Review of the DC voltage coordinated control strategies for multi-terminal VSC-MVDC distribution network

TLDR: The droop-based control strategies have been identified as reliable, flexible, and expandable with high dynamic performance and minimal communication needs in MTDC grids and are suitable and adaptable for stable and secure operation of the proposed multi-terminal MVDC distribution network.

Abstract: The multi-terminal voltage sourced converter medium-voltage DC (VSC-MVDC) distribution network has high prospects for future development, hence the proposed alternative for the AC distribution in commercial and industrial applications. However, a number of obstacles stand on its way in realising its immense potential in the modern power system. This study presents a review and focuses on the complexity of controlling DC voltage/power flow in the multi-terminal DC (MTDC) grids and the possible DC voltage coordinated control approaches aimed at identifying the suitable control strategies for the proposed MVDC distribution grids. Several centralised and distributed DC voltage control strategies for MTDC have been considered. In conclusion, the droop-based control strategies have been identified as reliable, flexible, and expandable with high dynamic performance and minimal communication needs in MTDC grids. These strategies are suitable and adaptable for stable and secure operation of the proposed multi-terminal MVDC distribution network. The study recommends a comparative study of the key DC voltage coordination control features of the droop-based control strategies using the multi-terminal VSC-MVDC distribution network dynamic model for future studies.