Research on positioning the fault locations automatically in a multi branch transmission line network

In recent years, a large number of transmission lines are converted into underground cables or are interrupted and reconnected into loop transmission lines with the transformation of the transmission network and the enlargement of the urban construction scale. In order to meet the requirements of power supply reliability and reducing the loss of the transmission line transporting electric energy in the smart grid, the T branches of a transmission line are increasing, which makes the high voltage transmission network change from a single mode to a tree structure, or even a network structure gradually. The principles of the traditional relay protection and the methods of measuring a fault distance can't locate the fault location accurately because of being influenced by the impedance reflection waves of T nodes in such a multi branch transmission line network. In view of the problems that the fault locations can't be positioned automatically and the fault defects can't be eliminated in the shortest time, the paper explore a principle of positioning a fault location automatically in a multi branch transmission line network based on the identification of fault current characteristics and the shelf-adaption for a lot of changing operations in the power grid. In the process of designing and realizing the principle of positioning a fault location automatically, the paper designs a intelligent detection device for the fault locations and creates the principle of selecting the installation positions for the intelligent detection devices, which can complete the active acquisition of the field fault information. On the other hand, the paper establishes information forwarding station model and the topology model of the transmission line network in order to realize the function of transmission fault information and positioning the fault locations automatically. Besides, the paper designs the backstage main station monitoring system, which can help realize real-time monitoring of the field equipments, the forwarding stations and the communication mode in a remote way. A system of positioning a transmission line fault location automatically is developed in the multi branch transmission network through integrating the above various functional modules. The system realizes the function of positioning a fault location automatically in the multi branch transmission network, and improves the anti impact ability of the power grid and the economic benefit of the power grid operation effectively, which is of great significance to the intelligent development of the power grid.