Research on electrical contact fault characteristics of GIS circuit breaker based on vibration signal

Abstract

In order to analyze the vibration characteristics of GIS equipment when the contact is poor, we established a threedimensional model of 40.5kV circuit breaker by using the magnetism and solid coupling method. By changing the ratio of the close contact area of moving and stationary contacts to the total area of moving contacts (contact ratio), the situation of poor electrical contact was simulated and analyzed. The simulation results show that, when the contact ratio is constant, the current increases from 1000A to 3000A, and the acceleration of the contact also increases. In the case of the same current, the acceleration value when the contact ratio is 0.3 is greater than the value when the contact ratio is 0.6. When the contact ratio is 0.3 and the current is 3000A, the acceleration amplitude of the component with the frequency of 100Hz is the largest, which is 0.07m/s2. After research and analysis, it is shown that the vibration signal is based on 100Hz as the fundamental frequency. At the same time, multiple frequency components such as 300Hz, 600Hz and some other high-frequency components are generated. Therefore, the contact state can be judged through the measurement and analysis of the vibration signal.