def test_pvsyst_recombination_loss(method, poa, temp_cell, expected, tol):
"""test PVSst recombination loss"""
pvsyst_fs_495 = get_pvsyst_fs_495()
# first evaluate PVSyst model with thin-film recombination loss current
# at reference conditions
x = pvsystem.calcparams_pvsyst(
effective_irradiance=poa, temp_cell=temp_cell,
alpha_sc=pvsyst_fs_495['alpha_sc'],
gamma_ref=pvsyst_fs_495['gamma_ref'],
mu_gamma=pvsyst_fs_495['mu_gamma'], I_L_ref=pvsyst_fs_495['I_L_ref'],
I_o_ref=pvsyst_fs_495['I_o_ref'], R_sh_ref=pvsyst_fs_495['R_sh_ref'],
R_sh_0=pvsyst_fs_495['R_sh_0'], R_sh_exp=pvsyst_fs_495['R_sh_exp'],
R_s=pvsyst_fs_495['R_s'],
cells_in_series=pvsyst_fs_495['cells_in_series'],
EgRef=pvsyst_fs_495['EgRef']
)
il_pvsyst, io_pvsyst, rs_pvsyst, rsh_pvsyst, nnsvt_pvsyst = x
voc_est_pvsyst = estimate_voc(photocurrent=il_pvsyst,
saturation_current=io_pvsyst,
nNsVth=nnsvt_pvsyst)
vd_pvsyst = np.linspace(0, voc_est_pvsyst, 1000)
pvsyst = bishop88(
diode_voltage=vd_pvsyst, photocurrent=il_pvsyst,
saturation_current=io_pvsyst, resistance_series=rs_pvsyst,
resistance_shunt=rsh_pvsyst, nNsVth=nnsvt_pvsyst,
d2mutau=pvsyst_fs_495['d2mutau'],
NsVbi=VOLTAGE_BUILTIN*pvsyst_fs_495['cells_in_series']
)
# test max power
assert np.isclose(max(pvsyst[2]), expected['pmp'], *tol)
# test short circuit current
isc_pvsyst = np.interp(0, pvsyst[1], pvsyst[0])
assert np.isclose(isc_pvsyst, expected['isc'], *tol)
# test open circuit voltage
voc_pvsyst = np.interp(0, pvsyst[0][::-1], pvsyst[1][::-1])
assert np.isclose(voc_pvsyst, expected['voc'], *tol)
# repeat tests as above with specialized bishop88 functions
y = dict(d2mutau=pvsyst_fs_495['d2mutau'],
NsVbi=VOLTAGE_BUILTIN*pvsyst_fs_495['cells_in_series'])
mpp_88 = bishop88_mpp(*x, **y, method=method)
assert np.isclose(mpp_88[2], expected['pmp'], *tol)
isc_88 = bishop88_i_from_v(0, *x, **y, method=method)
assert np.isclose(isc_88, expected['isc'], *tol)
voc_88 = bishop88_v_from_i(0, *x, **y, method=method)
assert np.isclose(voc_88, expected['voc'], *tol)
ioc_88 = bishop88_i_from_v(voc_88, *x, **y, method=method)
assert np.isclose(ioc_88, 0.0, *tol)
vsc_88 = bishop88_v_from_i(isc_88, *x, **y, method=method)
assert np.isclose(vsc_88, 0.0, *tol)
def test_numerical_precision():
"""
Test that there are no numerical errors due to floating point arithmetic.
"""
expected = pd.read_csv(DATA_PATH)
vdtest = np.linspace(0, estimate_voc(IL, I0, NNSVTH), IVCURVE_NPTS)
results = bishop88(vdtest, *ARGS, gradients=True)
assert np.allclose(expected['i'], results[0])
assert np.allclose(expected['v'], results[1])
assert np.allclose(expected['p'], results[2])
assert np.allclose(expected['grad_i'], results[3])
assert np.allclose(expected['grad_v'], results[4])
assert np.allclose(expected['grad'], results[5])
assert np.allclose(expected['grad_p'], results[6])
assert np.allclose(expected['grad2p'], results[7])
def test_numerical_precision():
"""
Test that there are no numerical errors due to floating point arithmetic.
"""
expected = pd.read_csv(DATA_PATH)
vdtest = np.linspace(0, estimate_voc(IL, I0, NNSVTH), IVCURVE_NPTS)
results = bishop88(vdtest, *ARGS, gradients=True)
assert np.allclose(expected['i'], results[0])
assert np.allclose(expected['v'], results[1])
assert np.allclose(expected['p'], results[2])
assert np.allclose(expected['grad_i'], results[3])
assert np.allclose(expected['grad_v'], results[4])
assert np.allclose(expected['grad'], results[5])
assert np.allclose(expected['grad_p'], results[6])
assert np.allclose(expected['grad2p'], results[7])
def simulate_full_curve(parameters, Geff, Tcell, ivcurve_pnts=1000):
"""
Use De Soto and Bishop to simulate a full IV curve with both
forward and reverse bias regions.
"""
# adjust the reference parameters according to the operating
# conditions using the De Soto model:
sde_args = pvsystem.calcparams_desoto(
Geff,
Tcell,
alpha_sc=parameters['alpha_sc'],
a_ref=parameters['a_ref'],
I_L_ref=parameters['I_L_ref'],
I_o_ref=parameters['I_o_ref'],
R_sh_ref=parameters['R_sh_ref'],
R_s=parameters['R_s'],
)
# sde_args has values:
# (photocurrent, saturation_current, resistance_series,
# resistance_shunt, nNsVth)
# Use Bishop's method to calculate points on the IV curve with V ranging
# from the reverse breakdown voltage to open circuit
kwargs = {
'breakdown_factor': parameters['breakdown_factor'],
'breakdown_exp': parameters['breakdown_exp'],
'breakdown_voltage': parameters['breakdown_voltage'],
}
v_oc = singlediode.bishop88_v_from_i(0.0, *sde_args, **kwargs)
# ideally would use some intelligent log-spacing to concentrate points
# around the forward- and reverse-bias knees, but this is good enough:
vd = np.linspace(0.99 * kwargs['breakdown_voltage'], v_oc, ivcurve_pnts)
ivcurve_i, ivcurve_v, _ = singlediode.bishop88(vd, *sde_args, **kwargs)
return pd.DataFrame({
'i': ivcurve_i,
'v': ivcurve_v,
})
def test_pvsyst_recombination_loss(poa, temp_cell, expected, tol):
"""test PVSst recombination loss"""
pvsyst_fs_495 = get_pvsyst_fs_495()
# first evaluate PVSyst model with thin-film recombination loss current
# at reference conditions
x = pvsystem.calcparams_pvsyst(
effective_irradiance=poa, temp_cell=temp_cell,
alpha_sc=pvsyst_fs_495['alpha_sc'],
gamma_ref=pvsyst_fs_495['gamma_ref'],
mu_gamma=pvsyst_fs_495['mu_gamma'], I_L_ref=pvsyst_fs_495['I_L_ref'],
I_o_ref=pvsyst_fs_495['I_o_ref'], R_sh_ref=pvsyst_fs_495['R_sh_ref'],
R_sh_0=pvsyst_fs_495['R_sh_0'], R_sh_exp=pvsyst_fs_495['R_sh_exp'],
R_s=pvsyst_fs_495['R_s'],
cells_in_series=pvsyst_fs_495['cells_in_series'],
EgRef=pvsyst_fs_495['EgRef']
)
il_pvsyst, io_pvsyst, rs_pvsyst, rsh_pvsyst, nnsvt_pvsyst = x
voc_est_pvsyst = estimate_voc(photocurrent=il_pvsyst,
saturation_current=io_pvsyst,
nNsVth=nnsvt_pvsyst)
vd_pvsyst = np.linspace(0, voc_est_pvsyst, 1000)
pvsyst = bishop88(
diode_voltage=vd_pvsyst, photocurrent=il_pvsyst,
saturation_current=io_pvsyst, resistance_series=rs_pvsyst,
resistance_shunt=rsh_pvsyst, nNsVth=nnsvt_pvsyst,
d2mutau=pvsyst_fs_495['d2mutau'],
NsVbi=VOLTAGE_BUILTIN*pvsyst_fs_495['cells_in_series']
)
# test max power
assert np.isclose(max(pvsyst[2]), expected['pmp'], *tol)
# test short circuit current
isc_pvsyst = np.interp(0, pvsyst[1], pvsyst[0])
assert np.isclose(isc_pvsyst, expected['isc'], *tol)
# test open circuit current
voc_pvsyst = np.interp(0, pvsyst[0][::-1], pvsyst[1][::-1])
assert np.isclose(voc_pvsyst, expected['voc'], *tol)
def test_pvsyst_recombination_loss(pvsyst_fs_495, poa, temp_cell, expected,
tol):
"""test PVSst recombination loss"""
# first evaluate PVSyst model with thin-film recombination loss current
# at reference conditions
x = pvsystem.calcparams_pvsyst(
effective_irradiance=poa, temp_cell=temp_cell,
alpha_sc=pvsyst_fs_495['alpha_sc'],
gamma_ref=pvsyst_fs_495['gamma_ref'],
mu_gamma=pvsyst_fs_495['mu_gamma'], I_L_ref=pvsyst_fs_495['I_L_ref'],
I_o_ref=pvsyst_fs_495['I_o_ref'], R_sh_ref=pvsyst_fs_495['R_sh_ref'],
R_sh_0=pvsyst_fs_495['R_sh_0'], R_sh_exp=pvsyst_fs_495['R_sh_exp'],
R_s=pvsyst_fs_495['R_s'],
cells_in_series=pvsyst_fs_495['cells_in_series'],
EgRef=pvsyst_fs_495['EgRef']
)
il_pvsyst, io_pvsyst, rs_pvsyst, rsh_pvsyst, nnsvt_pvsyst = x
voc_est_pvsyst = estimate_voc(photocurrent=il_pvsyst,
saturation_current=io_pvsyst,
nNsVth=nnsvt_pvsyst)
vd_pvsyst = np.linspace(0, voc_est_pvsyst, 1000)
pvsyst = bishop88(
diode_voltage=vd_pvsyst, photocurrent=il_pvsyst,
saturation_current=io_pvsyst, resistance_series=rs_pvsyst,
resistance_shunt=rsh_pvsyst, nNsVth=nnsvt_pvsyst,
d2mutau=pvsyst_fs_495['d2mutau'],
NsVbi=VOLTAGE_BUILTIN*pvsyst_fs_495['cells_in_series']
)
# test max power
assert np.isclose(max(pvsyst[2]), expected['pmp'], *tol)
# test short circuit current
isc_pvsyst = np.interp(0, pvsyst[1], pvsyst[0])
assert np.isclose(isc_pvsyst, expected['isc'], *tol)
# test open circuit current
voc_pvsyst = np.interp(0, pvsyst[0][::-1], pvsyst[1][::-1])
assert np.isclose(voc_pvsyst, expected['voc'], *tol)