Ground fault monitoring device and ground fault monitoring method based on hybrid method

Abstract

The invention discloses a ground fault monitoring device, which comprises at least two acquisition modules respectively arranged at a first position and a second position of a power transmission line,and an information centralized acquisition module respectively communicated with the acquisition modules, wherein each acquisition module comprises at least three information acquisition units used for respectively acquiring power supply parameters of each phase of the power transmission line, the information acquisition units send the acquired parameters to the information centralized acquisition module; the information centralized acquisition module determines whether a ground fault occurs based on the voltage and current phase difference abrupt change of the first position and the second position, determines whether a ground fault occurs based on the current of the first position and the current difference of the second position, and displays current parameters and ground fault information. The invention further discloses a ground fault monitoring method based on the hybrid method, whether a ground fault occurs or not is judged based on abrupt change of voltage and current phase difference and current vector sum, whether an interphase short-circuit fault occurs or not is judged through the current value, and the safety of a power distribution network and a power transmission line is guaranteed.

Description

technical field [0001] The invention relates to the field of ground fault location in a distribution network, in particular to a ground fault monitoring device and a ground fault monitoring method based on a hybrid method. Background technique [0002] When a ground fault occurs in the distribution network, it will cause a large-scale and long-term power outage on the entire line, which will have a major impact on the safe and stable operation of the power system. The introduction of the arc coil increases the compensation current in the system, making the relationship between the zero-sequence currents in the system more complicated, and relying on the comparison between the zero-sequence currents in various places to realize the grounding system of the neutral point through the arc suppression coil The difficulty of locating the ground fault is increasing. Although the residual incremental method, short-circuit fault indicator method, signal injection method and first half...

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Problems solved by technology

[0002] When a ground fault occurs in the distribution network, it will cause a large-scale and long-term power outage on the entire line, which will have a major impact on the safe and stable operation of the power system. The introduction of the arc coil increases the compensation current in the system, making the relationship between the zero-sequence currents in the system more complicated, and relying on the comparison between the zero-sequence currents in various places to realize the grounding system of the neutral point through the arc suppression coil The difficulty of locating the ground fault is increasing. Although the residual incremental method, short-circuit fault indicator method, signal injection method and first half-wave method have been proposed in China, these methods are not effective for high transition resistance ground faults. The success rate of positioning is not high, and it is impossible to monitor the ground fault accurately and in real time

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