Research On Corona Initiation Characteristics Of HVDC Transmission Line Based On Corona Current

With economic development and social needs,my country urgently needs to accelerate the development of UHVDC transmission technology.In UHVDC transmission projects,corona discharge in UHVDC lines will cause environmental pollution and power consumption.Regarding the problem of corona discharge,many studies have been carried out at home and abroad,but there are still relatively few studies on the systematic corona initiation characteristics of real conductors.And because of the different influences of various factors such as geography,weather and environment,the applicability of foreign research results in our country also needs to be studied.Therefore,the research on the corona effect of UHVDC lines is of great significance to the implementation of UHVDC transmission projects in our country.In order to accelerate the development of UHVDC transmission technology research,State Grid Corporation of China established an UHVDC experiment base in Changping District,Beijing.The corona cage in the experimental base is an important tool for studying the corona effect on the UHVDC line.This article uses the corona cage in the UHVDC experimental base of the State Grid Corporation of China in Beijing Changping District as the test platform.Based on the experimental data of the corona current measured by the wide-frequency domain corona current measurement system installed on the cage,the research on the corona initiation characteristics of UHVDC lines was carried out.First,the original corona current signal is filtered to reduce noise,and the processed corona current signal is time-frequency analyzed,and the influence of the voltage level on the positive and negative corona current signals is studied.The corona current signal related research can be divided into three parts:First,on the basis of the corona current signal analysis and research,it is proposed to filter out the harmonic interference in the corona current signal and the narrow band coupling in the signal.Interference algorithm;analyzed the characteristics of the time-domain characteristic parameters and frequency-domain characteristic parameters of the corona current signal after filtering and noise reduction processing,and proposed an algorithm to quantify the characteristics of the characteristic parameter change curve;The relationship between domain and frequency domain characteristic parameters and voltage levels has been studied.The filtering and noise reduction algorithm of corona current signal proposed in this paper has strong applicability and simple and convenient.It provides a fast processing method for the research of corona current signal processing.The time-frequency analysis of the corona current signal provides a theoretical basis for the research on the corona discharge characteristics of high-voltage DC lines.