Abstract:

Because the fault line detection of single-phase-to-earth fault in indirectly grounding power system was very difficult, a new method of fault line detection based on rough set theory was presented. The information fusion technology based on rough set theory was introduced in the fault line detection system by analyzing fault characteristics of the zero sequence current of lines in compensated distribution networks. Fault characteristics extracted by using wavelet transform method, zero sequence current active component method and the fifth harmonic current method were looked as condition attributes. The fault states of lines were used as decision attributes. After the constructed information system was reduced, the minimum solution of decision rules can be obtained to realize fault line detection. The simulation results proved its efficiency and feasibility.

Key words: indirectly grounding power system, fault line detection, rough set theory