# 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

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 [W/m^2]

T0float

cell temperature at STC, default 25 [C]

kfloat

1.38066E-23 J/K (Boltzmann’s constant)

qfloat

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_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

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