Grounding line selection method, grounding line selection device and application system based on active component of zero sequence current

Abstract

The invention discloses a grounding line selection method, a grounding line selection device and an application system based on an active component of a zero sequence current. The grounding line selection method and the grounding line selection device based on the active component of the zero sequence current are used for a distribution network system comprising a plurality of outgoing lines and a bus for grounding line selection protection when single-phase grounding failure occurs. The grounding line selection method comprises the steps of: zero sequence current compensation for compensating measured value of the active component of the aero sequence current of each outgoing line according to the distribution situation of the active component of the aero sequence current of the plurality of outgoing lines; line selection after the compensation, which is used for sequencing the active components of the compensated zero sequence currents of the plurality of outgoing lines according to the amplitude size and selecting the outgoing line the zero sequence current of which has maximum active component amplitude; and line selection protection which is used for comparing the maximum active component amplitude of the outgoing line of the zero sequence current with the threshold value, judging that the branch of the outgoing line is the grounding failure line if the maximum active component amplitude is more than the threshold value, otherwise, judging that the branch of the outgoing line is the bus grounding line if the maximum active component amplitude is less than the threshold value.

Description

technical field [0001] The invention relates to a grounding line selection technology of a power distribution network, in particular to a grounding line selection method, device and application system based on zero-sequence current active components. Background technique [0002] my country's 10kV distribution network has a large number, wide distribution range, low equipment insulation level, and is susceptible to various faults caused by the internal factors of the power grid and the external natural environment; among them, the probability of single-phase ground faults is the highest, which can account for the total faults. About 80% of it. When a single-phase ground fault occurs in the distribution network, the line voltage between the three phases is still symmetrical, and the fault current is small, which does not affect the continuous power supply to the load, and does not need to trip immediately. The regulations stipulate that it can continue to run for 1 to 2 hours....

AI Technical Summary

Problems solved by technology

However, in practical applications, especially in the use of the neutral point through the arc suppression coil grounding system, most of the existing grounding line selection devices are not ideal

Images