Shunt resistance light dependence

.gitignore

@@ -10,14 +10,14 @@ pvmismatch.sublime-workspace
 
 # files
 *.pyc
-*.orig
 
 # build
 dist/
 pvmismatch.egg-info/
 build/
 Makefile
 version.py
+__pycache__/
 
 # docs
 !docs/_templates/
@@ -28,7 +28,7 @@ testPV/
 benchmark_*/
 .coverage
 .cache/
-__pycache__/
+.pytest_cache/
 
 # virtualenv
 venv/

README.rst

@@ -35,6 +35,6 @@ history is also on `GitHub <https://github.com/SunPower/releases/>`__.
    :target: https://travis-ci.org/SunPower/PVMismatch
 
 Other Projects that use PVMismatch
------
+----------------------------------
 System level mismatch loss calculator using PVMismatch tool (STC and Annual energy loss)
 https://github.com/SunPower/MismatchLossStudy 

pv_tk.py

@@ -7,7 +7,7 @@
 @author: marko
 """
 from pvmismatch.pvmismatch_tk.pvapplication_tk import PVapplicaton
-from Tkinter import Tk
+from tkinter import Tk
 import sys
 import re
 
@@ -19,6 +19,7 @@ def showHelpError(argvs_):
     errMsg = errMsg + 'is not valid. See "wm_geometry help" above.'
     raise Exception(errMsg)
 
+
 if __name__ == "__main__":
     nargv = len(sys.argv)  # number of user arguments
     argvs = sys.argv[1:]  # will be empty if only sys.argv[0]
@@ -59,7 +60,7 @@ def showHelpError(argvs_):
         dims = None
     if dims is not None:
         dim_reset_or_dims = lambda dims: (not dims) * 'reset' + dims
-        print "dimensions: {}".format(dim_reset_or_dims(dims))
+        print("dimensions: {}".format(dim_reset_or_dims(dims)))
     root = Tk()
     app = PVapplicaton(root)
     root.geometry(dims)

pvmismatch/contrib/gen_coeffs/__init__.py

@@ -6,30 +6,43 @@
 import numpy as np
 from scipy import optimize
 from pvmismatch.contrib.gen_coeffs import diode, two_diode
-from pvmismatch.pvmismatch_lib.pvcell import ISAT1_T0, ISAT2_T0, RS, RSH
+from pvmismatch.pvmismatch_lib.pvcell import ISAT1_T0, ISAT2_T0, RS, RSH_E0
 
 # IEC 61853 test matrix
 TC_C = [15.0, 25.0, 50.0, 75.0]
 IRR_W_M2 = [100.0, 200.0, 400.0, 600.0, 800.0, 1000.0, 1100.0]
-TEST_MAT = np.meshgrid(TC_C, IRR_W_M2)
+TEST_MAT = np.meshgrid(TC_C, IRR_W_M2)  #: IEC61853 test matrix
 
 def gen_iec_61853_from_sapm(pvmodule):
     """
     Generate an IEC 61853 test from Sandia Array Performance Model (sapm).
 
-    :param pvmodule: PV module to be tested
-    :type pvmodule: dict
+    :param dict pvmodule: 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 :def:`pvlib.pvsystem.sapm`.
+    Module is a dictionary according to ``pvlib.pvsystem.sapm``.
     """
     tc, irr = TEST_MAT
     return sapm(irr / 1000.0, tc, pvmodule)
 
 
 def gen_two_diode(isc, voc, imp, vmp, nseries, nparallel,
-                  tc, x0 = None, *args, **kwargs):
+                  tc, ee, x0=None, *args, **kwargs):
     """
-    Generate two-diode model parameters for ``pvcell`` given 
+    Generate two-diode model parameters for ``pvcell`` given.
+
+    :param numeric isc: short circuit current [A]
+    :param numeric voc: open circuit voltage [V]
+    :param numeric imp: max power current [A]
+    :param numeric vmp: max power voltage [V]
+    :param int nseries: number of cells in series
+    :param int nparallel: number of parallel substrings in PV module
+    :param numeric tc: cell temperature [C]
+    :param numeric ee: effective irradiance [suns]
+    :param x0: optional list of initial guesses, default is ``None``
+    :returns: tuple ``(isat1, isat2, rs, rsh)`` of generated coefficients and
+        the solver output
     """
     isc_cell = isc / nparallel
     voc_cell = voc / nseries
@@ -39,7 +52,7 @@ def gen_two_diode(isc, voc, imp, vmp, nseries, nparallel,
         isat1 = ISAT1_T0  # [A]
         isat2 = ISAT2_T0
         rs = RS  # [ohms]
-        rsh = RSH  # [ohms]
+        rsh = RSH_E0  # [ohms]
     else:
         isat1 = x0[0]
         isat2 = x0[1]
@@ -48,7 +61,7 @@ def gen_two_diode(isc, voc, imp, vmp, nseries, nparallel,
     x = np.array([np.log(isat1), np.log(isat2), np.sqrt(rs), np.sqrt(rsh)])
     sol = optimize.root(
         fun=residual_two_diode, x0=x,
-        args=(isc_cell, voc_cell, imp_cell, vmp_cell, tc),
+        args=(isc_cell, voc_cell, imp_cell, vmp_cell, tc, ee),
         jac=True,
         *args, **kwargs
     )
@@ -78,17 +91,18 @@ def gen_sapm(iec_61853):
     return isc0, alpha_isc
 
 
-
-def residual_two_diode(x, isc, voc, imp, vmp, tc):
+def residual_two_diode(x, isc, voc, imp, vmp, tc, ee):
     """
     Objective function to solve 2-diode model.
-    :param x: parameters isat1, isat2, rs and rsh
-    :param isc: short circuit current [A] at tc [C]
-    :param voc: open circuit voltage [V] at tc [C]
-    :param imp: max power current [A] at tc [C]
-    :param vmp: max power voltage [V] at tc [C]
+
+    :param x: parameters ``isat1``, ``isat2``, ``rs``, and ``rsh``
+    :param isc: short circuit current [A] at ``tc`` [C]
+    :param voc: open circuit voltage [V] at ``tc`` [C]
+    :param imp: max power current [A] at ``tc`` [C]
+    :param vmp: max power voltage [V] at ``tc`` [C]
     :param tc: cell temperature [C]
-    :return: norm of the residuals its sensitivity
+    :param ee: effective irradiance [suns]
+    :returns: norm of the residuals and the Jacobian matrix
     """
     # Constants
     q = diode.QE  # [C/electron] elementary electric charge
@@ -99,11 +113,13 @@ def residual_two_diode(x, isc, voc, imp, vmp, tc):
     vt = kb * tck / q  # [V] thermal voltage
     # Rescale Variables
     isat1_t0 = np.exp(x[0])
-    isat2 = np.exp(x[1])
+    isat2_t0 = np.exp(x[1])
     rs = x[2] ** 2.0
-    rsh = x[3] ** 2.0
+    rsh_e0 = x[3] ** 2.0
+    rsh = rsh_e0 / ee
     # first diode saturation current
     isat1 = diode.isat_t(tc, isat1_t0)
+    isat2 = diode.isat_t(tc, isat2_t0)
     # Short Circuit
     vd_isc, _ = diode.fvd(vc=0.0, ic=isc, rs=rs)
     id1_isc, _ = diode.fid(isat=isat1, vd=vd_isc, m=1.0, vt=vt)

pvmismatch/contrib/gen_coeffs/example.py

@@ -1,7 +1,14 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+
 """
 Generate coefficients example.
 """
 
+from __future__ import (
+    absolute_import, division, print_function, unicode_literals)
+import os
+import sys
 from pvmismatch.contrib import gen_coeffs
 from pvmismatch import *
 from matplotlib import pyplot as plt
@@ -22,60 +29,86 @@
 
 iec61853 = gen_coeffs.gen_iec_61853_from_sapm(gen_coeffs.PVMODULES[PROD_NAME])
 iec61853['i_mp'] = iec61853['p_mp'] / iec61853['v_mp']
-#isc0, alpha_isc = gen_coeffs.gen_sapm(iec61853)
-#x, sol = gen_coeffs.gen_two_diode(ISC0, VOC0, IMP0, VMP0, NS, NP, T0)
-x, sol = gen_coeffs.gen_two_diode(
-    iec61853['i_sc'], iec61853['v_oc'], iec61853['i_mp'],
-    iec61853['v_mp'], NS, NP, tc=TC, method='lm',
-    x0=(2.25e-11, 1.5e-6, 0.004, 10.0)
-)
-isat1, isat2, rs, rsh = x
-
-pvc = pvcell.PVcell(
-    Rs=rs, Rsh=rsh, Isat1_T0=isat1, Isat2_T0=isat2,
-    Isc0_T0=ISC0/NP, alpha_Isc=AISC
-)
-f1 = plt.figure()
+isc0, alpha_isc = gen_coeffs.gen_sapm(iec61853)
+assert np.isclose(isc0, ISC0)
+assert np.isclose(alpha_isc, AISC)
 
-for m, _tc in enumerate(gen_coeffs.TC_C):
-    pvc.Tcell = _tc + 273.15
-    plt.subplot(2, 2, m+1)
-    plt.xlim([0, 0.8])
-    plt.ylim([0, 8])
-    res_norm = 0
-    for n, _irr in enumerate(gen_coeffs.IRR_W_M2):
-        pvc.Ee = _irr / 1000.0
-        plt.plot(pvc.Vcell, pvc.Icell, '-', pvc.Vcell, pvc.Pcell, ':')
-        plt.plot(
-            iec61853['v_mp'][n][m]/NS, iec61853['i_mp'][n][m]/NP, 'x',
-            iec61853['v_oc'][n][m]/NS, 0.0, 'x',
-            0.0, iec61853['i_sc'][n][m]/NP, 'x',
-            iec61853['v_mp'][n][m]/NS, iec61853['p_mp'][n][m]/NS/NP, 'o',
+if __name__ == '__main__':
+    test_cond = 'STC'
+    if len(sys.argv) > 1:
+        test_cond = sys.argv[1]
+    if test_cond.upper() == 'STC':
+        x, sol = gen_coeffs.gen_two_diode(ISC0, VOC0, IMP0, VMP0, NS, NP, T0, E0)
+    else:
+        x, sol = gen_coeffs.gen_two_diode(
+            iec61853['i_sc'], iec61853['v_oc'], iec61853['i_mp'],
+            iec61853['v_mp'], NS, NP, tc=TC, ee=IRR/1000., method='lm',
+            x0=(2.25e-11, 1.5e-6, 0.004, 10.0)
         )
-        res_norm += (
-            pvc.calcIcell(iec61853['v_mp'][n][m]/NS)
-            - iec61853['i_mp'][n][m]/NP
-        )**2 / (iec61853['i_mp'][n][m]/NP)**2
-        res_norm += (
-            pvc.calcVcell(iec61853['i_mp'][n][m]/NP)
-            - iec61853['v_mp'][n][m]/NS
-        )**2 / (iec61853['v_mp'][n][m]/NS)**2
-        res_norm += (
-            pvc.calcVcell(0.0) - iec61853['v_oc'][n][m]/NS
-        )**2 / (iec61853['v_oc'][n][m]/NS)**2
-        res_norm += (
-            pvc.calcIcell(0.0) - iec61853['i_sc'][n][m]/NP
-        )**2 / (iec61853['i_sc'][n][m]/NP)**2
-        rel_diff = (pvc.Pcell.max()*NS*NP - iec61853['p_mp'][n][m]) / PMP0
-        plt.annotate('$\Delta_{rel}$ = %.2g%%' % (rel_diff*100),
-                     (0.65, iec61853['p_mp'][n][m]/NS/NP))
-    plt.annotate('norm of residuals = %g' % np.sqrt(res_norm / (7*4)),
-                 (0.5, 7.5))
-    plt.grid(True)
-    plt.title(
-        'PVMismatch Generated Coefficients for %s at Tc = %g' % (PROD_NAME, _tc)
+    isat1, isat2, rs, rsh = x
+
+    pvc = pvcell.PVcell(
+        Rs=rs, Rsh_E0=rsh, Isat1_T0=isat1, Isat2_T0=isat2,
+        Isc0_T0=ISC0/NP, alpha_Isc=AISC
     )
-    plt.xlabel('voltage')
-    plt.ylabel('current [A]')
-    plt.xlabel('voltage [V]')
-f1.show()
+    f1 = plt.figure(figsize=(16, 10))
+
+    for m, _tc in enumerate(gen_coeffs.TC_C):
+        pvc.Tcell = _tc + 273.15
+        plt.subplot(2, 2, m+1)
+        plt.xlim([0, round(VOC0/NS*1.25, 2)])
+        plt.ylim([0, round(ISC0/NP*1.25, 1)])
+        res_norm = 0
+        for n, _irr in enumerate(gen_coeffs.IRR_W_M2):
+            pvc.Ee = _irr / 1000.0
+            plt.plot(pvc.Vcell, pvc.Icell, '-', pvc.Vcell, pvc.Pcell, ':')
+            plt.plot(
+                iec61853['v_mp'][n][m]/NS, iec61853['i_mp'][n][m]/NP, 'x',
+                iec61853['v_oc'][n][m]/NS, 0.0, 'x',
+                0.0, iec61853['i_sc'][n][m]/NP, 'x',
+                iec61853['v_mp'][n][m]/NS, iec61853['p_mp'][n][m]/NS/NP, 'o',
+            )
+            res_norm += (
+                pvc.calcIcell(iec61853['v_mp'][n][m]/NS)
+                - iec61853['i_mp'][n][m]/NP
+            )**2 / (IMP0/NP)**2
+            res_norm += (
+                pvc.calcVcell(iec61853['i_mp'][n][m]/NP)
+                - iec61853['v_mp'][n][m]/NS
+            )**2 / (VMP0/NS)**2
+            res_norm += (
+                pvc.calcVcell(0.0) - iec61853['v_oc'][n][m]/NS
+            )**2 / (VOC0/NS)**2
+            res_norm += (
+                pvc.calcIcell(0.0) - iec61853['i_sc'][n][m]/NP
+            )**2 / (ISC0/NP)**2
+            rel_diff = (pvc.Pcell.max()*NS*NP - iec61853['p_mp'][n][m]) / PMP0
+            plt.annotate('$\Delta_{STC}$ = %.2g%%' % (rel_diff*100),
+                         (0.65, iec61853['p_mp'][n][m]/NS/NP))
+            plt.annotate('$E_e$ = %.2g[suns]' % (_irr/1000),
+                         (0.05, 0.05+iec61853['i_sc'][n][m]/NP))
+        plt.annotate('STC RMSE = %.2g%%' % (np.sqrt(res_norm / (7*4))*100),
+                     (0.65, 7.5))
+        plt.annotate('$I_{sat,1}$ = %.4g' % isat1,
+                     (0.65, 7.2))
+        plt.annotate('$I_{sat,2}$ = %.4g' % isat2,
+                     (0.65, 6.9))
+        plt.annotate('$R_s$ = %.4g' % rs,
+                     (0.65, 6.6))
+        plt.annotate('$R_{sh}$ = %.4g' % rsh,
+                     (0.65, 6.3))
+
+        plt.grid(True)
+        plt.title(
+            'PVMismatch Generated Coefficients for %s at Tc = %g' % (PROD_NAME, _tc)
+        )
+        plt.xlabel('voltage')
+        plt.ylabel('current [A], power [W]')
+        plt.xlabel('voltage [V]')
+        plt.tight_layout()
+        if len(sys.argv) > 2:
+            test_save_dir = sys.argv[2]
+            os.makedirs(test_save_dir, exist_ok=True)
+            f1.savefig(os.path.join(test_save_dir, sys.argv[1]))
+        else:
+            f1.show()

pvmismatch/contrib/gen_coeffs/tests/test_diode.py

@@ -3,7 +3,7 @@
 """
 
 from pvmismatch.pvmismatch_lib.pvcell import (
-    RS as RS_2, RSH as RSH_2, ISAT1_T0 as ISAT1_2, ISAT2_T0 as ISAT2_2
+    RS as RS_2, RSH_E0 as RSH_2, ISAT1_T0 as ISAT1_2, ISAT2_T0 as ISAT2_2
 )
 from pvmismatch.contrib.gen_coeffs import diode
 from pvmismatch.contrib.gen_coeffs import PVMODULES