pvlib.iam.convert#

pvlib.iam.convert(source_name, source_params, target_name, weight=<function _sin_weight>, fix_n=True, xtol=None)[source]#

Convert a source IAM model to a target IAM model.

Parameters

  • source_name (str) – Name of the source model. Must be 'ashrae', 'martin_ruiz', or 'physical'.

  • source_params (dict) –

    A dictionary of parameters for the source model.

    If source model is 'ashrae', the dictionary must contain the key 'b'.

    If source model is 'martin_ruiz', the dictionary must contain the key 'a_r'.

    If source model is 'physical', the dictionary must contain the keys 'n', 'K', and 'L'.

  • target_name (str) – Name of the target model. Must be 'ashrae', 'martin_ruiz', or 'physical'.

  • weight (function, optional) – A single-argument function of AOI (degrees) that calculates weights for the residuals between models. Must return a float or an array-like object. The default weight function is \(f(aoi) = 1 - sin(aoi)\).

  • fix_n (bool, default True) –

    A flag to determine which method is used when converting from the ASHRAE model to the physical model.

    When source_name is 'ashrae' and target_name is 'physical', if fix_n is True, iam.convert() will fix n so that the returned physical model has the same x-intercept as the inputted ASHRAE model. Fixing n like this improves the fit of the conversion, but often returns unrealistic values for the parameters of the physical model. If more physically meaningful parameters are wanted, set fix_n to False.

  • xtol (float, optional) – Passed to scipy.optimize.minimize.

Returns

dict –

Parameters for the target model.

If target model is 'ashrae', the dictionary will contain the key 'b'.

If target model is 'martin_ruiz', the dictionary will contain the key 'a_r'.

If target model is 'physical', the dictionary will contain the keys 'n', 'K', and 'L'.

Note

Target model parameters are determined by minimizing

\[\sum_{\theta=0}^{90} weight \left(\theta \right) \times \| source \left(\theta \right) - target \left(\theta \right) \|\]

The sum is over \(\theta = 0, 1, 2, ..., 90\).

References

1

Jones, A. R., Hansen, C. W., Anderson, K. S. Parameter estimation for incidence angle modifier models for photovoltaic modules. Sandia report SAND2023-13944 (2023).

See also

pvlib.iam.fit, pvlib.iam.ashrae, pvlib.iam.martin_ruiz, pvlib.iam.physical

Examples using pvlib.iam.convert#

IAM Model Conversion

IAM Model Conversion

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