[Bug]:

[None2None]

PyBaMM Version

25.4.2

Python Version

Python3.12.7

Describe the bug

Code that works in my pybamm 25.1 version does not work in pybamm 25.4.2, for example:

If pybamm 25.4.2 makes changes to termination, please make the changes in Examples:Custom experiments as well:

Steps to Reproduce

import pybamm
import numpy as np
from scipy.signal import butter, lfilter, savgol_filter
import pandas as pd
import matplotlib.pyplot as plt

定义P2D模型

pybamm.set_logging_level("INFO")
model = pybamm.lithium_ion.DFN(
{
"SEI": "solvent-diffusion limited",
"SEI porosity change": "true",
"lithium plating": "partially reversible",
"lithium plating porosity change": "true",
}
)

定义参数与变量

parameter_values = pybamm.ParameterValues("OKane2022")
parameter_values.update({"Ambient temperature [K]": 298.15}) #定义温度298.15K 283.15 273.15 268.15

#在常规充电电流上叠加一正弦电流作为激励信号对电池进行充电
#值得注意的是，正弦电流被控制在充电电流的10%以内，以确保响应电压保持在10mV附近
#1.定义直流充电电流
C_rate = 0.25
I_dc = parameter_values["Nominal cell capacity [A.h]"] * C_rate
#2.定义扰动电流
AC_amp = 0.1 * I_dc
AC_fre = 1
Sample_rate = 20
Sample_period = 1 / Sample_rate
#3.定义总电流
def current_function(t):
I_total = I_dc + AC_amp * np.sin(2 * np.pi * AC_fre * t)
return -I_total

######划分网格######
var_pts = {
"x_n": 5,
"x_s": 5,
"x_p": 5,
"r_n": 15,
"r_p": 15,
}

######定义终止条件######
def soc_cutoff(variables):
return variables["Discharge capacity [A.h]"] + 4.5

soc_termination = pybamm.step.CustomTermination(name="SOC 90%", event_function=soc_cutoff)
terminations = [soc_termination, "4.3 V"]

######定义实验######
experiment = pybamm.Experiment(
[
pybamm.step.current(
current_function,
period=f"{Sample_period} seconds",
termination=terminations
),
]
)

######求解######
solver = pybamm.CasadiSolver(mode="safe")
sim = pybamm.Simulation(model, parameter_values=parameter_values, experiment=experiment, var_pts=var_pts, solver=solver)
sol = sim.solve(initial_soc=0)

Relevant log output

2025-05-16 20:45:02.214 - [INFO] base_model._build_model(890): Start building Doyle-Fuller-Newman model
2025-05-16 20:45:02.298 - [INFO] base_battery_model.build_model(1083): Finish building Doyle-Fuller-Newman model
Traceback (most recent call last):
  File "D:\post_graduate\Third_article\ThirdArticleModels\DEIS_CMWT.py", line 56, in <module>
    pybamm.step.current(
  File "D:\Anaconda\envs\py312\Lib\site-packages\pybamm\experiment\step\steps.py", line 143, in current
    return Current(value, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\Anaconda\envs\py312\Lib\site-packages\pybamm\experiment\step\steps.py", line 133, in __init__
    super().__init__(value, **kwargs)
  File "D:\Anaconda\envs\py312\Lib\site-packages\pybamm\experiment\step\base_step.py", line 449, in __init__
    super().__init__(*args, **kwargs)
  File "D:\Anaconda\envs\py312\Lib\site-packages\pybamm\experiment\step\base_step.py", line 177, in __init__
    operator, typ, val = _parse_termination(term, self.value)
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\Anaconda\envs\py312\Lib\site-packages\pybamm\experiment\step\base_step.py", line 606, in _parse_termination
    raise ValueError(
ValueError: Termination must include an operator when using InputParameter.