Analysis of the Impact of Ultra High Voltage AC/DC Integration on Transient Stability of the Western Inner Mongolia Power Grid

After the Ultra High Voltage Direct Current (UHVDC) is connected to the Western Inner Mongolia power grid, the characteristics of the power grid undergo fundamental changes, with transient stability constraints becoming the primary conditions for the operation and control of the Western Inner Mongolia power grid. Conducting an in-depth study of the transient stabilitylevel and its influencing factors under the background of AC-DC hybrid connection in the Western Inner Mongolia power grid has significant practical guiding significance. Accordingly, thispaper first establishes an AC system model above 220 kV and a ± 800kV hierarchical DC model of the Western Inner Mongolia power grid based on the PSASP program, and simulates and analyzes the impact of typical DC system faults, typical faults in the DC vicinity AC system, and the AC ring network on the transient stability of the power grid. Furthermore, countermeasures to improve the transient stability level are proposed, laying a foundation for the safe and stable operation of the power grid after the UHVDC connection.