Time-domain fault location method based on single-circuit electrical quantity double-circuit DC transmission line on the same tower

Abstract

The invention discloses a time-domain fault location method based on single-circuit electrical quantity double-circuit DC transmission line on the same tower. The method comprises the following steps: 1, extracting the impedance matrix and the admittance matrix of the double-circuit DC transmission line on the same tower; 2, obtaining a voltage phase mode transformation matrix; 3, obtaining a single-circuit voltage differential mode component and a common mode component based on the voltage electrical quantity phase mode transformation of the single-circuit electrical quantity; 4, according to the distribution characteristics of each line mode component of different pole line faults, calibrating the modulus traveling arrival time and selecting the modulus wave velocity by selecting a component with an obvious modulus amplitude; and 5, constructing a double-end traveling wave fault positioning principle and calculating a fault location. The method has the advantages of high computational accuracy, high reliability, short required data time window and easy realization.

Description

technical field [0001] The present invention relates to the technical field of relay protection for power systems, and in particular to a double-terminal traveling-wave fault location method for double-circuit DC transmission lines paralleled on the same pole. A double-terminal traveling wave ranging algorithm for returning measurement data. Background technique [0002] The erection of transmission lines on the same pole has the characteristics of small occupied corridors and fast construction speed, which alleviates the contradiction between the increasingly tight land resources and the demand for power grid construction. It is not only widely used in AC lines, but also gradually specific applications in DC transmission lines. . However, the DC transmission distance is long, generally exceeding 1000km, and the line is prone to failure. When a line fault occurs, accurate fault location can quickly eliminate the fault, prevent the recurrence of the fault, and reduce econom...

AI Technical Summary

Problems solved by technology

However, for the double-circuit DC transmission line erected on the same pole, there is a complex electromagnetic coupling relationship between the four pole lines. In actual engineering, the pole tower structure is arranged in a trapezoidal shape, and the line does not use symmetrical transposition, resulting in very complicated fault coupling characteristics.

In addition, it is worth noting that in actual engineering, the control and protection of each DC system are based on the electrical quantity information of this circuit, so it is impossible to achieve complete decoupling of the electrical quantities of each circuit

The above factors have increased the difficulty of accurate fault location of double-circuit DC transmission lines paralleled on the same pole

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