Current sharing in multiterminal DC Grids - The analytical approach

Abstract

This paper presents a new analytical approach for dc voltage control in dc grids. The control approach aims at improving the dc voltage droop control by generalized feedback which combines the local voltage signal available at the converter terminals with remote voltage signals at different locations in the dc system by means of communication. The main contribution is an analytical approach to derive the generalized feedback gain allowing to differentiating the system response for different converter outages. The goal of the system response is to share the power, in the event of disconnection of a converter, between the remaining converters according to a predetermined scheme. The local voltage feedback control is used for fast and reliable system response, and remote signals to achieve the goal. The analysis of the feasibility space the power shares is also presented, which is a direct function of the grid layout. Simulation results show the validity of the proposed control scheme.