Co-simulation Of PMSMs Traction System In High Speed Train Combining FE Motor And Control Strategy

In recent years, the construction of high-speed trains is developing quickly in China, and the rail mileage already ranks first in the word with almost half of the total. With the development of high-speed trains, the energy consumption is also amazing. Nowadays, most high speed trains are driven by induction motors (IMs) because of its more mature technology. To save energy, the PM synchronous motors (PMSMs) become a strong candidate to replacing IMs, and it has received much attention. Compared to IMs traction system, PMs traction system has many other advantages, such as higher power density, higher power factor, less noise.In this paper, finite element method (FEM) model of the PM traction motor is built for higher accuracy. Based on this model, the effects of flux-weakening current on motor parameters, output torque and motor power loss are investigated.Combining the FEM model motor, circuits and control strategy, a co-simulation model is built. In the co-simulation model, motor parameters change with speed, magnetic saturation and rotor position, so its simulation results could be more close to the actual. Its results are compared with those in simulation using analytical method (AM) of motor and response of FEM motor with sinusoidal current, to show the effect of parameter changes and differences between SVPWM supply and sinusoidal supply.Based on the co-simulation model, two methods for the train to pass neutral sections are investigated. During the passing period, Flux-weakening current keeping shows many advantages over blocking switching signals for inverters.Finally, a simple but effective method for the converter to switch from SVPWM to single-pulse control with smooth train speed transition is proposed and simulated. Moreover, the mechanical performances and power loss of PMSM are compared under single-pulse control and SVPWM with different switching frequencies. Motor power loss in the single-pulse control is lower and it can get better torque performance than SVPWM with inadequate switching frequency.