Softwaredesign And Implementation Of Discharge Monitoring System For High Voltage Cable

In order to meet the growing demand of production and life, recently, the national grid transmission line is constantly upgrading. The occurrence rate of the cable in the transmission process goes higher with the rise of the voltage level. Meanwhile,as a transmission line,cable is the most commonly used and also the most important power supply equipment. Once fault occurs, the normal power supply of the power sector and people’s daily life will be affected directly, even causing great loss to the industrial production. To keep such situation from happening,it is very important to carry out real-time monitoring of faults in the process of cable transmission.Aiming at the application requirements above,this thesis is to design the partial discharge monitoring system of 220 kV high voltage cable transmission line as the main research object. Based on the in-depth study and analysis of the main content on the theories and technology of the high voltage cable discharge monitoring, this thesis finishes the design and data processing algorithms of the High Voltage Cable Partial Discharge Monitoring System. The main contents areas follows:1.Analysing on the cause and principle of the electro-discharge, this thesis studies the monitoring system of the partial discharge of 220 kV high voltage cable on the basis of nonlinear mathematical algorithm. Through the methods of clustering analysis of multi phase spectrum and statistical analysis of typical defects, this thesis have a deep study on the discharge signal.2. Concentrating on the demand of this project, this thesis designs a method for extracting and locating the partial signal based on the methods and principle of high frequency current sensor and electromagnetic coupling. According to the signal extracted, it forms the structure of this monitoring system. To lay the foundation for next step of the system block, this thesis, with the help of this structure,fulfills the overall structure of the monitoring system, in accordance with the principle that system structure goes first, and technical route goes second.3.Basic on the requirement of user software, this thesis, according to the structure of this monitoring system,analyses and deigns the software ofthe monitoring system of the partial discharge of 220 kV electric power cable with the method of modular design.Through the research of the modules such as software communication mode,data processing module, human-computer interaction module, database management module and so on, it sets the PC as monitor host computer and realizes the functions such as multi node monitoring, monitoring results of real-time storing, fault diagnosis and alarm and so on. At the same time, it realizes the function of the automation of monitoring system and human-computer interaction.4.Through the research of the MySQL database system, based on this monitoring system, the thesis takes the method of embedded design and development on it,realizing the storage of data and the automation of access. This project provides a reliable data processing platform, with the authorization of the access and sharing of data for two years.