fix a bug in the detection of the main component

lightsim2grid/gridmodel/from_pypowsybl.py

@@ -38,7 +38,7 @@ def init(net : pypo.network,
          slack_bus_id: int = None,
          sn_mva = 100.,
          sort_index=True,
-         f_hz = 50.,
+         f_hz = 50.,  # unused
          only_main_component=True):
     model = GridModel()
     # model.set_f_hz(f_hz)
@@ -89,8 +89,8 @@ def init(net : pypo.network,
     for gen_id, is_disco in enumerate(gen_disco):
         if is_disco:
             model.deactivate_gen(gen_id)
-    model.set_gen_names(df_gen.index)        
-        
+    model.set_gen_names(df_gen.index)   
+
     # for loads
     if sort_index:
         df_load = net.get_loads().sort_index()
@@ -104,7 +104,7 @@ def init(net : pypo.network,
     for load_id, is_disco in enumerate(load_disco):
         if is_disco:
             model.deactivate_load(load_id)
-    model.set_load_names(df_load.index)     
+    model.set_load_names(df_load.index)
 
     # for lines
     if sort_index:
@@ -148,7 +148,7 @@ def init(net : pypo.network,
     for line_id, (is_or_disc, is_ex_disc) in enumerate(zip(lor_disco, lex_disco)):
         if is_or_disc or is_ex_disc:
             model.deactivate_powerline(line_id)
-    model.set_line_names(df_line.index)     
+    model.set_line_names(df_line.index)
 
     # for trafo
     if sort_index:
@@ -184,7 +184,7 @@ def init(net : pypo.network,
     for t_id, (is_or_disc, is_ex_disc) in enumerate(zip(tor_disco, tex_disco)):
         if is_or_disc or is_ex_disc:
             model.deactivate_trafo(t_id)
-    model.set_trafo_names(df_trafo.index)     
+    model.set_trafo_names(df_trafo.index)
 
     # for shunt
     if sort_index:
@@ -201,7 +201,7 @@ def init(net : pypo.network,
     for shunt_id, disco in enumerate(sh_disco):
         if disco:
            model.deactivate_shunt(shunt_id) 
-    model.set_shunt_names(df_trafo.index)     
+    model.set_shunt_names(df_trafo.index)
 
     # for hvdc (TODO not tested yet)
     df_dc = net.get_hvdc_lines().sort_index()
@@ -228,7 +228,7 @@ def init(net : pypo.network,
     for hvdc_id, (is_or_disc, is_ex_disc) in enumerate(zip(hvdc_from_disco, hvdc_to_disco)):
         if is_or_disc or is_ex_disc:
             model.deactivate_hvdc(hvdc_id)
-    model.set_dcline_names(df_sations.index)   
+    model.set_dcline_names(df_sations.index)
 
     # storage units  (TODO not tested yet)
     if sort_index:
@@ -243,7 +243,7 @@ def init(net : pypo.network,
     for batt_id, disco in enumerate(batt_disco):
         if disco:
            model.deactivate_storage(batt_id) 
-    model.set_storage_names(df_batt.index)   
+    model.set_storage_names(df_batt.index)
 
     # TODO dist slack
     if gen_slack_id is None and slack_bus_id is None:
@@ -262,8 +262,8 @@ def init(net : pypo.network,
             raise RuntimeError(f"There is no generator connected to bus {slack_bus_id}. It cannot be the slack")
         for gen_id, is_slack in enumerate(gen_is_conn_slack):
             if is_slack:
-                model.add_gen_slackbus(gen_id, 1. / nb_conn)
-            
+                model.add_gen_slackbus(gen_id, 1. / nb_conn)    
+
     # TODO
     # sgen => regular gen (from net.get_generators()) with voltage_regulator off TODO 
 

lightsim2grid/lightSimBackend.py

@@ -446,7 +446,6 @@ def make_complete_path(path, filename):
                     raise Grid2OpException('There is no powergrid at "{}"'.format(full_path))
                 return full_path
             full_path = make_complete_path(path, filename)
-
         grid_tmp = pypow_net.load(full_path)
         gen_slack_id = None
         if "gen_slack_id" in loader_kwargs:

lightsim2grid/tests/test_backend_pypowsybl.py

@@ -92,7 +92,8 @@ def test_init(self):
         grid.ac_pf(np.ones(14, dtype=np.complex128), 10, 1e-6)
 
     def test_runpf(self):
-        backend = LightSimBackend(loader_method="pypowsybl", loader_kwargs=_aux_get_loader_kwargs())
+        backend = LightSimBackend(loader_method="pypowsybl",
+                                  loader_kwargs=_aux_get_loader_kwargs())
         self._aux_prep_backend(backend)
         # AC powerflow
         conv, exc_ = backend.runpf()

src/GridModel.cpp

@@ -1002,20 +1002,25 @@ void GridModel::consider_only_main_component(){
     // TODO copy paste from SecurityAnalysis
     std::queue<Eigen::Index> neighborhood;
     for(const auto & el : slack_buses_id) neighborhood.push(el);
+    if(neighborhood.empty()){
+        throw std::runtime_error("There is no slack buses defined in your grid. You cannot isolate the main component.");
+    }
     std::vector<bool> visited(nb_busbars, false);
+    std::vector<bool> already_added(nb_busbars, false);
     while (true)
     {
         const Eigen::Index col_id = neighborhood.front();
+        neighborhood.pop();
         visited[col_id] = true;
         for (Eigen::SparseMatrix<real_type>::InnerIterator it(graph, col_id); it; ++it)
         {
             // add in the queue all my neighbor (if the coefficient is big enough)
-            if(!visited[it.row()] ){  // && abs(it.value()) > 1e-8
+            if(!visited[it.row()] && !already_added[it.row()]){  // && abs(it.value()) > 1e-8
                 neighborhood.push(it.row());
+                already_added[it.row()] = true;
             }
         }
         if(neighborhood.empty()) break;
-        neighborhood.pop();
     }
 
     // disconnected elements not in main component
@@ -1027,7 +1032,6 @@ void GridModel::consider_only_main_component(){
     storages_.disconnect_if_not_in_main_component(visited);
     generators_.disconnect_if_not_in_main_component(visited);
     dc_lines_.disconnect_if_not_in_main_component(visited);
-
     // and finally deal with the buses
     init_bus_status();
 }

src/SecurityAnalysis.cpp

@@ -12,6 +12,7 @@
 
 bool SecurityAnalysis::check_invertible(const Eigen::SparseMatrix<cplx_type> & Ybus) const{
     std::vector<bool> visited(Ybus.cols(), false); 
+    std::vector<bool> already_added(Ybus.cols(), false);
     std::queue<Eigen::Index> neighborhood;
     Eigen::Index col_id = 0;  // start by node 0, why not
     while (true)
@@ -20,8 +21,9 @@ bool SecurityAnalysis::check_invertible(const Eigen::SparseMatrix<cplx_type> & Y
         for (Eigen::SparseMatrix<cplx_type>::InnerIterator it(Ybus, col_id); it; ++it)
         {
             // add in the queue all my neighbor (if the coefficient is big enough)
-            if(!visited[it.row()] && abs(it.value()) > 1e-8){
+            if(!visited[it.row()] && !already_added[it.row()] && abs(it.value()) > 1e-8){
                 neighborhood.push(it.row());
+                already_added[it.row()] = true;
             }
         }
         if(neighborhood.empty()) break;