Studies On The On-line Insulation Monitoring System Of High Voltage Electric Equipment In Substations

In this thesis, firstly the importance of developing on-line insulation monitoring and the actuality and the development trend of this project in the world is narrated. Then the main job of this thesis and the existing problem of on-line insulation monitoring system are presented. In this thesis I take the high voltage electric capacity equipment as object of on-line monitoring system and specially develop such system which adopt field-bus technology. The on-line monitoring system's structure of high voltage electric equipment is introduced emphatically. The insulation character of high voltage capacity type equipment is analyzed in theory and the mathematical model is given. Digital waveform analytical method basing on FFT is presented and used to analyze signal and calculate signal, which was used as a basic method of on-line monitoring. And to each error which is likely to occur in high voltage capacity type equipment during the monitoring, analysis and judgment are given. The sensor is the key component of on-line monitoring system, so the technical requirement and design feature of sensor are introduced especially. The communication componenLs of on-line monitoring system are elucidated detailedly. Firstly the concept and character of field-bus technology is given, then the communication scheme is designed and applying gist is pointed. Then software flow chart of communication between upper control layer and lower intellectualized terminal layer which is on the spot. After the hardware component and the software component of on-line monitoring system are designed, the low voltage simulated test, high voltage test simulating the field and some aiti-interference designed with field-bus technology can work accurately and reliably. In the thesis some useful exploring about on-line monitoring system field is done and its returns have practicable significance to our country's on-line monitoring field.