The invention discloses a method and
system for detecting current data of an
alternating current fault series arc, and the method comprises the steps: carrying out the time-
frequency domain analysis of a current data sequence, and evaluating the characteristic performances of the current data sequence under the conditions of the disturbance of a combined electric appliance without a resistive shielding load, the single disturbance of the combined electric appliance with the resistive shielding load and the disturbance of the combined electric appliance through employing a relative lifting ratio index; and selecting and determining key parameters such as an arc characteristic form, a
decomposition scale, a characteristic
frequency band and the like, and comprehensively extracting fault information in the current data by using the optimal characteristic to serve as a basis for discriminating a fault arc. According to the method, the characteristic quantity amplitude can be obviously improved after the fault arc occurs, so that the fault arc under complex and diversified shielding load interference can be quickly and accurately identified, and the safe and stable operation capability of the whole low-
voltage alternating-current circuit
system is improved.