Commit efc7c457 authored by Turner, Sean's avatar Turner, Sean
Browse files

effective power fix

parent 24bc7847

src/lib.rs

+1 −3
Original line number Diff line number Diff line
@@ -308,7 +308,6 @@ fn simulate_timestep( 
        let mut head;

        let mut release;

        let mut target_release;

        let mut effective_power;

        let mut spill;



        for _ in 0..MAX_ITER {
@@ -322,7 +321,6 @@ fn simulate_timestep( 
                &reservoir.hpf_q,

            );

            target_release = release_result.release;

            effective_power = release_result.effective_power;



            release = if below_power_pool {

                0.0
@@ -367,7 +365,7 @@ fn simulate_timestep( 
            &reservoir.hpf_q,

        );

        target_release = release_result.release;

        effective_power = release_result.effective_power;

        let effective_power = release_result.effective_power;



        release = if below_power_pool {

            0.0

tests/test_dynamic_tailwater.py

+66 −1
Original line number Diff line number Diff line
@@ -12,7 +12,30 @@ import pandas as pd 
import pytest



import powersheds

from helpers import make_reservoir, make_cascade, run_single_reservoir

from helpers import (

    DEFAULT_HPF_H,

    DEFAULT_HPF_P,

    DEFAULT_HPF_Q,

    make_reservoir,

    make_cascade,

    run_single_reservoir,

)





def _interp_linear(x, xs, ys):

    """Simple clamped linear interpolation mirroring the Rust helper."""

    if x <= xs[0]:

        return ys[0]

    if x >= xs[-1]:

        return ys[-1]



    for i in range(len(xs) - 1):

        if xs[i] <= x <= xs[i + 1]:

            x1, x2 = xs[i], xs[i + 1]

            y1, y2 = ys[i], ys[i + 1]

            return y1 + (x - x1) * (y2 - y1) / (x2 - x1)



    return ys[0]





# =============================================================================
@@ -140,6 +163,48 @@ class TestConvergence: 
                f"NaN in tailwater_elevation at t={t}"

            )



    def test_tailwater_uses_converged_outflow_not_first_pass_guess(self):

        """Tailwater should reflect the converged fixed point, not a single pass.



        With a steep TW curve and high target power, the first-pass TW estimate

        from the initial head differs materially from the converged TW. This

        test fails if the model stops after the initial guess instead of

        iterating release/head/TW to consistency.

        """

        tw_outflow = [0.0, 100.0, 200.0]

        tw_elev = [140.0, 155.0, 170.0]

        target_power = 100.0



        result = run_single_reservoir(

            n_hours=1,

            capacity=1000.0,  # avoid spill so TW depends only on release

            catchment_inflow=[10.0],

            target_power=[target_power],

            max_release=[100.0],

            set_tw_outflow=tw_outflow,

            set_tw_elevation=tw_elev,

        )



        initial_tw = _interp_linear(0.0, tw_outflow, tw_elev)

        initial_head = 200.0 - initial_tw

        first_pass_release = powersheds.compute_release(

            target_power,

            initial_head,

            DEFAULT_HPF_H,

            DEFAULT_HPF_P,

            DEFAULT_HPF_Q,

        )

        first_pass_outflow_cumecs = first_pass_release * 1_000_000.0 / 3600.0

        first_pass_tw = _interp_linear(first_pass_outflow_cumecs, tw_outflow, tw_elev)



        final_release = result["release"][0]

        final_tw = result["tailwater_elevation"][0]

        final_outflow_cumecs = final_release * 1_000_000.0 / 3600.0

        fixed_point_tw = _interp_linear(final_outflow_cumecs, tw_outflow, tw_elev)



        assert final_tw == pytest.approx(fixed_point_tw, abs=0.2)

        assert abs(final_tw - first_pass_tw) > 1.0





# =============================================================================

# Mass balance preserved