def get_trader_scada_ramp_rate(trader_id, ramp_rates):
    """
    Extract SCADA ramp rate for a given trader. If the SCADA ramp rate is 0
    or missing return None.
    """

    if (trader_id in ramp_rates.keys()) and (ramp_rates[trader_id] > 0):
        return ramp_rates[trader_id]
    else:
        return None