Identification Method of the 220kV Key Transmission Line

How to quickly and accurately find out the key transmission lines of the power grid on the existing large-scale network is helpful to take preventive control measures to implement transformation or special protection of the key lines, and improve the reliability, robustness and security of the power system. The average sum of squares of the difference between the transmission line load rate of 220kV line and the line load rate under normal operation mode is considered. The difference index between the average load rate after other 220kV transmission lines N-1 failure and the load rate under normal operation mode is proposed. The proportion of the transmission power over the control power of the transmission line N −1 failure is calculated. Then, the transmission power margin change index of the 220kV transmission line is proposed when the generator N −1 failure occurs. The transmission power of the N-1 rear section of the unit is analyzed, and the 220kV key transmission lines in the region are identified and sorted. The proposed method can quickly identify the more important 220kV transmission lines in the regional power grid. Finally, a provincial regional power grid is used to verify the effectiveness and adaptability of the proposed method.