Protection and Fault Recovery Strategy of AC and DC System of Flexible Substation

The AC and DC system of flexible substation have been applied in the project, and it is imperative to study the protection scheme. Based on the basic structure of the AC and DC system of flexible substation, the partitioned and layered protection scheme are proposed. Both the component-level and the station-level protection configuration schemes are proposed. Based on two flexible substations connected to the grid, the fault recovery strategy is proposed, and the fault recovery processes of 10kV AC line fault and ± 10kV DC line fault of two flexible substations are simulated and analyzed. The simulation results are consistent with the proposed strategy. The proposed fault recovery strategy has reference significance for the device or system composed of converter interconnections in multiple operating states.