         </dependency>
+        <!-- Test dependencies -->
         <dependency>
-            <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-cgmes-conversion</artifactId>
+            <groupId>com.google.jimfs</groupId>
+            <artifactId>jimfs</artifactId>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-cgmes-conformity</artifactId>
+            <artifactId>powsybl-config-test</artifactId>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-triple-store-impl-rdf4j</artifactId>
+            <artifactId>powsybl-cgmes-conformity</artifactId>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-open-loadflow</artifactId>
-            <version>${powsyblopenloadflow.version}</version>
-            <scope>runtime</scope>
+            <artifactId>powsybl-cgmes-conversion</artifactId>
+            <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-ucte-converter</artifactId>
-            <scope>runtime</scope>
+            <artifactId>powsybl-glsk-document-io-api</artifactId>
+            <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>ch.qos.logback</groupId>
-            <artifactId>logback-classic</artifactId>
-            <scope>runtime</scope>
+            <groupId>com.powsybl</groupId>
+            <artifactId>powsybl-glsk-document-ucte</artifactId>
+            <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>com.google.jimfs</groupId>
-            <artifactId>jimfs</artifactId>
+            <groupId>com.powsybl</groupId>
+            <artifactId>powsybl-iidm-test</artifactId>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>com.powsybl</groupId>
-            <artifactId>powsybl-config-test</artifactId>
+            <artifactId>powsybl-triple-store-impl-rdf4j</artifactId>
             <scope>test</scope>
         </dependency>
         <dependency>

flow-decomposition/src/main/java/com/powsybl/flow_decomposition/DecomposedFlow.java

@@ -60,7 +60,7 @@ public String getContingencyId() {
     }
 
     public String getId() {
-        return NetworkUtil.getXnecId(contingencyId, branchId);
+        return getXnecId(contingencyId, branchId);
     }
 
     public Country getCountry1() {
@@ -140,4 +140,8 @@ private TreeMap<String, Double> getAllKeyMap() {
         localDecomposedFlowMap.putAll(loopFlowsMap);
         return localDecomposedFlowMap;
     }
+
+    public static String getXnecId(String contingencyId, String branchId) {
+        return contingencyId.isEmpty() ? branchId : String.format("%s_%s", branchId, contingencyId);
+    }
 }

flow-decomposition/src/main/java/com/powsybl/flow_decomposition/FlowDecompositionComputer.java

@@ -141,31 +141,27 @@ private void decomposeFlowForState(Network network,
                                        Map<Country, Double> netPositions,
                                        Map<Country, Map<String, Double>> glsks,
                                        LoadFlowRunningService.Result loadFlowServiceAcResult) {
-        saveAcReferenceFlows(flowDecompositionResultsBuilder, xnecList, loadFlowServiceAcResult);
-        compensateLosses(network);
-        observers.computedAcFlows(network, loadFlowServiceAcResult);
+        // AC load flow
+        saveAcReferenceFlows(flowDecompositionResultsBuilder, network, xnecList, loadFlowServiceAcResult);
 
-        // None
-        NetworkMatrixIndexes networkMatrixIndexes = new NetworkMatrixIndexes(network, new ArrayList<>(xnecList));
-        observers.computedAcNodalInjections(networkMatrixIndexes, loadFlowServiceAcResult.fallbackHasBeenActivated());
+        // Losses compensation
+        compensateLosses(network);
 
+        // DC load flow
         runDcLoadFlow(network);
-        observers.computedDcFlows(network);
-        observers.computedDcNodalInjections(networkMatrixIndexes);
+        saveDcReferenceFlow(flowDecompositionResultsBuilder, network, xnecList);
 
-        SparseMatrixWithIndexesTriplet nodalInjectionsMatrix = getNodalInjectionsMatrix(network,
-            netPositions, networkMatrixIndexes, glsks);
-        saveDcReferenceFlow(flowDecompositionResultsBuilder, xnecList);
-        observers.computedNodalInjectionsMatrix(nodalInjectionsMatrix);
+        // Nodal injections
+        NetworkMatrixIndexes networkMatrixIndexes = new NetworkMatrixIndexes(network, new ArrayList<>(xnecList));
+        SparseMatrixWithIndexesTriplet nodalInjectionsMatrix = getNodalInjectionsMatrix(network, netPositions,
+            networkMatrixIndexes, glsks);
 
-        // DC Sensi
+        // Sensitivity
         SensitivityAnalyser sensitivityAnalyser = getSensitivityAnalyser(network, networkMatrixIndexes);
         SparseMatrixWithIndexesTriplet ptdfMatrix = getPtdfMatrix(networkMatrixIndexes, sensitivityAnalyser);
-        observers.computedPtdfMatrix(ptdfMatrix);
         SparseMatrixWithIndexesTriplet psdfMatrix = getPsdfMatrix(networkMatrixIndexes, sensitivityAnalyser);
-        observers.computedPsdfMatrix(psdfMatrix);
 
-        // None
+        // Flows
         computeAllocatedAndLoopFlows(flowDecompositionResultsBuilder, nodalInjectionsMatrix, ptdfMatrix);
         computePstFlows(network, flowDecompositionResultsBuilder, networkMatrixIndexes, psdfMatrix);
 
@@ -184,11 +180,13 @@ private LoadFlowRunningService.Result runAcLoadFlow(Network network) {
         return loadFlowRunningService.runAcLoadflow(network, loadFlowParameters, parameters.isDcFallbackEnabledAfterAcDivergence());
     }
 
-    private void saveAcReferenceFlows(FlowDecompositionResults.PerStateBuilder flowDecompositionResultBuilder, Set<Branch> xnecList, LoadFlowRunningService.Result loadFlowServiceAcResult) {
+    private void saveAcReferenceFlows(FlowDecompositionResults.PerStateBuilder flowDecompositionResultBuilder, Network network, Set<Branch> xnecList, LoadFlowRunningService.Result loadFlowServiceAcResult) {
         Map<String, Double> acTerminal1ReferenceFlows = FlowComputerUtils.calculateAcTerminalReferenceFlows(xnecList, loadFlowServiceAcResult, TwoSides.ONE);
         Map<String, Double> acTerminal2ReferenceFlows = FlowComputerUtils.calculateAcTerminalReferenceFlows(xnecList, loadFlowServiceAcResult, TwoSides.TWO);
         flowDecompositionResultBuilder.saveAcTerminal1ReferenceFlow(acTerminal1ReferenceFlows);
         flowDecompositionResultBuilder.saveAcTerminal2ReferenceFlow(acTerminal2ReferenceFlows);
+        observers.computedAcFlows(network, loadFlowServiceAcResult);
+        observers.computedAcNodalInjections(network, loadFlowServiceAcResult.fallbackHasBeenActivated());
     }
 
     private Map<Country, Double> getZonesNetPosition(Network network) {
@@ -220,11 +218,15 @@ private SparseMatrixWithIndexesTriplet getNodalInjectionsMatrix(Network network,
                                                                     NetworkMatrixIndexes networkMatrixIndexes,
                                                                     Map<Country, Map<String, Double>> glsks) {
         NodalInjectionComputer nodalInjectionComputer = new NodalInjectionComputer(networkMatrixIndexes);
-        return nodalInjectionComputer.run(network, glsks, netPositions);
+        SparseMatrixWithIndexesTriplet nodalInjectionsMatrix = nodalInjectionComputer.run(network, glsks, netPositions);
+        observers.computedNodalInjectionsMatrix(nodalInjectionsMatrix);
+        return nodalInjectionsMatrix;
     }
 
-    private void saveDcReferenceFlow(FlowDecompositionResults.PerStateBuilder flowDecompositionResultBuilder, Set<Branch> xnecList) {
+    private void saveDcReferenceFlow(FlowDecompositionResults.PerStateBuilder flowDecompositionResultBuilder, Network network, Set<Branch> xnecList) {
         flowDecompositionResultBuilder.saveDcReferenceFlow(FlowComputerUtils.getTerminalReferenceFlow(xnecList, TwoSides.ONE));
+        observers.computedDcFlows(network);
+        observers.computedDcNodalInjections(network);
     }
 
     private SensitivityAnalyser getSensitivityAnalyser(Network network, NetworkMatrixIndexes networkMatrixIndexes) {
@@ -233,9 +235,11 @@ private SensitivityAnalyser getSensitivityAnalyser(Network network, NetworkMatri
 
     private SparseMatrixWithIndexesTriplet getPtdfMatrix(NetworkMatrixIndexes networkMatrixIndexes,
                                                          SensitivityAnalyser sensitivityAnalyser) {
-        return sensitivityAnalyser.run(networkMatrixIndexes.getNodeIdList(),
+        SparseMatrixWithIndexesTriplet ptdfMatrix = sensitivityAnalyser.run(networkMatrixIndexes.getNodeIdList(),
             networkMatrixIndexes.getNodeIndex(),
             SensitivityVariableType.INJECTION_ACTIVE_POWER);
+        observers.computedPtdfMatrix(ptdfMatrix);
+        return ptdfMatrix;
     }
 
     private void computeAllocatedAndLoopFlows(FlowDecompositionResults.PerStateBuilder flowDecompositionResultBuilder,
@@ -248,8 +252,10 @@ private void computeAllocatedAndLoopFlows(FlowDecompositionResults.PerStateBuild
 
     private SparseMatrixWithIndexesTriplet getPsdfMatrix(NetworkMatrixIndexes networkMatrixIndexes,
                                                          SensitivityAnalyser sensitivityAnalyser) {
-        return sensitivityAnalyser.run(networkMatrixIndexes.getPstList(),
+        SparseMatrixWithIndexesTriplet psdfMatrix = sensitivityAnalyser.run(networkMatrixIndexes.getPstList(),
             networkMatrixIndexes.getPstIndex(), SensitivityVariableType.TRANSFORMER_PHASE);
+        observers.computedPsdfMatrix(psdfMatrix);
+        return psdfMatrix;
     }
 
     private void computePstFlows(Network network,

flow-decomposition/src/main/java/com/powsybl/flow_decomposition/FlowDecompositionObserverList.java

@@ -107,24 +107,24 @@ public void computedDcFlows(Network network) {
         }
     }
 
-    public void computedAcNodalInjections(NetworkMatrixIndexes networkMatrixIndexes, boolean fallbackHasBeenActivated) {
+    public void computedAcNodalInjections(Network network, boolean fallbackHasBeenActivated) {
         if (observers.isEmpty()) {
             return;
         }
 
-        Map<String, Double> results = new ReferenceNodalInjectionComputer().run(networkMatrixIndexes.getNodeList());
+        Map<String, Double> results = new ReferenceNodalInjectionComputer().run(NetworkUtil.getNodeList(network));
 
         for (FlowDecompositionObserver o : observers) {
             o.computedAcNodalInjections(results, fallbackHasBeenActivated);
         }
     }
 
-    public void computedDcNodalInjections(NetworkMatrixIndexes networkMatrixIndexes) {
+    public void computedDcNodalInjections(Network network) {
         if (observers.isEmpty()) {
             return;
         }
 
-        Map<String, Double> results = new ReferenceNodalInjectionComputer().run(networkMatrixIndexes.getNodeList());
+        Map<String, Double> results = new ReferenceNodalInjectionComputer().run(NetworkUtil.getNodeList(network));
 
         for (FlowDecompositionObserver o : observers) {
             o.computedDcNodalInjections(results);

flow-decomposition/src/main/java/com/powsybl/flow_decomposition/FlowDecompositionResults.java

@@ -77,7 +77,7 @@ void saveDcReferenceFlow(Map<String, Double> dcReferenceFlow) {
         void build(DecomposedFlowRescaler decomposedFlowRescaler) {
             allocatedAndLoopFlowsMatrix.toMap()
                 .forEach((branchId, decomposedFlow) -> {
-                    String xnecId = NetworkUtil.getXnecId(contingencyId, branchId);
+                    String xnecId = DecomposedFlow.getXnecId(contingencyId, branchId);
                     decomposedFlowMap.put(xnecId, createDecomposedFlow(branchId, decomposedFlow, decomposedFlowRescaler));
                 });
         }