Line Model Tuning for Distribution System State Estimation

Maintaining an accurate system model is one of the significant challenges in applications for distribution system monitoring and control. While keeping track of topology changes is important, keeping accurate model of the circuit elements is equally important, and it has not been emphasized in practice at distribution level. The current approach is to use constant parameters for line models. However, line impedances vary with the weather conditions and ampere loading of the line. This paper investigates the impact of line impedance variations and its impact on distribution system state estimation (DSSE). Test results show that the effect of the parameter changes is considerable on distribution system state estimation accuracy. The paper proposes a method to tune line models periodically in order to address this issue.