FIELD: electricity.
SUBSTANCE: invention relates to the sphere of electrical engineering. According to the invention the suggested method and device for fault directional detection in a multiphase power system are based on current harmonics analysis as per the addition of half periods of currents with similar polarity in each phase of the power system as well as comparison of changes in the amplitude or any other rated value of current in each phase (4A, 4B, 4C). In particular, harmonic component 2 corresponding to harmonic component 1 of the previous current 1 is compared to the zero harmonic component, and depending on their ratio a fault may be classified as double-phase or single-phase. Comparison of the rated (||IA||, ||IB||, ||IC||) mean value (µ) for each phase with each rate guarantees additional fault localisation in regard to phase current sensors (12).
EFFECT: guaranteed differentiation between double-phase or single-phase earth fault.
18 cl, 6 dwg
