527 / 2017-05-11 17:04:03

Research on Impact of Opening Velocity in DRM Tests of SF6 High Voltage Circuit Breakers

DRM,opening velocity,touching area

High voltage circuit breakers are most important protective devices in power system. Dynamic contact resistance measurement (DRM) is considered to be an effective assessment technique for contact ablation which has been widely used for many years. However, the contact resistance curves will be influenced by many factors, such as injected current and velocity. In power systems, circuit breakers often work under non-normal conditions, like the fatigue of spring and the insufficient of hydraulic pressure. A finite element simulation model has been built to prove that the frictional heat can be ignored in DRM tests. In this paper, the concept of effective contact coefficient is introduced to describe the relationship between the opening velocity. Through the above analysis, it is proved that the frictional heat has little effect in DRM tests and the average contact resistance will increase with the increasing of opening velocity.