**Ahmed Fathy Abouzeid 1, Juan Manuel Guerrero 1, Aitor Endemaño 2, Iker Muniategui 2, David Ortega 2, Igor Larrazabal <sup>2</sup> and Fernando Briz 1,\***


Received: 30 December 2019; Accepted: 3 February 2020; Published: 6 February 2020

**Abstract:** This paper analyzes control strategies for induction motors in railway applications. The paper will focus on drives operating with a low switching to fundamental frequency ratio and in the overmodulation region or six-step operation, as these are the most challenging cases. Modulation methods, efficient modes of operation of the drive and the implications for its dynamic performance, and machine design will also be discussed. Extensive simulation results, as well as experimental results, obtained from a railway traction drive, are provided.

**Keywords:** railway traction drives; induction motor drives; high-speed drives; maximum torque per ampere; overmodulation and six-step operation
