Application of DFA Technology for Improved Reliability and Operations

DFA Technology, developed by Texas A&M Engineering in collaboration with EPRI and the utility industry, provides operational visibility and awareness of distribution circuit events, based upon real-time, autonomous monitoring of substation-based CTs and PTs. DFA monitoring devices monitor current and voltage waveforms continuously, detect anomalies, infer circuit events that likely caused those anomalies, and report conditions such as faults and incipient failures via web interface. DFA does not require communications to reclosers, capacitor banks, AMI systems, or other devices downstream of the substation. Examples of detectable conditions include faultinduced conductor slap, pre-failure clamps and switches, problems with unmonitored capacitors, problems with unmonitored reclosers, and recurrent faults resulting from conditions such as cracked bushings. DFA technology provides advance notice of some faults and also helps diagnose vague symptoms and complaints. Texas A&M Engineering manages an ongoing DFA field demonstration that involves more than sixty distribution circuits at eight Texas-based utility companies, six of which are rural electric cooperatives. Pedernales Electric Cooperative is one of those participants and, based on experiences gained during the demonstration project, plans to fit most of their 200 distribution circuits with DFA in the next three years.