pvlib.ivtools.sdm.fit_pvsyst_sandia#

pvlib.ivtools.sdm.fit_pvsyst_sandia(ivcurves, specs, const=None, maxiter=5, eps1=0.001)[source]#

Estimate parameters for the PVsyst module performance model.

Parameters:

ivcurves (dict) –

iarray
One array element for each IV curve. The jth element is itself an array of current for jth IV curve (same length as v[j]) [A]

varray
One array element for each IV curve. The jth element is itself an array of voltage for jth IV curve (same length as i[j]) [V]

eearray
effective irradiance for each IV curve, i.e., POA broadband irradiance adjusted by solar spectrum modifier [W / m^2]

tcarray
cell temperature for each IV curve [°C]

i_scarray
short circuit current for each IV curve [A]

v_ocarray
open circuit voltage for each IV curve [V]

i_mparray
current at max power point for each IV curve [A]

v_mparray
voltage at max power point for each IV curve [V]
specs (dict) –

cells_in_seriesint
number of cells in series

alpha_scfloat
temperature coefficient of isc [A/C]
const (dict) –

E0float
effective irradiance at STC, default 1000 [Wm⁻²]

T0float
cell temperature at STC, default 25°C. [°C]

kfloat
Boltzmann’s constant [J/K]

qfloat
elementary charge [Coulomb]
maxiter (int, default 5) – input that sets the maximum number of iterations for the parameter updating part of the algorithm.
eps1 (float, default 1e-3) – Tolerance for the IV curve fitting. The parameter updating stops when absolute values of the percent change in mean, max and standard deviation of Imp, Vmp and Pmp between iterations are all less than eps1, or when the number of iterations exceeds maxiter.

Returns:

dict –

I_L_reffloat: light current at STC [A]
I_o_reffloat: dark current at STC [A]
EgReffloat: effective band gap at STC [eV]
R_sfloat: series resistance at STC [ohm]
R_sh_reffloat: shunt resistance at STC [ohm]
R_sh_0float: shunt resistance at zero irradiance [ohm]
R_sh_expfloat: exponential factor defining decrease in shunt resistance with increasing effective irradiance
gamma_reffloat: diode (ideality) factor at STC [unitless]
mu_gammafloat: temperature coefficient for diode (ideality) factor [1/K]
cells_in_seriesint: number of cells in series
ipharray: light current for each IV curve [A]
ioarray: dark current for each IV curve [A]
rsarray: series resistance for each IV curve [ohm]
rsharray: shunt resistance for each IV curve [ohm]
uarray: boolean for each IV curve indicating that the parameter values are deemed reasonable by the private function _filter_params

Notes

The PVsyst module performance model is described in [1], [2], and [3]. The fitting method is documented in [4], [5], and [6]. Ported from PVLib Matlab [7].

References