Bi-Directional DCM DC to DC Converter for Hybrid Electric Vehicles

This paper presents a bi-directional DC to DC converter with a unique concept in control. The converter was designed for hybrid electric vehicles,so size becomes a pressing design parameter. For that reason a buck converter in DCM was used to realize the DC to DC converter. The DCM operation was used in order to shrink the magnetic components, as described in the paper. However, DCM converters are not inherently bi-directional. The unique controller developed here allows for the DCM converter to seamlessly direct power from low voltage side to high voltage side and from high voltage side back to low voltage side. A power management technique was also developed to handle a wide array of conditions present in hybrid electric vehicle applications. The technology developed here offers the designer the option to utilize the benefits of a buck converter in DCM while still maintaining a bi-directional power flow.