Application of the double domain simulation in comparison of new current control methods for PWM controlled AC electric locomotives

Nowadays the series wound DC traction motor driven locomotives are still widely used. These vehicles inject harmonics into the AC line and distort the line voltage. In our work we examined and compared current control methods that can be achieved by “network-friendly” locomotives connected to the distorted line. The modern locomotives strive to consume sinusoidal current from the AC network, in phase with the network voltage fundamental. We compared current control methods with this “common” strategy. One of them can reduce the consumed root mean square or fundamental current of a distorted line connected modern locomotive in motor mode. Other one can increase the generated RMS and fundamental current in generator mode. With these strategies the harmonic currents can be used for active power. Moreover it turned out that the harmonic content of the network can be reduced by the “new” strategies. We built simulation models and double domain simulation was used for this study.