Novel Modular Multiple-Input Bidirectional DC–DC Power Converter (MIPC) for HEV/FCV Application
This paper proposes a novel multiple-input bidirectional dc–dc power converter to interface more than two dc sources of different voltage levels. This finds applications in hybrid electric/fuel cell vehicles (FCVs), where different dc sources of unequal voltage levels need to be connected with bidirectional power flow capability. The converter can be used to operate in both the buck and boost modes with bidirectional power control. It is also possible to independently control power flow between any two sources when more than two sources are actively transferring power in either direction.
To start the operation of the FC system and also to share the load, a battery unit that can supply power to the same dc link is used. The battery unit also helps to overcome the slower response time of the FC stack by providing peak power during the acceleration of the vehicle. In addition,
the peak power transients during acceleration and regenerative braking can be avoided by the inclusion of a higher power density element such as an ultracapacitor. This can be used to store regenerative energy during deceleration to provide the supplemental power during acceleration. The ability of the ultracapacitor to handle higher power for higher number of charge/discharge cycles not only increases the life span of both the FC and battery but also improves the overall system efficiency.
The proposed power converter topology shown in Fig can be built by connecting a switching leg for each source through an inductor. Additional sources can be added by having an additional switching leg and an inductor for each source. A similar topology is presented, but power flow between only two of the sources is described—in boost mode from the battery/ultracapacitor to the dc link and in buck mode in the opposite direction. This Project presents detailed analysis, operation, and experimental results for all modes of operation. In addition, this topology has been extended to operate the converter over a wide range of voltage levels.
TOOLS AND SOFTWARE USED:
- MP LAB
Andrew Hintz, Udupi R. Prasanna, Member, IEEE, and Kaushik Rajashekara, Fellow, IEEE, “Novel Modular Multiple-Input Bidirectional DC–DC Power Converter (MIPC) for HEV/FCV Application”, IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 62, NO. 5, MAY 2015.