Study On Intelligent Electroscope Of Ultra-high Voltage Based On Ultraviolet Detection

The reliability and running status of ultra-high voltage(UHV) transmission lines determines the stability and security of the transmission system. So it is extremely important to adopt advanced detection technology to monitor its status, find out hidden trouble and eliminate accidents. This paper emphatically researches on intelligent UHV electroscope based on ultraviolet detection technology. The electroscope is suitable for detecting the discharge of the transmission lines and equipments of the power system, with sound alarm, liquid crystal display, etc. Experiments show that it is friendly to use and convenient to operate. It also has full functions and high anti-jamming performance.Firstly, this paper describes the principle of UHV corona discharge and UV detection technology at the beginning. It also analyses the key technology of UV detection and researches to use UV sensor as the probe of the system. It takes the number of UV pulse corona to represent the discharged level, providing numerical criterion for the transmission lines discharged condition, and carries out the discharged detection.Secondly, this paper designs the electroscope function modules. It proposes a new development program of intelligent electroscope of UHV system based on DSP and LabVIEW. The system takes DSP as the core of intelligent electroscope of the UHV system and LabVIEW as developing platform of the management software. The data acquired by DSP are transmitted to host PC through CAN-bus for further analysis and processing. The paper focuses on hardware and software design, including UV sensor driving circuit, liquid crystal display module, communication module and PC interface design. In addition, this paper also researches on the electromagnetic compatibility and anti-jamming technology of the system. It combines the electromagnetic shielding technology to provide a good shield for the electroscope, and to ensure the operation of the electroscope normally.Finally, in terms of the interference problem in corona discharge of transmission lines,this paper discusses the wavelet analysis to extract discharge pulse signal form interference signals. It elaborates the basic principle and the denoising steps of wavelet analysis method and the key aspects in wavelet denoising processing. The paper adopts MATLAB wavelet toolbox to carry out the simulation corona discharge signals denoising experiments, including wavelet denoising, wavelet packet denoising and layered denoising methods. And it uses signal to noise ratio(SNR) and root mean square error(RMSE) to compare the denoising effects of the above three methods. Experiments indicate that the layered denoising method is the best to extract the pulse signal form the interference signals.