Rang-measuring method for transmission line one-phase earth fault of small current neutral grounding system

Abstract

This invention discloses a range-measuring method for transmission line one-phase earth fault of small current neutral grounding system. Uses including on position machine and the lower position machine, and on the position machine and between the lower position machine communication connection connection constitution system, the breakdown range finder process includes: From data acquisition to when the zero foreword signal is bigger than the threshold value, start breakdown range finder algorithm: To gathers to the breakdown voltage data or the fault current data carries on high passes filter processing, filters the labor frequency and below the low frequency harmonic component; Computation after filter processing breakdown signal cyclical index, according to breakdown signal cyclical index determination line fault distance. The advantages are effectively remove the load perturbation to the breakdown range finder precision influence. Overcome the arc light non-linearity transition resistance to the breakdown range finder accuracy influence. To disturbs has the strong suppression ability with the noise; This breakdown range finder algorithm is easy to apply to the undercurrent earth system breakdown range finder in.

Description

technical field [0001] The invention relates to a distance measuring method for a single-phase ground fault of a transmission line of a small current grounding system, which belongs to the fault distance measurement technology of a transmission line of a power system. Background technique [0002] The power grid whose neutral point is not grounded or grounded by the arc suppression coil is called an indirect grounded grid or a small current grounded system. This mode of operation is often used in power distribution systems and power supply systems of 35kV and below. When a single-phase ground fault occurs in a small current grounding system, since the fault current at the grounding point is relatively small, and the line voltage between the three phases is still symmetrical, it does not affect the continuous operation of electrical equipment in the grid and the continuous power supply to the load . As long as the fault current flowing through the grounding point is not too...

AI Technical Summary

Problems solved by technology

Since the fault wave head between the fault point, the bus monitoring point and the remote bus can have multiple reflections and transmissions, it is often difficult to distinguish the fault wave head in the fault waveform, especially in the small current system, the fault signal Very weak, the fault wave head is more difficult to distinguish

Due to the characteristics of weak fault information, the influence of power system interference noise and the existence of sensor errors in data sampling systems, these effective location methods in large current systems fail in fault location in small current systems.

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