Current-second-order-difference-based single-phase ground fault line selection method of power distribution network

Abstract

The invention discloses a current-second-order-difference-based single-phase ground fault line selection method of a power distribution network. A measurement point is set at each line at a certain interval. The method comprises: step one, acquiring current signals of all phases of all points at power distribution network lines in real time; step two, calculating second order difference values ofthe current signals; and step three, carrying out comparison on the second order difference values with the maximum absolute average values of all lines to determine a faulty line. According to the invention, fault data are analyzed; when occurrence of a single-phase ground fault in the line is analyzed from the data, the second-order difference value of the current data flowing through the faultpoint and the adjacent current data becomes abnormal and thus the abnormal second-order difference value is used as the fault feature quantity for line selection. Therefore, a problem of the certain restriction of the line selection plan due to the defect of physical model in the traditional line selection scheme is solved. The current-second-order-difference-based single-phase ground fault line selection method has high adaptability to complex practical problems.

Description

technical field [0001] The invention belongs to the technical field of power system fault line selection, and more specifically relates to a high-accuracy single-phase ground fault line selection method for a power distribution network based on the second-order difference of current. Background technique [0002] The distribution network is the most direct link with users in the power system. It has a wide coverage, but it has a higher failure rate than the transmission network, and single-phase grounding is the most important type of failure in the operation of the distribution network. When a single-phase ground fault occurs in the distribution network whose neutral point is grounded through the arc-suppression coil, the three-phase line voltages of the power grid always maintain symmetry. Due to the compensation effect of the arc-suppression coil, the fault current generated is small. The failure continues to run for 1h ~ 2h, maintaining the continuity of power supply to ...

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Problems solved by technology

[0004] Aiming at the defects of the prior art, the purpose of the present invention is to provide a high-accuracy single-phase-to-ground fault line selection method of the distribution network based on the second-order difference of the current, aiming to solve the fault caused by the dependence on the physical model in the prior art The problem of line selection has great limitations

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