Contributions

Contributions to pvmismatch that are considered useful enough to be distributed but are not necessarily considered part of pvmismatch core.

Generate Coefficients

Methods to generate diode coefficients.

pvmismatch.contrib.gen_coeffs.TEST_MAT = [array([[15., 25., 50., 75.], [15., 25., 50., 75.], [15., 25., 50., 75.], [15., 25., 50., 75.], [15., 25., 50., 75.], [15., 25., 50., 75.], [15., 25., 50., 75.]]), array([[ 100., 100., 100., 100.], [ 200., 200., 200., 200.], [ 400., 400., 400., 400.], [ 600., 600., 600., 600.], [ 800., 800., 800., 800.], [1000., 1000., 1000., 1000.], [1100., 1100., 1100., 1100.]])]

IEC61853 test matrix

pvmismatch.contrib.gen_coeffs.gen_iec_61853_from_sapm(pvmodule)

Generate an IEC 61853 test from Sandia Array Performance Model (sapm).

Parameters:pvmodule (dict) – PV module to be tested Returns:a pandas dataframe with columns i_mp, v_mp, i_sc, and v_oc and rows corresponding to the IEC61853 test conditions

Module is a dictionary according to pvlib.pvsystem.sapm.

pvmismatch.contrib.gen_coeffs.gen_two_diode(isc, voc, imp, vmp, nseries, nparallel, tc, x0=None, *args, **kwargs)

Generate two-diode model parameters for pvcell given.

Parameters:

• isc (numeric) – short circuit current [A]
• voc (numeric) – open circuit voltage [V]
• imp (numeric) – max power current [A]
• vmp (numeric) – max power voltage [V]
• nseries (int) – number of cells in series
• nparallel (int) – number of parallel substrings in PV module
• tc (numeric) – cell temperature [C]
• x0 – optional list of initial guesses, default is None

Returns:

tuple (isat1, isat2, rs, rsh) of generated coefficients and the solver output

pvmismatch.contrib.gen_coeffs.residual_two_diode(x, isc, voc, imp, vmp, tc)

Objective function to solve 2-diode model.

Parameters:

• x – parameters isat1, isat2, rs, and rsh
• isc – short circuit current [A] at tc [C]
• voc – open circuit voltage [V] at tc [C]
• imp – max power current [A] at tc [C]
• vmp – max power voltage [V] at tc [C]
• tc – cell temperature [C]

Returns:

norm of the residuals and the Jacobian matrix

Example

Run the example in gen_coeffs:

python pvmismatch/contrib/gen_coeffs/example.py STC ./examples

This creates a figure examples/STC.png which calculates the coefficients using only STC conditions, and displays the power error relative to STC, and the RMSE of the IV curve relative to IMP0, VMP0, ISC0, and VOC0.

Run the example again with IEC61853 as the first argument:

python pvmismatch/contrib/gen_coeffs/example.py IEC61853 ./examples

This creates a figure examples/IEC61853.png which calculates the coefficients using the IEC61853 test conditions, and displays the power error relative to STC, and the RMSE of the IV curve relative to IMP0, VMP0, ISC0, and VOC0.

Note: You can see that the lack of irradiance correction on shunt resistance in PVMismatch causes a larger error when the IEC61853 test results are used.

Module Mismatch Simulator

Created on Mar 29, 2013

This script allows the user to dynamically investigate the IV and PV characteristics of a single module. The user chooses the modules size–72 or 96 cells. A GUI is then generated that allows the user to change the size, location, and irradiance level of a single “shade rectangle”. Outputs include cell, substring, and module level IV and PV curves as well as a module diagram showing the shade location, any reverse biased cells, and any active diodes.

@author: bmeyers