Add PVSPEC spectral correction factor model

pvlib/tests/test_pelland.py

@@ -0,0 +1,74 @@
+import numpy as np
+from warnings import warn
+
+def spectral_factor_pelland(airmass_absolute, clearness_index,
+ module_type = None, coefficients = None,
+ min_airmass_absolute = 0.58,
+ max_airmass_absolute = 10):
+ #0.58 -> same as spectral_factor_firstsolar
+# =============================================================================
+# model implemented: https://ieeexplore.ieee.org/document/9300932
+# inputs: air mass, clearness index
+# coefficients: six modules
+# =============================================================================
+# =============================================================================
+# --- Screen Input Data ---
+# =============================================================================
+ #kc
+ kc = np.atleast_1d(clearness_index)
+ kc = kc.astype('float64')
+ if np.min(kc) < 0:
+ raise ValueError('Clearness index cannot be less than 0')
+ if np.max(kc) > 1:
+ raise ValueError('Clearness index cannot be grater than 1')
+ #ama
+ if np.max(airmass_absolute) > max_airmass_absolute:
+ warn('High air mass values greater than 'f'{max_airmass_absolute} '+
+ 'in dataset')
+ # Warn user about exceptionally low ama data
+ if np.min(airmass_absolute) < min_airmass_absolute:
+ airmass_absolute = np.maximum(airmass_absolute, min_airmass_absolute )
+ warn('Exceptionally low air mass: ' +
+ 'model not intended for extra-terrestrial use')
+# =============================================================================
+# --- Default coefficients ---
+# =============================================================================
+ _coefficients = {}
+ _coefficients['polysi'] = (
+ 0.9847, -0.05237, 0.03034)
+ _coefficients['monosi'] = (
+ 0.9845, -0.05169, 0.03034)
+ _coefficients['fs-2'] = (
+ 1.002, -0.07108, 0.02465)
+ _coefficients['fs-4'] = (
+ 0.9981, -0.05776, 0.02336)
+ _coefficients['cigs'] = (
+ 0.9791, -0.03904, 0.03096)
+ _coefficients['asi'] = (
+ 1.051, -0.1033, 0.009838)
+ _coefficients['multisi'] = _coefficients['polysi']
+ _coefficients['xsi'] = _coefficients['monosi']
+# =============================================================================
+# --- Check arguments ---
+# =============================================================================
+ if module_type is not None and coefficients is None:
+ coefficients = _coefficients[module_type.lower()]
+ elif module_type is None and coefficients is not None:
+ pass
+ elif module_type is None and coefficients is None:
+ raise TypeError('No valid input provided, both module_type and ' +
+ 'coefficients are None. module_type can be one of ' +
+ 'poly-Si, monosi, fs-2, fs-4, cigs, or asi')
+ else:
+ raise TypeError('Cannot resolve input, must supply only one of ' +
+ 'module_type and coefficients. module_type can be ' +
+ 'one of poly-Si, monosi, fs-2, fs-4, cigs, or asi')
+# =============================================================================
+# --- Specral mismatch calculation ---
+# =============================================================================
+ coeff = coefficients
+ ama = airmass_absolute
+ kc = clearness_index
+ modifier = coeff[0]*kc**(coeff[1])*ama**(coeff[2])
+
+ return modifier