High voltage DC power transmission line shielding failure current waveform inversion recovery method

Abstract

The invention relates to a high voltage DC power transmission line shielding failure current waveform inversion recovery method. When the transmission line suffers the lightning stroke, the transient state traveling wave is spread and transmitted by the power transmission line, so the transient response at the protection installation place is different. The transmission line is equivalent to a natural lightning current air-termination system, and when the shielding failure happens, the prior traveling wave fault location technology can precisely locate the lightning stroke point; the parameters of the power transmission line can be obtained by measuring and analyzing on line; and with the transfer function of the transmission line deduced by the method, the lightning current waveform at the lightning stroke point can be finally obtained by carrying out the phase amplitude transformation, noise reduction, and Prony fit process, and deconvolution operation of on the transient voltage which is obtained through a high-speed collection at the protection installation place of the transmission line.

Description

Technical field [0001] The invention relates to the technical field of lightning electromagnetic transient monitoring of electric power systems, in particular to a method for inversion and recovery of lightning shielding current waveforms of high-voltage direct current transmission lines. Background technique [0002] Lightning strikes are the main cause of line trips and power supply interruptions. The proportion of the total trip rate of transmission line lightning strikes increases as the voltage level increases. For UHV DC transmission lines, accidents caused by lightning strikes cannot be ignored. The Yunnan-Guangzhou UHV DC transmission project has a total length of 1438km and has been operated in unipolar and half voltage. The bipolar was completed in 2010. Since there is no similar engineering experience as a reference, it is difficult to prevent the line from being tripped by lightning. High altitude, variable weather, and frequent thunderstorm activities have caused th...

AI Technical Summary

Problems solved by technology

However, this kind of measuring device is installed on the tower, which is expensive and difficult to maintain. Especially for long-distance transmission lines, it can only be installed selectively in the flashing section, and it is difficult to obtain the lightning parameters of the entire line corridor.

Also, due to the nature of measuring flashover current, such measurement methods will not work for lightning strikes on lines that did not cause flashover

The lightning location system has been applied in 30 domestic provincial network companies. With the help of this system, the basic data of lightning current polarity and amplitude can be obtained, and then the lightning day, lightning hour, ground flash density, ground lightning density, and ground flash Frequency, lightning current amplitude probability distribution and other important lightning parameters, but due to the attenuation and deformation of lightning electromagnetic wave propagation, and the lack of basic boundary conditions for electromagnetic wave waveform inversion, the system is still unable to give correct parameters such as lightning current waveform and steepness , and for long-distance ultra-high voltage transmission lines across multiple provinces, it is necessary to solve the compatibility of lightning location systems between provincial networks and the coordination of system operation and maintenance work

The above lightning (parameter) measurement methods all have their own limitations, so that there is still a lack of suitable methods for obtaining the lightning current parameters of the entire corridor of high-voltage transmission lines

Images