split test_sdm.py accordingly

pvlib/tests/ivtools/sdm/conftest.py

@@ -0,0 +1,12 @@
+import pytest
+
+
+@pytest.fixture
+def cec_params_cansol_cs5p_220p():
+ return {'ivcurve': {'V_mp_ref': 46.6, 'I_mp_ref': 4.73, 'V_oc_ref': 58.3,
+ 'I_sc_ref': 5.05},
+ 'specs': {'alpha_sc': 0.0025, 'beta_voc': -0.19659,
+ 'gamma_pmp': -0.43, 'cells_in_series': 96},
+ 'params': {'I_L_ref': 5.056, 'I_o_ref': 1.01e-10,
+ 'R_sh_ref': 837.51, 'R_s': 1.004, 'a_ref': 2.3674,
+ 'Adjust': 2.3}}

pvlib/tests/ivtools/sdm/test__fit_desoto_pvsyst_sandia.py

@@ -0,0 +1,102 @@
+import numpy as np
+
+import pytest
+from numpy.testing import assert_allclose
+
+from pvlib.ivtools.sdm._fit_desoto_pvsyst_sandia import (
+ _calc_theta_phi_exact,
+ _update_rsh_fixed_pt,
+ _update_io
+)
+
+
+@pytest.mark.parametrize('vmp, imp, iph, io, rs, rsh, nnsvth, expected', [
+ (2., 2., 2., 2., 2., 2., 2., np.nan),
+ (2., 2., 0., 2., 2., 2., 2., np.nan),
+ (2., 2., 2., 0., 2., 2., 2., np.nan),
+ (2., 2., 2., 2., 0., 2., 2., np.nan),
+ (2., 2., 2., 2., 2., 0., 2., np.nan),
+ (2., 2., 2., 2., 2., 2., 0., np.nan)])
+def test__update_rsh_fixed_pt_nans(vmp, imp, iph, io, rs, rsh, nnsvth,
+ expected):
+ outrsh = _update_rsh_fixed_pt(vmp, imp, iph, io, rs, rsh, nnsvth)
+ assert np.all(np.isnan(outrsh))
+
+
+def test__update_rsh_fixed_pt_vmp0():
+ outrsh = _update_rsh_fixed_pt(vmp=0., imp=2., iph=2., io=2., rs=2.,
+ rsh=2., nnsvth=2.)
+ assert_allclose(outrsh, np.array([502.]), atol=.0001)
+
+
+def test__update_rsh_fixed_pt_vector():
+ outrsh = _update_rsh_fixed_pt(rsh=np.array([-1., 3, .5, 2.]),
+ rs=np.array([1., -.5, 2., 2.]),
+ io=np.array([.2, .3, -.4, 2.]),
+ iph=np.array([-.1, 1, 3., 2.]),
+ nnsvth=np.array([4., -.2, .1, 2.]),
+ imp=np.array([.2, .2, -1., 2.]),
+ vmp=np.array([0., -1, 0., 0.]))
+ assert np.all(np.isnan(outrsh[0:3]))
+ assert_allclose(outrsh[3], np.array([502.]), atol=.0001)
+
+
+@pytest.mark.parametrize('voc, iph, io, rs, rsh, nnsvth, expected', [
+ (2., 2., 2., 2., 2., 2., 0.5911),
+ (2., 2., 2., 0., 2., 2., 0.5911),
+ (2., 2., 0., 2., 2., 2., 0.),
+ (2., 0., 2., 2., 2., 2., 1.0161e-4),
+ (0., 2., 2., 2., 2., 2., 17.9436)])
+def test__update_io(voc, iph, io, rs, rsh, nnsvth, expected):
+ outio = _update_io(voc, iph, io, rs, rsh, nnsvth)
+ assert_allclose(outio, expected, atol=.0001)
+
+
+@pytest.mark.parametrize('voc, iph, io, rs, rsh, nnsvth', [
+ (2., 2., 2., 2., 2., 0.),
+ (-1., -1., -1., -1., -1., -1.)])
+def test__update_io_nan(voc, iph, io, rs, rsh, nnsvth):
+ outio = _update_io(voc, iph, io, rs, rsh, nnsvth)
+ assert np.isnan(outio)
+
+
+@pytest.mark.parametrize('vmp, imp, iph, io, rs, rsh, nnsvth, expected', [
+ (2., 2., 2., 2., 2., 2., 2., (1.8726, 2.)),
+ (2., 0., 2., 2., 2., 2., 2., (1.8726, 3.4537)),
+ (2., 2., 0., 2., 2., 2., 2., (1.2650, 0.8526)),
+ (0., 2., 2., 2., 2., 2., 2., (1.5571, 2.))])
+def test__calc_theta_phi_exact(vmp, imp, iph, io, rs, rsh, nnsvth, expected):
+ theta, phi = _calc_theta_phi_exact(vmp, imp, iph, io, rs, rsh, nnsvth)
+ assert_allclose(theta, expected[0], atol=.0001)
+ assert_allclose(phi, expected[1], atol=.0001)
+
+
+@pytest.mark.parametrize('vmp, imp, iph, io, rs, rsh, nnsvth', [
+ (2., 2., 2., 0., 2., 2., 2.),
+ (2., 2., 2., 2., 2., 2., 0.),
+ (2., 0., 2., 2., 2., 0., 2.)])
+def test__calc_theta_phi_exact_both_nan(vmp, imp, iph, io, rs, rsh, nnsvth):
+ theta, phi = _calc_theta_phi_exact(vmp, imp, iph, io, rs, rsh, nnsvth)
+ assert np.isnan(theta)
+ assert np.isnan(phi)
+
+
+def test__calc_theta_phi_exact_one_nan():
+ theta, phi = _calc_theta_phi_exact(imp=2., iph=2., vmp=2., io=2.,
+ nnsvth=2., rs=0., rsh=2.)
+ assert np.isnan(theta)
+ assert_allclose(phi, 2., atol=.0001)
+
+
+def test__calc_theta_phi_exact_vector():
+ theta, phi = _calc_theta_phi_exact(imp=np.array([1., -1.]),
+ iph=np.array([-1., 1.]),
+ vmp=np.array([1., -1.]),
+ io=np.array([-1., 1.]),
+ nnsvth=np.array([1., -1.]),
+ rs=np.array([-1., 1.]),
+ rsh=np.array([1., -1.]))
+ assert np.isnan(theta[0])
+ assert np.isnan(theta[1])
+ assert np.isnan(phi[0])
+ assert_allclose(phi[1], 2.2079, atol=.0001)

pvlib/tests/ivtools/sdm/test_cec.py

@@ -0,0 +1,41 @@
+import numpy as np
+import pandas as pd
+
+import pytest
+
+from pvlib.ivtools import sdm
+
+from pvlib.tests.conftest import requires_pysam
+
+
+@requires_pysam
+def test_fit_cec_sam(cec_params_cansol_cs5p_220p):
+ input_data = cec_params_cansol_cs5p_220p['ivcurve']
+ specs = cec_params_cansol_cs5p_220p['specs']
+ I_L_ref, I_o_ref, R_s, R_sh_ref, a_ref, Adjust = \
+ sdm.fit_cec_sam(
+ celltype='polySi', v_mp=input_data['V_mp_ref'],
+ i_mp=input_data['I_mp_ref'], v_oc=input_data['V_oc_ref'],
+ i_sc=input_data['I_sc_ref'], alpha_sc=specs['alpha_sc'],
+ beta_voc=specs['beta_voc'],
+ gamma_pmp=specs['gamma_pmp'],
+ cells_in_series=specs['cells_in_series'])
+ expected = pd.Series(cec_params_cansol_cs5p_220p['params'])
+ modeled = pd.Series(index=expected.index, data=np.nan)
+ modeled['a_ref'] = a_ref
+ modeled['I_L_ref'] = I_L_ref
+ modeled['I_o_ref'] = I_o_ref
+ modeled['R_s'] = R_s
+ modeled['R_sh_ref'] = R_sh_ref
+ modeled['Adjust'] = Adjust
+ assert np.allclose(modeled.values, expected.values, rtol=5e-2)
+
+
+@requires_pysam
+def test_fit_cec_sam_estimation_failure(cec_params_cansol_cs5p_220p):
+ # Failing to estimate the parameters for the CEC SDM model should raise an
+ # exception.
+ with pytest.raises(RuntimeError):
+ sdm.fit_cec_sam(celltype='polySi', v_mp=0.45, i_mp=5.25, v_oc=0.55,
+ i_sc=5.5, alpha_sc=0.00275, beta_voc=0.00275,
+ gamma_pmp=0.0055, cells_in_series=1, temp_ref=25)

pvlib/tests/ivtools/sdm/test_desoto.py

@@ -0,0 +1,70 @@
+import numpy as np
+import pandas as pd
+
+import pytest
+
+from pvlib.ivtools import sdm
+from pvlib import pvsystem
+
+from pvlib.tests.conftest import requires_statsmodels
+
+
+def test_fit_desoto():
+ result, _ = sdm.fit_desoto(v_mp=31.0, i_mp=8.71, v_oc=38.3, i_sc=9.43,
+ alpha_sc=0.005658, beta_voc=-0.13788,
+ cells_in_series=60)
+ result_expected = {'I_L_ref': 9.45232,
+ 'I_o_ref': 3.22460e-10,
+ 'R_s': 0.297814,
+ 'R_sh_ref': 125.798,
+ 'a_ref': 1.59128,
+ 'alpha_sc': 0.005658,
+ 'EgRef': 1.121,
+ 'dEgdT': -0.0002677,
+ 'irrad_ref': 1000,
+ 'temp_ref': 25}
+ assert np.allclose(pd.Series(result), pd.Series(result_expected),
+ rtol=1e-4)
+
+
+def test_fit_desoto_failure():
+ with pytest.raises(RuntimeError) as exc:
+ sdm.fit_desoto(v_mp=31.0, i_mp=8.71, v_oc=38.3, i_sc=9.43,
+ alpha_sc=0.005658, beta_voc=-0.13788,
+ cells_in_series=10)
+ assert ('Parameter estimation failed') in str(exc.value)
+
+
+@requires_statsmodels
+def test_fit_desoto_sandia(cec_params_cansol_cs5p_220p):
+ # this test computes a set of IV curves for the input fixture, fits
+ # the De Soto model to the calculated IV curves, and compares the fitted
+ # parameters to the starting values
+ params = cec_params_cansol_cs5p_220p['params']
+ params.pop('Adjust')
+ specs = cec_params_cansol_cs5p_220p['specs']
+ effective_irradiance = np.array([400., 500., 600., 700., 800., 900.,
+ 1000.])
+ temp_cell = np.array([15., 25., 35., 45.])
+ ee = np.tile(effective_irradiance, len(temp_cell))
+ tc = np.repeat(temp_cell, len(effective_irradiance))
+ IL, I0, Rs, Rsh, nNsVth = pvsystem.calcparams_desoto(
+ ee, tc, alpha_sc=specs['alpha_sc'], **params)
+ ivcurve_params = dict(photocurrent=IL, saturation_current=I0,
+ resistance_series=Rs, resistance_shunt=Rsh,
+ nNsVth=nNsVth)
+ sim_ivcurves = pvsystem.singlediode(**ivcurve_params).to_dict('series')
+ v = np.linspace(0., sim_ivcurves['v_oc'], 300)
+ i = pvsystem.i_from_v(voltage=v, **ivcurve_params)
+ sim_ivcurves.update(v=v.T, i=i.T, ee=ee, tc=tc)
+
+ result = sdm.fit_desoto_sandia(sim_ivcurves, specs)
+ modeled = pd.Series(index=params.keys(), data=np.nan)
+ modeled['a_ref'] = result['a_ref']
+ modeled['I_L_ref'] = result['I_L_ref']
+ modeled['I_o_ref'] = result['I_o_ref']
+ modeled['R_s'] = result['R_s']
+ modeled['R_sh_ref'] = result['R_sh_ref']
+ expected = pd.Series(params)
+ assert np.allclose(modeled[params.keys()].values,
+ expected[params.keys()].values, rtol=5e-2)