HEV Thermal Demo: Cold Start, Cold Ambient

This demo simulates a Hybrid Electric Vehicle (HEV) with thermal modeling under cold start and cold ambient conditions, where the cabin, battery, and engine begin at the same temperature as the surrounding air.

import os
import sys
from pathlib import Path

import seaborn as sns

sys.path.insert(0, str(next(p / "demo_scripts" for p in (Path.cwd(), *Path.cwd().parents) if (p / "demo_scripts").is_dir())))

import fastsim as fsim
from plot_utils import (
    plot_hev_fc_energy,
    plot_hev_fc_pwr,
    plot_hev_res_energy,
    plot_hev_res_pwr,
    plot_hev_temperatures,
    plot_road_loads,
)

sns.set_theme()

SHOW_PLOTS = os.environ.get("SHOW_PLOTS", "true").lower() == "true"
SAVE_FIGS = os.environ.get("SAVE_FIGS", "false").lower() == "true"

Setup and Simulation¶

Load a thermal HEV, set cold initial temperatures for the cabin, battery, and engine to match the cold ambient, and run the simulation.

celsius_to_kelvin = 273.15
temp_amb_and_init = -6.7 + celsius_to_kelvin

# load 2021 Hyundai Sonata HEV with thermal model
veh_dict = fsim.Vehicle.from_resource(
    "2021_Hyundai_Sonata_Hybrid_Blue_thrml.yaml",
).to_pydict()
veh_dict["cabin"]["LumpedCabin"]["state"]["temperature_kelvin"] = temp_amb_and_init
veh_dict["pt_type"]["HEV"]["res"]["thrml"]["RESLumpedThermal"]["state"]["temperature_kelvin"] = (
    temp_amb_and_init
)
veh_dict["pt_type"]["HEV"]["fc"]["thrml"]["FuelConverterThermal"]["state"]["temperature_kelvin"] = (
    temp_amb_and_init
)
veh = fsim.Vehicle.from_pydict(veh_dict)

veh.set_save_interval(1)

disch_buffer < self.res.energy_capacity_usable()
disch_buffer: 1.0674736149042887 kWh
RES usable energy capacity: 0.8800000000000001 kWh
disch_buffer < self.res.energy_capacity_usable()
disch_buffer: 1.0674736149042887 kWh
RES usable energy capacity: 0.8800000000000001 kWh

# load cycle and set ambient temperature
cyc_dict = fsim.Cycle.from_resource("udds.csv").to_pydict()
cyc_dict["temp_amb_air_kelvin"] = [temp_amb_and_init] * len(cyc_dict["time_seconds"])
cyc = fsim.Cycle.from_pydict(cyc_dict)

sd = fsim.SimDrive(veh, cyc)
sd.walk()

df = sd.to_dataframe()
sd_dict = sd.to_pydict(flatten=True)

Visualize Results¶

Fuel converter power and energy, battery power and energy, component temperatures, and road loads under cold start, cold ambient conditions.

fig_fc_pwr, ax_fc_pwr = plot_hev_fc_pwr(df, save_figs=SAVE_FIGS, show_plots=SHOW_PLOTS)

fig_fc_energy, ax_fc_energy = plot_hev_fc_energy(df, save_figs=SAVE_FIGS, show_plots=SHOW_PLOTS)

fig_res_pwr, ax_res_pwr = plot_hev_res_pwr(df, save_figs=SAVE_FIGS, show_plots=SHOW_PLOTS)

fig_res_energy, ax_res_energy = plot_hev_res_energy(df, save_figs=SAVE_FIGS, show_plots=SHOW_PLOTS)

fig_temps, ax_temps = plot_hev_temperatures(df, save_figs=SAVE_FIGS, show_plots=SHOW_PLOTS)

fig, ax = plot_road_loads(df, veh, save_figs=SAVE_FIGS, show_plots=SHOW_PLOTS)

Source: fastsim/docs/demo_scripts/thermal/demo_hev_thrml_cs_ca.py