Using the characteristics of the imaginary part of the voltage drop to realize the single-end distance measurement method of the phase-to-phase fault of the line

Abstract

The invention discloses a method for achieving circuit phase-to-phase fault single-ended distance measurement by means of voltage drop imaginary part characteristics. According to the method, fault phase-to-phase negative sequence voltage and unit length power transmission line positive sequence impedance are used for calculating a voltage phase angle of a phase-to-phase short-circuit fault point, therefore, an additional fault distance caused by transition resistance is calculated, and an imaginary part of a specific value of fault phase-to-phase voltage and a fault phase-to-phase current is used for dividing an imaginary part of the unit length power transmission line positive sequence impedance and then subtracting the additional fault distance to obtain a fault distance between the protection installation position of a power transmission line and the phase-to-phase short-circuit fault point. According to the method for achieving the circuit phase-to-phase fault single-ended distance measurement by means of the voltage drop imaginary part characteristics, the problem that the transition resistance and a load current have an influence on accuracy of the single-ended fault distance measurement is solved, when a power transmission line phase-to-phase high-resistance short-circuit fault exists, the accuracy of the distance measurement is quite high, the principle of the distance measurement is simple, a program is easy to achieve, the fault distance is directly calculated without the requirement for adopting a search algorithm, the speed of the distance measurement is high, and real-time performance is strong.

Description

Technical field [0001] The invention relates to the technical field of power system relay protection, in particular to a method for realizing single-ended distance measurement of line-phase faults by utilizing the characteristics of the imaginary part of the voltage drop. Background technique [0002] The single-ended fault location method only uses the electrical quantity at one end of the transmission line to locate the fault, without communication and data synchronization equipment, low operating cost and stable algorithm, and is widely used in transmission lines. Single-ended ranging methods are mainly divided into traveling wave method and impedance method. The traveling wave method uses the transmission properties of the fault transient traveling wave to perform single-ended fault location. It has high accuracy and is not affected by the operation mode or excessive resistance. However, it has high requirements on the sampling rate, requires a special recording device, and h...

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, due to the influence of the additional fault distance caused by the transition resistance, the measurement result of the fault distance will seriously deviate from the real fault distance, and even the fault distance measurement failure will occur.

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