pvl_est_Rs_Swanson

PVL_EST_RS_SWANSON Estimate Rs using the method of Swanson.

Contents

Syntax

Description:

The method of Swanson (see [1]) estimates series resistance using points from two IV curves at unequal but similar irradiance, e.g., at 950 W/m2 and 1000 W/m2. The cell temperature is assumed to be the same for both IV curves. A point is selected on each IV curve where the current is less than Isc by the input delI. If optional arguments are provided, the difference between the returned Rs value and the Rs parameter for the single diode equation is estimated, see [2].

Inputs:

Outputs:

Example

clearvars

% Set up parameters for a representative 60 cell cSi module using the Desoto model
Const.q = 1.60218E-19;
Const.k = 1.38066E-23;
Const.E0 = 1000;
Const.T0 = 25;

param.aIsc = 0.0008;  % A/C
param.bVoc = -0.1900; % V/C

param.Rs_ref = 0.2;
param.Rsh_ref = 1000;
param.IL_ref = 8.0;
param.I0_ref = 5e-10;

param.a_ref = 1.05 * 60 * Const.k/Const.q * (273.15 + Const.T0);

EgRef = 1.121;
dEgdT = -0.0002677;

% Calculate first IV curve
Ee = 1000;
Tc = 25;
nPts = 100;
[IL, I0, Rs, Rsh1, nNsVth] = pvl_calcparams_desoto(Ee, Tc, param.aIsc, param, EgRef, dEgdT);
IVcurve1 = pvl_singlediode(IL, I0, Rs, Rsh1, nNsVth, nPts);

% Calculate second IV curve
Ee = 950;
[IL, I0, Rs, Rsh2, nNsVth] = pvl_calcparams_desoto(Ee, Tc, param.aIsc, param, EgRef, dEgdT);
IVcurve2 = pvl_singlediode(IL, I0, Rs, Rsh2, nNsVth, nPts);

% Current differential
delI = 0.95*(IVcurve1.Isc - IVcurve1.Imp);

% Estimate Rs
Rs = pvl_est_Rs_Swanson(IVcurve1.V, IVcurve1.I, IVcurve2.V, IVcurve2.I, delI)
Rs =

    0.2117

References:

See also

pvl_est_Rs_Bowden , pvl_est_Rs_sunsVoc , pvl_est_Rs_Pysch , pvl_est_Rs_IEC60891_1 , pvl_est_Rs_IEC60891_2

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