I. Introduction
In recent years, concerns about environment and energy security put ever-increasingly higher requirements on energy sustainability and efficiency. In the transportation sector, the automotive industry has recognized that vehicle electrification is one of the key technologies toward addressing environmental and energy issues [1]. The development of new grid-enabled passenger vehicles, like electric vehicles (EV), is critical to the future of the industry and global economy. However, technical challenges like EV range and ownership cost have to be overcome before they achieve greater market penetration.