By summarizing the research status, it is found that there are many schemes suitable for bi-directional DC converter, and each scheme has its own advantages and disadvantages, so it can be applied to different occasions to achieve the best matching effect. No scheme is the best in all applications, so a trade-off must be made. This section analyzes the working principles, control methods and problems existing in the application of phase-shifted full-bridge bidirectional DC-DC and staggered parallel bidirectional DC-DC, and finally chooses the staggered parallel scheme to design.