Comprehensive inertia control for hybrid AC/DC distribution system

Abstract

In this study, a comprehensive inertia control strategy is proposed for the distribution system consisting of AC/DC sub-grids. The coupling relationship of the AC and DC systems is analysed, and the comprehensive inertia control method of hybrid AC/DC system is proposed. More specifically, the operational characteristics of the wind turbine generator (WTG) are utilised to design the virtual inertial response strategy, which enables the WTGs in distribution network to provide flexible voltage and frequency support. Further, since the distributed energy storage (DES) is taken into account, the virtual inertial response of WTGs can be more controllable, which fully utilises the capacity of DES without the risk of halt of the WTGs. In addition, the mutual power support is designed based on the coupling relationship of the hybrid system, which can enhance the overall inertia of the distribution network. Finally, the effectiveness of the proposed strategy is verified by the simulation studies, which shows that the strategy can enhance the power quality and dynamics of the hybrid AC/DC system and thus improves the robustness of the distribution network.

Keywords

• wind turbines
• turbogenerators
• power grids
• wind power plants
• energy storage
• power generation control
• comprehensive inertia control strategy
• AC/DC sub-grids
• coupling relationship
• comprehensive inertia control method
• hybrid AC/DC system
• virtual inertial response strategy
• WTGs
• distribution network
• distributed energy storage
• hybrid system
• hybrid AC/DC distribution system