Set DC and CH4 links bidirectional

The way the unit commitment attributes are set currently overwrite existing entries

etrago/execute/market_optimization.py

@@ -328,7 +328,7 @@ def build_market_model(self):
     net.links.min_up_time = net.links.min_up_time.astype(int)
     net.links.min_down_time = net.links.min_down_time.astype(int)
     net.links[committable_links.columns].loc["ramp_limit_down"] = 1.
-
+    net.links.loc[net.links.carrier.isin(["CH4", "DC", "AC"]), "p_min_pu"] =-1.
     # Set stores and storage_units to cyclic
     net.stores.loc[net.stores.carrier!="battery_storage", "e_cyclic"] = True
     net.storage_units.cyclic_state_of_charge = True
@@ -402,7 +402,7 @@ def build_shortterm_market_model(self):
     m.links[committable_links.columns] = committable_links
     m.links.min_up_time = m.links.min_up_time.astype(int)
     m.links.min_down_time = m.links.min_down_time.astype(int)
-
+    m.links.loc[m.links.carrier.isin(["CH4", "DC", "AC"]), "p_min_pu"] =-1.
     # Set stores and storage_units to not cyclic
     # That would be in conflict with the e_min_pu and e_max_pu limit
     m.stores.loc[m.stores.carrier!="battery_storage", "e_cyclic"] = False