Simulation Research on Lightning Withstand Level of $500 \text{kV} / \pm 800 \text{kV}$ Hybrid Tower Large Crossing Transmission Line Considering Leader Current

The project involved in the calculation of this paper is a large crossing project with hybrid voltage, which is characterized by high towers, long spanning distance, and hybrid voltage, etc. The lightning performance calculation for it should have better accuracy and higher efficiency compared with that of general transmission line. However, the present insulator string flashover calculation based on the leader development method usually ignores the leader current, in order to more accurately calculate the lightning withstand level of the AC/DC hybrid tower in the large crossing section, this paper establishes a leader development model considering the leader current through ATP/EMTP, and calculates the leader development speed and leader current based on the recommended formula of CIGRE, and adopts a controllable time-varying resistor in the EMTP/ATP, In EMTP/ATP, the flashover model of insulator string considering leader current is established by using controllable time-varying resistance, TACS controllable switch and MODEL module, and the simulation study on the lightning withstand level of $500 \text{kV} / \pm 800 \text{kV}$ AC/DC hybrid tower transmission line.