def add_default_module_params(module_parameters):
    """

    Adds default fields to the module_parameters dictionary.

    Parameters
    ----------
    module_parameters : dict

    Examples
    --------

    >> module = add_default_module_params(module)

    Returns
    -------
    module_parameters : dict
        Same as input, except default values are added for the following fields:

        'Mbvoc' : 0

        'FD' : 1

        'iv_model' : 'sapm'

        'aoi_model' : 'no_loss'



    """

    if not 'Mbvoc' in module_parameters:
        module_parameters['Mbvoc'] = 0

    if not 'FD' in module_parameters:
        module_parameters['FD'] = 1

    if not 'iv_model' in module_parameters:
        module_parameters['iv_model'] = 'sapm'

    if not 'aoi_model' in module_parameters:
        module_parameters['aoi_model'] = 'no_loss'

    return module_parameters