Optimization of readhesion control of Shinkansen trains with wheel-rail adhesion prediction

The authors propose a new practical re-adhesion control technique for electric railway vehicles with three-phase motor drives. The control circuit will not promote wheelslip/slide phenomenon when it occurs, and the torque is slightly reduced. The former is achieved by using the lowest axle velocity of all as a frequency reference of inverters feeding asynchronous traction motors. The latter is realized by an accurate slip/slide velocity detection. By running tests with a prototype Shinkansen train "STAR 21" of the East Japan Railway, they succeeded in utilizing as high a traction force as possible under any wheel-rail conditions, with the introduction of wheel-rail adhesion prediction.