Qilong Wang, Chi Song
The rapid expansion of offshore wind energy and its integration into weak power grids have introduced significant challenges to system stability, particularly under fault conditions that cause voltage sags. Ensuring adequate Low Voltage Ride Through has become essential for maintaining grid reliability and preventing large-scale disconnections of wind farms.To address voltage sags caused by short-circuit faults during the grid integration of large-capacity offshore wind farms via weak networks, this paper establishes a simulation model of a permanent magnet synchronous generator (PMSG)-based offshore wind farm in the PSAT platform. Taking the Critical Clearing Time (CCT) as the core evaluation index, the Low Voltage Ride-Through (LVRT) capability is systematically assessed. By simulating short-circuit disturbances, the transient voltage response at the point of common coupling is analyzed, followed by a comparative evaluation of the voltage support effects of three dynamic reactive power compensation devices: Static Var Compensator (SVC), Static Synchronous Compensator (STATCOM), and Unified Power Flow Controller (UPFC). Results indicate that the rational configuration of dynamic reactive power compensation effectively mitigates voltage drops, significantly extends the CCT, and enhances transient stability margins. The distinct response characteristics and support efficacies of different devices are clarified, providing a theoretical foundation for optimizing LVRT strategies and selecting compensation equipment in offshore wind integration.