Protection system and method for hybrid AC filter

The invention belongs to the technical field of power systems, and particularly relates to a protection system and method for a hybrid AC filter, and the method comprises the steps: detecting a fault region of the hybrid AC filter, and enabling the hybrid AC filter to be divided into a bus region, a passive region and an active region; when a fault occurs in a certain area, corresponding protection action is performed according to the fault type of the fault area, when the passive area of the hybrid AC filter still has a corresponding fault after the protection action, the passive area of the bus area of the hybrid AC filter is cut off, and when the active area of the hybrid AC filter is subjected to the protection action, the bus area of the hybrid AC filter is cut off. If a corresponding fault still exists, the active area is removed from the passive area of the hybrid AC filter. According to the method and the device, each area and the protection action corresponding to each fault are determined according