---

The book analyzed the harmonic of the SPWM inverter and traction motor. In Simpack simulation software, subway train model is established, with motor, rotor, big gear and small gear and so on in metro traction electric drive system. In the Simulink simulation software, traction motor direct torque control model is established, and electromechanical coupling model is established by using the software co-simulation. Simulation analysis is conducted under constant speed condition of 60 km/h, finding that 12 times rotor fundamental wave frequency have a great effect on the vibration of the bogie.

---

Xun Wang, lecturer, graduated in Transportation Engineering from Southwest Jiao Tong University (both bachelor, master degree). Since graduating in 2015, she has worked as a full-time teacher in Chongqing Vocational College of Public Transportation, and the research direction is rail transit vehicle control.

---