State estimation of distribution network using simulated annealing

Abstract

Knowledge about bus voltage and power losses in primary distribution feeders is important to system planning and operation. However, to obtain this information is not a simple task because there are a few measurements just ever. Many times, measurements are only taken in the substation exit or in the beginning of feeders. Usually, one applies a load flow program to calculate bus voltages and power losses. As the actual demand is not known, one supposes the load curve in each bus is similar to the load curve of the whole feeder, determined from measurements on the substation [1]. Another usual way to remove this trouble is taken by typical load curve in substitution to the proper load curve that i s not given [2]. At any rate, the result of the load flow program can be too unrealistic. This paper presents a different procedure to estimate bus voltage and power losses on radial distribution feeders, which is based on the optimization algorithm so-called simulated annealing. The proposed method has been applied to the IEEE 13, 34, 37 and 123 buses test feeders and the validation is done confronting the results to known values, as it is explained just beyond. The total power losses estimated are close to the actual losses.