def combine_mv_and_lv(mv, lv):
    """Combine MV and LV grid topology in PyPSA format
    """

    combined = {
        c: pd.concat([mv[c], lv[c]], axis=0) for c in list(lv.keys())
    }

    combined['Transformer'] = mv['Transformer']

    return combined
Combine MV and LV grid topology in PyPSA format