System for limiting a peak current of short-circuit current

The present invention discloses a system for limiting a peak current of short-circuit current, which comprises a first a first high-frequency branch configured to provide a first high-frequency current to a first switch (1SKa) of a first phase branch of a three-phase AC when the first phase branch occurs a short-circuit, wherein the first high-frequency current is configured to cause a zero-crossing point of a short-circuit current to appear before a zero-crossing point of the three-phase AC; a second high-frequency branch configured to provide a second high-frequency current to a second switch (1SKc) of a second phase branch of the three-phase AC when the second phase branch occurs a short-circuit, wherein the second high-frequency current is configured to cause a zero-crossing point of a short-circuit current to appear before a zero-crossing point of the three-phase AC, a third phase branch of the three-phase AC connected in parallel with the first phase branch and the second phase branch and configured to always supply power. The present invention superimposes the high-frequency current on the original short-circuit current of the switch, thereby the total time from the arc generation to extinction at the zero-crossing point and then to the judgement by the control system is shorter than the time that the short-circuit current peak appears. Therefore, it can effectively lower the damage of the short-circuit current peak to the dynamic stability of the switch and lower the impact on system equipment.