Researching On The Induction Motor Traction Control System Of The Shanghai Metro Vehicles

In recent years,as China's urban population increased,the expansion of residential areas,metro has become the main means of transport in major cities.Metro vehicles due to the short distance between stations,frequent acceleration and braking,required traction motor of large capacity,high speed,high requirements for motor control.The current MTR traction system is to use the three-phase AC Induction Motor VVVF traction technology.In this paper,the research object is Shanghai Metro Line 1 vehicle whose traction motor was changed from DC motor to AC motor,and focusing on researching it's traction system main circuit,the brake system and direct torque traction control system,and using the U.S NI's data acquisition system,did on-site real vehicle testing,collected the bus voltage, vehicle current,motor line voltage,motor phase current, brake resistor current signals and so on, and through the data packets into Matlab software, did data analysis and calculation, the measured results and the experimental test method has good use of values.Induction motor is a high-level, strong coupling, nonlinear multi-variable systems.The current metro traction system, there are traction system based on vector control, but also based on direct torque control. Vector control has decoupled based on the current and voltage decoupling two kinds of vector control methods. In this paper,for Shanghai Metro Line 1 vehicle whose traction motor was changed from DC motor to AC motor,builting it's simulation model based on Matlab simulink and the simulation results are consistent with the measured results, at the same time,by the researching on the vector control traction system and simulation,study results show that the above-mentioned two kinds of traction control system have good dynamic performance and control performance, are high-effective control methods, as compared with the vector control, direct torque control need not magnetic field orientation and coordinate transformation, is easier and faster control torque,overcome the vector control system's shortcomings that depends on the motor rotor parameters and controlling complexly, but there is a larger torque ripple, switching frequency is not fixed and other issues.