Source code for psc_sim.eis_lumped

"""Lumped-element EIS: canonical series blocks (HTML computeEIS)."""

from __future__ import annotations

import numpy as np

from psc_sim.parameters import CellParameters
from psc_sim.simulation.eis_grid import default_eis_freqs




def eis_impedance(p: CellParameters, freqs: np.ndarray) -> tuple[np.ndarray, np.ndarray]:
    """
    Return Zre, Zim (mathematical Im) for the canonical series model:

    Z = Rs + Z_parallel(Rsh, Cj) + (Rion + 1/(jω Cion))

    Same algebra as solar_cell_sim_app.html ``computeEIS``.
    """
    Rs, Rsh, Cj, Rion, Cion = p.Rs, p.Rsh, p.Cj, p.Rion, p.Cion
    f = np.asarray(freqs, dtype=float)
    w = 2.0 * np.pi * f
    zsh_den = 1.0 + (Rsh * w * Cj) ** 2
    zsh_re = Rsh / zsh_den
    zsh_im = -Rsh * Rsh * w * Cj / zsh_den
    zion_re = np.full_like(f, Rion, dtype=float)
    zion_im = -1.0 / (w * Cion)
    zre = Rs + zsh_re + zion_re
    zim = zsh_im + zion_im
    return zre, zim



def eis_default_sweep(p: CellParameters) -> tuple[np.ndarray, np.ndarray, np.ndarray]:
    freqs = default_eis_freqs()
    zre, zim = eis_impedance(p, freqs)
    return freqs, zre, zim