The dynamic interaction between various power electronic devices and power grids in modern power systems can lead to serious sub/super-synchronous oscillation issues. Due to the insufficient real-time performance of controller parameter/structure modification

current oscillation suppression methods mostly employ direct wind farm tripping strategy

which exacerbate grid impacts and exhibit poor economy. Therefore

this paper proposes a sub/super- synchronous oscillation suppression method for direct-driven wind farm based on variable operating condition equivalent model and optimal emergency power control. Firstly

an equivalent mathematical model is established by characterizing direct-driven wind farm admittance under multiple operating conditions as functions of operational variables. Based on the impedance method

a method for determining the controllable domain of direct-driven wind farm power adjustment is proposed with the objective of mitigating oscillation. Within this domain

the oscillation suppression problem is formulated as a multi-objective optimization problem that simultaneously considers economic efficiency and suppression effectiveness

and an emergency power control strategy is proposed for sub/super-synchronous oscillation suppression. The proposed method does not require modifying converter control parameters or structures

and can achieve oscillation suppression through optimal emergency power control while minimizing power loss. Finally

a simulation model based on actual multiple wind farms is analyzed to verify the effectiveness and economy of the proposed method

as well as its advantages over existing methods.