FOR energy, environment, and many other reasons, the
electrification for transportation has been carrying out for
many years. In railway systems, the electric locomotives have
already been well developed for many years. A train runs on a
fixed track. It is easy to get electric power from a conductor rail
using pantograph sliders. However, for electric vehicles (EVs),
the high flexibility makes it not easy to get power in a similar
way. Instead, a high power and large capacity battery pack is
usually equipped as an energy storage unit to make an EV to
operate for a satisfactory distance.