Evaluation of Permanent Magnet Motor energy saving technology for different types of railways

The majority of drive chain losses in railway vehicles are attributable to motor inefficiency. An attractive solution to reduce these losses, and the associated energy consumption, is the implementation of Permanent Magnet Synchronous Motor (PMSM) technology. PMSMs are not only more efficient, but smaller and lighter than traditional induction machines, which can further benefit energy saving. However, introducing this technology and the associated control systems can be expensive and complex. Therefore, in this study, the authors evaluate the cost benefit of introducing PMSMs into different railway sub-modes to see where this solution is most appropriate, in terms of energy saved. The impact of regenerative braking on the cost is also considered, by simulating dynamic braking characteristics and the receptivity of different systems.