Simulation Analysis of DC Transfer Switch for ±800kV Ultra-High Voltage DC Project

DC transfer switch is a key equipment responsible for operating mode transfer and fault removal in UHV DC engineering, which directly affects the safe and reliable operation of the DC system. Aiming at the DC transfer switch in a ±800kV UHVDC transmission project in China, this paper is based on the engineering specification requirements and actual operation strategy. The simulation models of middle bus transfer switch(MBTS), neutral bus transfer switch(NBS) and neutral bus ground transfer switch(NBGS) are built in the electromagnetic transient environment. At the same time, combined with the conversion current requirements of each transfer switch and the actual parameters of the line, the current conversion process of the above three types of transfer switches is calculated and analyzed, and the configuration of each transfer switch is given, that is, the energy absorbed by the lightning arrester of the middle bus transfer switch in A converter station is 9.062MJ; and the absorbed energy of the neutral bus transfer switch arrester at converter station A and converter station B is 20.233MJ and 20.428MJ respectively, and the absorbed energy of the neutral bus grounding switch arrester at converter station A and converter station B is 8.022MJ and 8.124MJ respectively.