DC Substation for DC Grid—Part I: Comparative Evaluation of DC Substation Configurations

DC grid has been deemed as the enabling technology for future power systems. Within the dc grid, multi-terminal dc node (MTDN) serves as the key component for voltage/power conversion and fault protection. Configurations of MTDN are explored in this paper. The similarity of MTDN to a classical ac substation is first identified, and three series of “dc substation” have been developed on the basis of classical ac substation structures. To evaluate the influence of different “power conversion technology” and “system structure” on dc substation performance, the proposed configurations are compared under a four-terminal dc node case. Potential applications of dc/dc converters in dc substation are investigated, and each configuration is evaluated in terms of system cost, efficiency, and reliability.