New generation of trams with gearless wheel PMSM drives: From simple diagnostics to sensorless control

This paper deals with a propulsion system of new full low-floor trams manufactured by Škoda Plzeň company employing gearless wheel drives with surface-mounted permanent magnet synchronous motors (PMSM). Main attention is paid to developed drive control and its smart diagnostics — specifically, we present proposed algorithms for automatic identification of an incorrect rotor position sensor calibration, making possible its on-line recalibration and allowing to check in real-time the proper operation of the rotor position sensor. Moreover, proposed stochastic algorithms for identification of rotor position make possible to operate the drive in wide speed range in sensorless mode under emergency conditions. This smart diagnostics significantly increase reliability and safety of the drive. The experiments made on a prototype of tram ŠKODA For City document proper function of developed drive and its control. Performance of proposed sensorless rotor position identification algorithms for drive of tram ŠKODA For City is analyzed by tests made on designed small-scale prototype of tram wheel drive of rated power of 10.7kW.