Traveling wave integrated distance measuring method combining impedance method with traveling wave method

Abstract

The invention discloses a traveling wave integrated distance measuring method combining an impedance method with a traveling wave method, for oscilloscope determination through monitoring power frequency voltages and power frequency currents of a power transmission line. A power frequency oscilloscope file and a high-frequency oscilloscope file are generated in case of a fault in the power transmission line; by use of the impedance method, a fault line is obtained through determining a starting phase in the power frequency oscilloscope file, and an impedance distance measuring length is obtained through performing impedance analysis and calculation on power frequency voltage and power frequency current data; and by use of the travelling wave method, a travelling wave distance measuring length is obtained through performing travelling method distance measurement on high-frequency current oscilloscope data by taking the fault line and fault time provided by the impedance method as references. According to the invention, a travelling wave integrated distance measuring length is obtained through integrated analysis on the impedance distance measuring length and the travelling wave distance measuring length. Various distance measuring methods are combined so that the distance measuring reliability is guaranteed, and conditions of distance measurement failure are reduced.

Description

technical field [0001] The invention relates to the field of distance measurement of transmission line faults in power systems, especially in power transmission networks with high voltage, long distance, complex terrain and difficult line inspection, which can correctly judge faulty lines and accurately locate fault points. Background technique [0002] Existing fault location methods for transmission lines in power systems mainly include impedance method and traveling wave method, both of which have their own advantages and disadvantages in the process of use. [0003] Impedance method is usually used as an additional function of microcomputer protection and wave recording device. It has the characteristics of starting fixed value quantification and less investment. However, its ranging accuracy is greatly affected by factors such as transition resistance, distributed capacitance, and system operation mode. It meets the requirements of the power system for ranging accuracy....

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem that the distance measurement accuracy cannot meet the distance measurement requirements when relying solely on the impedance method in the transmission line of the power system, and is easily affected by factors such as transition resistance. It is difficult to identify reflected waves, and there are factors such as network instability and time synchronization signal loss during double-ended ranging. A comprehensive ranging method combining impedance method and traveling wave method is proposed, which avoids the simple traveling wave method. The false start phenomenon existing in the transmission line improves the reliability of transmission line fault location

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