Method for distinguishing back flashover faults and shielding failure faults of power transmission line

Abstract

The invention discloses a method for distinguishing back flashover faults and lightning shielding failure faults of a power transmission line. The method comprises the following steps of: sampling and recording three-phase transient current on the power transmission line in real time by using a high-speed acquisition device; comparing maximum amplitudes of the three-phase transient current at the same observation point, and judging fault phases; analyzing transient waveforms of fault phase current, and identifying forwarding waves of lightning current; and identifying whether pulses with the polarity opposite to that of the forwarding waves and small amplitudes exist, and determining the pulses as the back flashover faults or the lightning shielding failure faults. The method for identifying fault types by using power frequency voltage in the past is often influenced by load current, the length of a circuit and transition resistance. On the basis of characteristic differences of fault high-frequency transient signals, the method is not influenced by the load current, the length of the circuit and the transition resistance, and has the advantage of simple criterion and easiness in implementation.

Description

technical field [0001] The invention relates to the technical field of identifying types of lightning strike faults on transmission lines, in particular to a method for identifying lightning strike faults and shielding strike faults on transmission lines. Background technique [0002] Transmission lines often cross mountains or pass through open areas, and overhead lines are often high, so they are prone to lightning strikes and trips due to faults during thunderstorms. Lightning strikes on the line often cause equipment damage, and in severe cases, the line trips, the system loses voltage and affects the grid power supply. [0003] After a lightning strike fault occurs on a high-voltage transmission line, it is required to accurately identify the fault type. On the one hand, this is of great significance for analysis and troubleshooting, and on the other hand, it has a guiding role in effectively taking protective measures for transmission lines. At present, there is ...

AI Technical Summary

Problems solved by technology

At present, there is no direct monitoring technology in China to realize lightning counterattack and shielding fault identification. Due to the lack of effective technical means to identify the cause of the fault, and at the same time, the work quality of line hunting is sometimes difficult to control, and it is difficult to find the real cause of some accidents.

This restricts the improvement of the operation and maintenance level of the transmission line, and directly affects the reliability of the safe operation of the transmission line.

Images