Comparison of several speed sensorless strategies of two different dual drive induction motor control structures

The studied system mainly represents a mono-inverter dual induction motor drive system for a railway traction locomotive bogie. It is proposed instead of the classical drive bogie system, where an inverter supplies only one motor. Moreover, four partial speed sensorless methods are applied in it. Then, a comparison between these applied operating structures in two different control strategies for parallel connected dual induction motors is presented in this paper. The system behavior comparison takes into account two internal motor parameter variations and one external perturbation. It is important to note that the system presents two important interactions. On one hand, an electrical coupling is established by the voltage inverter, which supplies both motors. On the other hand, the common load, here represented by the locomotive, is relied to the motors by the mechanical transmissions imposing a mechanical coupling. The system has been modeled using the SABER solver from Avant! Corporation.