Hybrid Excitation Synchronous Machine modeling and optimal sizing for railway traction

This paper aims to study the Hybrid Excitation Synchronous Machine (HESM) performances for railway traction. Owing to the extra degree of freedom provided by the DC field excitation coil, it is possible to improve the overall efficiency of operating cycle comparing to other structures. An optimization algorithm is implemented. It allows finding a compromise machine that minimizes the average cycle losses and the mass.