Applied Research Of Online Partial Discharge Monitoring System For GIS In Zhaoqing 500kV Yucheng Substation

With the rapid development of the global power systems, the power grid requirements on the reliability of the system is increasing day by day. Insulated Switchgear Gas(GIS) equipment has the advantages of compact structure, small size, high reliability, flexible installation and configuration, and its environmental adaptability and good security, so it is more and more widely used in electric power system.But in recent years, with the grid voltage levels and power system capacity is rising, the GIS equipment working environment is even worse, its internal failure of the situation is also increasingly frequent and intense. Because the GIS equipment compared with conventional equipment the internal insulation distance becomes smaller, and run at a higher operating voltage,so the internal electric field intensity of GIS device is greatly improved. If there are some minor defects in the production or assembly process of GIS, such as insulation air gap, metal particles, etc. These minor defects in a strong electric field is easy to make local electric field distortion and a high degree of local electric field intensity, which easily lead to the insulating medium within the scope of partial discharge to form dangerous discharge channel, and ultimately lead to insulation breakdown accident.In a variety of ways online monitoring partial discharge, GIS partial discharge monitoring technology based on the UHF(Ultra High Frequency) for its high sensitivity, the larger the scope of monitoring, jamming ability, can identify the fault type and conduct fault location, etc. is more suitable for partial discharge monitoring. Therefore, this paper focuses on the basic principle of the UHF PD monitoring technology, combined with engineering experience in research 500 kV Yu Cheng station 220 kV GIS equipment partial discharge monitoring system to discuss the practical application of the GIS partial discharge monitoring technology based on the UHF in power system.Firstly, this paper analyzes the common causes, performance characteristics and damage of GIS partial discharge, and discusses the basic principle of partial discharge monitoring based on UHF technology.Secondly, this paper combined with the 200 kV GIS partial discharge online monitoring system project of 500 kV YuCheng station to introduce GIS partial discharge on-line monitoring system performance technical requirements and the relevant technical standards. This paper also describes the basic structure and the main technical parameters of the PDM-S05-OL model of GIS partial discharge online monitoring system and focused on the major hardware and software of the system configuration and summarized the installation methods and experiences of the main elements of the device.Finally, this paper describes the application analysis and judgment of three cases of engineering applications of GIS partial discharge online monitoring system, and introduced the maintenance management mode change and emergency treatment measures and other related applications when the system put into use.