Control of induction machine drive for multisystem locomotive: Design considerations regarding problems of conductive currents affecting railway safety system

This paper describes design of a new control and PWM algorithms for a main drive of a multisystem locomotive with special focus on investigation into the trolley-wire current which could disturb railway safety systems. Designed control is based on rotor flux oriented vector control in Cartesian coordinates which is unusually operated due to specific PWM in whole speed range. We employ a synchronous PWM based on a harmonic elimination strategy which is optimized regarding mitigation of the drive interaction with railway safety system. Verification of proper function of proposed control including trolley-wire current analysis has been done on designed laboratory prototype of locomotive drive. Major results of extensive experimental study made on this prototype are introduced in this contribution.