Method And System Experimental Test On Traveling Wave Based On Faults Location For Distribution Power Networks

Distribution systems have some characteristics such as low-insulation level,wide network distribution,different operating modes and frequent fault.However,the modern society increasingly demands the high reliability of power supply,and the economic losses and negative social influence caused by blackout are also growing.Furthermore,the study of the distribution network fault location technology becomes an imminence requirement for the development of smart distribution grid.Therefore,the paper studied fault location based on traveling wave theory in distribution networks,is expected to solve the problems of precise fault location for all types of distribution networks.In the paper,the existing fault location methods for distribution network have been made a detailed overview,and the main influence factors of traveling wave fault location,including traveling wave velocity,signal acquisition and location algorithm of traveling waves,are described.Then,the transmission characteristics of traveling waves at distribution network and the transmission of traveling wave modulus are analyzed,the surge identification of transient traveling wave are proposed.On this basis,according to the structure features of the radial distribution network supplied by single power,an traveling wave fault location algorithm that do not need to be setting traveling wave velocity and line length is proposed,and can be summarized as follows:1)Builds the standard array of the difference of traveling wave arrival time calculated in the traveling wave acquisition device at each end,when a simulated fault happened in a specific point at distribution networks.2)Compares the actual array of the difference of traveling wave arrival time with the standard array to distinguish fault section when the actual fault happened.3)Calculates the length ratio between the distance from the fault point to the head of trouble section and the whole length of the fault line,and then accurately confirms the fault location based on the location of each tower or cable joint.In addition,the paper puts forward a fault location algorithm based on distributed traveling wave detection for the complex and multi-string distribution network.Firstly,the multi-terminal location algorithm is established to find out fault trunk line and narrow fault location scope.Secondly,a double-terminal fault location algorithm based on the time gap between zero mode and aerial mode traveling is put forward to calculate the fault distance.Finally,according to the information of multi-terminal and double-terminal fault location,the fault point is determined.In the end of the paper,the major components of traveling wave fault location systems are introduced and built.The experiments are performed,and its results that the location error is less than 77m.The proposed the fault location methods and system in distribution networks have the advantages of the simple algorithm,high practicality and fault location accuracy,it can realize accurate fault location and provide a solid foundation for developing the traveling wave fault location technology in distribution networks.