def i_base_ka(sb_mva, vbll_kv):
    """Returns the base current based on the base power and voltage.

    Args:
        sb_mva: Base power in MVA.
        vbll_kv: Base voltage in kV.

    Returns:
        Base current in kA.
    """
    sb_mva = float(sb_mva)
    vbll_kv = float(vbll_kv)
    return sb_mva / (vbll_kv * 3 ** 0.5)
