Evolution and future of traction transformer on rolling stocks

One of the main historic component of the electro technical domain, the electrical transformer, is close to be revolutionized thanks to high power semi-conductors for railway application : conventional traction transformer is dead ? Maybe, but first, it´s important to understand how this evolution happens and why the interest is so important? What are the impacts and the benefits for traction drive chain, for the train, for railway operators? This paper will try to present the history and the major events of the traction transformer used in railway rolling stock and will show the beginning of new technology revolution for the future of our trains.