Power distribution network single-phase earth fault active arc extinction method and system considering line voltage drop

Abstract

The invention discloses a power distribution network single-phase earth fault active arc extinction method and system considering line voltage drop. The method comprises the steps of: obtaining the operation voltage and current data of a power distribution network, and judging whether a single-phase earth fault occurs or not; if the single-phase earth fault occurs, selecting a fault phase by using the amplitude and phase relationship of three-phase bus voltages after the fault occurs, and selecting a fault line by using the direction of the zero-sequence current of each outgoing line; injecting current into the power distribution network by using an active arc extinguishing device; calculating a fault distance based on a neutral point voltage before and after the active arc extinguishing device is put, the injection current of the active arc extinguishing device, the three-phase current of the fault outgoing line and the zero-sequence current; and updating a control target of the neutral point voltage of the power distribution network based on the fault distance so as to suppress the voltage of the fault point to be zero. According to the method and system, the influence of the line voltage drop between a fault phase bus and a fault point on the arc extinguishing effect can be reduced, and reliable arc extinguishing can be realized under the conditions of different loads, transition resistances and fault distances.

Description

technical field [0001] The invention relates to the technical field of arc suppression for single-phase grounding faults in distribution networks, in particular to an active arc suppression method and system for single-phase grounding faults in distribution networks considering line voltage drop. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] The structure of the distribution network is complex, and single-phase ground faults occur frequently, which poses a great threat to the safety of electrical equipment and personal safety. [0004] Traditionally, after a single-phase ground fault occurs in the distribution network, the three-phase line voltage of the distribution network is still symmetrical, and it is generally allowed to continue to run for 1-2 hours. However, for arc faults, during the intermittent arc grounding period, a huge ar...

AI Technical Summary

Problems solved by technology

The control objective of this method is simple and clear, and does not need to calculate the capacitance parameters to ground, but this method also ignores the line voltage drop between the fault bus and the fault point, and the residual voltage will also be left when the line end is faulted under heavy load and low transition resistance. Larger fault currents exist

[0009] It can be seen that the existing single-phase grounding arc suppression scheme of the distribution network does not take into account the influence of the line voltage drop, and is a reliable scheme that can control the fault point voltage to zero and accurately suppress each component of the fault arc

Images