PROBABILISTIC STATE ESTIMATION IN DISTRIBUTION NETWORKS

State estimation is a procedure that can be used to obtain an estimate of the network state by processing the available set of measurements. The state of a network is commonly defined as the voltage magnitude and angle at every bus. Other parameters in the network such as power flows and currents can be calculated from the network state. The information provided by the state estimation is used to assess the network security, to analyze contingencies, and to make decisions on required control actions. The concept of applying state estimation to power systems was developed around 1970 [1]. Since then state estimation has become a routine task in transmission systems. Over time a large number of redundant measurement devices were installed throughout transmission networks, and accurate network models have been developed. As a result, it is usually possible to estimate the state of a transmission network with a high degree of accuracy.