Electric line fault alternating-current impedance fast tracking and judging method

Abstract

The invention discloses an electric line fault alternating-current impedance fast tracking and judging method. The method relates to a high voltage alternating-current detection power supply (1), a current detection unit (2), a voltage detection unit (3) and a line sensor (4). After an electric line is tripped due to a fault, high-voltage alternating-current detection signals are sequentially applied to the phase-to-ground and the interphase of the line through the line sensor installed on the outer side of a line switch, and phase-to-ground impedances Za0, Zb0 and Zc0 and interphase impedances ZAb, Zbc and ZAc of the line fault are calculated. The detection result is compared with the lowest operation criterions Za0j, Zb0j, Zc0j, ZAbj, Zbcj and ZAcj, whether the line fault is an instant fault or a permanent fault is tracked and judged, and the fault recovery is conducted. The electric line fault alternating-current impedance fast tracking and judging method is fast in speed, accurate in judgment, suitable for a line grounded short circuit and an interphase short circuit, thereby having the better practicability.

Description

technical field [0001] The present invention mainly relates to the field of fault diagnosis of transmission and distribution lines, in particular to a method for quickly tracking and detecting faulty lines after a fault trips on a transmission and distribution line, which is applicable to the rapid detection and judgment of the nature of a fault after a fault trips on a transmission and distribution line and the fault Status fast track. Background technique [0002] The faults of power lines are divided into two types: transient faults and permanent faults. After the transient faults are removed by relay protection, the arc at the fault point will be extinguished immediately and the insulation strength will be restored. At this time, if the disconnected line is reclosed Reclosing restores normal power supply. However, permanent faults may also occur on the line. Permanent faults refer to permanent insulation breakdown short circuits between phases or phases, such as faults...

AI Technical Summary

Problems solved by technology

However, if the DC high voltage is used to track the insulation resistance of the faulty line, the charging time of the long line or the cable line will be long, and the faulty line cannot be diagnosed quickly.

If it is a phase-to-phase fault of the line, it cannot be realized by using the method of detecting insulation resistance with DC high voltage due to the existence of phase-to-phase components (such as phase-to-phase windings of transformers) in the line.

Images