Rough set methods in power system fault classification

This paper presents an approach to classifying power system faults using rough set methods. A knowledge-based fault detection and identification (FDI) system for power system faults has been introduced. The FDI system has the ability to detect and classify power system faults by combining conventional signal analysis methods (e.g., FFT, IFFT and wavelets) with granular computing and rough set methods. In granular computing, experimental data is partitioned into collections of data (called information granules) that are in some way similar. Rough set methods are based on set approximation, partition of each finite universe using an indiscernibility relation, attribute reduction, decision-rule derivation, and many useful measures such as approximation accuracy and rough inclusion. Traditional fuzzy set theory is also as part of fault signal feature extraction. The FDI system derives an indication of the type of faults that have occurred and also generates classification rules for the fault classification. This system has resulted from a study of fault files recorded by the Transcan Recording System (TRS) at the Manitoba Hydro Dorsey Station over several years. The contribution of this paper is the introduction of an approach to classifying power system faults using a combination of traditional signal analysis methods and a number of computational intelligence methods (granular computing, and rough set theory).