The pressure of energy conservation and environmental protection and energy security are the internal driving forces for the growth of the demand for new energy vehicles In comparison, on the one hand, new energy vehicles meet the objective requirements of environmental protection and energy security; on the other hand, as an important economic growth point, new energy vehicle industry has been vigorously promoted by various countries, including the Freedomcar plan launched by the United States, the smart grid plan, and the NEDO plan of Japan.