HEV Thermal Demo: Warm Start, Cold Ambient

This demo simulates a Hybrid Electric Vehicle (HEV) with thermal modeling under warm start and cold ambient conditions, where the cabin and battery begin warm, the engine begins hot, and the surrounding air is cold.

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 warm initial temperatures for the cabin and battery, a hot initial temperature for the engine, and a cold ambient temperature, then run the simulation.

celsius_to_kelvin = 273.15
temp_amb = -6.7 + celsius_to_kelvin
temp_init_bat_and_cab = 22.0 + celsius_to_kelvin
temp_init_eng = 70.0 + 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_init_bat_and_cab
veh_dict["pt_type"]["HEV"]["res"]["thrml"]["RESLumpedThermal"]["state"]["temperature_kelvin"] = (
    temp_init_bat_and_cab
)
veh_dict["pt_type"]["HEV"]["fc"]["thrml"]["FuelConverterThermal"]["state"]["temperature_kelvin"] = (
    temp_init_eng
)
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] * 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 warm 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_ws_ca.py