#492 reformat constant current to be a submodel

examples/scripts/compare_lead_acid_3D.py

@@ -21,22 +21,20 @@
     #     {"current collector": "potential pair", "dimensionality": 2}, name="2+1D LOQS"
     # ),
     pybamm.lead_acid.Full(
-        {"current collector": "potential pair", "dimensionality": 1}, name="1+1D Full"
+        {"current collector": "uniform", "dimensionality": 1}, name="1+1D Full"
     ),
     # pybamm.lead_acid.Full(
     #     {"dimensionality": 1}, name="1+1D uniform Full"
     # ),
     pybamm.lead_acid.Composite(
-        {"current collector": "potential pair quite conductive", "dimensionality": 1},
-        name="1+1D composite",
+        {"current collector": "uniform", "dimensionality": 1}, name="1+1D composite"
     ),
     pybamm.lead_acid.Composite(
-        {"current collector": "potential pair", "dimensionality": 1},
-        name="1+1D composite",
+        {"current collector": "uniform", "dimensionality": 1}, name="1+1D composite"
     ),
     # # pybamm.lead_acid.Composite({"dimensionality": 1}, name="composite"),
     pybamm.lead_acid.LOQS(
-        {"current collector": "potential pair", "dimensionality": 1}, name="1+1D LOQS"
+        {"current collector": "uniform", "dimensionality": 1}, name="1+1D LOQS"
     ),
     # pybamm.lead_acid.LOQS({"dimensionality": 1}, name="LOQS"),
 ]

pybamm/__init__.py

@@ -159,6 +159,7 @@ def version(formatted=False):
     current_collector,
     electrolyte,
     electrode,
+    external_circuit,
     interface,
     oxygen_diffusion,
     particle,

pybamm/models/full_battery_models/base_battery_model.py

@@ -141,6 +141,7 @@ def options(self):
     @options.setter
     def options(self, extra_options):
         default_options = {
+            "operating mode": "current",
             "dimensionality": 0,
             "surface form": False,
             "convection": False,
@@ -161,6 +162,10 @@ def options(self, extra_options):
                     raise pybamm.OptionError("option {} not recognised".format(name))
 
         # Some standard checks to make sure options are compatible
+        if options["operating mode"] not in ["current", "potential"]:
+            raise pybamm.OptionError(
+                "operating mode '{}' not recognised".format(options["operating mode"])
+            )
         if (
             isinstance(self, (pybamm.lead_acid.LOQS, pybamm.lead_acid.Composite))
             and options["surface form"] is False
@@ -341,18 +346,6 @@ def set_standard_output_variables(self):
 
         self.variables = {}
 
-        # Current
-        i_cell = pybamm.electrical_parameters.current_with_time
-        i_cell_dim = pybamm.electrical_parameters.dimensional_current_density_with_time
-        I = pybamm.electrical_parameters.dimensional_current_with_time
-        self.variables.update(
-            {
-                "Total current density": i_cell,
-                "Total current density [A.m-2]": i_cell_dim,
-                "Current [A]": I,
-            }
-        )
-
         # Time
         time_scale = pybamm.electrical_parameters.timescale
         self.variables.update(
@@ -361,7 +354,6 @@ def set_standard_output_variables(self):
                 "Time [s]": pybamm.t * time_scale,
                 "Time [min]": pybamm.t * time_scale / 60,
                 "Time [h]": pybamm.t * time_scale / 3600,
-                "Discharge capacity [A.h]": I * pybamm.t * time_scale / 3600,
             }
         )
 
@@ -491,6 +483,20 @@ def build_model(self):
 
         self._built = True
 
+    def set_external_circuit_submodel(self):
+        """
+        Define how the external circuit defines the boundary conditions for the model,
+        e.g. (not necessarily constant-) current, voltage, etc
+        """
+        if self.options["operating mode"] == "current":
+            self.submodels[
+                "external circuit"
+            ] = pybamm.external_circuit.ConstantCurrent(self.param)
+        if self.options["operating mode"] == "voltage":
+            self.submodels[
+                "external circuit"
+            ] = pybamm.external_circuit.ConstantVoltage(self.param)
+
     def set_thermal_submodel(self):
 
         if self.options["thermal"] == "isothermal":

pybamm/models/full_battery_models/lead_acid/base_lead_acid_model.py

@@ -116,5 +116,5 @@ def set_soc_variables(self):
         if "Fractional Charge Input" not in self.variables:
             fci = pybamm.Variable("Fractional Charge Input", domain="current collector")
             self.variables["Fractional Charge Input"] = fci
-            self.rhs[fci] = -self.param.current_with_time * 100
+            self.rhs[fci] = -self.variables["Total current density"] * 100
             self.initial_conditions[fci] = self.param.q_init * 100

pybamm/models/submodels/current_collector/homogeneous_current_collector.py

@@ -21,12 +21,15 @@ class Uniform(BaseModel):
     def __init__(self, param):
         super().__init__(param)
 
-    def get_fundamental_variables(self):
+    def get_derived_variables(self, variables):
 
         # TODO: grad not implemented for 2D yet
         i_cc = pybamm.Scalar(0)
+        import ipdb
+
+        ipdb.set_trace()
         i_boundary_cc = pybamm.PrimaryBroadcast(
-            self.param.current_with_time, "current collector"
+            variables["Total current density"], "current collector"
         )
         phi_s_cn = pybamm.PrimaryBroadcast(0, "current collector")
 

pybamm/models/submodels/current_collector/potential_pair.py

@@ -60,8 +60,7 @@ def set_algebraic(self, variables):
 
     def set_initial_conditions(self, variables):
 
-        param = self.param
-        applied_current = param.current_with_time
+        applied_current = variables["Total current density"]
         cc_area = self._get_effective_current_collector_area()
         phi_s_cn = variables["Negative current collector potential"]
         i_boundary_cc = variables["Current collector current density"]
@@ -84,7 +83,7 @@ def set_boundary_conditions(self, variables):
         phi_s_cp = variables["Positive current collector potential"]
 
         param = self.param
-        applied_current = param.current_with_time
+        applied_current = variables["Total current density"]
         cc_area = self._get_effective_current_collector_area()
 
         # cc_area appears here due to choice of non-dimensionalisation
@@ -124,7 +123,7 @@ def set_boundary_conditions(self, variables):
         phi_s_cp = variables["Positive current collector potential"]
 
         param = self.param
-        applied_current = param.current_with_time
+        applied_current = variables["Total current density"]
         cc_area = self._get_effective_current_collector_area()
 
         # Note: we divide by the *numerical* tab area so that the correct total

pybamm/models/submodels/current_collector/quite_conductive_potential_pair.py

@@ -47,7 +47,7 @@ def get_fundamental_variables(self):
     def set_algebraic(self, variables):
 
         param = self.param
-        applied_current = param.current_with_time
+        applied_current = variables["Total current density"]
         cc_area = self._get_effective_current_collector_area()
         z = pybamm.standard_spatial_vars.z
 
@@ -73,7 +73,7 @@ def set_algebraic(self, variables):
     def set_initial_conditions(self, variables):
 
         param = self.param
-        applied_current = param.current_with_time
+        applied_current = variables["Total current density"]
         cc_area = self._get_effective_current_collector_area()
         phi_s_cn = variables["Negative current collector potential"]
         i_boundary_cc = variables["Current collector current density"]

pybamm/models/submodels/current_collector/set_potential_single_particle.py

@@ -85,7 +85,7 @@ def set_algebraic(self, variables):
     def set_initial_conditions(self, variables):
 
         param = self.param
-        applied_current = param.current_with_time
+        applied_current = variables["Total current density"]
         cc_area = self._get_effective_current_collector_area()
         phi_s_cn = variables["Negative current collector potential"]
         phi_s_cp = variables["Positive current collector potential"]

pybamm/models/submodels/external_circuit/__init__.py

@@ -0,0 +1,4 @@
+from .base_external_circuit import BaseModel
+from .current_control_external_circuit import CurrentControl
+
+# from .voltage_control_external_circuit import VoltageControl

pybamm/models/submodels/external_circuit/base_external_circuit.py

@@ -0,0 +1,11 @@
+#
+# Base model for the external circuit
+#
+import pybamm
+
+
+class BaseModel(pybamm.BaseSubModel):
+    """Model to represent the behaviour of the external circuit. """
+
+    def __init__(self, param):
+        super().__init__(param)

pybamm/models/submodels/external_circuit/current_control_external_circuit.py

@@ -0,0 +1,27 @@
+#
+# External circuit with current control
+#
+import pybamm
+from .base_external_circuit import BaseModel
+
+
+class CurrentControl(BaseModel):
+    """External circuit with current control. """
+
+    def __init__(self, param):
+        super().__init__(param)
+
+    def get_fundamental_variables(self):
+        # Current is given as a function of time
+        i_cell = self.param.current_with_time
+        i_cell_dim = self.param.dimensional_current_density_with_time
+        I = self.param.dimensional_current_with_time
+
+        variables = {
+            "Total current density": i_cell,
+            "Total current density [A.m-2]": i_cell_dim,
+            "Current [A]": I,
+            "Discharge capacity [A.h]": I * pybamm.t * self.param.time_scale / 3600,
+        }
+
+        return variables

pybamm/models/submodels/external_circuit/voltage_control_external_circuit.py

@@ -0,0 +1,27 @@
+#
+# External circuit with voltage control
+#
+import pybamm
+from .base_external_circuit import BaseModel
+
+
+class VoltageControl(BaseModel):
+    """External circuit with voltage control. """
+
+    def __init__(self, param):
+        super().__init__(param)
+
+    def get_fundamental_variables(self):
+        # Current is given as a function of time
+        i_cell = pybamm.electrical_parameters.current_with_time
+        i_cell_dim = pybamm.electrical_parameters.dimensional_current_density_with_time
+        I = pybamm.electrical_parameters.dimensional_current_with_time
+
+        variables = {
+            "Total current density": i_cell,
+            "Total current density [A.m-2]": i_cell_dim,
+            "Current [A]": I,
+            "Discharge capacity [A.h]": I * pybamm.t * self.param.time_scale / 3600,
+        }
+
+        return variables