PSS/E export fails to export all existing buses in Node Breaker voltage level

[rolnico]

Describe the current behavior

When exporting a network in PSS/E format, the buses in node-breaker voltage levels are detected by first lsiting all the sets of nodes connected by either a switch or an internal connection. However, in the current version, there is no condition on the state of the switch, meaning that two nodes with a switch in-between will be considered connected, even if that switch is open. The result is that there are less buses than expected in the exported file.

Describe the expected behavior

The number of exported switches should be consistent with the network.

Describe the steps

The two files exported by this code should have more differences than what is currently present:

    @Test
    void tempTest() {
        // Create the network
        Network network = FourSubstationsNodeBreakerFactory.create();

        // Set the IIDM export version
        Properties properties = new Properties();
        properties.put(XMLExporter.VERSION, IidmVersion.V_1_13.toString("."));

        // Export the network in PSS/E
        DataSource dataSource1 = new DirectoryDataSource(Path.of("."), "issue_network_switch_closed");
        new PsseExporter().export(network, null, dataSource1);

        // Open a switch
        network.getSwitch("S1VL2_COUPLER").setOpen(true);

        // Export the network in PSS/E
        DataSource dataSource2 = new DirectoryDataSource(Path.of("."), "issue_network_switch_open");
        new PsseExporter().export(network, null, dataSource2);
    }

Environment

• PowSyBl core v7.0.1
• OS: any

Relevant Log Output

No response

Extra Information

There might be more issues, yet to be identified, in the exporter.

[rolnico]

The issue might be in the following code, from VoltageLevelConverter.java:

    private static List<Set<Integer>> connectedSetsBySwitchesAndInternalConnections(VoltageLevel voltageLevel) {
        Graph<Integer, Pair<Integer, Integer>> swIcGraph = new Pseudograph<>(null, null, false);

        addInternalConnections(voltageLevel, swIcGraph);

        voltageLevel.getNodeBreakerView().getSwitches().forEach(sw -> {
            int node1 = voltageLevel.getNodeBreakerView().getNode1(sw.getId());
            int node2 = voltageLevel.getNodeBreakerView().getNode2(sw.getId());
            swIcGraph.addVertex(node1);
            swIcGraph.addVertex(node2);
            swIcGraph.addEdge(node1, node2, Pair.of(node1, node2));
        });

        return new ConnectivityInspector<>(swIcGraph).connectedSets();
    }

I would at least add a check on the state of the switch:

    private static List<Set<Integer>> connectedSetsBySwitchesAndInternalConnections(VoltageLevel voltageLevel) {
        Graph<Integer, Pair<Integer, Integer>> swIcGraph = new Pseudograph<>(null, null, false);

        addInternalConnections(voltageLevel, swIcGraph);

        voltageLevel.getNodeBreakerView().getSwitches().forEach(sw -> {
            if (!sw.isOpen()) {
                int node1 = voltageLevel.getNodeBreakerView().getNode1(sw.getId());
                int node2 = voltageLevel.getNodeBreakerView().getNode2(sw.getId());
                swIcGraph.addVertex(node1);
                swIcGraph.addVertex(node2);
                swIcGraph.addEdge(node1, node2, Pair.of(node1, node2));
            }
        });

        return new ConnectivityInspector<>(swIcGraph).connectedSets();
    }

[rolnico]

Another unexpected behavior is that, in these voltage levels, the selected bus is not always the same, it might depend on the stream order, which makes the result not consistent in time (hence the differences observed in the PR #3628)

[zamarrenolm]

If detailed connectivity is exported to PSSE, PSSE requires the two ends have the same bus. PSSE automatically creates and handles “bus sections” when the main bus is split based on open switches. This is the reason why switch open status must not be considered when building the connectivity sets.

If no detailed connectivity is exported (the export is bus/branch mode), then we may have to export multiple buses, one for each connected set, now taking into account the open status. The current code should do it, we will verify it.

[zamarrenolm]

The info about detailed connectivity (switches, which equipment are connected to each node) is put in the output PSSE file in a section called "SUBSTATION DATA". An example of the first substation in the test resource full_export.raw:

0 / END OF INDUCTION MACHINE DATA, BEGIN SUBSTATION DATA
1,'Sub1',0.0,0.0,0.1
1,'Vl1-Sub1-1',1,1,1.0,0.0
2,'Vl1-Sub1-2',1,1,1.0,0.0
3,'Vl1-Sub1-3',1,1,1.0,0.0
4,'Vl1-Sub1-4',1,1,1.0,0.0
5,'Vl1-Sub1-5',1,1,1.0,0.0
6,'Vl1-Sub1-6',1,1,1.0,0.0
7,'Vl1-Sub1-7',1,1,1.0,0.0
0 /  END OF SUBSTATION NODE DATA, BEGIN SUBSTATION SWITCHING DEVICE DATA
1,2,'01','Sw1-Vl1-Sub1',2,1,1,1.0E-4,0.0,0.0,0.0
1,3,'01','Sw-Line-Vl1-Sub1-Sub2',2,1,1,1.0E-4,0.0,0.0,0.0
2,4,'01','Sw-Gen-Vl1-Sub1',2,1,1,1.0E-4,0.0,0.0,0.0
2,5,'01','Sw-Line-Vl1-Sub1-Sub7',2,1,1,1.0E-4,0.0,0.0,0.0
2,6,'01','Sw-Line-Vl1-Sub1-Sub4',2,1,1,1.0E-4,0.0,0.0,0.0
2,7,'01','Sw-Line-Vl1-Sub1-Sub5',2,1,1,1.0E-4,0.0,0.0,0.0
0 /  END OF SUBSTATION SWITCHING DEVICE DATA, BEGIN SUBSTATION EQUIPMENT TERMINAL DATA
1,4,'M','01'
1,3,'B',2,'01'
1,5,'B',12,'01'
1,6,'B',6,'01'
1,7,'B',9,'01'