Add assertion error if flows in and out of battery are detected

smooth/components/component_battery.py

@@ -252,6 +252,18 @@ def add_to_oemof_model(self, busses, model):
         model.add(battery)
         return battery
 
+    def update_flows(self, results, comp_name=None):
+        """Update flow values for each flow in the 'flows' dict of results
+
+        :param results: The oemof results for the given time step
+        :type results: object
+        :param comp_name: The name of the component - while components can generate more
+            than one oemof model, they sometimes need to give a custom name, defaults to None
+        :type comp_name: str, optional
+        """
+        Component.update_flows(self, results, self.name)
+        self.check_flows()
+
     def update_states(self, results):
         """Updates the states of the battery component for each time step
 
@@ -271,3 +283,27 @@ def update_states(self, results):
                 # Check if this result is the state of charge.
                 self.soc = df_storage[i_result][0] / self.battery_capacity
                 self.states["soc"][self.sim_params.i_interval] = self.soc
+
+    def check_flows(self):
+        """ Checks if there are flows in and out of the battery and if so triggers an AssertionError
+
+        :raises: ValueError if flows in and out of the battery at the same time are detected
+        """
+        # get current time index
+        time_idx = self.sim_params.i_interval
+        # get number of current non-zero flows
+        non_zero_flows = sum([1 if flow[time_idx] else 0 for flow in self.flows.values()])
+        if non_zero_flows > 1:
+            # more than one non-zero flow detected
+            # compute vac_out_threshold: the minimum vac_out required to prevent circular flows
+            vac_out_threshold = -self.vac_in / (self.efficiency_charge * self.efficiency_discharge)
+            if self.vac_in < 0 and self.vac_out < vac_out_threshold:
+                # vac_in/vac_out invalid: charging and discharging at the same time is incentivized
+                raise ValueError('There are flows in and out of the Battery \'' + self.name +
+                                 '\'. If the Battery is incetivised to be charged using negative '
+                                 'vac_in, vac_out has to be chosen higher than: '
+                                 '-vac_in / (efficiency_charge * efficiency_discharge)')
+            else:
+                # something different went wrong. Does this even happen?
+                raise ValueError('There are flows in and out of the Battery \'' + self.name +
+                                 '\'. Please reevaluate your settings')