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investigate and maybe fix some unexpected behavior with derating in Hybrid #126

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investigate and maybe fix some unexpected behavior with derating in Hybrid #126

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16 changes: 9 additions & 7 deletions altrios-core/src/consist/locomotive/powertrain/fuel_converter.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -80,8 +80,8 @@ pub struct FuelConverter {
pub(crate) pwr_for_peak_eff: si::Power,
/// idle fuel power to overcome internal friction (not including aux load)
pub pwr_idle_fuel: si::Power,
/// Interpolator for derating dynamic engine peak power based on altitude
/// and temperature. When interpolating, this returns fraction of normal
/// Interpolator for derating dynamic engine peak power based on altitude [m]
/// and temperature [*C]. When interpolating, this returns fraction of normal
/// peak power, e.g. a value of 1 means no derating and a value of 0 means
/// the engine is completely disabled.
#[api(skip_get, skip_set)]
Expand Down Expand Up @@ -190,10 +190,12 @@ impl FuelConverter {

let pwr_max_derated = match (&mut self.elev_and_temp_derate, elev_and_temp) {
(Some(elev_and_temp_derate), Some(elev_and_temp)) => {
elev_and_temp_derate.interpolate(&[
let derate_factor = elev_and_temp_derate.interpolate(&[
elev_and_temp.0.get::<si::meter>(),
elev_and_temp.1.get::<si::degree_celsius>(),
])? * self.pwr_out_max
])?;
ensure!(derate_factor <= 1.0 && derate_factor >= 0.0, format_dbg!());
derate_factor * self.pwr_out_max
}
(None, Some(_)) => bail!(
"{}\nExpected (self.elev_and_temp_derate, elev_and_temp) to both be Some or None",
Expand All @@ -209,7 +211,6 @@ impl FuelConverter {
self.pwr_out_max_init = self.pwr_out_max_init.max(self.pwr_out_max / 10.);
self.state.pwr_out_max = (self.state.pwr_mech_out
+ (self.pwr_out_max / self.pwr_ramp_lag) * dt)
.min(self.pwr_out_max)
.min(pwr_max_derated)
.max(self.pwr_out_max_init);
Ok(())
Expand Down Expand Up @@ -319,8 +320,9 @@ impl FuelConverter {
fn set_default_elev_and_temp_derate(&mut self) {
self.elev_and_temp_derate = Some(
Interp2D::new(
array![0.0, 3_000.0, 6_000.0],
array![0.0, 35.0, 45.0, 50.0],
array![0.0, 1_000.0, 2_000.0], // elevation in meters
array![0.0, 35.0, 45.0, 50.0], // temperature in degrees Celsius
// Fraction of static peak power
array![
[1.0, 1.0, 0.95, 0.8],
[0.95, 0.95, 0.9025, 0.76],
Expand Down
54 changes: 16 additions & 38 deletions python/altrios/demos/speed_limit_train_sim_demo_with_derating.py
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Original file line number Diff line number Diff line change
Expand Up @@ -47,24 +47,24 @@
fc_with_derate.set_default_elev_and_temp_derate()
fc_with_derate_dict = fc_with_derate.to_pydict()
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@calbaker calbaker May 22, 2025 •
edited
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@FDsteven this fc_with_derate_dict is the conventional FC. We need to make an equivalent for the hybrid and set the derate on it instead!

  • get the HEL dict
  • pull the FC out
  • instantiate a new FC for the HEL
  • run the set_...derate method
  • turn it back into a dict
  • put in the HEL dict
  • turn the HEL dict back into a HEL


hel_new_dict = copy(hel_dict)
hel_new_dict['loco_type']['HybridLoco']['fc'] = fc_with_derate_dict
hel_with_derate = alt.Locomotive.from_pydict(hel_new_dict)
hel_with_derate_dict = copy(hel_dict)
hel_with_derate_dict['loco_type']['HybridLoco']['fc'] = fc_with_derate_dict
hel_with_derate = alt.Locomotive.from_pydict(hel_with_derate_dict)

conv_new_dict = alt.Locomotive.default().to_pydict()
conv_new_dict['loco_type']['ConventionalLoco']['fc'] = fc_with_derate_dict
conv_with_derate = alt.Locomotive.from_pydict(conv_new_dict)
conv_with_derate_dict = alt.Locomotive.default().to_pydict()
conv_with_derate_dict['loco_type']['ConventionalLoco']['fc'] = fc_with_derate_dict
conv_with_derate = alt.Locomotive.from_pydict(conv_with_derate_dict)

# construct a vector of one BEL, one HEL, and several conventional locomotives
loco_vec = (
[hel.clone()]
+ [alt.Locomotive.default()] * 1
[alt.Locomotive.default()] * 2
# + [hel.clone()]
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@FDsteven uncomment this

)

# construct a vector of one BEL, one HEL, and several conventional locomotives
loco_vec_with_derating = (
[hel_with_derate.clone()]
+ [conv_with_derate] * 1
[conv_with_derate] * 2
# + [hel_with_derate.clone()]
)

# instantiate consist
Expand Down Expand Up @@ -476,10 +476,10 @@ def plot_bel_pwr_and_soc(ts: alt.SpeedLimitTrainSim, mod_str: str) -> Tuple[plt.
ax[0].plot(
df_with_derate['history.time_seconds'],
df_with_derate['loco_con.history.energy_fuel_joules'] / 1e9,
label='with derate',
label='with derate',u
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  • remove the ,u at the end of this line, d'oh!

)
ax[0].legend()
ax[0].set_ylabel("Cumulative Fuel [GJ]")
ax[0].set_ylabel("Cumu. Fuel [GJ]")

ax[1].plot(
df_no_derate['history.time_seconds'],
Expand All @@ -492,7 +492,7 @@ def plot_bel_pwr_and_soc(ts: alt.SpeedLimitTrainSim, mod_str: str) -> Tuple[plt.
label='with derate pwr max',
)
ax[1].legend()
ax[1].set_ylabel("Engine Power [MW]")
ax[1].set_ylabel("Eng. Pwr. [MW]")

ax[2].plot(
df_no_derate['history.time_seconds'],
Expand All @@ -512,41 +512,19 @@ def plot_bel_pwr_and_soc(ts: alt.SpeedLimitTrainSim, mod_str: str) -> Tuple[plt.
fig0, ax0 = plot_train_level_powers(train_sim, "No Derating")
fig1, ax1 = plot_train_network_info(train_sim, "No Derating")
fig2, ax2 = plot_consist_pwr(train_sim, "No Derating")
fig3, ax3 = plot_hel_pwr_and_soc(train_sim, "No Derating")
# fig3, ax3 = plot_hel_pwr_and_soc(train_sim, "No Derating")
# fig3.savefig("plots/hel with buffers.svg")
# fig4, ax4 = plot_bel_pwr_and_soc(train_sim, "No Derating")

fig0_sans_buffers, ax0_sans_buffers = plot_train_level_powers(train_sim_with_derating, "With Altitude and Temperature Derating")
fig1_sans_buffers, ax1_sans_buffers = plot_train_network_info(train_sim_with_derating, "With Altitude and Temperature Derating")
fig2_sans_buffers, ax2_sans_buffers = plot_consist_pwr(train_sim_with_derating, "With Altitude and Temperature Derating")
fig3_sans_buffers, ax3_sans_buffers = plot_hel_pwr_and_soc(train_sim_with_derating, "With Altitude and Temperature Derating")
# fig3_sans_buffers, ax3_sans_buffers = plot_hel_pwr_and_soc(train_sim_with_derating, "With Altitude and Temperature Derating")
# fig3_sans_buffers.savefig("plots/hel sans buffers.svg")
# fig4_sans_buffers, ax4_sans_buffers = plot_bel_pwr_and_soc(train_sim_sans_buffers, "With Altitude and Temperature Derating")

if SHOW_PLOTS:
plt.tight_layout()
plt.show()
# Impact of sweep of battery capacity TODO: make this happen

# whether to run assertions, enabled by default
ENABLE_ASSERTS = os.environ.get("ENABLE_ASSERTS", "true").lower() == "true"
# whether to override reference files used in assertions, disabled by default
ENABLE_REF_OVERRIDE = os.environ.get(
"ENABLE_REF_OVERRIDE", "false").lower() == "true"
# directory for reference files for checking sim results against expected results
ref_dir = alt.resources_root() / "demo_data/speed_limit_train_sim_demo/"

if ENABLE_REF_OVERRIDE:
ref_dir.mkdir(exist_ok=True, parents=True)
df: pl.DataFrame = train_sim.to_dataframe().lazy().collect()[-1]
df.write_csv(ref_dir / "to_dataframe_expected.csv")
if ENABLE_ASSERTS:
print("Checking output of `to_dataframe`")
to_dataframe_expected = pl.scan_csv(
ref_dir / "to_dataframe_expected.csv").collect()[-1]
assert to_dataframe_expected.equals(train_sim.to_dataframe()[-1]), \
f"to_dataframe_expected: \n{to_dataframe_expected}\ntrain_sim.to_dataframe()[-1]: \n{train_sim.to_dataframe()[-1]}" + \
"\ntry running with `ENABLE_REF_OVERRIDE=True`"
print("Success!")

# %%

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