A Restart Control Method For Position Sensorless Pmsm Drive Systems Without Potential Transformer For Railway Vehicle Traction

This paper proposes a restart control method for position sensorless PMSM drive systems without a potential transformer for railway vehicle traction. This method can estimate the initial rotor speed and position under coasting conditions over the entire speed range. The method can also be used when the back-EMF voltage is higher than the inverter DC link voltage. The proposed method is verified by experiments using a 200-kW PMSM.