Gis Uhf Partial Discharge On-line Monitoring And Diagnosis System Research And Application

Gas Insulated Switchgears has more and more applications in the modern power system due to its characteristics advantage,such as small volume, high reliability, etc.At the present time, on-line monitoring of the GIS insulation has become a very significant research subject. Partial discharge (PD) earlier phenomena is the most common characteristic before insulation breakdown in GIS. So it’s an effective means to detect the internal defect and diagnosis and give alarm upload in necessity by monitoring PD sersor of GIS in service, and then the occurrence of fatal failure can be avoided.In this thesis, the partial discharge on-line detection methods are proposed. Based on the development of partial discharge on-line monitoring technology in GIS, a integrated on-line PD monitoring by Ultra-High-Frequency (UHF) in GIS is manufactured. The part of hardware designed in this system includes the UHF sensor, RF multichannel switches, amplifier, filter and signal conditioning. Moreover, the virtual oscilloscope and industrial boards were selected as data acquisition unit and data analyzing-processing-storage unit to building a PD data acquisition and analyzing system by UHF according to the requirements of system. At the same time, the software of system was designed based on VB software, which can realize hardware boards configuration, data acquisition, I/O data control. It also gives the maximum discharge quantity, real-time PD waveform display. In addition, the multiple BP neural network is designed to analyse and mange the PD event types and then the alarm for equipment occurred PD is gived. Moreover, the system would automatically store the real-time discharge data, managed and reproduced historical data.Based on system requirements in the thesis, the experimental simulation testing platform and high voltage test equipment were bulided under laboratory conditions. It was designed to simulate the internal defect model of GIS equipment and a variety of models for analysis. While under laboretory conditions, the fault positioned for further testing and research.Finally, the UHF partial discharge monitoring system was installed and running in the GIS substation site based on the actual situation. The results show that the system is stable and reliable. So it is very significant to improve reliability and security of GIS equipment operation by such system.