Abstract: When large-scale wind power are integrated to the grid in a centralized way, an N-1 fault in the sending transmission channel may overload the transmission lines and step-up transformers. However, the existing overload protection and stability and control strategies cannot adapt to this short-term power flow overload, so a large number of wind turbines need to be cut off, which is not conducive to wind power consumption. The paper analyzes the key parameters and safety boundaries of safety overload capacity for power equipment, and determines the long-term and short-term overload zones of transmission lines and transformers.According to the safety overload capacity of the equipment, the emergency overload operation strategy of the transmission channel is proposed, which is suitable for the grid connection of the wind farm cluster, including the heavy overload alarm based on the long-term overload zone, the wind turbine cutting-off and the over-limit-tripping due to the temperature rising of the equipment based on the short-term overload zone. The test results show that the proposed strategy is feasible, which can fully tap the overload capacity of the transmission channel and improve the wind power transmission capacity on the premise of ensuring the safe operation of the transmission channel.