Identifying fault clearing operations in distribution systems

Identification of recloser and fuse operations is an important task in a distribution system to help evaluate overcurrent coordination, detect incorrect relay settings, and estimate fault location. The main purpose of this paper is to develop rule-based screening module that can identify the protective device clearing the short-circuit fault. Necessary features that characterize fault clearing devices are calculated from input voltage and current waveforms captured at intelligent electronic devices (IED) such as digital relays, digital fault recorders, and power quality monitors. Rule-based expert system then utilizes these features to determine whether the fault was cleared by recloser, fuse, or self-cleared. The effectiveness of the proposed approach is validated using actual fault data recorded in a distribution circuit.