With the large-scale integration of wind turbines into power systems, the voltage at the grid connection point exhibits continuous oscillation characteristics, which significantly increases the ride-through difficulty and off-grid risk of wind turbines during faults. To address the above problems, this paper proposes a low-high voltage ride-through (L-HVRT) control strategy based on rotor energy storage. This strategy reduces the load on the unloading resistor by decreasing the active power output from the machine-side converter (MSC). To prevent overspeed disconnection during this process, an active power reference value for the MSC output is preset to proactively suppress rotor overspeed, thereby preventing the permanent magnet synchronous generator (PMSG) speed from exceeding the safety limit. Based on the PSCAD simulation platform, a corresponding simulation model is established to verify the feasibility of the proposed control strategy. The simulation results show that the strategy can effectively improve the continuous fault ride-through capability of wind turbines.
Wang et al. (Thu,) studied this question.