Hybrid AC filter starting resistor fault detection and protection method and system

The invention belongs to the field of hybrid AC filter fault detection, and particularly relates to a hybrid AC filter starting resistor fault detection and protection method and system. According to the invention, fault detection and protection strategies of starting resistor thermal overload, starting resistor overcurrent and starting resistor open circuit are respectively set, so that the existence of faults can be timely detected and corresponding protection actions can be triggered according to fault conditions in the face of different starting resistor fault working conditions; starting and input of the hybrid AC filter under the condition that the starting resistor fails to work are avoided as much as possible, and therefore the safety of the hybrid AC filter in the starting process is effectively guaranteed. Moreover, two-stage fault detection and protection are set for thermal overload of the starting resistor, and a protection mode of first alarming and then automatic tripping triggering is adopted,