Inductor Current Minimization and Dynamic Analysis of DC-DC Converter for Interconnection of CSI/VSC HVDC Networks

The rapid development of HVDC grids is becoming inevitable for long-distance power transmission. Therefore, the need for DC-DC converters arises to allow the interconnection of multivendor systems, provide system isolation and voltage stepping. Thus, this paper set forth the dynamic study of a three-phase hybrid DC-DC converter that allows the interconnection between hybrid DC grids. Additionally, it unlocks the full potential of the DC-DC converter by considering four degrees of freedom for control. Also, it utilizes four degree-of-freedom control variables to minimize the peak inductor current. Henceforth, it reduces the capital cost due to parasitic losses. Furthermore, it explores the controllability and observability of the mathematical model to achieve lower capital cost of measurements. Moreover, it studies the zero dynamics of the system and derives the condition to ensure the internal stability of the system.