Multi-port multi-cell DC/DC converter topology for electric vehicle's power distribution networks

In today's electric vehicles (EV), power density is a key criterion for electrical systems, due to the strongly limited available space. Thereby, a high integration level of the electric distribution network is inevitable. In this paper, a novel multi-port multi-cell (MPMC) topology is proposed, which combines the features of two independent two-port converter systems, which are commonly used in state-of-the-art EVs. Consequently, this results in a higher overall power-density of the overall electric distribution system. The proposed converter comprises multiple identical subconverters (cells), where each cell processes the same share of the total converter power. Furthermore, as will be shown in this paper, the multi-cell approach mitigates several technological design challenges arising in single-cell solutions, where, in contrast to the multi-port multi-cell approach, extremely high output currents and high step-down ratios are required. Finally, a MPMC control strategy is introduced, which guarantees stable operation and balanced cell powers in the converter for all operating points.