Single-ended distance measurement method for phase-to-phase faults against the influence of additional fault distance

Abstract

The invention discloses a circuit interphase fault single-terminal location method capable of preventing additional fault location influence. According to the method, the fault interphase electrical capacity at the relay location of a transmission line is adopted to calculate additional fault location aroused by transitional resistance, and the ratio of the fault interphase voltage and the voltage drop of the transmission line per unit length subtracts the additional fault location aroused by the transitional resistance to obtain the fault location from the relay location of the transmission line to the interphase short circuit fault point. The method provided by the invention solves the problem that the transitional resistance and the load current influence the single-terminal fault location precision, has high location precision and simple location principle, achieves easy program implementation without directly calculating the fault location through the search algorithm, and is high in location speed and strong in real-time performance.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a single-end distance measuring method for phase-to-phase faults of lines that is resistant to the influence of additional fault distances. Background technique [0002] The single-ended fault location 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 resistance. However, it requires a high sampling rate, requires a special wave recordin...

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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