Study on Lightning Intruding Overvoltage on DC Side of ±1100kV Converter Station

The Ultra-High Voltage (UHV) converter station is the hub of DC transmission system. If the converter station is damaged by lightning strikes, the safe and stable state of the DC transmission system will be greatly threatened. Relying on Zhundong-Wannan ±1100kV UHV project, this paper simulates and analyzes the overvoltage level on the DC side of the converter station by lightning. Firstly, the non-uniform transmission line model is built, and then the whole transient simulation model of the converter station is built. Secondly, the overvoltage under the non-uniform transmission line model and the multi-surge impendence model is compared to verify its applicability. Finally, under the suitable operation mode of the converter station, the overvoltage of the converter station is calculated. Besides, the protection level of the converter station equipment is checked so as to provide a basis for the arrester arrangement and insulation level of the converter station.