Using Lumped Parameters to Realize Single-end Distance Measurement Method for Single-phase-to-ground Fault

Abstract

The invention discloses a method utilizing lumped parameters to realize line single-phase ground fault single-terminal location. According to the method, the lumped parameters are adopted to describe physical properties of voltage and current transmission of a transmission line; the fault-phase negative sequence current phase angle of a relay location is adopted to calculate the voltage phase angle of a single-phase ground fault point; and the fault location is calculated according to the linear relationship between the voltage drop from the relay location of the transmission line to the single-phase ground fault point and the fault location. According to the invention, as the fault location is calculated according to the linear relationship between the voltage drop from the relay location of the transmission line to the single-phase ground fault point and the fault location, the influences of the transitional resistance and the load current to the location precision are avoided, the location precision is high, the location principle is simple and the practicability is strong. The method does not need to adopt the search algorithm, so that fault location can be directly calculated, location speed is quick and real-time performance is strong.

Description

technical field [0001] The invention relates to the technical field of distance measurement for single-end faults in power systems, in particular to a single-end distance measurement method for line single-phase ground faults using lumped parameters. Background technique [0002] According to the division of electrical quantity sources, fault location methods are mainly divided into double-ended location methods and single-ended location methods. The double-terminal ranging method uses the electrical quantities at both ends of the transmission line to locate faults. It needs to obtain the electrical quantities at the opposite end through the data transmission channel, which is highly dependent on the data transmission channel. The single-ended 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 wid...

AI Technical Summary

Problems solved by technology

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

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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