Fix/#929 reactors missing powerconnection adapters

docs/whats_new/v0-9-14.rst

@@ -14,7 +14,10 @@ Bug Fixes
   silent error because if not used, it did not do any trouble. Only when
   importing a :code:`Network` and reconstructing the component parameters the
   :code:`CharMap` could not be constructed successfully because it was missing
-  dimensions (`PR #934 <https://github.com/oemof/tespy/pull/934>`__).
+  dimensions (`PR #933 <https://github.com/oemof/tespy/pull/933>`__).
+- The reactor classes :code:`FuelCell` and :code:`WaterElectrolyzer` were
+  missing the implementation for a :code:`PowerConnection`
+  (`PR #934 <https://github.com/oemof/tespy/pull/934>`__).
 
 Other Changes
 #############

src/tespy/components/reactors/fuel_cell.py

@@ -214,7 +214,7 @@ def get_parameters(self):
         }
 
     def get_mandatory_constraints(self):
-        return {
+        constraints = {
             'mass_flow_constraints': dc_cmc(**{
                 'func': self.reactor_mass_flow_func,
                 'deriv': self.reactor_mass_flow_deriv,
@@ -247,6 +247,14 @@ def get_mandatory_constraints(self):
                 "description": "reactor pressure equality equations"
             })
         }
+        if len(self.power_outl) > 0:
+            constraints["energy_connector_balance"] = dc_cmc(**{
+                "func": self.energy_connector_balance_func,
+                "dependents": self.energy_connector_dependents,
+                "num_eq_sets": 1
+            })
+
+        return constraints
 
     @staticmethod
     def get_bypass_constraints():
@@ -260,6 +268,10 @@ def inlets():
     def outlets():
         return ['out1', 'out2']
 
+    @staticmethod
+    def poweroutlets():
+        return ["power"]
+
     def _add_missing_fluids(self, connections):
         if self.inl[1] in connections:
             return ["O2"]
@@ -325,6 +337,28 @@ def calc_e0(self):
 
         return e0
 
+    def energy_connector_balance_func(self):
+        r"""
+        (optional) energy balance equation connecting the power connector to
+        the component's power. Since the power of the FuelCell is negative by
+        definition of the system, the two quantities are added in the residual
+        so the power on the PowerConnection is positive again.
+
+        Returns
+        -------
+        residual : float
+            Residual value of equation
+
+            .. math::
+
+                0=\dot E + P
+        """
+        return self.power_outl[0].E.val_SI + self.P.val_SI
+
+    def energy_connector_dependents(self):
+        return [self.power_outl[0].E, self.P]
+
+
     def eta_func(self):
         r"""
         Equation for efficiency.
@@ -454,7 +488,7 @@ def energy_balance_deriv(self, increment_filter, k, dependents=None):
 
         # derivatives for variable P
         if self.P.is_var:
-            self.jacobian[k, self.p.J_col] = 1
+            self.jacobian[k, self.P.J_col] = 1
 
     def energy_balance_dependents(self):
         return [

src/tespy/components/reactors/water_electrolyzer.py

@@ -253,7 +253,7 @@ def get_parameters(self):
         }
 
     def get_mandatory_constraints(self):
-        return {
+        constraints = {
             'mass_flow_constraints': dc_cmc(**{
                 'func': self.reactor_mass_flow_func,
                 'deriv': self.reactor_mass_flow_deriv,
@@ -291,6 +291,14 @@ def get_mandatory_constraints(self):
                 "description": "equation for same temperature of product gases"
             })
         }
+        if len(self.power_inl) > 0:
+            constraints["energy_connector_balance"] = dc_cmc(**{
+                "func": self.energy_connector_balance_func,
+                "dependents": self.energy_connector_dependents,
+                "num_eq_sets": 1
+            })
+
+        return constraints
 
     @staticmethod
     def get_bypass_constraints():
@@ -304,6 +312,10 @@ def inlets():
     def outlets():
         return ['out1', 'out2', 'out3']
 
+    @staticmethod
+    def powerinlets():
+        return ["power"]
+
     def _add_missing_fluids(self, connections):
         if self.inl[1] in connections:
             return ["H2O"]
@@ -369,6 +381,25 @@ def calc_e0(self):
 
         return e0
 
+    def energy_connector_balance_func(self):
+        r"""
+        (optional) energy balance equation connecting the power connector to
+        the component's power
+
+        Returns
+        -------
+        residual : float
+            Residual value of equation
+
+            .. math::
+
+                0=\dot E - P
+        """
+        return self.power_inl[0].E.val_SI - self.P.val_SI
+
+    def energy_connector_dependents(self):
+        return [self.power_inl[0].E, self.P]
+
     def gas_temperature_func(self):
         r"""
         Equation for temperature equality of product gases.