Effective Steady-state Security Regions Accounting for Short-circuit Current Constraints

With the promotion of national “peak carbon dioxide emissions” and “carbon neutrality” goals, the application of wind power, photovoltaic and other renewable energy sources is becoming more and more widespread, photovoltaic power, photovoltaic and other renewable energy sources are connected to the grid in large quantities, and the level of disturbance has increased sharply, which poses a serious challenge to the safe and stable operation of the power system. Photovoltaic power, photovoltaic and other renewable energy sources are often connected to the grid through power electronic inverters, which can provide a small short-circuit current in the fault state due to the limited overload capacity of the semiconductor, and the protection device may refuse to operate in the event of a short-circuit fault. This paper proposes an effective safety domain method that takes into account the short-circuit current, establish a two-stage robust optimization unit commitment model, introduce the CCG (column-and-constraint generation) algorithm to solve the problem, and fully consider the source and load uncertainty of the renewable energy system after a large number of grid connection. The model takes into account the source-load uncertainty after the grid connection of a large number of renewable energy sources, improves the safety and stability of system operation by optimizing the effective safety domain of the system, and provides a quantitative reference for system operation state evaluation.