Method of Line Parameter Estimation in Distribution Network Based on Geographic Information

Abstract

Distribution line parameter estimation is the basis of state estimation for distribution network, which directly affects the accuracy of state estimation results, however, not only the distribution network has many load points and wide power supply area but also the structure of medium and low voltage lines in it is complex, which challenges the estimation of line parameters. This paper proposes a method for estimating the line parameters of the radial distribution network based on geographic information. Firstly, carry out cluster analysis for the spatial power load points, which are mined from the open source POI information set that collected by the web crawler technology, to extract the load aggregation points, and then the cable selection and the line length estimation are performed on the main trunk line and the branch line respectively: for the main trunk line, cable selection is performed according to the total load of its power supply area and the line length is estimated using the geographic information of its beginning and ending points and corner points, which is extracted from the main trunk line, that determined by the distribution of power pipeline, power load, urban block and the road; for the branch line, the length of branch line is estimated based on its geographic information, which is extracted by determining branch line path with the detailed geographic information of the main trunk line extracted based on the RGB color mode and the spatial distribution of the load aggregation points, and the cable selection is performed according to the power load of the load aggregation point connected to the line. Finally, according to cable selection result, determine the impedance value per unit length of cable and multiply it to the branch line length to get the line parameters. Taking a medium voltage distribution network as an example, this paper completes the estimation of distribution network line parameters based on open source information and geographic information system, which shows that the method proposed in this paper provides a feasible estimation method of line parameter for medium and low voltage distribution networks and it has practical application value.