Evaluating distribution system losses using data from deployed AMI and GIS systems

Distribution system losses are a reality due to the physics associated with various system components that make up any power system. Techniques for analyzing losses are not new but have primarily focused on evaluating system losses during certain peak demand periods due to limitations on available data. Such “traditional” analyses estimate energy losses using industry accepted approaches that rely heavily on assumptions and that focus only on peak and average demands on major system components. Another potential shortcoming of a traditional loss analysis is the level of system detail evaluated. A gross analysis in terms of system components such as substation power transformers, distribution lines, distribution transformers, secondary conductors, etc. is typical. The disadvantage is that the relative contribution of various system components to the overall system losses may not be defined to the level required to truly evaluate mitigation techniques, especially when time periods other than peak demand times are being evaluated. Given the limitations of traditional loss evaluations, this paper will explore enhanced loss evaluation techniques utilizing interval load data collected from a deployed Advanced Metering Infrastructure (AMI) system and detailed system data from an available Geographic Information System (GIS). The test case system used to present this approach was a distribution cooperative with these systems presently in place.