High speed rail awaits the next breakthrough of power semiconductors

High Speed Rail (HSR) is expanding rapidly in the whole world in this decade. Almost all the high-speed trains are fed by high-voltage AC and are equipped with several large motors. In addition, High-speed trains have a strict restriction for both mass and size. Thus, HSR needs power semiconductors that can handle high-voltage and giant current. From simple silicon diodes in 1960s, thyristors, GTO thyristors, IGBTs and until new wide gap devices such like SiC, the progress of power semiconductor and cooling system directly pulls the performance of high-speed rolling stock. In some cases, fixed installations for HSR are equipped with flexible AC transmission systems (FACTS) such as static VAR compensators (SVC), also.