Transient Performance of Grid-Forming SVG for Transient Voltage Recovery Enhancement in Urban Power Grids

Urban power grids are increasingly confronted with structural challenges such as insufficient local power generation, reliance on AC/DC hybrid infeed, and a continuously rising cable ratio, which impose higher demands on steady-state voltage regulation capability and dynamic reactive power reserves. This paper aims to investigate an optimal configuration method for grid-forming static var generators (SVG) to enhance the transient voltage recovery capability of urban power grids. Firstly, the incremental mechanism of dynamic reactive power support requirements in receiving-end power grids with multi-infeed HVDC is analyzed. Secondly, the voltage support characteristics of grid-forming SVG during transient processes are compared, and its technical advantages in voltage construction and overvoltage suppression are clarified. Finally, taking an actual urban power grid with multi-infeed HVDC as an example, electromagnetic transient simulation is carried out to compare and analyze the suppression capabilities of transient undervoltage and overvoltage between grid-forming SVG and conventional capacitor banks. The results show that the grid-forming SVG can significantly shorten the voltage recovery time after faults, increase the voltage sag magnitude, suppress transient overvoltage, and effectively mitigate voltage fluctuations during the recovery process.