Transmission line’s parameter estimation using state estimation algorithms

Some experiences on the use of state estimation methods for identifying the parameters of transmission lines are described. As a result, an algorithm to estimate the parameters of transmission lines and transformers is proposed. It uses a set of measurements for different operating conditions; these measurements can be obtained from historical records. Using measurements of voltage and active and reactive power flows on both ends of a given line, an estimator is built that can compute the parameters of a line, independently of the condition of the rest of the system. In a similar way, it can compute the parameters and, more importantly, the position of the tap of a transformer. The method has been used to identify the parameters of all lines and transformers for the IEEE 30-node system. The performance of the estimation process, as proposed, is independent of the number of lines to be identified as long as there is enough variability in the linepsilas loading, so the size of the system is not relevant, as long as there are enough measurements.