The switching process of AC filter in the converter station will produce larger inrush current and overvoltage

causing great impact on the internal element and bus and seriously threatening safety of the system. In this paper

the pre-arcing time and actual making time are calculated with combination of the distribution feature of electric field of high voltage circuit breaker at different clearances. The DC transmission system model is set up by the use of PSCAD/EMTDC simulation software and the effectiveness of phase selective switching technology on suppressing closing inrush current and over voltage which takes into accounts both breakdown feature and mechanical dispersion is simulated and analyzed. At the same time

the relationship among capacitive residual voltage

phase angle at closing and closing inrush current at such special condition as switching AC filter at live condition is analyzed. Finally

it is concluded with combination of simulation experiment that with consideration of pre-arcing feature and mechanical dispersion of circuit breaker

the phase selective switching technology can suppress 74% of operating over voltage below 0.02 p.u.

Selection of appropriate closing phase angle for different capacitive residual voltage can reduce effectively both closing inrush current and over voltage.