Identification of Critical Times for Distribution System Time Series Analysis

Online power distribution system time series analyses are typically divided into uniform intervals (e.g., market-driven) ranging from minutes to hours. This paper presents a constraint-driven approach to refining an initial time window structure at critical times within an injection forecast. Implicit temporal load capability (ITLC), which is formalized in this paper, uses forecasted nodal injection characteristics to identify critical times when control actions are necessary in order to maintain feasibility. ITLC and control selection algorithms are presented. Quasi-static time series and ITLC simulation results are presented using a multiphase, 2556-node distribution test circuit. With ITLC, a subset of the initial time windows are subdivided at the analytically-selected critical times. This approach is more efficient than using a large number of short time windows that span the entire forecast horizon.