Merge pull request #2518 from pybamm-team/issue-2358-add-temperature-to-experiment

Issue 2358 add temperature to experiment

Author: valentinsulzer

CHANGELOG.md

@@ -2,8 +2,13 @@
 
 ## Features
 
+- Added temperature control to experiment class. ([#2518])(https://github.com/pybamm-team/PyBaMM/pull/2518)
 - The "particle size" option can now be a tuple to allow different behaviour in each electrode([#2672](https://github.com/pybamm-team/PyBaMM/pull/2672)).
 
+## Bug fixes
+
+- Fixed the length scaling for the first dimension of r-R plots ([#2663](https://github.com/pybamm-team/PyBaMM/pull/2663)).
+
 # [v23.1](https://github.com/pybamm-team/PyBaMM/tree/v23.1) - 2023-01-31
 
 ## Features
@@ -17,7 +22,6 @@
 
 - Fixed a bug where the solid phase conductivity was double-corrected for tortuosity when loading parameters from a BPX file ([#2638](https://github.com/pybamm-team/PyBaMM/pull/2638)).
 - Changed termination from "success" to "final time" for algebraic solvers to match ODE/DAE solvers ([#2613](https://github.com/pybamm-team/PyBaMM/pull/2613)).
-- Fixed the length scaling for the first dimension of r-R plots ([#2663](https://github.com/pybamm-team/PyBaMM/pull/2663)).
 
 # [v22.12](https://github.com/pybamm-team/PyBaMM/tree/v22.12) - 2022-12-31
 

examples/scripts/run_ecm.py

@@ -2,43 +2,22 @@
 
 pybamm.set_logging_level("INFO")
 
-# options = {"number of rc elements": 2}
-options = {}
-model = pybamm.equivalent_circuit.Thevenin(options=options)
-
-parameter_values = model.default_parameter_values
-# parameter_values.update(
-#     {
-#         "R2 [Ohm]": 0.3e-3,
-#         "C2 [F]": 1000 / 0.3e-3,
-#         "Element-2 initial overpotential [V]": 0,
-#     },
-#     check_already_exists=False,
-# )
+model = pybamm.equivalent_circuit.Thevenin()
 
 experiment = pybamm.Experiment(
     [
         (
-            "Discharge at C/10 for 10 hours or until 3.3 V",
-            "Rest for 1 hour",
-            "Charge at 100 A until 4.1 V (1 second period)",
-            "Hold at 4.1 V until 5 A (1 seconds period)",
-            "Rest for 1 hour",
+            "Discharge at C/10 for 10 hours or until 3.3 V at 15oC",
+            "Rest for 30 minutes at 15oC",
+            "Rest for 2 hours at 35oC",
+            "Charge at 100 A until 4.1 V at 35oC (1 second period)",
+            "Hold at 4.1 V until 5 A at 35oC (1 seconds period)",
+            "Rest for 30 minutes at 35oC",
+            "Rest for 1 hour at 25oC",
         ),
     ]
 )
 
-sim = pybamm.Simulation(model, experiment=experiment, parameter_values=parameter_values)
+sim = pybamm.Simulation(model, experiment=experiment)
 sim.solve()
-sim.plot(
-    output_variables=[
-        "SoC",
-        "Open circuit voltage [V]",
-        "Current [A]",
-        "Cell temperature [degC]",
-        "Entropic change [V/K]",
-        "R0 [Ohm]",
-        "R1 [Ohm]",
-        "C1 [F]",
-    ]
-)
+sim.plot()

pybamm/experiments/experiment.py

@@ -3,25 +3,28 @@
 #
 
 import numpy as np
+import re
+import pybamm
 
 examples = """
 
-    Discharge at 1C for 0.5 hours,
-    Discharge at C/20 for 0.5 hours,
-    Charge at 0.5 C for 45 minutes,
-    Discharge at 1 A for 90 seconds,
-    Charge at 200mA for 45 minutes (1 minute period),
-    Discharge at 1 W for 0.5 hours,
-    Charge at 200 mW for 45 minutes,
-    Rest for 10 minutes (5 minute period),
-    Hold at 1 V for 20 seconds,
-    Charge at 1 C until 4.1V,
-    Hold at 4.1 V until 50 mA,
-    Hold at 3V until C/50,
-    Run US06 (A),
-    Run US06 (A) for 20 seconds,
-    Run US06 (V) for 45 minutes,
-    Run US06 (W) for 2 hours,
+    "Discharge at 1C for 0.5 hours at 27oC",
+    "Discharge at C/20 for 0.5 hours at 29oC",
+    "Charge at 0.5 C for 45 minutes at -5oC",
+    "Discharge at 1 A for 0.5 hours at -5.1oC",
+    "Charge at 200 mA for 45 minutes at 10.2oC (1 minute period)",
+    "Discharge at 1W for 0.5 hours at -10.4oC",
+    "Charge at 200mW for 45 minutes",
+    "Rest for 10 minutes (5 minute period)",
+    "Hold at 1V for 20 seconds",
+    "Charge at 1 C until 4.1V",
+    "Hold at 4.1 V until 50mA",
+    "Hold at 3V until C/50",
+    "Discharge at C/3 for 2 hours or until 2.5 V at 26oC",
+    "Run US06 (A) at -5oC",
+    "Run US06 (V) for 5 minutes",
+    "Run US06 (W) for 0.5 hours",
+
     """
 
 
@@ -31,12 +34,18 @@ class Experiment:
     list of operating conditions should be passed in. Each operating condition should
     be of the form "Do this for this long" or "Do this until this happens". For example,
     "Charge at 1 C for 1 hour", or "Charge at 1 C until 4.2 V", or "Charge at 1 C for 1
-    hour or until 4.2 V". The instructions can be of the form "(Dis)charge at x A/C/W",
-    "Rest", or "Hold at x V". The running time should be a time in seconds, minutes or
+    hour or until 4.2 V at 25oC". The instructions can be of the form
+    "(Dis)charge at x A/C/W", "Rest", or "Hold at x V until y A at z oC". The running
+    time should be a time in seconds, minutes or
     hours, e.g. "10 seconds", "3 minutes" or "1 hour". The stopping conditions should be
     a circuit state, e.g. "1 A", "C/50" or "3 V". The parameter drive_cycles is
     mandatory to run drive cycle. For example, "Run x", then x must be the key
-    of drive_cycles dictionary.
+    of drive_cycles dictionary. The temperature should be provided after the stopping
+    condition but before the period, e.g. "1 A at 25 oC (1 second period)". It is
+    not essential to provide a temperature and a global temperature can be set either
+    from within the paramter values of passing a temperature to this experiment class.
+    If the temperature is not specified in a line, then the global temperature is used,
+    even if another temperature has been set in an earlier line.
 
     Parameters
     ----------
@@ -45,6 +54,10 @@ class Experiment:
     period : string, optional
         Period (1/frequency) at which to record outputs. Default is 1 minute. Can be
         overwritten by individual operating conditions.
+    temperature: float, optional
+        The ambient air temperature in degrees Celsius at which to run the experiment.
+        Default is None whereby the ambient temperature is taken from the parameter set.
+        This value is overwritten if the temperature is specified in a step.
     termination : list, optional
         List of conditions under which to terminate the experiment. Default is None.
     drive_cycles : dict
@@ -60,6 +73,7 @@ def __init__(
         self,
         operating_conditions,
         period="1 minute",
+        temperature=None,
         termination=None,
         drive_cycles={},
         cccv_handling="two-step",
@@ -71,12 +85,15 @@ def __init__(
         self.args = (
             operating_conditions,
             period,
+            temperature,
             termination,
             drive_cycles,
             cccv_handling,
         )
 
         self.period = self.convert_time_to_seconds(period.split())
+        self.temperature = temperature
+
         operating_conditions_cycles = []
         for cycle in operating_conditions:
             # Check types and convert strings to 1-tuples
@@ -163,16 +180,26 @@ def read_string(self, cond, drive_cycles):
             cond_CC, cond_CV = cond.split(" then ")
             op_CC = self.read_string(cond_CC, drive_cycles)
             op_CV = self.read_string(cond_CV, drive_cycles)
+
+            if op_CC["temperature"] != op_CV["temperature"]:
+                raise ValueError(
+                    "The temperature for the CC and CV steps must be the same."
+                    f"Got {op_CC['temperature']} and {op_CV['temperature']}"
+                    f"from {op_CC['string']} and {op_CV['string']}"
+                )
+
             tag_CC = op_CC["tags"] or []
             tag_CV = op_CV["tags"] or []
             tags = list(np.unique(tag_CC + tag_CV))
             if len(tags) == 0:
                 tags = None
+
             outputs = {
                 "type": "CCCV",
                 "Voltage input [V]": op_CV["Voltage input [V]"],
                 "time": op_CV["time"],
                 "period": op_CV["period"],
+                "temperature": op_CC["temperature"],
                 "dc_data": None,
                 "string": cond,
                 "events": op_CV["events"],
@@ -198,6 +225,11 @@ def read_string(self, cond, drive_cycles):
             period = self.convert_time_to_seconds(time.split())
         else:
             period = self.period
+
+        # Temperature part of the condition is removed here
+        unprocessed_cond = cond
+        temperature, cond = self._read_and_drop_temperature(cond)
+
         # Read instructions
         if "Run" in cond:
             cond_list = cond.split()
@@ -234,13 +266,17 @@ def read_string(self, cond, drive_cycles):
                 cond_list = cond.split()
                 idx_for = cond_list.index("for")
                 idx_until = cond_list.index("or")
+
                 electric = self.convert_electric(cond_list[:idx_for])
+
                 time = self.convert_time_to_seconds(cond_list[idx_for + 1 : idx_until])
                 events = self.convert_electric(cond_list[idx_until + 2 :])
+
             elif "for" in cond:
                 # e.g. for 3 hours
                 cond_list = cond.split()
                 idx = cond_list.index("for")
+
                 electric = self.convert_electric(cond_list[:idx])
                 time = self.convert_time_to_seconds(cond_list[idx + 1 :])
                 events = None
@@ -264,8 +300,9 @@ def read_string(self, cond, drive_cycles):
             **electric,
             "time": time,
             "period": period,
+            "temperature": temperature,
             "dc_data": dc_data,
-            "string": cond,
+            "string": unprocessed_cond,
             "events": events,
             "tags": tags,
         }
@@ -329,6 +366,9 @@ def convert_electric(self, electric):
                     raise ValueError(
                         "Instruction must be 'discharge', 'charge', 'rest', 'hold' or "
                         f"'Run'. For example: {examples}"
+                        ""
+                        "The following instruction does not comply: "
+                        f"{instruction}"
                     )
             elif len(electric) == 2:
                 # e.g. 3 A, 4.1 V
@@ -377,6 +417,44 @@ def convert_electric(self, electric):
                     )
                 )
 
+    def _detect_mistyped_temperatures(self, cond):
+        if "oC" in cond:
+            raise ValueError(f"Temperature not written correctly on step: '{cond}'")
+
+    def _read_and_drop_temperature(self, cond):
+        matches = re.findall(r"at\s-*\d+\.*\d*\s*oC", cond)
+
+        if len(matches) == 0:
+            self._detect_mistyped_temperatures(cond)
+
+            if self.temperature is None:
+                pybamm.logger.warning(
+                    "Temperature not found on step: "
+                    f"'{cond}', using temperature "
+                    "from parameter values."
+                )
+
+            else:
+                pybamm.logger.warning(
+                    f"Temperature not found on step: '{cond}', "
+                    f"using global temperature "
+                    f"({self.temperature}oC) instead"
+                )
+
+            temperature = self.temperature
+            reduced_cond = cond
+
+        elif len(matches) == 1:
+            match = matches[0]
+            numerical_part = re.findall(r"-*\d+\.*\d*", match)[0]
+            temperature = float(numerical_part)
+            reduced_cond = cond.replace(match, "")
+
+        else:
+            raise ValueError(f"More than one temperature found on step: '{cond}'")
+
+        return temperature, reduced_cond
+
     def convert_time_to_seconds(self, time_and_units):
         """Convert a time in seconds, minutes or hours to a time in seconds"""
         time, units = time_and_units
@@ -442,7 +520,7 @@ def is_cccv(self, step, next_step):
         # e.g. step="Charge at 2.0 A until 4.2V"
         # next_step="Hold at 4.2V until C/50"
         if (
-            step.startswith("Charge")
+            (step.startswith("Charge") or step.startswith("Discharge"))
             and "until" in step
             and "V" in step
             and "Hold at " in next_step

pybamm/input/parameters/ecm/example_set.py

@@ -79,11 +79,10 @@ def get_parameter_values():
     values = {
         "chemistry": "ecm",
         "Initial SoC": 0.5,
-        "Initial cell temperature [degC]": 25,
-        "Initial jig temperature [degC]": 25,
+        "Initial temperature [K]": 25 + 273.15,
         "Cell capacity [A.h]": cell_capacity,
         "Nominal cell capacity [A.h]": cell_capacity,
-        "Ambient temperature [degC]": 25,
+        "Ambient temperature [K]": 25 + 273.15,
         "Current function [A]": 100,
         "Upper voltage cut-off [V]": 4.2,
         "Lower voltage cut-off [V]": 3.2,

pybamm/parameters/ecm_parameters.py

@@ -42,11 +42,14 @@ def _set_compatibility_parameters(self):
 
     def _set_initial_condition_parameters(self):
         self.initial_soc = pybamm.Parameter("Initial SoC")
-        self.initial_T_cell = pybamm.Parameter("Initial cell temperature [degC]")
-        self.initial_T_jig = pybamm.Parameter("Initial jig temperature [degC]")
+        self.initial_T_cell = pybamm.Parameter("Initial temperature [K]") - 273.15
+        self.initial_T_jig = pybamm.Parameter("Initial temperature [K]") - 273.15
 
     def T_amb(self, t):
-        return pybamm.FunctionParameter("Ambient temperature [degC]", {"Time [s]": t})
+        ambient_temperature_K = pybamm.FunctionParameter(
+            "Ambient temperature [K]", {"Time [s]": t}
+        )
+        return ambient_temperature_K - 273.15
 
     def ocv(self, soc):
         return pybamm.FunctionParameter("Open circuit voltage [V]", {"SoC": soc})