Power regulation and generator tripping control strategy for direct-drive wind farms under sub/super-synchronous oscillation risk

Direct-drive wind farms usually trip all wind turbines to ensure power grid security when facing sub/super-synchronous oscillation risks. Tripping the entire wind farm not only seriously damages the production operation of the wind farm, but also causes a large impact on the power grid, which is an emergency measure that has to be taken after the situation escalates. To address this problem, this paper proposes a wide-frequency measurement device assisted power regulation and generator tripping control strategy for direct-drive wind farms, to achieve early warning and rapid suppression of sub/super-synchronous oscillation accidents. The wind farm pays attention to events such as lightning tripping in the regional power grid that may induce oscillations at any time. When receiving an event report, the wind farm immediately enters a pre-warning state and adjusts the power of each wind turbine according to the pre-action strategy to enter a low-inducing state, while the wide-frequency measurement device enters an emergency state to monitor whether the wind farm has sub/super-synchronous oscillations. When oscillations are detected, the wind farm defines the tripping intensity index according to the distance between each wind turbine and the grid-connected point and the power of each wind turbine, and executes the tripping strategy for some wind turbines to achieve oscillation elimination. This paper establishes relevant simulation examples to verify the feasibility and effectiveness of the control strategy. The simulation results show that the proposed power regulation and generator tripping control strategy achieves the suppression of oscillations in direct-drive wind farms, while avoiding the tripping of all wind turbines in the wind farm, reducing the impact on the power grid.