High voltage direct current transmission line thunderbolt shielding failure and counterattack recognition method

Abstract

The invention relates to a method for recognizing the shielding failure and the counterattack of a high-voltage DC transmission line. The shielding failure of the line means that the thunderbolt directly strikes on the transmission line by steering clear of a ground wire; the counterattack means that the thunderbolt directly strikes on the ground wire or a pole tower, the electric potential on thetop of the tower increases instantaneously, which causes the insulation flashover due to the existence of a pole tower earth resistor. The different theories generated by the electromagnetic transient component of the shielding failure and the counterattack of the high-voltage DC transmission line and different paths of transmission of the thunderbolt electromagnetic transient component on the circuit cause that the energy distribution of different frequency bands of the generated voltage transient state signals are different greatly. In a travelling wave analysis and high-speed acquisition system at the protective installation position, the small wave analysis is adopted to extract the energy of the zero modulus voltage in different frequency bands. The shielding failure and the counterattack are differentiated according to the property of the energy distribution. A large amount of emulations show that the method is reliable and effective. The method has intuitive and clear physicalconcepts, is easy to implement, can be widely applied to a high-voltage DC system protective device, provides important data for the lightening protection design of the line and provides reference forthe operation and maintenance of the line.

Description

technical field [0001] The invention relates to the technical field of lightning electromagnetic transient monitoring in a power system, in particular to an identification method for lightning shielding and counterattack of a high-voltage direct current transmission line. Background technique [0002] With the rapid development of economic construction, long-distance power transmission across regions has become inevitable [1] . Therefore, the ±800kV ultra-high voltage direct current (UHVDC) transmission system has attracted more and more attention. By 2010, my country will build the world's first ±800kV UHVDC transmission project - Yunguang DC transmission project. Due to the long-distance power transmission, the probability of short circuit and lightning strike on the line is greatly increased, which seriously threatens the stable operation of the DC system. How to prevent lightning flashover of the transmission line and avoid lightning tripping are the problems that the p...

AI Technical Summary

Problems solved by technology

[0004] With the in-depth research on traveling wave protection and transient protection, some researchers have paid attention to the distinction between lightning faults and non-lightning faults, and have achieved certain results [7-16] , but the distinction between shielding and counterattack in lightning faults needs further study

Images