Line Insulation Monitoring

The key that weapon kit such as missile satellite launcher , radar station run safely and utilize normally is the electrical device insulation status. But most effective approach to be carried out detection on on-line insulation monitoring is to test and abstract weapon system insulation's parameter realtime. Namely it is on-line insulation monitoring. In this thesis by analyzing on-line insulation monitoring transition digital waveform based on FFT is brought up. At the on-line monitoring system's structure of high voltage electric equipment is introduced emphatically. The insulation character of high voltage capacity equipment is analyzed in theory and the mathematical model is given. Digital waveform analytical method based on FFT is presented and used to analyze signal and calculate signal,which was used as a basic method of on-line monitoring. The selection of signal sensor is the key to implement hardware circuit. It designed signal amplifying circuit,frequency tricking circuit,data sampling and keeping circuit. The choice of 12 bits high accuracy A/D integrated data Sampling card made program simply,high flexible and expandable. And to each error which is likely to occur in high voltage capacity type equipment during the monitoring,analysis and judgement are given. On hardware and soft ware,good anti-disturbances measures has been adapted considering environmental factors such as high altitude,temperature difference.The anti-disturbances ability was enhanced. Cooperation of hardware and software make hardware circuit simple and little effect of zero point shifting,and easy for software system to be modified.After the hardware component and the software component of on-linemonitoring system are designed,the low voltage simulated test,high votage test simulating the field can work accurately and reliably.It has showed efficiciency,stability and accuracy to on line monitor dielectric loss,leaking current and equivalent capacitance for capacitive device.