Online Estimation of Load and PV Output with Power Flow Data in Distribution System

Abstract

In service restoration against a fault in distribution system, estimation of load flow is needed to avoid overloading of feeder and voltage violation; this has been performed based on the load flow before the fault occurrence. However, in the distribution system with a number of photovoltaic generation systems (PVs), the load flows during the service restoration varies from ones before the fault occurrence due to the disconnection of PVs. Therefore, it is important to estimate the magnitude of actual load accurately before the fault occurrence. This paper proposes the method to estimate the actual load and PV power output online from the power flow data measured before the fault occurrence. The proposed method consists of two processes. The first process is tentative load and PV power estimation by means of the Independent Component Analysis with heuristic knowledge on PV power factor. Second process is correction of tentative estimation values based on the recurrence formula. The validity of proposed method is investigated through some computational simulations.