Method for realizing line single-phase earth fault single-terminal fault locating by using real part of voltage drop along line

Abstract

The invention discloses a method for realizing line single-phase earth fault single-terminal fault locating by using a real part of voltage drop along a line. The method comprises the following steps of: calculating the real part of the voltage drop from a power transmission line protection installation part to a single-phase earth fault point by using fault phase electrical capacity, and dividing the real part of the voltage drop from the line protection installation part to the single-phase earth fault point by a real part of voltage drop of a power transmission line per unit length to obtain a fault distance. The method solves the problem that transition resistance and load current influence single-phase earth fault single-terminal fault locating accuracy; when single-phase high-resistance earth faults of the power transmission line occur, high fault locating accuracy can be achieved, the fault locating principle is simple, and the program is easy to realize; and the fault distance can be calculated under the condition that a search algorithm is not needed to be adopted; the fault locating speed is high; and strong real-time performance is guaranteed.

Description

technical field [0001] The invention relates to the technical field of single-end fault distance measurement in electric power systems, in particular to a method for realizing single-phase ground fault single-end distance measurement of a line by using the distribution characteristics of the real part of the voltage drop along the line. Background technique [0002] In the prior art, the single-end ranging method only uses the electrical quantity at one end of the transmission line for fault location, does not require communication and data synchronization equipment, has low operating costs and stable algorithms, and has been widely used in transmission lines. Single-ended ranging methods are mainly divided into traveling wave method and impedance method. The traveling wave method utilizes the transmission properties of fault transient traveling waves to perform single-ended fault location. It has high precision and is not affected by the operation mode and excessive resista...

AI Technical Summary

Problems solved by technology

The traveling wave method utilizes the transmission properties of fault transient traveling waves to perform single-ended fault location. It has high precision and is not affected by the operation mode and excessive resistance. However, it requires a high sampling rate, requires a special wave recording device, and has high application costs.

The impedance method uses the voltage and current after the fault to calculate the fault loop impedance, and performs single-ended fault distance measurement according to the characteristic that the line length is proportional to the impedance. It is simple and reliable, but the distance measurement accuracy is seriously affected by factors such as transition resistance and load current, especially When the transition resistance is large, the ranging result of the impedance method will seriously deviate from the real fault distance, and even the ranging failure will occur.

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