Disc PMSM direct drive for Low Floor Tramcar

Abstract:

To overcome the disadvantages of conventional motor in low floor tramcar with difficult installation arrangement and low transmission efficiency, a new solution was proposed with disc permanent magnet synchronous motor(PMSM) direct drive and independent rotating wheels. The disc PMSM was overhung in the bogie frame with elastic suspension, which made them as the sprung mass. A 60kW disc PMSM was designed under developed motor Computer aided Design(CAD) program to meet the traction power demand, after estimating the overall dimensions according to the size equation of motor. Sensorless vector control based on the sliding mode observer(SMO) was adopted in speed control and torque control of PMSM. The same side and both side motors will control speed difference under the steering control strategy of tramcar. Finally, motor control model was set up in MATLAB/Simulink to check the control strategy. The simulation results show that the PMSM control based on SMO has rapid and robust response. Multi motors with good steering performance adapt to the the straight or curve track well.

Key words:low floor tramcar; disc permanent magnet synchronous motor(PMSM); computer aided design(CAD); sliding mode observer(SMO); steering control