Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Appearance settings

Commit 47b8df2

Browse filesBrowse files
kandersolarkandersolar
authored
Make i_x and i_xx SAPM parameters optional (#2433)
* make C4-C7 optional in pvlib.pvsystem.sapm * make optional in PVSystem and ModelChain as well * incidental cleanup * whatsnew * lint * make IXO and IXXO optional too
1 parent 8a7927a commit 47b8df2
Copy full SHA for 47b8df2

File tree

Expand file treeCollapse file tree

5 files changed

+39
-13
lines changed
Filter options
Expand file treeCollapse file tree

5 files changed

+39
-13
lines changed

‎docs/sphinx/source/whatsnew/v0.12.1.rst

Copy file name to clipboardExpand all lines: docs/sphinx/source/whatsnew/v0.12.1.rst
+4Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -17,6 +17,10 @@ Enhancements
1717
* :py:mod:`pvlib.ivtools.sdm` is now a subpackage. (:issue:`2252`, :pull:`2256`)
1818
* Add a function for estimating PVsyst SDM parameters from IEC 61853-1 matrix
1919
data (:py:func:`~pvlib.ivtools.sdm.fit_pvsyst_iec61853_sandia_2025`). (:issue:`2185`, :pull:`2429`)
20+
* The parameters for the Ix and Ixx points are now optional when using
21+
:py:func:`pvlib.pvsystem.sapm` directly and through
22+
:py:class:`~pvlib.pvsystem.PVSystem` and :py:class:`~pvlib.modelchain.ModelChain`.
23+
(:issue:`2402`, :pull:`2433`)
2024
* Add optional arguments ``temperature_ref`` and ``irradiance_ref`` to
2125
:py:func:`~pvlib.pvsystem.sapm`(:issue:`2432`, :pull:`2434`)
2226
* Add NREL NSRDB PSM v4 API client to :py:mod:`pvlib.iotools`. See

‎pvlib/modelchain.py

Copy file name to clipboardExpand all lines: pvlib/modelchain.py
+1-1Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -611,7 +611,7 @@ def infer_dc_model(self):
611611
"""Infer DC power model from Array module parameters."""
612612
params = _common_keys(
613613
tuple(array.module_parameters for array in self.system.arrays))
614-
if {'A0', 'A1', 'C7'} <= params:
614+
if {'A0', 'A1', 'C3'} <= params:
615615
return self.sapm, 'sapm'
616616
elif {'a_ref', 'I_L_ref', 'I_o_ref', 'R_sh_ref', 'R_s',
617617
'Adjust'} <= params:

‎pvlib/pvsystem.py

Copy file name to clipboardExpand all lines: pvlib/pvsystem.py
+15-11Lines changed: 15 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -27,10 +27,10 @@
2727
# a dict of required parameter names for each DC power model
2828
_DC_MODEL_PARAMS = {
2929
'sapm': {
30-
'C0', 'C1', 'C2', 'C3', 'C4', 'C5', 'C6', 'C7',
30+
# i_x and i_xx params (IXO, IXXO, C4-C7) not required
31+
'C0', 'C1', 'C2', 'C3',
3132
'Isco', 'Impo', 'Voco', 'Vmpo', 'Aisc', 'Aimp', 'Bvoco',
32-
'Mbvoc', 'Bvmpo', 'Mbvmp', 'N', 'Cells_in_Series',
33-
'IXO', 'IXXO'},
33+
'Mbvoc', 'Bvmpo', 'Mbvmp', 'N', 'Cells_in_Series'},
3434
'desoto': {
3535
'alpha_sc', 'a_ref', 'I_L_ref', 'I_o_ref',
3636
'R_sh_ref', 'R_s'},
@@ -2229,9 +2229,11 @@ def sapm(effective_irradiance, temp_cell, module, *, temperature_ref=25,
22292229
* v_mp : Voltage at maximum-power point (V)
22302230
* p_mp : Power at maximum-power point (W)
22312231
* i_x : Current at module V = 0.5Voc, defines 4th point on I-V
2232-
curve for modeling curve shape
2232+
curve for modeling curve shape. Omitted if ``IXO``, ``C4``, and
2233+
``C5`` parameters are not supplied.
22332234
* i_xx : Current at module V = 0.5(Voc+Vmp), defines 5th point on
2234-
I-V curve for modeling curve shape
2235+
I-V curve for modeling curve shape. Omitted if ``IXXO``, ``C6``,
2236+
and ``C7`` parameters are not supplied.
22352237
22362238
Notes
22372239
-----
@@ -2335,13 +2337,15 @@ def sapm(effective_irradiance, temp_cell, module, *, temperature_ref=25,
23352337

23362338
out['p_mp'] = out['i_mp'] * out['v_mp']
23372339

2338-
out['i_x'] = (
2339-
module['IXO'] * (module['C4']*Ee + module['C5']*(Ee**2)) *
2340-
(1 + module['Aisc']*(temp_cell - temperature_ref)))
2340+
if 'IXO' in module and 'C4' in module and 'C5' in module:
2341+
out['i_x'] = (
2342+
module['IXO'] * (module['C4']*Ee + module['C5']*(Ee**2)) *
2343+
(1 + module['Aisc']*(temp_cell - temperature_ref)))
23412344

2342-
out['i_xx'] = (
2343-
module['IXXO'] * (module['C6']*Ee + module['C7']*(Ee**2)) *
2344-
(1 + module['Aimp']*(temp_cell - temperature_ref)))
2345+
if 'IXXO' in module and 'C6' in module and 'C7' in module:
2346+
out['i_xx'] = (
2347+
module['IXXO'] * (module['C6']*Ee + module['C7']*(Ee**2)) *
2348+
(1 + module['Aimp']*(temp_cell - temperature_ref)))
23452349

23462350
if isinstance(out['i_sc'], pd.Series):
23472351
out = pd.DataFrame(out)

‎tests/test_modelchain.py

Copy file name to clipboardExpand all lines: tests/test_modelchain.py
+10Lines changed: 10 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1762,6 +1762,16 @@ def test_invalid_dc_model_params(sapm_dc_snl_ac_system, cec_dc_snl_ac_system,
17621762
ModelChain(pvwatts_dc_pvwatts_ac_system, location, **kwargs)
17631763

17641764

1765+
def test_sapm_optional_params(sapm_dc_snl_ac_system, location):
1766+
# inference works when the optional (i_x, i_xx) SAPM parameters are missing
1767+
for array in sapm_dc_snl_ac_system.arrays:
1768+
for key in ['IXO', 'IXXO', 'C4', 'C5', 'C6', 'C7']:
1769+
array.module_parameters.pop(key)
1770+
1771+
# no error:
1772+
ModelChain(sapm_dc_snl_ac_system, location)
1773+
1774+
17651775
@pytest.mark.parametrize('model', [
17661776
'dc_model', 'ac_model', 'aoi_model', 'spectral_model',
17671777
'temperature_model', 'losses_model'

‎tests/test_pvsystem.py

Copy file name to clipboardExpand all lines: tests/test_pvsystem.py
+9-1Lines changed: 9 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -17,7 +17,6 @@
1717
from pvlib.location import Location
1818
from pvlib.pvsystem import FixedMount
1919
from pvlib import temperature
20-
from pvlib._deprecation import pvlibDeprecationWarning
2120
from pvlib.tools import cosd
2221
from pvlib.singlediode import VOLTAGE_BUILTIN
2322

@@ -197,6 +196,15 @@ def test_sapm(sapm_module_params):
197196
pvsystem.sapm(effective_irradiance, temp_cell,
198197
pd.Series(sapm_module_params))
199198

199+
# ensure C4-C7 are optional
200+
optional_keys = ['IXO', 'IXXO', 'C4', 'C5', 'C6', 'C7']
201+
params_no_c4c7 = {
202+
k: v for k, v in sapm_module_params.items() if k not in optional_keys
203+
}
204+
out = pvsystem.sapm(effective_irradiance, temp_cell, params_no_c4c7)
205+
assert 'i_x' not in out.keys()
206+
assert 'i_xx' not in out.keys()
207+
200208

201209
def test_PVSystem_sapm(sapm_module_params, mocker):
202210
mocker.spy(pvsystem, 'sapm')

0 commit comments

Comments
0 (0)
Morty Proxy This is a proxified and sanitized view of the page, visit original site.