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) –
    i : array
    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]
    v : array
    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]
    ee : array
    effective irradiance for each IV curve, i.e., POA broadband irradiance adjusted by solar spectrum modifier [W / m^2]
    tc : array
    cell temperature for each IV curve [C]
    i_sc : array
    short circuit current for each IV curve [A]
    v_oc : array
    open circuit voltage for each IV curve [V]
    i_mp : array
    current at max power point for each IV curve [A]
    v_mp : array
    voltage at max power point for each IV curve [V]
  • specs (dict) –
    cells_in_series : int
    number of cells in series
    alpha_sc : float
    temperature coefficient of isc [A/C]
  • const (dict) –
    E0 : float
    effective irradiance at STC, default 1000 [W/m^2]
    T0 : float
    cell temperature at STC, default 25 [C]
    k : float
    1.38066E-23 J/K (Boltzmann’s constant)
    q : float
    1.60218E-19 Coulomb (elementary charge)
  • 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_ref : float

light current at STC [A]

I_o_ref : float

dark current at STC [A]

EgRef : float

effective band gap at STC [eV]

R_s : float

series resistance at STC [ohm]

R_sh_ref : float

shunt resistance at STC [ohm]

R_sh_0 : float

shunt resistance at zero irradiance [ohm]

R_sh_exp : float

exponential factor defining decrease in shunt resistance with increasing effective irradiance

gamma_ref : float

diode (ideality) factor at STC [unitless]

mu_gamma : float

temperature coefficient for diode (ideality) factor [1/K]

cells_in_series : int

number of cells in series

iph : array

light current for each IV curve [A]

io : array

dark current for each IV curve [A]

rs : array

series resistance for each IV curve [ohm]

rsh : array

shunt resistance for each IV curve [ohm]

u : array

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

[1]K. Sauer, T. Roessler, C. W. Hansen, Modeling the Irradiance and Temperature Dependence of Photovoltaic Modules in PVsyst, IEEE Journal of Photovoltaics v5(1), January 2015.
[2]A. Mermoud, PV Modules modeling, Presentation at the 2nd PV Performance Modeling Workshop, Santa Clara, CA, May 2013
[3]A. Mermoud, T. Lejeuene, Performance Assessment of a Simulation Model for PV modules of any available technology, 25th European Photovoltaic Solar Energy Conference, Valencia, Spain, Sept. 2010
[4]C. Hansen, Estimating Parameters for the PVsyst Version 6 Photovoltaic Module Performance Model, Sandia National Laboratories Report SAND2015-8598
[5]C. Hansen, Parameter Estimation for Single Diode Models of Photovoltaic Modules, Sandia National Laboratories Report SAND2015-2065
[6]C. Hansen, Estimation of Parameters for Single Diode Models using Measured IV Curves, Proc. of the 39th IEEE PVSC, June 2013.
[7]PVLib MATLAB https://github.com/sandialabs/MATLAB_PV_LIB